Report ITU-R M.2478-0 (09/2019)

Spectrum needs for the amateur service in the frequency band 50-54 MHz in Region 1 and sharing with mobile, fixed, radiolocation and broadcasting services

M Series Mobile, radiodetermination, amateur and related satellite services

ii Rep. ITU-R M.2478-0

Foreword

The role of the Radiocommunication Sector is to ensure the rational, equitable, efficient and economical use of the radio- frequency spectrum by all radiocommunication services, including satellite services, and carry out studies without limit of frequency range on the basis of which Recommendations are adopted. The regulatory and policy functions of the Radiocommunication Sector are performed by World and Regional Radiocommunication Conferences and Radiocommunication Assemblies supported by Study Groups.

Policy on Intellectual Property Right (IPR)

ITU-R policy on IPR is described in the Common Patent Policy for ITU-T/ITU-R/ISO/IEC referenced in Resolution ITU- R 1. Forms to be used for the submission of patent statements and licensing declarations by patent holders are available from http://www.itu.int/ITU-R/go/patents/en where the Guidelines for Implementation of the Common Patent Policy for ITU-T/ITU-R/ISO/IEC and the ITU-R patent information database can also be found.

Series of ITU-R Reports (Also available online at http://www.itu.int/publ/R-REP/en)

Series Title BO Satellite delivery BR Recording for production, archival and play-out; film for television BS Broadcasting service (sound) BT Broadcasting service (television) F Fixed service M Mobile, radiodetermination, amateur and related satellite services P Radiowave propagation RA Radio astronomy RS Remote sensing systems S Fixed-satellite service SA Space applications and meteorology SF Frequency sharing and coordination between fixed-satellite and fixed service systems SM Spectrum management

Note: This ITU-R Report was approved in English by the Study Group under the procedure detailed in Resolution ITU-R 1.

Electronic Publication Geneva, 2019  ITU 2019 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without written permission of ITU. Rep. ITU-R M.2478-0 1

REPORT ITU-R M.2478-0

Spectrum needs for the amateur service in the frequency band 50-54 MHz in Region 1 and sharing with mobile, fixed, radiolocation and broadcasting services

(2019)

TABLE OF CONTENTS Page

1 Introduction ...... 7 1.1 Background to this Report ...... 7 1.2 Structure of this Report ...... 8 1.3 Geographic considerations ...... 8

2 Current usage of the 50-54 MHz frequency band in Region 1 ...... 8 2.1 The amateur service ...... 8 2.2 The radiolocation service ...... 9 2.3 The broadcasting service ...... 9 2.4 The fixed and mobile services ...... 10 2.5 Inter-regional sharing between services ...... 11 2.6 Others applications in the 50-54 MHz frequency band ...... 11

3 Spectrum needs for the amateur service in Region 1 ...... 11 3.1 General considerations ...... 11 3.2 Background on current usage on national basis in Region 1 ...... 11 3.3 Other envisaged applications ...... 12 3.4 Designated application categories to be taken into account in spectrum needs estimation ...... 12 3.5 Application based assessment of spectrum needs ...... 13 3.6 Study 1 based on spectrum occupancy and contest log data analysis ...... 13 3.7 Study based on estimations and long term experience ...... 16 3.8 Reasons for differences between the studies ...... 18 3.9 Summary of spectrum needs from the studies ...... 18 3.10 Status of possible allocation ...... 20 Page 2 Rep. ITU-R M.2478-0

4 Characteristics of amateur stations for sharing studies ...... 20 4.1 Global characteristics ...... 20 4.2 Specific Region 1 characteristics ...... 20 4.3 Antenna type and polarization ...... 21 4.4 Propagation Factors ...... 22

5 Sharing with the mobile service ...... 22 5.1 System parameters of the mobile service ...... 23 5.2 Minimum coupling loss calculations ...... 24 5.3 Radio Interference coverage mapping ...... 28 5.4 A Monte-Carlo simulation of amateur service versus mobile service using the P.2001-2 propagation model ...... 28 5.5 A Monte-Carlo simulation using the CEPT SEAMCAT simulation software ... 30 5.6 Sharing possibilities ...... 31 5.7 Summary of conclusions ...... 33

6 Sharing with the fixed service ...... 33

7 Sharing with the radiolocation service ...... 33 7.1 Background ...... 33 7.2 Study details ...... 34 7.3 Study results ...... 34 7.4 Regulatory aspects ...... 34

8 Sharing with the broadcasting service ...... 34 8.1 Sharing study details ...... 34 8.2 Study 1 description ...... 34 8.3 Study 1 results ...... 35 8.4 Study 2 description ...... 35 8.5 Study 2 results ...... 35 8.6 Study 3 description ...... 36 8.7 Study 3 results ...... 37 8.8 Summary of study results ...... 37

9 Mitigation Factors...... 38

10 Conclusion of the Report ...... 39 Rep. ITU-R M.2478-0 3

Page 10.1 Study components ...... 39 10.2 Spectrum needs ...... 39 10.3 Sharing with the mobile service ...... 39 10.4 Sharing with the broadcasting service ...... 39 10.5 Sharing with the radiolocation service ...... 40 10.6 Status of allocation ...... 40

Annex 1 – Spectrum needs and associated information ...... 40 A1.1 Introduction ...... 40 A1.2 Regulatory history ...... 40 A1.3 Current and future regulatory issues ...... 41 A1.4 General information about the amateur service ...... 41 A1.5 CEPT Provisions in Region 1 ...... 41 A1.6 Article 5 – VHF Amateur Spectrum Shortfall in Region 1 ...... 41 A1.7 Detailed 50 MHz band usage and propagation mechanisms relevant to the Amateur Service ...... 42 A1.8 Propagation ...... 42 A1.9 50-52 MHz band usage ...... 44 A1.10 52-54 MHz band usage ...... 45 A1.11 Power flux density ...... 46 A1.12 Station identification by call-sign ...... 46 A1.13 Listen before talk (transmit) ...... 46 A1.14 Band Availability ...... 47

Annex 2 – Statistics – number of amateur stations and density ...... 47

Annex 3 – An application-based approach to calculation of spectrum needs ...... 49 A3.1 Principles for calculating spectrum needs ...... 49 A3.2 Geographic Parameters ...... 49 A3.3 Traffic Parameters ...... 49 A3.4 Technology ...... 50 A3.5 Calculations ...... 50 A3.6 Results of application-based approach ...... 51

Annex 4 – Another analysis of amateur band occupancy ...... 51 4 Rep. ITU-R M.2478-0

Page

Annex 5 – Amateur service sharing with (analogue television) broadcasting service ...... 55 A5.1 Introduction ...... 55 A5.2 Method ...... 56 A5.3 Variables for the unwanted amateur station signal ...... 57 A5.4 Variables for the wanted TV signal ...... 58 A5.5 The calculation ...... 58 A5.6 Sharing scenario ...... 59 A5.7 An alternative approach ...... 59 A5.8 Summary and conclusions ...... 60

Annex 6 – A Monte-Carlo simulation study of compatibility between the analogue TV broadcast service and the amateur service ...... 61 A6.1 Introduction and summary ...... 61 A6.2 Study details ...... 61 A6.3 The major metropolitan area study ...... 61 A6.4 The rural centre study ...... 62

Annex 7 – Amateur service stations interference to television receivers of the broadcasting service in the band 50-54 MHz...... 69 A7.1 Introduction ...... 69 A7.2 Working Assumptions ...... 69 A7.3 Calculation results ...... 72 A7.4 Findings and Proposals ...... 81

Annex 8 – Information concerning current and past sharing arrangements between the amateur service and other services in the 50-52 MHz frequency band ...... 82 A8.1 Introduction ...... 82 A8.2 Sharing scenarios ...... 82 A8.3 Country information ...... 82 A8.4 Summary ...... 87

Annex 9 – Background information on TV in Region 1...... 89 A9.1 Broadcasting plans ...... 89 A9.2 The 2016 Situation ...... 89 A9.3 Digital Terrestrial Television Broadcasting in Band 1: 47-68 MHz ...... 90 A9.4 Analogue Television Broadcasting in Band 1: 47-68 MHz ...... 91 Rep. ITU-R M.2478-0 5

Page

Annex 10 – A Monte-Carlo simulation of sharing with the mobile service ...... 91 A10.1 Introduction ...... 91 A10.2 Background ...... 91 A10.3 The study scenarios and basic system parameters ...... 92 A10.4 Operational considerations ...... 96 A10.5 Estimating the service range of the tactical links ...... 97 A10.6 Range of the amateur service links assumed in this study ...... 97 A10.7 Results of the simulations ...... 98 A10.8 Conclusion ...... 99

Annex 11 – Minimum Coupling Loss sharing study between amateur radio stations and governmental mobile systems ...... 99 A11.1 Propagation model ...... 100 A11.2 Global approach ...... 100 A11.3 Protection criterion and ambient noise figure ...... 100 A11.4 Radiated power for co- and adjacent channels ...... 101 A11.5 Determination of minimum path attenuation ...... 101 A11.6 MCL Results ...... 102

Attachment 1 to Annex 11 – Amateur radio transmission mask ...... 102

Attachment 2 to Annex 11 – Propagation scenarios for MCL calculations ...... 105

Attachment 3 to Annex 11 – Radiated Power for Co-adjacent and spurious domain ...... 109

Attachment 4 to Annex 11 – Minimum required path loss ...... 111

Annex 12 – Radio Interference coverage mapping ...... 112 A12.1 Determination of the interference level ...... 113 A12.2 Simulation results ...... 113 A12.3 Results for Yverdon-Les-Bains Switzerland ...... 113 A12.4 Results for Aachen (Germany) ...... 116 A12.5 Results for Faux d’Enson (Swiss/French border) ...... 118 A12.6 Results for Vallon-En-Sully (France) ...... 121

Annex 13 – Amateur service vs. Mobile service Monte-Carlo study details ...... 123 A13.1 Determination of the interference level ...... 123 A13.2 Amateur service characteristics ...... 123 6 Rep. ITU-R M.2478-0

Page A13.3 Propagation Model ...... 123 A13.4 Protection criterion and ambient noise figure ...... 124 A13.5 Amateurs Emission masks/Mobile reception mask ...... 124 A13.6 SSB Case ...... 124 A13.7 FM case ...... 129 A13.8 Wideband Digital ...... 132

Annex 14 – Sharing with the radiolocation service (WPR) ...... 134 A14.1 Background ...... 134 A14.2 WPR location and parameters ...... 135 A14.3 In-band separation distances ...... 136 A14.4 Separation distances ...... 137 A14.5 Conclusions ...... 139

Annex 15 – Spectrum needs evaluation based on spectrum monitoring ...... 140 A15.1 Spectrum needs evaluation ...... 140 A15.2 Current amateur station activity and spectrum needs for the average use case .. 141 A15.3 Future spectrum needs for the average use case in a country with average amateur license density ...... 142 A15.4 Current amateur station activity and spectrum needs during a SSB contest in a country with average amateur license density ...... 144 A15.5 Future amateur spectrum needs for the case where additional spectrum is required in a country with average amateur license density ...... 145 A15.6 Future amateur spectrum needs in a country with high amateur license density ...... 146 A15.7 Spectrum needs summary ...... 146

Attachment 1 to Annex 15 – Spectrum Monitoring and Spectrum Occupancy Results ...... 147

Summary This Report responds to the invitations of Resolution 658 (WRC-15) to conduct studies to provide information for the deliberations of WRC-19 on agenda item 1.1 which is for a possible new allocation to the amateur service in the 50-54 MHz frequency band. The Report provides information on three major topics; spectrum needs of the amateur service, sharing scenarios between the amateur and incumbent services and possible status of any allocated spectrum. Rep. ITU-R M.2478-0 7

The Report is applicable to typical contemporary analog and digital amateur applications, contemporary TV broadcasting, land mobile and wind profiler systems which are operating in the 50-54 MHz frequency band.

Related Recommendations, Reports and Standards Recommendation ITU-R SM.329 – Unwanted emissions in the spurious domain Recommendation ITU-R P.372 – Radio noise Recommendation ITU-R SM.851 – Sharing between the broadcasting service and the fixed and/or mobile services in the VHF and UHF bands Recommendation ITU-R SM.1055 – The use of Spread Spectrum Techniques Recommendation ITU-R M.1226 – Technical and operational characteristics of Wind Profiler Radars in the bands in the vicinity of 50 MHz Recommendation ITU-R BT.1368 – Planning criteria, including protection ratios, for digital terrestrial television services in the VHF/UHF bands Recommendation ITU-R M.1634 – Interference protection of terrestrial mobile service systems using Monte Carlo simulation with application to frequency sharing Recommendation ITU-R M.1825 – Guidance on technical parameters and methodologies for sharing studies related to systems in the land mobile service Recommendation ITU-R P.2001 – A general purpose wide-range terrestrial propagation model in the frequency range 30 MHz to 50 GHz Recommendation ITU-R BT.2033 – Planning criteria, including protection ratios, for second generation of digital terrestrial television broadcasting systems in the VHF/UHF bands Report ITU-R M.2013 – Wind profiler radars Report ITU-R SM.2028-1 – Monte Carlo simulation methodology for the use in sharing and compatibility studies between different radio services or systems Report ITU-R BT.2387-0 – Spectrum/frequency requirements for bands allocated to broadcasting on a primary basis Final Acts of the European Broadcasting Conference (Stockholm, 1961 as revised in Geneva, 2006) (“ST61”) in the European Broadcasting Area. Final Acts of the African Broadcasting Conference (Geneva, 1989 as revised in Geneva, 2006) (“GE89”) in the African Broadcasting Area and neighbouring countries. Resolution 217 (WRC-97) – Implementation of wind profiler radars. ETSI Standard EN301783 – Commercially available amateur radio equipment; Harmonised Standard covering the essential requirements of article 3.2 of the Directive 2014/53/EU

1 Introduction

1.1 Background to this Report This Report responds to the invitations of Resolution 658 (WRC-15) to conduct the following studies in order to support the deliberations of WRC-19 on agenda item 1.1: 1) to study spectrum needs in Region 1 for the amateur service in the frequency band 50-54 MHz; 8 Rep. ITU-R M.2478-0

2) taking into account the results of the above studies, to study sharing between the amateur service and the mobile, fixed, radiolocation and broadcasting services, in order to ensure protection of these services. The frequency band 50-54 MHz is allocated on a primary basis to the Amateur Service in Regions 2 and 3 and the intent of Resolution 658 (WRC-15) is to study a possible global frequency harmonization.

1.2 Structure of this Report This Report is divided into two parts: the body of the Report, from sections 1 to 10 provides a summary of the studies and results; and the Annexes (1 through 15) provide complete technical details of the studies. The Annexes are attached more-or-less as they were submitted in the various input contributions that were made to Working Party meetings; the only changes were editorial to make the style consistent throughout the Report.

1.3 Geographic considerations The geographic focus of this Report is almost entirely European due to the fact that most contributions were received from European countries.

2 Current usage of the 50-54 MHz frequency band in Region 1

2.1 The amateur service In Region 1, African countries listed in No. 5.169 of the Radio Regulations (RR) have an allocation to the amateur service in the 50-54 MHz frequency band on a primary basis. A number of other Region 1 countries have authorized the use of all or parts of the 50-52 MHz frequency band by the amateur service on a mainly national secondary (but sometimes national primary) basis in accordance with RR No. 4.4. CEPT’s European Table of Frequency Allocations allocates the 50-52 MHz frequency band to the amateur service on a secondary basis. Thus 75% of CEPT’s membership authorize amateur usage within the 50-52 MHz frequency band mainly on a secondary basis. The permitted maximum power of such stations is mostly 100 W, in some countries there are territorial limitations with regard to power and frequencies. Table 1 provides a list of Region 1 Administrations and the conditions for using the 50-54 MHz frequency band.

TABLE 1 Conditions for amateur service usage of the 50-54 MHz band in Region 1, as at May 2019

Country Band Status1 RR2 Country Band Status1 RR2 Country Band Status1 RR2 Country Band Status1 RR2

AFS 50-54 P 5.169 DNK 50-52 S LBR No Info S 50-52 S No No ALB 50-52 S E 50-52 S LBY Info SDN Info 50- 5.16 52 ALG NO EGY NO LIE S SEN 50-51 P 9 No 50- 5.16 No Info 54 Info AND 50-52 S ERI LSO P 9 SEY No 50- AGL Info EST 50-52 S LTU 52 S SMR 50-52 S ARM NO ETH No Info LUX 50-52 S SOM 50-54 Rep. ITU-R M.2478-0 9

TABLE 1 (end)

Country Band Status1 RR2 Country Band Status1 RR2 Country Band Status1 RR2 Country Band Status1 RR2

ARS NO F 50-52 S LVA 50-52 S SRB 50-51.9 S AUT 50-52 S FIN 50-52 S MAU NO SRL No Info AZE NO 50-51 P MCO 50-52 S SSD No Info BEL 50-52 S G 51-52 S MDA NO STP No Info BEN No Info GAB No Info MDG No Info SUI 50-52 S BFA No Info GEO NO MKD 50-52 S SVK 50-52 S 50-50.5 P GHA No Info MLI No Info SVN 50-52 S BHR 50.5-52 S GMB No Info MLT 50-52 S SWZ 50-54 P 5.169 BIH 50-52 S GNE No Info MNE 50-52 S SYR No Info BLR NO GNB No Info MNG No Info TZA No Info BOT 50-54 P 5.169 GRC 50-52 S MOZ No Info TCD No Info GUI No info

BUL 50.05-50.2 S HNG 50-52 S MRC No Info TGO No Info BDI No Info HOL 50-52 S MTN No Info TJK NO CAF No Info HRV 50-51.9 S MWI 50-54 P 5.169 TKM NO CME No Info I 50-52 S NGR No Info TUN NO COD 50-54 P 5.169 IRL 50-52 S NIG NO TUR NO COG No Info IRQ No Info NMB 50-54 P 5.169 UAE No Info COM No Info ISL 50-52 S NOR 50-52 P UGA No Info CPV No Info ISR 50-52 S OMA 50-52 S UKR 50.08-50.28 S CTI No Info JOR 50-51.5 S POL 50-52 S UZB NO CVA 50-52 S KAZ NO POR 50-52 S YEM No Info CYP 50-51 S KEN NO QAT No Info ZMB 50-54 P 5.169 CZE 50-52 S KGZ NO ROU 50-52 S ZWE 50-54 P 5.169 D 50.03-51 S KWT No Info RUS NO DJI No Info LBN 50-51.975 RRW 50-54 P 5.169 5.169 Alternative allocation: in Botswana, Lesotho, Malawi, Namibia, the Dem. Rep. of the Congo, Rwanda, South Africa, Swaziland, Zambia and Zimbabwe, the band 50-54 MHz is allocated to the amateur service on a primary basis. In Senegal, the band 50-51 MHz is allocated to the amateur service on a primary basis. (WRC-12) 1 Status: P = primary, S = Secondary, No info = no information available. 2 RR is the applicable Radio Regulation Article 5 footnote.

According to IARU Region 1 frequency planning, in countries where allowed, the frequency range 50.0-50.5 MHz is utilized for weak signal communications, which would derive great benefit from harmonization with Regions 2 and 3. The frequency range 50.5-52 MHz is currently utilized for voice communications using frequency or phase modulation, digital communications, Gateways and FM Repeaters.

2.2 The radiolocation service RR No. 5.162A provides for an additional allocation to the radiolocation service on a secondary basis in a number of countries in Region 1, limited to the operation of wind profiler radars in accordance with Resolution 217 (WRC-97). Very few wind profiler radars currently operate in the 50-54 MHz frequency band.

2.3 The broadcasting service The 47-68 MHz frequency band is allocated to the broadcasting service on a primary basis in Region 1. In recent years, in the majority of Region 1 countries broadcasting has significantly declined in the 47-68 MHz frequency band and analogue television is expected to be phased out by 2020 as 10 Rep. ITU-R M.2478-0 conversion to digital television broadcasting in a different part of the spectrum proceeds. However in parts of Eastern Europe the band is still used for analogue television. As of March 2019 the number of television stations included in the MIFR within the frequency band 48-56 MHz (1st TV channel) in some Region 1 countries is provided in Table 2.

TABLE 2

Number of ITU code records ARM 19 AZE 22 BLR 2 GEO 2 KAZ 8 KGZ 10 MDA 5 RUS 344 TJK 18 TKM 2 UKR 18 UZB 22

A number of other countries in Region 1 still have records in the MIFR and in regional Plans in this frequency band. Some administrations have already indicated analogue switch-off in the upper VHF and UHF bands, but the operational status of the lower Band I VHF relevant assignments is not known. However, the total number of operational high and medium-power television transmitters within the 48-56 MHz frequency band in the Russian Federation is about 500 (344 in the MIFR as of 28th of March 2019) and it is expected that a large number of these will remain operational for the foreseeable future. The frequency band 48-56 MHz is also being considered by some administrations for the deployment of digital television and multimedia broadcasting systems. There are also proposals to expand the use of the DVB-T2 system in frequency bands below 174 MHz, as well as the introduction of advanced sound and multimedia broadcasting systems in the lower part of broadcasting band 1, including frequencies from 50-54 MHz.

2.4 The fixed and mobile services Footnote RR No. 5.164 allocates part, or all, of the frequency band 47-68 MHz to the land mobile service on a primary basis in a number of countries in Region 1, and footnote RR No. 5.165 allocates this frequency band to the fixed service and the mobile (except aeronautical mobile) service in a number of African countries. It has to be noted that RR No. 5.167 and RR No 5.167A provide allocations to the fixed service on a primary basis in the 50-54 MHz frequency band to countries in Region 3 which border Region 1. An examination of the ITU Master International Frequency Register (MIFR) indicates a number of notifications for fixed services in the 50-54 MHz frequency band with none in administrations bordering Region 1. The MIFR also indicates that there are four notifications in one Region 1 administration which date back many years. Rep. ITU-R M.2478-0 11

There may also be fixed usage in Region 1 which has not been notified to the MIFR which may include short range fixed use on a national basis.

2.5 Inter-regional sharing between services Due to the different service allocations as given in various footnotes in the Radio Regulations there is inter-regional sharing between services at the borders between Region 1 and Regions 2 and 3.

2.6 Others applications in the 50-54 MHz frequency band For information, the radioastronomy service has no allocations in the 50-54 MHz band. However some radio astronomy instruments are operating on a non-protection basis in the band 50-54 MHz in Region 1. This application is not covered by Resolution 658 (WRC-15) and no studies have been carried out for its protection.

3 Spectrum needs for the amateur service in Region 1 This section of the Report together with Annexes 1, 3, 4 and 15 addresses the spectrum needs for an allocation in the frequency band 50-54 MHz to the amateur service in accordance with Resolution 658 (WRC-15). In particular current and future spectrum applications, usage and needs are discussed and an application-based method for determining spectrum needs in the amateur service has been developed.

3.1 General considerations Activities in the frequency band 50-54 MHz feature many of the key aspects of the amateur service e.g. two-way communication, technical investigation and self-training. Furthermore, propagation characteristics in this part of the spectrum are highly attractive for amateur investigations since 50-54 MHz lies in the transition zone between HF with its sky wave propagation and VHF with its more line of sight propagation modes. A 50-54 MHz frequency allocation in Region 1 will allow for harmonised spectrum in all three ITU Regions and will enable the International Amateur Radio Union (IARU) to develop harmonised band utilisation plans. More than that, access to the 50-54 MHz frequency band in Region 1 would ease problems experienced by the amateur service caused by the widespread rise in environmental noise in the MF and HF spectrum which increasingly renders frequencies less than 30 MHz allocated to the amateur service subject to disturbance and harmful interference, particularly in urban environments. It would also alleviate the lack of VHF spectrum allocated to the amateur service in Region 1, since there are only 2 MHz of VHF spectrum in one sub-band allocated to the amateur service, whereas Region 2 currently has 13 MHz of spectrum in three sub-bands available to the amateur service for experimentation.

3.2 Background on current usage on national basis in Region 1 At present, where use is permitted in the 50-52 MHz frequency band in Region 1, the most common analogue and digital amateur service applications use bandwidths of less than 25 kHz, within which long distance weak-signal and propagation beacon applications are globally coordinated within 50.0-50.5 MHz. The frequency range 50.5-52 MHz is currently utilised for two-way voice communications using frequency or phase modulation, data, gateways and FM repeaters. Digital voice and data is already being used for 50 MHz networks in the amateur service incorporating text 12 Rep. ITU-R M.2478-0 and simple voice messaging. Such systems have shown to be of considerable value in emergency communications. See RR No. 25.3.

3.3 Other envisaged applications Based on current experimentation, digital communication applications are to be envisaged, combining voice, video and data encompassing a wide range of necessary bandwidths not exceeding 500 kHz for which usage is not currently possible in some countries. Examples of such new application scenarios will include: – Reduced Bandwidth Digital Amateur Television (RB-DATV). With leading-edge amateur innovation, currently the lowest data rate achievable for RB-DATV (MPEG 4/DVB-S QPSK) is 333 kb/s requiring a necessary bandwidth of 500 kHz. – IP links/mesh networks and innovative compressed multimedia transmission systems (currently based on DVB-S2/MPEG technologies adapted for terrestrial use). – Adaptations of HAMNET mobile terminal devices. Many of these applications currently exist in the amateur service microwave bands and in a few Region 1 countries where experimental amateur VHF developments are occurring. Their further development and adaptation to the frequency band 50-54 MHz requires the certainty of a sufficiently wide frequency allocation in Region 1. Access to more VHF spectrum would additionally encourage development of new technologies to support disaster relief in accordance with the IARU-ITU and IARU-Red Cross/Red Crescent Memoranda of Understandings on disaster relief operations.

3.4 Designated application categories to be taken into account in spectrum needs estimation Based on the above elements and on the background of existing usage and anticipated growth in digital systems, it is necessary to determine spectrum needs based on the following application categories within the range 50-54 MHz:

TABLE 3 Application categories to be considered when assessing amateur spectrum needs in the frequency band 50-54 MHz

Contact range at Required Designated application categories usable SNR bandwidth per (km) channel Narrowband weak-signal communications e.g. CW, SSB and 250 500-3 000 Hz digital weak signal data modes1 24/7 propagation beacons 500-1 000 Hz Relatively narrowband (≤ 25 kHz) digital voice, FM voice, data. 70 25 kHz Repeaters and gateways 100 25 kHz Wider bandwidth predominantly digital applications (see A1.10 40/70 500 kHz and A1.11)

1 ‘Weak signal data modes’ are structured for very basic communications with low data rate and narrow bandwidth for best weak signal performance. Rep. ITU-R M.2478-0 13

Where “Contact Range at usable SNR” is the distance between the transmitter and receiver at which the receiver is able to receive a signal at a level which permits demodulation and the correct recovery of the transmitted message.

3.5 Application based assessment of spectrum needs An application-based approach suitably adapted to amateur service usage is considered appropriate for the amateur service to assess spectrum needs in the frequency band 50-54 MHz with a focus on the specific applications expected in this frequency band. (See Annex 3.) An example of this approach can be found in Recommendation ITU-R M.1651 – A method for assessing the required spectrum for broadband nomadic wireless access systems including radio local area networks using the 5 GHz band, which provides a similar methodology for assessing spectrum requirements for RLANs. This Recommendation has since been further developed and is one of the methods used for other WRC agenda items. The method can: – take account of the expected capabilities and usage scenarios, and – be readily implemented using common software tools such as a spreadsheet. Details of the spectrum needs calculation process using this approach are provided together with a spreadsheet containing typical values. The results derived from using this approach are strongly dependent upon the input parameters used. Results from two different studies are provided in this Report. Both studies are based on the same application based approach, but using different parameters for the number of active amateur stations and session durations. The first study presented in § 3.6 applies parameter values derived from spectrum monitoring measurement results together with a contest log data analyses. In addition, for average as well as for high density amateur population areas, two spectrum use situations are considered: an average, every day spectrum use situation and an exceptionally intensive spectrum use occurring e.g. during contests or situations of exceptional propagation conditions. A second study, presented in § 3.7, was developed based on long term amateur usage experience of the different applications highlighted in Table 4, along with the amateur population density. This study calculates the spectrum required for average and high-density amateur population cases, which are representative of the situation in a number of European countries. Both studies considered the applications highlighted in Table 4.

TABLE 4 Assumed application usage distribution used for the studies

Wideband SSB FM Repeaters Infrastructure modes App 1 App 2 App 3 App 4 App 5 60% 5% 5% 20% 10%

3.6 Study 1 based on spectrum occupancy and contest log data analysis Section 3.6 is based on the work presented in Annex 15. 14 Rep. ITU-R M.2478-0

3.6.1 Spectrum needs evaluation methodology and parameters The application based methodology to estimate the spectrum needs for amateur radio service in the frequency band 50-54 MHz can be found in Annex 3. The spectrum need is calculated for average and high population density areas, taking into account everyday usage situations as well as exceptional usage situations where additional spectrum is required. Accordingly the spectrum needs are calculated for the following cases: – Case A: Average, everyday use case which occurs with a probability of 98% in time. – Case B: Where additional spectrum is required. This situation occurs e.g. during contests, exceptional propagation conditions, public service and special events. It is assumed, that those cases do not occur during more than seven days a year. This corresponds to situations which occur with a probability of less than 2% in time. Both usage situations are considered in calculations for European countries with a typical as well as with maximum amateur station density. The spectrum needs evaluation based on the application based approach considers different parameters which need to be defined or derived. The derivation of the parameters for active amateur stations density and session duration is not straightforward but are of central importance. For this study, they are obtained through an analysis of IARU 2017 50 MHz contest log data together with the analysis of spectrum monitoring data as well as application of correction factors regarding the forecasted growth of the amateur radio community and propagation conditions. To obtain figures for future spectrum use and future conditions, the following data and procedures are used: – The number of active amateur stations for the Case A situation in a typical European country is evaluated based on spectrum monitoring results obtained through a measurement campaign which has taken place in the period of April to July 2018. It turns out, that for Case A the spectrum occupancy is well below 1%. – The session duration for an active amateur station in a Case A scenario is assumed to be 2 hours/day on average when about 3% of the existing amateur licenses are daily accessing the band 50-52 MHz. – The session duration for Case B is calculated based on the maximum duration of a two way contact during the IARU 2017 50 MHz contest. Therefore the evaluated figure for the session duration during contests may represent an overestimation. – The number of active amateur station for the case B is evaluated based through an analysis of IARU 2017 50 MHz contest log data. The spectrum monitoring results of the IARU 2018 50 MHz contest showed a lower activity than the activity of the IARU 2017 50 MHz contest (evaluated based on contest log data). This may be caused by significantly worse propagation conditions during the 2018 contest compared to the 2017 contest. Therefore, the monitoring data of the IARU 2018 50 MHz contest are disregarded for the spectrum needs analysis. When assuming a session duration as described above, it was found that the evaluated number of active amateur stations was 68% of the existing amateur licenses. – For the evaluation of the future need, the growth of the number for amateur licenses is linearly extrapolated to the year 2038. – It is shown that the current spectrum use in the frequency band 50-52 MHz for the average, everyday use case is very low, while during contests a strong increase of the use can be observed, but only for narrow band modes. However, the use of the spectrum in the 50.5- 52 MHz frequency band by all other modes like FM, RTTY, digital communication, etc. is always very low. Accordingly, for the determination of future requirements, the ratios of the case B are considered for narrowband applications, while for FM, repeaters, Infrastructure and Wideband modes the circumstances of daily use (case A) are considered. Rep. ITU-R M.2478-0 15

– It is shown, that the number of active amateur stations during the IARU 2017 50 MHz contest was significantly higher, than during the ‘big opening’ on the 28.05.2018. Therefore no data from this ‘big opening’ but only from the IARU 2017 50 MHz contest is considered for Case B spectrum needs evaluation. – Because future maximum solar activity may stimulate a more intense use of the Band 50- 52 MHz, the calculation for future spectrum needs considers in average 50% additional amateur activity due to high solar activity. – Figures for high amateur station populations are obtained based on data for average amateur population density corrected through linear interpolation. 3.6.2 Spectrum needs summary The spectrum need is calculated for average and high population density areas, taking into account everyday usage situations as well as exceptional usage situations where additional spectrum is required. Accordingly the spectrum needs are calculated for two different cases: – Case A: Average, everyday use case which occurs with a probability of 98% in time. – Case B: Where additional spectrum is required. This situation occurs e.g. during contests, exceptional propagation conditions, public service and special events. It is assumed, that those cases do not occur during more than 7 days a year. This corresponds to situations which occur with a probability of less than 2% in time. Both usage situations are considered in calculations for European countries with a typical as well as with maximum amateur station density. It is shown, that the current spectrum use in the frequency band 50-52 MHz for the average, everyday use case is very low, while during contests a strong increase of the use can be observed only for narrow band modes. The use of the spectrum in the 50.5-52 MHz frequency band by all other modes like FM, RTTY, digital communication, etc. is always very low, independent of usage situations like contests or propagation conditions. Accordingly, for the determination of future requirements, the ratios of the case B are considered for narrowband applications, while for FM, repeaters, Infrastructure and Wideband modes only the circumstances of the everyday use case (case A) applies. Current and future spectrum needs of the Amateur Service in the 50 MHz frequency band are shown in Table 5. The index “av” and “high” for the calculated bandwidth numbers in the Table 5 stand for countries with average respectively high amateur station density. Values in brackets represent real calculated, respectively measured values, while all other numbers are rounded up to integer multiples of the respective channel bandwidth. 16 Rep. ITU-R M.2478-0

TABLE 5 Current and future spectrum needs

Current average occupied bandwidth Future spectrum in a typical Spectrum usage needs (MHz) Applications European country situation Frequency according to measured during a range Study 1 four-month period (MHz) in spring 2018

Total 1.365 MHzav All applications 0.226 MHzav maximum 1.702 MHzhigh 0.003 MHz Narrow band and 0.009 MHz 50.0-50.5 (0.0561 kHz av Telegraphy 0.021 MHz Case A Existing + 2.52 kHz) high During average applications FM, Repeaters, 0.025 MHz 0.125 MHz days 50.5-52.0 av Digital, etc. (1.69 kHz) 0.225 MHz (98% of time) high New Wide Band, 1.0 MHz > 50.5 n.a. av applications Infrastructure 1.0 MHzhigh Narrow band and 0.240 MHz Case B 50.0-50.5 0.219 MHz av During contests Existing Telegraphy 0.477 MHzhigh and exceptional applications FM, Repeaters, 0.025 MHz 0.125 MHz 50.5-52.0 av conditions Digital, etc. (0.033 kHz) 0.225 MHzhigh (during 2% of New Wide band, 1.0 MHzav time) > 50.5 n.a. applications infrastructure 1.0 MHzhigh

3.7 Study based on estimations and long term experience Section 3.7 is based on the work presented in Annex 1. 3.7.1 Introduction An application based approach as described in § 3.5 above was used. This has been found to be suitable for estimating the spectrum needs for current and envisaged amateur applications in the 50-54 MHz frequency band. A nominal set of frequency ranges has been used to align with the existing and expected categories of applications. The results from this calculation procedure need to be considered carefully given that the output might be sensitive to the input parameter values on the usage of advanced applications which can be drawn from a large range of possible values. This input parameter, on the other hand, could reflect the different situation in particular regions or countries.

3.7.2 Spectrum needs evaluation methodology and parameters This paragraph describes the various parameters used to calculate the spectrum needs when using the above described application based methodology to estimate the spectrum needs for the amateur radio service in the frequency band 50-54 MHz. The characteristics of amateur service stations used in spectrum needs calculations are contained in Table 9 of this Report. In addition to the number of amateurs in Europe, it is estimated that 8% of these will use the 50-54 MHz band. Rep. ITU-R M.2478-0 17

The duration of a spectrum access is assumed to be 2 hours/day except for the repeaters and infrastructure applications which are assumed to operate 24 hours/day with a duty cycle of 50%. The split between the various applications is taken from Table 4. In addition the contact range at usable SNR for infrastructure is set from operational experience to 70 km. A circular ‘cell’ is also defined based on the contact range at usable SNR for each application according to Table 4. Bandwidth for each application is taken from Table 3 with the addition of propagation beacons with a spectrum usage of 100 kHz. To accommodate a mix of analogue and digital applications all calculations are based on a simple channel bandwidth. However many transmission modes are not compatible with each other and cannot share spectrum, therefore a summation of spectrum is required for each individual application. Additionally, the calculated spectrum for each application is rounded up to the next integer multiple of the application channel bandwidth as a fractional bandwidth would not allow the application to function correctly. 3.7.3 Calculation steps This section shows how the spectrum needs are calculated. 1 Calculate the average number of amateurs or transmitters per km2 at any time in the year using spectrum in the 50-54 MHz frequency band for a specific application. 2 Calculate the number of amateurs within one ‘cell’ using a specific application within 50- 54 MHz band. (A ‘cell’ is a circle with a radius of the “Contact range at usable SNR”.) 3 Calculate the required spectrum within a ‘cell’ for a specific application. 4 Calculate the average bandwidth for the specific application over the operating session time. 5 Sum up the aggregate spectrum required within the band 50-54 MHz. An embedded Spread Sheet that reflects these calculations has been provided in Annex 3. 3.7.4 Results of study Two sets of calculations have been performed and documented in the embedded Spread Sheet in Annex 3. In addition to the two cases studied in § 3.6 (A and B) two cases (C and D) dealing with two amateur population densities are considered in this section. – Case C: The spectrum requirements of the amateur service in the frequency band 50-54 MHz, has been calculated from the number of radio amateurs in Europe as found in Annex 2 divided by the area of Europe based an average amateur population density for 100% of time. This gives 0.073 amateur stations per km2 for the case of average amateur population. The spectrum requirement for each application in this case is shown in Table 6 column A and shows that a total of 4.162 MHz of spectrum is currently required to meet the average European spectrum requirements of the amateur service in the frequency band 50-54 MHz. – Case D: The spectrum requirements of the amateur service in the frequency band 50-54 MHz, has also been calculated with a higher number of amateurs per km2 to reflect the situation in areas with a high amateur population density e.g. in the case of Germany. This gives 0.209 amateur stations per km2 for the case of areas with a high amateur population. The spectrum requirement for each application in this case is shown in Table 6 column B and shows that a total of 10.024 MHz would be required to meet the spectrum needs in such an area with a higher density of radio amateurs. 18 Rep. ITU-R M.2478-0

TABLE 6 Required spectrum for average and high-density amateur population

Required Spectrum (MHz) Required Spectrum (MHz) Applications C D Average amateur population High amateur population SSB 0.087 0.249 FM 0.025 0.025 Wideband modes 0.500 0.500 Repeaters (FM) 0.950 2.650 Infrastructure 2.500 6.500 Propagation beacons 0.100 0.100 Total amount of spectrum 4.162 MHz 10.024 MHz

The detailed evaluation of the spectrum needs figures can be found in the Annex 3.

3.8 Reasons for differences between the studies For both studies the same application based approach, the same technical and operational parameters for the different amateur applications. It should further be noted: – Analysis of contest reception logs makes the assumption that all band activity is reported, while cross checking of reports provides some confidence there is still the possibility that band usage is under reported. This is compensated by a margin in Study 1. – Although some of the applications are based on current experience in other frequency bands, there remain uncertainties concerning future developments and this may affect the spectrum needs calculations. Therefore the calculations need to be interpreted carefully. The main different assumptions in the respective studies are: – Study 1 calculates the needs based on the population density of active amateur licensees (percentage of amateurs using this application e.g. SSB, FM, etc.), which is calculated to be a maximum of 68% of the density of 50 MHz stations during a contest and less than 5% for everyday use. Study 2 calculates with the total (100%) of 50 MHz stations. This explains the similarity of spectrum needs calculation results between Study 1 for SSB contest case and Study 2 for SSB. – Contest like situations for Repeaters, Infrastructure and WB modes are excluded in Study 1. Based on today’s knowledge the spectrum needs for the latter mentioned application does not increase during contest or during occurrence of exceptional propagation conditions. Accordingly, Study 1 calculates for those applications with less than 5% active stations while Study 2 calculates with all (100%) of 50 MHz stations. This explains the main difference in the results of both studies. – Study 1 uses a session duration for contest situation of 4.65h/24h while Study 2 uses 2h/24h for average use, thus Study 1 is based on higher activity. Rep. ITU-R M.2478-0 19

3.9 Summary of spectrum needs from the studies The results of Study 1 and Study 2 regarding current and future spectrum needs of the Amateur Service in the 50 MHz frequency band are summarized in Tables 7 and 8. The index ‘av’ and ‘high’ for the numbers in the Table 7 stand for countries with average or high amateur station density. All numbers are rounded up to integer multiples of the respective channel bandwidth

TABLE 7 Current and future spectrum needs of existing and new Amateur service applications

Future Future Spectrum Frequency Current spectrum needs spectrum needs usage Applications range occupied (MHz) (MHz) situation (MHz) bandwidth(1) according according Study 1 Study 2

Narrow band (SSB 0.087 MHzav 0.009 MHzav & telegraphy) 50.0-50.5 0.003 MHzav 0.25 MHzhigh During Existing 0.021 MHzhigh Beacons 0.1 MHz average applications days FM, repeaters, NB 0.125 MHzav 0.975 MHzav 50.5-52.0 0.025 MHzav (98% of digital, etc. 0.225 MHzhigh 2.7 MHzhigh time) New Wide band, 1.0 MHz 3.0 MHz > 50.5 n.a. av av applications infrastructure 1.0 MHzhigh 7.0 MHzhigh

During Narrow band (SSB) 0.24 MHzav 50.0-50.5 0.219 MHzav n.a. contests Existing & telegraphy 0.477 MHzhigh and applications FM, repeaters, 0.125 MHzav exceptional 50.5-52.0 0.025 MHzav n.a. digital, etc. 0.225 MHzhigh conditions New Wide band, 1.0 MHz (during 2% > 50.5 n.a. av n.a. of time) applications infrastructure 1.0 MHzhigh (1) In a typical European country measured during a four-month period (April – July) in spring 2018.

As it is shown in the Table 7 depending on the conducted studies, the spectrum needs for amateur service in the band 50-54 MHz for the average usage days scenario and average amateur station density are estimated as: – for Narrow band SSB and Telegraphy applications: 0.009/0.087 MHz; – for Beacons: 0.1 MHz; – for FM, Repeaters, NB Digital applications: 0.125/ 0.975 MHz; – for Wide Band, Infrastructure applications (new applications): 1/3 MHz; – for all applications: 1.234 / 4.162 MHz. For the average usage days scenario and high amateur station density the spectrum needs are: – for Narrow band SSB and Telegraphy applications: 0.009/0.087 MHz; – for Beacons: 0.1 MHz; – for FM, Repeaters, NB Digital applications: 0.125/ 0.975 MHz; – for Wide Band, Infrastructure applications (new applications): 1/3 MHz; – for all applications: 1.234 / 4.162 MHz. For the contests and exceptional conditions scenario and average / high amateur station density the spectrum needs are estimated as: 20 Rep. ITU-R M.2478-0

– for Narrow band SSB, Telegraphy, Beacons applications: 0.24 / 0.477 MHz; – for FM, Repeaters, NB Digital applications: 0.125 / 0.225 MHz; – for Wide Band, Infrastructure applications (new applications): 1 MHz; – for all applications: 1.365 / 1.702 MHz. In the studies the average amateur station density corresponds a population density of amateur operators equal 0.073 licensees/km2, the high amateur station density corresponds – 0.2092 licensees/km2. There are no particular studies for the low amateur station density scenario, e.g. for a population density of amateur operators less than 0.007 licensees/km2. But from studies results for the average usage days scenario it could be observed that there is approximately a linear relationship between density of amateur operators and spectrum needs (1.234 MHz for 0.073 licensees/ km2 and 4.162 MHz for 0.2092 licensees/km2). So for the density of amateur operators less than 0.007 licensees/km2 (it is 10 times less than 0.073 licensees/km2), for all applications spectrum demand could be assessed as 0.1234 / 0.4162 MHz for the average usage days scenario. Taking into account the minimum bandwidths required by existing and new amateur applications, it could be assumed that for the average all usage day scenarios the maximum spectrum needs for existing applications will be less than 200 kHz. In Table 8 maximum needs for amateur service in the band 50-54 MHz is presented according to the provided studies.

TABLE 8 Current and future total spectrum needs of existing and new Amateur service applications

Future spectrum needs Future spectrum needs Current occupied Applications (MHz) according (MHz) according bandwidth(1) Study 1 Study 2

Maximum need 0.244 MHzav 1.365 MHzav 4.162 MHzav

considering all 1.702 MHzhigh 10.024 MHzhigh applications Beacons not included (1) In a typical European country measured during a 4 month period (April – July) in spring 2018.

3.10 Status of possible allocation One view is that sharing studies (see § 5, 7 and 8) have demonstrated that large separation distances are required to allow coexistence with incumbent services. Given those results, introducing a new service in the band needs to be done with appropriate status that will allow to avoid placing any additional constraint on the secondary services in place but also to ensure coexistence with the primary incumbent services in place. Thus, a primary allocation to the amateur service in this band should not be considered, only a secondary allocation on the whole envisaged spectrum would allow maintaining equilibrium in the band. An alternative view was expressed that that the amateur service seeks primary status within the 50-54 MHz frequency band, in common with Regions 2 and 3 as per ITU Recommendation 34. In addition a secondary allocation in the band would not satisfy the concerns of the amateur service e.g. that due account would be taken of a secondary allocation to the amateur service in Region 1 in any future frequency allocation activity. Experience has shown that when studying a new allocation with regards to sharing with the amateur service as secondary incumbent service, does not achieve support when ITU plans WRCs agenda items, even if the need to address incumbent services is Rep. ITU-R M.2478-0 21 specified. For example, see Resolution 239 (WRC-15) invites ITU-R b) in respect of the band 5 725- 5 850 MHz where the secondary amateur service was not included.

4 Characteristics of amateur stations for sharing studies

4.1 Global characteristics There is an existing allocation to the amateur service between 50-54 MHz in ITU Regions 2 and 3; therefore the most recent version of Recommendation ITU-R M.1732 – Characteristics of systems operating in the amateur and amateur-satellite services for use in sharing studies, contains the range of current characteristics that might be used by the amateur service across the world.

4.2 Specific Region 1 characteristics Considering contemporary and future likely use of the 50-54 MHz frequency band by the amateur service in Region 1, a subset of characteristics is suggested for use in the sharing analyses that are contained in this Report. Typical transmission modes that may be used in this band are Morse telegraphy, analogue and digital voice, narrow band data modes and reduced bandwidth digital television; Tables 3 and 9 provides the necessary parameters used in the studies that follow. These parameters are based on the following considerations: – The suggested modes specified in § 3.3 are subject to future development; however the maximum bandwidth and power given in the Table are likely to be maximum values irrespective of future transmission modes. – The height of amateur station antennas are generally limited by local housing planning considerations and economic factors, moreover, amateur stations may be used ‘in the field’ for special events, contests etc. so a probability distribution is appropriate to cover these situations. – The percentage of time a station transmits cannot be precisely known, however even a very active amateur operator is unlikely to transmit for more than approximately one hour per day (on average), so a 5% duty cycle is assumed.

TABLE 9 Suggested parameters of the amateur service for use in the sharing studies of this Report

Parameter Value Frequency range 50.0-54.0 MHz Emission mode SSB (J3E) FM (F3E) Wideband Digital CW (A1A) OFDM, QPSK, QAM Power and duty cycle 20 dBW @ 2.5% 13 dBW @ 5% 17 dBW @ 5% or 10 dBW @ 5% 4 dBW in 16 kHz Emission masks: ITU-R SM.1541-6 Annex 9 Out of band domain ITU-R SM.329-12 Spurious domain Necessary emission 3 kHz 16 kHz 300 kHz bandwidth 300 Hz 22 Rep. ITU-R M.2478-0

TABLE 9 (end)

Parameter Value Forward antenna gain 9.4 dBi 2.5 dBi 2.5 dBi (Directional) (Omni-Directional) (Omni-Directional) 4 dBi (Directional) Polarisation Horizontal Vertical Vertical Antenna type Yagi Monopole Monopole or low gain directional antenna Antenna heights for use in 10 m @ 95% 10 m @ 95% 10 m @ 95% simulations and probability of 20 m @ 2.5% 20 m @ 5% 20 m @ 5% use 100 m @ 1.8% 1 000 m @ 0.7%

4.3 Antenna type and polarization The suggested antenna types are representative of typical contemporary amateur practice. Usual practice of the amateur service is to use horizontally polarized Yagi antennas in the 50-50.5 MHz frequency range and vertically polarized monopole antennas above 50.5 MHz for FM and other relatively short range transmission modes. However individual amateur operators are free to use whatever polarization is appropriate for the best link performance, consequently the only mention is to note that cross-polarization may potentially reduce the probability of interference by some amount in some cases.

4.4 Propagation Factors This Report only considers radio propagation characteristics that are found in the various propagation models: Extended-Hata, Recommendations ITU-R P.1546, ITU-R P.2001, ITU-R P.526, etc. (see Table 10). Factors such as troposcatter and anomalous propagation conditions play an important role in radio propagation for the considered frequency range when time percentage of less than 50% and long distance ranges are considered. Those propagation factors are taken into account in the interference studies in the section “sharing with the mobile service” in which the propagation model ITU-R P.2001 is applied. This propagation model is recommended by ITU-R Working Party 3L to be used for these studies.

TABLE 10 Propagation Models – ITU Radiocommunication Services sharing with Amateur Service

Land mobile Broadcasting Radiolocation SEAMCAT – X X EHATA SEAMCAT-1546 X E-HATA X X ITU-R P.1546 X ITU-R P.2001 X X ITU-R P.526 X

Rep. ITU-R M.2478-0 23

Towards the conclusion of work on this Report ITU-R Working Party 3L expressed concern about the applicability of the Extended-Hata (E-Hata) propagation model that has been used in some studies, because the lower frequency limit of the Extended-Hata model is 150 MHz and because this model does not take into account the effects of troposcatter. The CEPT document ECC Report 252 published in April 2016 indicates that the E-Hata model as implemented in the Spectrum Engineering Advanced Monte Carlo Analysis Tool (SEAMCAT) is applicable over the frequency range 30 MHz – 3 GHz and recommended for distance ranges of up to 40 km for services working in non-LOS/cluttered environment. On that basis the model was used to simulate a number of interference scenarios as part of assessing the possibility of the amateur service sharing with the broadcasting, mobile and radiolocation services in some situations.

5 Sharing with the mobile service According to RR Article 5.164 and the European Table of Frequency Allocations (ECA TABLE), the frequency band 47-68 MHz is allocated to the land mobile service on a primary basis. Four approaches have been studied: – A Monte-Carlo simulation of sharing with mobile service, performed with the CEPT SEAMCAT simulation software and using the Extended-HATA propagation model (Annex 10); – A Minimum-Coupling Loss sharing study between amateur radio stations and governmental mobile systems, using the P.2001-2 propagation model (Annex 11), – A coverage mapping study between amateur radio stations and governmental mobile systems, using the P.2001-2 propagation model (Annex 12) – A Monte-Carlo simulation of amateur service versus mobile service using the P.2001-2 propagation model (Annex 13).

5.1 System parameters of the mobile service One incumbent land mobile system is the Governmental Mobile Radio system. The Governmental Mobile Radio systems enclose several kinds of devices. They are integrated into: – Land Vehicles. – Portable Handsets. – Base stations. Many of these stations can be operated in Fixed Frequency mode only. Fixed Frequency is thus a nominal mode to be considered in the compatibility studies. For the purposes of this Report the Governmental Mobile Radio System is assumed to operate within the Land Mobile Service as defined in the Radio Regulations.

TABLE 11 System parameters System Type Governmental Mobile Frequency tuning range with 25 kHz steps 30-88 MHz Receiver bandwidth 16 kHz Protection criteria I/N = –6 dB Receiver sensitivity –112 dBm @ 10 dB SINAD 24 Rep. ITU-R M.2478-0

TABLE 12 Vehicular parameters Transmitter/receiver type Vehicle Antenna height (metres) 2 m Antenna polarization Vertical Note: May be slightly tilted Antenna gain (dBi) –3 dBi Antenna radiation pattern Omnidirectional Transmitter output power 0.4 W to 50 W Out of band emission ITU-R SM.329 Adjacent channel protection 60 dB

TABLE 13 Handset parameters Transmitter/receiver type Handset Antenna height (meters) 1.5 m Antenna polarization Vertical Note: May be slightly tilted Antenna gain (dBi) –10 dBi Antenna radiation pattern Omnidirectional Transmitter output power 0.2 to 5 W Out of band emission ITU-R SM.329 Adjacent channel protection 60 dB

TABLE 14 Base station Transmitter/receiver type Base station Antenna height (meters) 8 m Antenna polarization Vertical Antenna gain (dBi) 2.15 dBi Antenna radiation pattern Omnidirectional Transmitter output power 5 to 50 W Out of band emission ITU-R SM.329 Adjacent channel protection 60 dB

5.2 Minimum coupling loss calculations Detailed Minimum Coupling Loss (MCL) analysis results on minimum separation distances are shown in Annex 11 and are summarized below. The following scenarios and parameters are considered: Rep. ITU-R M.2478-0 25

– Flat terrain scenarios with 10% and 50% propagation time probability. – SSB, FM and wide band operation mode for the interfering transmitters, considering the corresponding antenna heights of 10 m, 20 m and 1 000 m. – Mobile handset, vehicular and base station receivers as victim of the governmental mobile system. Minimum separation distances between the interfering transmitters and the victim receiver are determined for co-channel, adjacent channels and spurious domain frequencies. A 25 kHz channel raster is assumed. The results are shown in the Tables below. Further two considered emission mask options are labelled M1 for Mask option 1 (representing the emission mask according the ITU-R Recommendations) and M2 for Mask option 2 (with reduced adjacent channel emission power) please see Annex 11.4. Evaluated minimum separation distance between amateur stations and governmental radio receivers are shown in the following Tables. Values are calculated with different amateur station antenna heights (Htx), for propagation time probability Tpc = 50% and Tpc = 10% and for different operating radio channels of the governmental radio system. – Table 15 shows minimum separation distances between SSB and FM amateur station transmitters and vehicular governmental radio receiver. – Table 16 shows minimum separation distance between wide band amateur station transmitters and vehicular governmental radio receiver. – Table 17 shows minimum separation distances between SSB and FM amateur station transmitters and handset governmental radio receiver. – Table 18 shows minimum separation distance between wide band amateur station transmitters and handset governmental radio receiver. – Table 19 shows minimum separation distances between SSB and FM amateur station transmitters and base station governmental radio receiver. – Table 20 shows minimum separation distance between wide band amateur station transmitters and base station governmental radio receiver.

TABLE 15 Minimum separation distances between SSB, respectively FM amateur station and vehicular mobile

Separation distance (km) 2nd adjacent Spurious Operation mode Tpc Co- channel 1st adjacent channel channel Domain SSB 10% 435 7.2 7.2 7.2 Htx = 10 m 50% 349 1.2 1.2 1.2 SSB 10% 440 7.4 7.4 7.4 Htx = 20 m 50% 352 1.6 1.6 1.6 SSB 10% >500 25.6 25.6 25.6 Htx = 1 000 m 50% 433 9.9 9.9 9.9 FM 10% 328 149(M1) 1.3 1.3 Htx = 10 m 65 (M2) 50% 238 81 (M1) 0.4 0.4 27 (M2) FM 10% 332 152 (M1) 1.1 1.1 Htx = 20 m 67 (M2) 50% 241 84 (M1) 0.4 0.4 29 (M2) 26 Rep. ITU-R M.2478-0

TABLE 16 Minimum separation distances between wide band amateur station and vehicular mobile

Separation distance (km) 16th – 30th Operation Co-channel 7th – 12th Tpc adjacent mode –6th channel channel channel Wide Band 10% 260 172 (M1) 1.7 Htx = 10 m 70 (M2) 50% 172 98 (M1) 1.2 30 (M2) Wide Band 10% 263 176( M1) 1.7 Htx = 20 m 73 (M2) 50% 175 100 (M1) 1.2 31 (M2)

TABLE 17 Minimum separation distances between SSB respectively FM amateur station and mobile handset

Separation distance (km) Operation Co- 1st adjacent 2nd adjacent Spurious Tpc mode channel channel channel Domain SSB 10% 435 7.3 7.3 7.3 Htx = 10 m 50% 348 1.1 1.1 1.1 SSB 10% 439 7.6 7.6 7.6 Htx = 20 m 50% 352 1.2 1.2 1.2 SSB 10% >500 10.5 10.5 10.5 Htx = 50% 435 9.9 9.9 9.9 1 000 m FM 10% 328 149 (M1) 0.9 0.9 Htx = 10 m 62 (M2) 50% 237 89 (M1) 0.35 0.35 25 (M2) FM 10% 331 161 (M1) 0.9 0.9 Htx = 20 m 65 (M2) 50% 240 90 (M1) 0.35 0.35 27 (M2)

Rep. ITU-R M.2478-0 27

TABLE 18 Minimum separation distances between wide band amateur station and mobile handset

Separation distance (km) Operation Co-channel – 6th 7th – 12th adjacent 16th – 30th adjacent Tpc mode adjacent channel channel channel Wide Band 10% 259 172 (M1) 1.7 Htx = 10 m 70.2 (M2) 50% 172 97.4 (M1) 0.95 29.5 (M2) Wide Band 10% 262 175 (M1) 1.8 Htx = 20 m 72.2 (M2) 50% 175 100 (M1) 1.2 30.6 (M2)

TABLE 19 Minimum separation distances between SSB, respectively FM amateur station and mobile base station

Separation distance (km) Operation 1st adjacent 2nd adjacent Spurious Tpc Co- channel mode channel channel Domain SSB 10% 440 7.7 7.7 7.7 Htx = 10 m 50% 352 1.0 1.0 1.0 SSB 10% 444 7.9 7.9 7.9 Htx = 20 m 50% 357 1.5 1.5 1.5 SSB 10% >500 25.7 25.7 25.7 Htx = 1 000 m 50% 440 2.4 2.4 2.4 FM 10% 332 151 (M1) 1.1 1.1 Htx = 10 m 64 (M2) 50% 240 91 (M1) 0.35 0.35 27 (M2) FM 10% 335 155 (M1) 1.1 1.1 Htx = 20 m 68 (M2) 50% 245 90 (M1) 0.35 0.35 27 (M2)

28 Rep. ITU-R M.2478-0

TABLE 20 Minimum separation distances between wide band amateur station and mobile base station

Separation distance (km) Operation Co-channel – 6th 7th – 12th 16th – 30th Tpc mode adjacent channel adjacent channel adjacent channel Wide band 10% 263 176 (M1) 2.0 Htx = 10 m 73 (M2) 50% 175 101 (M1) 1.2 33.5 (M2) Wide band 10% 267 179 (M1) 2.1 Htx = 20 m 75 (M2) 50% 179 103 (M1) 1.7 34.7

To safeguard interference free governmental radio co-channel operation in 90% of time (Tpc = 10%) on flat terrain environments, a minimum separation distance of ~440 km between SSB amateur station transmitter and any type of governmental radio receivers must be respected (average over the three different governmental receiver types). This minimum distance reduces to a value of 350 km in case where interference free operation is required only during 50% (Tpc = 50%) of time. Those evaluated figures are confirmed by both applied methods, MCL and coverage mapping. When considering SSB amateur station on top of 1000 m mountain, which represents a typical amateur contest situation, then the minimum separation distance is more than 500 km for 90% of time and ~435 km for 50% of time. Governmental radio operation in adjacent channels, separated by 25 kHz from SSB carrier, requires a separation distance of just a few kilometres. In case of FM amateur stations as interferers, the co-channel separation distances are ~330 km @ Tpc = 10% respectively ~240 km @ Tpc = 50%. Governmental radio operation in adjacent channels (separated by 25 kHz from SSB carrier) requires a separation distance of ~90 km @ Tpc =10% and ~40 km @ Tpc = 50% when considering mask option 2. This consideration is justified by the fact, that FM transmitters do not produce intermodulation distortion but just spurious emissions. Interference from wide band amateur stations are particularly critical because of the large affected bandwidth. For interference free governmental radio operation in 90% of time within a bandwidth of 13 channels, a minimum separation distance of 260 km is required. Considering a 25 kHz channels operational bandwidth for governmental radio operation, a minimum separation distance of ~170 km is required. The figure for the 25 kHz channel wide interference is based on mask option 1. This assumption is justified by the fact that spectrum efficient modulation techniques applied for wide band operation operate a high peak to average power ratio (PAPR) which consequently produces significant intermodulation interference. However, when reducing the requirement of interference free operation to 50% of time, the separation distances reduce to ~175 km respectively to ~ 100 km accordingly.

5.3 Radio Interference coverage mapping This Report also considered plotting the interference created by an amateur station on a real geographic map in order to better visualise and interpret the propagation phenomena. To do so, an amateur station is placed in a given geographical location, and then the amount of interference created by this station in the adjacent geographical location area is computed and plotted on a map. Rep. ITU-R M.2478-0 29

Results of the coverage mapping analysis illustrates in a very intuitive way the long interference range of amateur radio stations and confirm the MCL calculation results also as representative values. All the results can be consulted in Annex 12. It can easily be recognized on the coverage map results representation, that in many cases a single amateur station interfere simultaneously with governmental radio receivers in different European countries.

5.4 A Monte-Carlo simulation of amateur service versus mobile service using the P.2001-2 propagation model In this section, a study based on a Monte-Carlo approach, aiming to determine to which probability radio amateurs would interfere with a mobile radio equipment operating in the same geographical area is discussed. The study is conducted for the different modes intended by amateur radio in this band, namely: SSB, FM, wideband digital, as described in Table 4. Only interference from the amateur to the mobile is considered. The study is detailed in Annex 13. The global Monte-Carlo approach consists in localising a mobile station in a given area with a fixed operational frequency, and then spread a certain number of amateurs station around it. Those amateurs are scattered within a certain range according to propagation effects and attributed different frequency channels (thus different incident power to the victim) and different azimuths. The aggregated interference to the mobile is then computed. This process is repeated a certain number of times and a cumulative distribution function is deduced. The simulations are carried out for two different amateurs’ emission mask. The first one is as described in Recommendations ITU-R SM.1541-6 Annex 9, ITU-R SM.329-12 and ETSI EN 301 78. A second option mask has been introduced where additional 15 dB attenuation is considered for the first floor Out-of-Band (OoB) emissions, in order to better reflect amateurs operation (see § A13.6). Some separation distances are considered in the simulation for the sake of information. However, one should note that the application of a separation distance could be very difficult given that the land mobile has to operate in unknown places without notice. Simulations have shown that depending on the number of amateur users present inside the simulation radius, and on the considered protection distance, the probability of interference for the SSB mode ranges between 3.57 and 86.5%, detailed results are depicted in Table 21. For the FM mode, only one user is considered inside the simulation radius, and the probability of interference achieves 28.31%, as depicted in Table 22. Regarding the WB digital mode, interference is created over a large band affecting a number of mobile operating channels. When considering a channel raster of 25 kHz for the Land Mobile and a simulation radius of 70 km, simulations have shown that the probability of interference for the in- band case (affecting up to 20 mobile channels) can achieve 93.12%. This probability decreases for the different floors of the OoB emission but stays important for some cases. It is achieves the null value for the spurious domain. All the results are reflected in Table 23. 30 Rep. ITU-R M.2478-0

TABLE 21 Option mask 2, SSB mode

Number of users inside 200 km circle area

1 2 5 10 14 19

None 8.49% 17.21% 38.18% 62.77% 75.45% 86.5%

10 7.46% 14.35% 31.99% 55.04% 68.47% 80.2% 30 6.35% 11.58% 26.77% 47.78% 61.62% 73.73% 50 5.06% 9.05% 22.86% 41.76% 53.84% 65.82% 70 4.1% 8.57% 19.36% 36.75% 48.12% 58.94% 90 3.59% 6.77% 16.6% 31.56% 42.58% 52.8%

Protection distance Protection 100 3.54% 6.57% 15.33% 29.10% 40.28% 51.1%

TABLE 22 Probability of interference according to the applied protection distance, FM mode, mask Option 2, only one amateur is active within the 120 km circle area Protection distance (km) None 10 30 50 70 90 Probability of interference 28.31% 23.7% 16.54% 13.53% 11.35% 9.85%

TABLE 23 Probability of interference according to the applied protection distance, WB digital case

1st floor OoB 11th Inband up to 2nd floor OoB 21th to 3rd floor OoB 26th to to 20th channel, Spurious 10th channel 25th channel 50th channel M1|M2

None 93.65% 78.90%|50.13% 10.81% 3.15% 0.85% 10 km 91.14% 73.15%|37.45% 0.40% 0.01% 0% 30 km 86.37% 55.98%|11.85% 0.04% 0% 0% 50 km 75.92% 38.80%|2.72% 0.01% 0% 0%

5.5 A Monte-Carlo simulation using the CEPT SEAMCAT simulation software A study based on a Monte-Carlo approach as given in Annex 10 using the CEPT SEAMCAT modelling software, aims to determine the probability of interference from amateur service transmitters causing harmful interference to mobile radio links operating in the same geographical area and on the same frequency of 52 MHz. The study is conducted for the most common transmission mode (application) used by amateur operators in the band 50-54 MHz frequency band, namely SSB. The amateur transmitter operates with an output power of 100 W Peak Envelope Power and the amateur antenna is a Yagi array of modest gain that is commonly used in the frequency range being considered. The specifications of the mobile service equipment are the same as those used in the other studies in this Report. Only interference from the amateur transmitter to the mobile receiver is considered. Rep. ITU-R M.2478-0 31

The global Monte-Carlo approach consists of localising a mobile service transmitter in a given location with a fixed operational frequency, and then moving a mobile service receiver around the mobile service transmitter through a variety of azimuth angles and radial separation distances. The maximum separation distance between the mobile service transmitter and mobile receiver is based on mobile transmitter power, mobile receiver sensitivity, antenna height and gain; the maximum operational distance of the mobile link was calculated to be 40 km. The interfering amateur service transmitter is free to randomly move around within a 40 km radius of the mobile service transmitter i.e. anywhere in the mobile transmitter service area. The amateur service receiver is free to move around within a radial distance of 40 km of each amateur transmitter, therefore the direction of the amateur link with respect to the victim mobile service receiver will vary in a random manner. The Extended-Hata propagation model is used for each service and a protection criterion of I/N = –6 dB is used for the mobile service link. 20 000 random situations within a variety of operational scenarios are considered and these operational scenarios are: – Base station transmitting to vehicle receiver. – Base station transmitting to handset receiver. – Vehicle transmitting to base station receiver. – Vehicle transmitting to handset receiver. – Handset transmitting to base station receiver. – Handset transmitting to vehicle receiver. The results of this study are given in Table 24 below. The figures quoted in the C/I and C/(N+I) columns are the percentage probability that the scenario fails to meet the respective signal to noise and signal to noise plus interference ratios while the I/N column shows the percentage probability that this protection criteria is exceeded.

TABLE 24 Predicted co-channel average interference probability for each study scenario

Radius C/(N+I)% I/N% Link C/I% (17 dB) (km) (10 dB) (-6 dB) Base-to-vehicle 40 2.73 1.78 14.16 Base-to-handset 15 1.11 0.66 6.43 Vehicle-to-base 40 8.73 5.47 38.11 Vehicle-to-handset 3 1.19 0.66 6.45 Handset-to-base 7.5 10.1 6.25 44.65 Handset-to-vehicle 1 3.82 2.44 17.53

5.6 Sharing possibilities New and existing applications of the amateur service using this frequency band are assumed to be of fixed or nomadic type. It is assumed, that the new amateur service application ‘infrastructure’ and the application ‘repeater’, which requires the largest portion of bandwidth, are of fixed type. 32 Rep. ITU-R M.2478-0

Values for the parameters “Fraction of time transmitting within a single session”, “Session Duration” as well as the values for the amateur station density are different for the both use cases A and B as defined in the section “spectrum needs”. It can be concluded, that because of low active amateur station density for SSB and FM, low session durations as well as relatively narrow bandwidth for both applications, sharing of those two applications with the mobile service may be possible in the average use case. Sharing with mobile service and wide band modes in average use case may be possible, because of low station density and low session duration. However careful evaluation of sharing conditions need to be done. Sharing with mobile service and Repeaters during average use case may cause problems because of long session duration and higher range. Under the conditions described in Table 9, sharing between the application ‘infrastructure’ and the mobile service in the average use case is not feasible: The very high session durations, large bandwidth and interference range of up to 172 km (for 50% of propagation probability), causes high interference probability. In can be concluded, that in the average use case a single infrastructure station causes interference with a level above the protection criteria I/N = –6 dB (as used in the study) in an area of more than 92 000 km2. In the average use case there is about one infrastructure transmitter operating in an area of the size of Switzerland. It should be noted, that the interference occupies a bandwidth of 12 mobile service channels in co-channel scenarios. Considering adjacent band interference, 36 mobile service channels would be interfered in a range of 30-170 km, dependent on mask option and propagation channel time probability. It should further be noted that within the coverage range of the ‘infrastructure’ transmitter of 70 km the protection criterion I/N = –6 dB is by far exceeded. An area with a radius of 70 km may represent a significant fraction of the area of some countries. Sharing with SSB in use case where additional spectrum is required may be possible due to the very limited session duration and the relatively narrow bandwidth. All the above mentioned sharing situations are summarized in the Table 25.

TABLE 25 Sharing options considering different amateur radio applications and the two use cases “Average and additional spectrum required”

Amateur Required Spectrum Usage Option Applications population Spectrum (MHz) needs in % Sharing situation density (Needs Study 1) of time average 0.534 1 Case A SSB, FM, WB 98% May be possible high 0.546 average 0.765 2 Case B SSB, FM, WB 2% May be possible high 1.002 average 0.634 May be possible SSB, FM, WB, 3 Case A 98% (conditions to Repeaters high 0.746 be defined) average 0.865 May be possible SSB, FM, WB, 4 Case B 2% (conditions to Repeaters high 1.202 be defined) Rep. ITU-R M.2478-0 33

TABLE 25 (end)

Amateur Required Spectrum Usage Option Applications population Spectrum (MHz) needs in % Sharing situation density (Needs Study 1) of time SSB, FM, WB, average 1.034 5 Case A Repeaters, 98% Not possible Infrastructure high 1.246 SSB, FM, WB, average 1.365 6 Case B Repeaters, high 2% Not possible Infrastructure 1.702

Different countries are operating governmental communication systems of mobile and nomadic types in the frequency band 50-54 MHz. New and existing amateur service applications are using the frequency band of 50-54 MHz as fixed as well as nomadic type will exceed the –6 dB I/N protection criteria over several hundred kilometres and multiple mobile channels. Therefore coordination is very difficult or not possible. Harmful interference probability with wide band applications is significantly higher than with SSB, in particular due to the very high occupied bandwidth and adjacent channel interference. There is no technical reason identified, why amateur stations need the same level of protection than governmental communication in the mentioned interference situation. Therefore a frequency assignment to the amateur service in a portion of the 50-54 MHz frequency band on a secondary basis seems to be reasonable. For the application “infrastructure”, no e.i.r.p. value is known. A service area for this application of 15 393 km2 respectively a range of 70 km is assumed. For the application “wide band mode” a range of 40 km is assumed. The reason for the long range of the infrastructure application is unclear. It could be explained by extreme antenna height, antenna gain or increased TX power. However it can be concluded that the interference range of the infrastructure application is larger than the interference range of the wide band mode. It should be noted, that any mobile receiver located within 70 km of the amateur infrastructure transmitter experiences an unwanted signal which exceeds the protection criterion of –6 dB I/N by 16 dB or more.

5.7 Summary of conclusions A study using Minimum Coupling Loss analysis shows very long interference ranges for some type of amateur service applications. Due to different usage patterns and activities of the different applications, sharing is not only dependent on the interference range. It is shown, that use of the current SSB application in average situations has low to moderate impact on mobile service and can therefore be shared. On the other hand, applications occupying very large portion of the bandwidth and transmitting in networks with high duty cycle, such as the ‘infrastructure’ application, cannot coexist with the mobile service. It should be noted that within the coverage range of the ‘infrastructure’ transmitter of 70 km, the protection criterion I/N = –6 dB is by far exceeded. An area with a radius of 70 km may represent a significant fraction of the area of some countries. Repeaters may be shared under certain sharing conditions which need to be defined. One Monte-Carlo study has shown that given the amateur density and usage activity provided in § 3.7, the probability of inference caused by the amateur service to the land mobile service is very high in the case of co-channel usage. This probability decreases for adjacent channel usage, but still remains above tolerable percentages. 34 Rep. ITU-R M.2478-0

Another study in Annex 10 using SEAMCAT Monte-Carlo simulation shows the predicted probability of interference and service degradation for the scenarios in Table 25. The Monte-Carlo simulations indicate that the probability of interference between the amateur service and mobile within is very high in the case of co-channel operation if both services operate within the same or adjacent service areas. Results of the coverage mapping analysis in Annex 12 illustrates in a very intuitive way the long interference range of amateur radio stations and confirm the MCL calculation results also as representative values. It can easily be recognized on the coverage map results representation, that in many cases a single amateur station interfere simultaneously with governmental radio receivers in different European countries.

6 Sharing with the fixed service In the European Common Allocation table there is no allocation to the fixed service in the 50-54 MHz frequency band though there may also be fixed usage in Region 1 which has not been notified to the MIFR, which may include short range fixed use on a national basis. Given the likely small number of affected sites in Region 1 it is expected that, if required, any interference can be dealt with on a case by case basis. An analysis of the details of the notifications shows that the assignments are generally FM stations with characteristics similar to stations of the mobile service so similar protection and interference mitigation schemes could be applied to fixed service stations if required.

7 Sharing with the radiolocation service

7.1 Background In the frequency band 46-68 MHz, RR No. 5.162A provides an additional allocation to the radiolocation service on a secondary basis in a number of countries and is limited to the use of wind profiler radars.

7.2 Study details The detailed study is contained in Annex 14; the propagation model used is E-Hata (rural) at 52 MHz (median case).

7.3 Study results The calculations show that typical separation distance between Amateur service systems and Wind profiler would range from 30 km to 300 km, confirming the need for specific protection measures.

7.4 Regulatory aspects Taking into account the low number of WPRs and the low number of amateur systems in their vicinity, sharing could probably be considered on a case-by-case basis. The relevant procedure would need additional consideration providing that the status of the new allocation to the amateur service provides the radiolocation service equality of precedence to the amateur service. Rep. ITU-R M.2478-0 35

8 Sharing with the broadcasting service Annexes 5, 6 and 7 contain the detailed sharing studies which cover sharing between the amateur service and the broadcasting service. Annex 8 contains details of current and past sharing arrangements used in some countries.

8.1 Sharing study details Annexes 5, 6 and 7 provide details of the studies undertaken to determine if the amateur service can share with the broadcasting service in Region 1 in the 50-54 MHz frequency band. Study 1 (Annex 5) considers the maximum permissible amateur field strength at the TV receiver to avoid harmful interference using the relevant ITU-R Recommendations. Study 2 (Annex 6) are Monte-Carlo simulations which provide statistical estimates of the likelihood of interference between the amateur service and the broadcasting service for two situations: – A major metropolitan area with a high powered TV broadcast transmitter. – A small rural township serviced by a relatively lower power transmitter. Study 3 (Annex 7) provides details of the likelihood of interference between the amateur service and the broadcasting service using an electromagnetic compatibility (EMC) approach.

8.2 Study 1 description The minimum field strength for which protection against interference is provided in planning should never be lower than 46 dBµV/m from Table 1 of Recommendation ITU-R SM.851-1. Remaining analogue television transmitters in Region 1 generally utilise the SECAM System D/K standard with a channel centre frequency of 52.50 MHz, vision carrier frequency 49.75 MHz and sound carrier 56.25 MHz. Carrier offsets may be used. The method (detailed in Annex 5) involves calculating the difference between the wanted TV signal's field and the field resulting from an amateur transmitter operating on a frequency within the TV channel some distance away from the edge of the TV service area. If the amateur signal is less than the minimum signal strength based on the minimum required TV signal field strength adjusted for the protection ratio, then no harmful interference will occur.

8.3 Study 1 results This study shows that sharing is possible using the method described without any harmful interference occurring from an amateur transmitter with a power level (e.r.p. of 30 dBW) at a distance of 50 km from a television transmitters’ service area in the frequency band 50-54 MHz. This study details a method (see Annex 5) of ascertaining whether a rather basic sharing scenario will likely protect remaining analogue television broadcasting applications in Region 1 in the band 50-54 MHz, until this band is no longer used for broadcasting.

8.4 Study 2 description This study considers two typical scenarios: – A major metropolitan area with a high powered TV broadcast transmitter. – A small rural township serviced by a relatively lower power transmitter. Two propagation models were used in the simulations, with the most appropriate model selected for each service: 36 Rep. ITU-R M.2478-0

– For the TV broadcasting service ‘ITU-R P.1546-4 Land’ with the analogue broadcasting option selected and signal strength calculations are for between 10% and 50% of the time. ITU-R P.1546 calculations are only valid for field strengths exceeded for percentage times in the range from 1% to 50%. – For the amateur service the ‘Extended-Hata’ model was used. For further details please see Annex 6. For the TV receiver, the required protection ratio of wanted to unwanted signal strengths (C/I) is 54 dB. The sensitivity of the TV receiver is –48 dBm (~1 mV into 50 Ohms) and the bandwidth of the TV signal is assumed to be 5 MHz. The TV receiving antenna used in the study is a low gain design which is ‘built in’ to SEAMCAT and it would be suitable for short to medium range reception of TV signals; however it is likely, and experience suggests, that receivers on the outskirts of the TV coverage area will use antennas with higher gains and more directional characteristics which will reduce the potential for interference from any directions other than the main lobe that will be pointing towards the TV broadcast transmitter antenna. The study assumes two amateur stations operating anywhere within a 50 km radius of the TV broadcast transmitter. The two amateur stations have a 100 W transmitter and use four-element Yagi antennas at 10 m elevation and are operating on a 5% duty cycle. The amateur transmitters may be communicating to receivers either inside or outside of the TV service area. All the parameters used by SEAMCAT are given in Table A6.3.

8.5 Study 2 results The results of Study 2 are given in Tables A6.1 and A6.2 where the probability of interference and signals strengths are given. Table 26 provides a summary of the calculated probability of interference for the two cases considered in the study:

TABLE 26 Probability of interference for the major city calculated by SEAMCAT using the parameters given in Table A6.3. The C/I column is the calculated percentage of interference for the C/I protection criteria of 54 dB

Probability of interference Study (C/I exceeds protection limit) Case 1: Major metropolitan station – Suburban 0.14% Case 1: Major metropolitan station – Rural 0.81% Case 2: Regional station 1.57%

8.6 Study 3 description A deterministic approach to evaluate interference impact of amateur stations on the coverage area of broadcasting stations was used (for details see Annex 7). In the band 50-54 MHz maximum acceptable field strength from amateur stations at the border of analogue broadcasting coverage area was calculated based on the Recommendations ITU-R M.851, ITU-R ВТ.417 and ITU-R ВТ.1368. Different interference cases between amateur service stations, with parameters corresponding to Recommendation ITU-R M.1732, and existing TV broadcasting stations were considered. For two type of amateur stations (portable station with antenna height of 2 m and fixed station with antenna Rep. ITU-R M.2478-0 37 height of 15 m) single interferer and multiple interferer (from six amateur stations) impact on the TV broadcasting coverage area were calculated in accordance with Recommendation ITU-R P.1546. The calculation of electromagnetic compatibility is based on the application of Recommendation ITU-R SM.851-1 – Sharing between the broadcasting service and the fixed and/or mobile services in the VHF and UHF bands, and Recommendation ITU-R P.1546 – Method for point-to-area predictions for terrestrial services in the frequency range 30 MHz to 3 000 MHz. The calculation assumptions used: – In the frequency band 50-54 MHz, the characteristics of amateur service stations are taken from Recommendation ITU-R M.1732-2 – Characteristics of systems operating in the amateur and amateur satellite services for use in sharing studies mobile service stations; – At is the factor that determines amateur service stations’ antenna selectivity. In calculations in accordance with Recommendation ITU-R P.1546, the amateur service station antenna's directivity is taken into account for each direction of transmission as the e.i.r.p. is re- calculated based on the antenna pattern radiation reductions. For non-directional antennas At is assumed to be 0 dB; – Ol is the propagation loss resulting from the limited size of the Fresnel zone. The calculation assumes 0 dB, since losses due to irregular terrain have already been addressed in the calculation, and the boundary of the TV broadcasting area is not in built-up areas; – Cp is a factor that accounts for polarization discrimination of the broadcasting service station and amateur service station antennas; – Here and hereinafter, TV stations’ reception area boundary locations affected by interference from amateur service stations are determined through calculations of the area with an interference level of 6 dBμV/m at a height of 10 metres with tropospheric interference (10% of the time) and –4 dBμV/m for continuous interference (50% of the time). The maximum interference is calculated by using the formula: Еint_max = Tfs-N-At-Ol-Cp-Ad-PR where Tfs is the minimum wanted field strength of the broadcasting service station in the frequency band 48.5-56.5 MHz, determined in accordance with Recommendation ITU-R SM.851-1.

8.7 Study 3 results The calculations showed that maximum acceptable field strength from amateurs stations are 6 dBμV/m at a height of 10 metres with tropospheric interference (10% of the time) and –4 dBμV/m for continuous interference (50% of the time). For the portable amateur stations (antenna height of 2 m) and fixed amateur stations (antenna height of 15 m) the necessary separation distances between edge of broadcasting coverage area and amateur stations varies from 70 km to 175 km. At smaller distances between amateur station and broadcasting coverage area, e.i.r.p. of amateur stations needs to be reduced to ensure protection of the considered broadcasting stations. The results of this study are visualized as a number of maps which show signal strength contours in Figures A7.3 through A7.12. The study results show that the amateur service stations’ field strength values at the test points exceed the previously determined threshold that supports interference-free operation of the broadcasting service stations, which equals 6 dBμV/m. 38 Rep. ITU-R M.2478-0

Values by which the field strength threshold is exceeded and the frequency and territorial separations required depend on the characteristics and relative location of the amateur service stations and TV broadcasting station. Thus, to compensate for the level of interference on the boundary of the TV broadcasting station’s reception area, additional restrictions should be imposed on amateur service stations’ e.r.p. in the direction of the boundary of the TV broadcasting station’s reception area, with the e.r.p. reduced to values below 0 dBW. The necessary protection distances vary from 70 km to 175 km.

8.8 Summary of study results Sharing between analogue television and the amateur service is not new in this frequency band. Annex 8 provides information concerning current and past sharing arrangements for the amateur service and other services in the 50 MHz frequency band. The Studies 1 (Annex 5) and 3 (Annex 7) are based on the minimum coupling loss method, protection of minimum wanted field strength of the broadcasting station equal to 46 dBµV/m according to the Recommendation ITU-R SM.851-1 and maximum amateur stations e.i.r.p. of 28-30 dBW. Depending on the used assumptions the calculated separation distances vary from 50 km (Study 1) up to 175 km (Study 3). The Study 2 (Annex 6) based on the Monte Carlo method and considered amateur stations power of 100 W and assumption that two amateur stations operating anywhere within a 50 km radius of the TV broadcasting station. For used C/I protection criteria of 54 dB calculated interference (to broadcasting station) probability vary from 0.14% (major metropolitan TV station) up to 1.57% (regional TV station). The differences in the results and its reasons could be explained by the following: – For Study 1, the assumptions given in Table A5.2 are an optimistic scenario taking into account a number of discriminations and attenuations simultaneously on the path between potential interferer and the broadcast receiver. This leads to potentially underestimate the required separation distance. – For Study 2, the concept of duty cycles and the presentation of a result as “interference probability” is not always suitable for use in broadcasting unless the quality of required reception conditions per hour is also taken into account. – The Study 3 is based on the method which closer corresponds practice in ITU-R in broadcasting sharing and compatibility studies with other services, for example the application of Recommendation ITU-R SM.851. Taking into account the results of the conducted studies and difficulties of defining a single necessary separation distance between amateur and broadcasting stations, the appropriate condition for protection of the broadcasting station from harmful interference, would be that a field strength from an amateur station at the edge of the service area of a broadcasting transmitter shall not exceed 6 dBμV/m for 10% of the time at a height of 10 m above ground. It also should be noted that harmful interference to broadcasting television reception arising from the Amateur service is likely to be intermittent and therefore difficult to trace to the originating station of the Amateur Service. So any harmful interference which does occur will need to be handled bilaterally between concerned administrations, particularly in line with Regional Agreements done at Stockholm in 1961 (for the European Broadcasting Area) and at Geneva in 1989 (for the African Broadcasting Area). Rep. ITU-R M.2478-0 39

If digital television technologies are introduced in the 48-56 MHz band, additional compatibility studies will be required to develop conditions for the sharing of amateur and broadcasting stations in the band 50-54 MHz.

9 Mitigation Factors Concern has been expressed regarding the feasibility of sharing between the amateur service and incumbent services featured in sharing studies especially in relation to the broadcasting service (analogue television) and land mobile service (governmental systems). It is therefore necessary to examine the possibility of introducing mitigation measures particularly in areas of Region 1 where there is a high density of amateur service licensees. In terms of the avoidance of harmful interference in Region 1 the most critical geographical area with the highest density of amateur licensees is Europe. Most of the concern expressed by administrations appears to apply to the 52-54 MHz frequency band. The lack of concern with respect to the 50-52 MHz frequency band, where most European administrations have provided for amateur usage, using existing applications, under Article 4.4 of the Radio Regulations (see § 2.1 and Table 1 above). It is believed that in practice there have been minimal cases of harmful interference reported. In administrations where such use is allowed, the following characteristics of the infrastructure applications such as propagation beacons, voice repeaters, simplex gateways and some data systems could facilitate the sharing of the band 50-52 MHz between the amateur and other services: – Such stations are licensed by a national administration with technical characteristics specific to an individual station. – They have fixed and published locations. – Their choice of channels and location are coordinated as part of their licensing process with the express intention of avoiding interference. – They are typically restricted to lower output or radiated power compared to standard individual amateur licences and may have other parameters in their licences including automatic call-sign identifiers, etc. – They typically may also require contact lists of responsible persons and remote control facilities to be maintained, to facilitate spectrum management or rapid closedown. The same mitigation measures could also apply to many wide-band digital applications envisaged for the 50-54 MHz frequency band. These mitigation measures might be implemented on a national, sub- regional or regional basis to remove the possibility of harmful interference to incumbent services in the 50-54 MHz frequency band. See also A1.12 to A1.16. It should be noted that none of the techniques mentioned above have been included in the sharing studies to test their efficiency by simulation or experimentation for the bands studied under WRC-19 agenda item 1.1. Operational experience shows that these measures have been effective under RR No. 4.4 operations in the 50-52 MHz with some existing applications. These techniques have not been studied for new applications in this band under agenda item 1.1.

10 Conclusion of the Report

10.1 Study components This Report addressed the invitation in the Resolution 658 (WRC-15) to evaluate the amateur service spectrum needs in the band 50-54 MHz and to conduct sharing studies between the amateur service and the incumbent mobile, fixed, radiolocation and broadcasting (TV) services, in Region 1, under 40 Rep. ITU-R M.2478-0

WRC-19 agenda item 1.1. This Report mainly considers the European context in accordance with the received contributions.

10.2 Spectrum needs The evaluation of spectrum needs is shown to be dependent on the amateur population density, type of application and assumed usage patterns, with the result being that the calculated spectrum needs varies significantly between studies. A first study has shown that in exceptional high use cases, the spectrum need is about 1.7 MHz in European Countries with high population density. A second study has shown that the spectrum need is around 4 MHz (in European countries with an average amateur density population), and can reach up to 10 MHz. According to a third view, 200 kHz would satisfy the spectrum needs of the amateur service in Region 1. Based on the result of the studies, a Region 1 allocation to the amateur service may be considered in part or all of the 50-54 MHz.

10.3 Sharing with the mobile service Protection distances up to 400 km may be required for co-channel operation with decreasing distances for increasing frequency spacing, to respect the –6 dB I/N protection criterion in case of one amateur application. For the proposed amateur service infrastructure applications, the protection criteria is exceeded by 16 dB or more simultaneously on more than 10 mobile channels in a range of 70 km. An area with a radius of 70 km may represent a significant fraction of the area of some countries. Monte-Carlo simulations indicate that the probability of interference between the amateur service and mobile service is very high in the case of co-channel operation if both services operate within the same or adjacent service areas.

10.4 Sharing with the broadcasting service Sharing studies with the broadcasting service have shown that adequate protection of the broadcasting service requires that the amateur service stations’ field strength values do not exceed 6 dBμV/m for more than 10% of time along the border of a country with operational analogue broadcasting stations, measured at a height of 10 m above ground. The 6 dBµV/m field strength limitation means that a separation distance of up to 175 km may be required from the potentially affected TV transmitter with an alternative being a reduction in the allowed amateur transmitter power. Given that the 175 km distance may in some cases be beyond national boundaries some form of coordination between affected states may be required.

10.5 Sharing with the radiolocation service In the frequency band 50-54 MHz, the radiolocation service is restricted to wind profiler radar (WPR) systems. Sharing studies indicate that separation distances of 30 to 300 km may be required between WPR systems and stations of the amateur service. Taking into account the limited numbers of systems in or immediately adjacent to, the 50-54 MHz frequency band, sharing could probably be considered on a case-by-case basis using local arrangements to solve any interference problems. Any regulatory procedures to ensure that the status of the radiolocation service has precedence over any new allocation to the amateur service will need additional consideration.

10.6 Status of allocation Based on the result of the studies, the status of any new Region 1 allocation to the amateur service in part or all of the 50-54 MHz frequency band should ensure the protection of, and avoid placing any Rep. ITU-R M.2478-0 41 additional constraint on, the incumbent Region 1 primary and secondary services in the band. Appropriate regulatory actions may be required to maintain the current equilibrium between services in the band in Region 1.

Annex 1

Spectrum needs and associated information

A1.1 Introduction Section 3 of this Report addresses the spectrum needs element of WRC-19 agenda item 1.1 concerning the frequency band 50-54 MHz. Annex 1 provides additional detail concerning the application-based method and the background to the requirement for a globally harmonised allocation in the frequency band 50-54 MHz.

A1.2 Regulatory history The first administrative radiocommunication conference was held simultaneously with the Administrative Telegraph and Telephone Conference in Cairo, 1938 under the banner of the International Telecommunication Conferences. In the European Region as well as other regions radio amateurs had access to the frequency band 56-60 Mc/s which was harmonically related to other amateur allocations in lower frequencies (e.g. 28-30 Mc/s). The subsequent International Radio Regulations were developed at the Atlantic City Conference in 1947. These regulations reflected the great advances made in the development of television broadcasting with the band 41-68 Mc/s being allocated to the broadcasting service in Region 1. In Regions 2 and 3 the band 44-50 Mc/s was allocated to the broadcasting service along with 54-72 Mc/s in Region 2 and 54-70 Mc/s in Region 3. This clearly shows the origins of the current frequency allocation of 50-54 MHz in Regions 2 and 3 which replaced the original 56-60 Mc/s allocation, leaving amateurs in Region 1 without frequencies to conduct experimentation in this unique part of the radio spectrum. NOTE – Mc/s is used because the text is from the original Radio Regulations.

A1.3 Current and future regulatory issues Recommendations 1 and 2 of Recommendation 34 of the Radio Regulations (version of 2016) are particularly relevant e.g. that future world radiocommunication conferences: 1) should, wherever possible, allocate frequency bands to the most broadly defined services with a view to providing the maximum flexibility to administrations in spectrum use, taking into account safety, technical, operational, economic and other relevant factors; 2) should, wherever possible, allocate frequency bands on a worldwide basis (aligned services, categories of service and frequency band limits) taking into account safety, technical, operational, economic and other relevant factors.

A1.4 General information about the amateur service The amateur service, with more than three million operators worldwide, continues to grow. Radio amateurs utilise frequency allocations to the amateur service to engage in two-way communications, 42 Rep. ITU-R M.2478-0 scientific and technical investigation and experimentation. In addition amateurs provide communication in the wake of natural disasters, provide non-commercial public service communications, conduct other activities to advance technical education, develop radio operating technique and enhance international goodwill. The 50-54 MHz frequency band is allocated to the amateur service in Regions 2 and 3. While the Region 1 African countries listed in No. 5.169 of the Radio Regulations (RR) have an allocation to the amateur service in the 50-54 MHz frequency band on a primary basis, a number of other Region 1 countries have authorised the use of all or part of the 50-52 MHz frequency band by the amateur service on a mainly secondary (but sometimes national primary) basis in accordance with RR No. 4.4.

A1.5 CEPT Provisions in Region 1 CEPT’s European Table of Frequency Allocations allocates the 50-52 MHz frequency band to the amateur service on a secondary basis. As of October 2016, twenty-four of the forty-eight member administrations of CEPT have notified an allocation to the amateur service in the CEPT European Communications Office’s online Frequency Information System (EFIS). In addition, a further twelve CEPT administrations have indicated that amateur usage is an application in this band. This demonstrates that 75% of CEPT’s membership authorise amateur usage within the 50-52 MHz frequency band. The permitted maximum transmitter power of such stations is mostly 100 W, in some countries there are territorial limitations with regard to power and frequencies.

A1.6 Article 5 – VHF Amateur Spectrum Shortfall in Region 1 The opportunity provided by WRC-19 AI 1.1 to achieve global spectrum harmonisation would provide the means to introduce new and innovative communications applications for the amateur service. Additionally the amateur service sees a need to bridge the very wide gap between the existing allocations at 28 MHz and 144 MHz in Region 1 thus avoiding the use of RR No. 4.4 by those administrations in Region 1 not party to RR No. 5.169 which have provided at a national level an allocation to the amateur service within the 50-54 MHz frequency range. Furthermore, access to the entire 50-54 MHz frequency band would help to compensate for the possible loss of spectrum identified for IMT in the 2.3 GHz and 3.4 GHz frequency bands at recent WRCs. It would also ease problems experienced by the amateur service caused by the widespread rise in background noise in the MF and HF spectrum which increasingly renders lower frequencies allocated to the amateur service subject to disturbance and harmful interference, particularly in urban environments. Unlike Region 2 and in some cases Region 3, the amateur service in Region 1 does not have allocations elsewhere in the VHF range at 146-148 MHz and 220-225 MHz; harmonisation with Regions 2 and 3 in the 50-54 MHz frequency band would therefore additionally seem appropriate, especially if global amateur networks are to be realised. In the range 30-300 MHz the amateur service in most of Region 1 currently has access to only 2 MHz, in most of Region 2 amateurs currently have access to 13 MHz and in most of Region 3 amateurs currently have access to 8 MHz of VHF spectrum.

A1.7 Detailed 50 MHz band usage and propagation mechanisms relevant to the Amateur Service In common with all allocations to the amateur service the International Amateur Radio Union (IARU) has developed a utilization plan to facilitate intercommunication and technical investigations in the 50 MHz range. IARU band plans are generally flexible and are regularly reviewed in order to reflect technical developments and user requirements. For example in 2011 the range 50.0-50.5 MHz was the subject of detailed re-planning and beacon upgrades in Region 1 to accommodate demand and Rep. ITU-R M.2478-0 43 technology advances. Such reviews can be expected to continue as technology and amateur ingenuity evolves. Based on a background of existing usage and anticipated growth in digital systems, it is necessary to determine spectrum needs based on the following application categories within the range 50-54 MHz.

TABLE A1.1 Application categories in the 50-54 MHz frequency range

Typical Frequency Designated application categories Distance2 range (km) (MHz) Narrowband weak-signal communications e.g. CW, SSB & digital 250 50.0-50.5 weak signal data modes.3 24/7 propagation beacons Relatively narrowband (≤ 25 kHz) digital voice, FM voice, data. 70 50.5-52.0 Repeaters and gateways 100 Wider bandwidth predominantly digital applications (see 40 52.0-54.0 Annex 1.3)

A1.8 Propagation Table A3.1 details the principal frequency bands used by the Amateur Service in Region 1. Radio wave propagation falls into three categories: ground wave, direct wave and skywave. At frequencies above 144 MHz, direct wave is the usual mode of propagation for communications requiring good quality communications. Emissions in HF (3-30 MHz) spectrum as well as high MF and low VHF spectrum in the range 1.5-70 MHz can travel great distances over land and even greater distances over sea water for percentages of time which vary according to daily (daylight or darkness), seasonal (summer or winter) and cyclical (11 year solar cycle) variations. Nevertheless if sufficient spectrum is available in the HF range for users, skywave propagation should be able to provide single hop communications to span distances as great as 3 000 km. Multi-hop or chordal hop propagation can also utilised if propagation conditions permit, particularly when solar flux is high. Skywave propagation occurs when the radio wave is refracted in the ionosphere. At altitudes between 50 and 400 km, ultraviolet light from the sun ionizes air molecules, creating a layer of free electrons that sharply bends incident HF radio waves back to the Earth. HF spectrum is required for reliable skywave propagation because lower frequencies tend to be absorbed by the ionosphere and higher frequencies tend to penetrate the ionosphere. The ionosphere has four layers: The D layer occupies the region from of 50 to 90 km above the earth and exists only during daylight hours. The D layer completely absorbs medium frequencies (e.g., the 1.8-2.0 MHz band) and weakens high frequencies through partial absorption.

2 Same as ‘typical service area radius’ used in calculations. 3 ‘Weak signal modes’ are structured for very basic communications with low data rate and narrow bandwidth for best weak signal performance. 44 Rep. ITU-R M.2478-0

The E layer exists at a height of roughly 110 km and is responsible for most daytime HF skywave propagation at distances less than 1 500 km. Between 175 and 250 km the F1 layer, exists only during the day. It is occasionally used for daytime skywave propagation, but transmissions that penetrate the E layer often penetrate the F1 layer too (with additional absorption). The F2 layer, at 250 to 400 km is the main ionospheric layer for long-distance HF radio communications. It exists day and night, but there are significant altitude and electron density variations by day, season and sunspot cycle. Depending on the electron density at each layer, there is a critical highest frequency (CF) at which the layer reflects a vertically incident wave. Frequencies higher than the FC pass through the layer at vertical incidence. Frequencies below the FC are reflected back from the ionosphere. Absorption is least at frequencies near the maximum usable frequency (MUF), so frequencies just below the MUF are most desirable. HF frequency planning is a complicated process that involves different optimal frequencies depending on the path length, time of day, season and sunspot cycle. The challenge is complicated by the fact that the optimal frequency changes rapidly at day/night transitions, and for long east-west links, the two ends see sunset and sunrise hours apart. It often is the case that the optimal frequency simply is not available because it is already in use. As a consequence HF skywave communications invariably operates with sub-optimal parameters. If it is desirable to use HF for short links, frequencies at 3.5 MHz, 5.3 MHz or 7.1 MHz are sometimes feasible. In particular spectrum users will likely operate at near vertical incidence skywave (NVIS) with antennas that focus their main lobe vertically. Concerning the bands available to the amateur service below 50 MHz; because of propagation variations dependent on time of day, summer or winter and high or low solar flux levels the frequencies listed in Table A3.1 are unlikely to usable at any geographical location on a twenty four hours a day, seven days a week basis. However at times of high solar flux and minimal geomagnetic disturbances near the 11 year solar maximum there is a general increase in amateur radio activity when the higher HF bands above 14 MHz support inter-continental communications for longer periods of time. It is for the foregoing reasons that stations monitoring HF Amateur Service frequency allocations will detect minimal activity at certain times. At such times allocations adjacent to Amateur Service allocations will also appear to be under-utilised. The frequency band 144-146 (148 in Region 2) MHz supplements the direct wave Amateur Service usage that is found in the frequency band 50.5-52 (54 in Region 2) MHz. There is an urgent need to provide alternative spectrum for broadband direct wave communications previously implemented in the frequency bands 430-440 MHz, 1 240-1 300 MHz and 2 300-2 450 MHz. The following paragraphs focus on propagation issues directly related to the 50-54 MHz frequency band. The frequency range 30-80 MHz marks the transition area between ionospheric and non ionospheric propagation modes, which makes it particularly interesting for communication, experimentation and study within the amateur service. A number of propagation modes are used by amateurs in the range 50-54 MHz: – Free-space (line of sight) – Sporadic-E ‘clouds’ – E and F2 multi-hop and chordal-hop – Trans-equatorial spread-F – E-layer Field Aligned Irregularities (FAI) Rep. ITU-R M.2478-0 45

– Aurora backscatter – Meteor scatter – Earth-Moon-Earth (using the moon's surface as a passive reflector).Tropospheric super- refraction and ducting – Tropospheric scatter – Scatter from aircraft and objects in near Earth orbits (e.g. International Space Station). An allocation within this frequency range in Article 5 of the Radio Regulations has not been generally available to the amateur service in Region 1 for well over half a century. Alignment with Regions 2 and 3 would facilitate the general understanding and prediction of propagation events as data accumulates and more Region 1 administrations grant their amateur licensees access to spectrum in the 50-54 MHz frequency band. Therefore, longer-term propagation studies would continue and thrive.

A1.9 50-52 MHz band usage At present, in the 50-52 MHz frequency band, the most common analogue and digital applications to date use bandwidths of less than 25 kHz, within which long distance weak-signal and propagation beacon applications are globally coordinated in the segment 50.0-50.5 MHz. This frequency range would derive great benefit from harmonisation with Regions 2 and 3. The essential requirement is 500 kHz of spectrum for narrowband applications including propagation beacons. The frequency range 50.5-52 MHz is currently utilised for two-way voice communications using frequency or phase modulation, data, gateways and FM repeaters. Digital voice and data is already being used for 50 MHz networks in the amateur service incorporating text and simple voice messaging. Such systems have already shown to be of considerable value in emergency communications on other frequency bands. See RR No. 25.3. The segment 50-52 MHz would therefore be utilised to satisfy current and continuing analogue/digital usage and developments on a global basis. The 50-54 MHz frequency band is well supported by amateur developers, including those employing the latest Software Defined Radio (SDR) techniques, partly as a consequence of the entire frequency band 50-54 MHz being allocated in RR Article 5 in ITU Regions 2 and 3 and part of Region 1. Thus growth in digital modes can be expected to continue in the existing 50-52 MHz range, assisted by 52-54 MHz developments and vice versa.

A1.10 52-54 MHz band usage In those Region 1 countries where 52-54 MHz (or parts thereof) is allocated, its use is designated for wide band applications an area where significant innovation, growth and benefits are forecast, should it become more generally available in Region 1. 52-54 MHz is also needed to satisfy the wider bandwidths and data rates of advanced digital application scenarios and is currently planned on the basis of up to 4 × 500 kHz blocks which may be sub-divided or merged to suit digital applications. There would be no aggregation of spectrum, thus the maximum band width would be 500 kHz. IARU has updated its band plan accordingly. A and C would be reserved for narrow band modulation methods of less than 500 kHz whilst B and D would be reserved for applications utilizing a whole 500 kHz channel. Amateurs using digital transmission methods should are urged to ensure that their transmissions do not spread beyond band edges. Such usage guidelines could be incorporated into IARU Handbook and operating recommendations, which provide amateurs with guidance on assisting compatibility with primary users in other shared allocations to the amateur service. The four blocks that are the basis of the scheme are illustrated in Table A1.2. 46 Rep. ITU-R M.2478-0

TABLE A1.2 Guidance for 52-54 MHz amateur applications Block A B C D Block centre frequency 52.25 52.75 53.25 53.75 (MHz)

Post WRC-19 further IARU band planning may be initiated to accommodate specific applications. For example full size blocks may be needed for DATV or regional/trunk data-links, whereas other blocks may be subdivided for local 100 kb/s simplex user access. A particular benefit of VHF for this is that amateurs can achieve non-line of site data communications, which is not possible in UHF/Microwave bands with conventional Wi-Fi, etc. The scheme is also adaptable for countries where parts of the 52-54 MHz range may have existing assignments to other services and will facilitate sharing. New applications include: – Reduced Bandwidth Digital Amateur Television (RB-DATV) could be implemented above 52 MHz. Current trials have shown that with leading-edge amateur innovation the lowest data rate achievable for RB-DATV (MPEG-4/DVB-S QPSK) is 333 kb/s requiring a necessary bandwidth of 500 kHz. See examples from the Radio Society of Great Britain; the British Amateur Television Club and proceedings of the June 2017 UK Ofcom BRIG for further details of this experimental work. – IP links/mesh networks and innovative compressed multimedia transmission systems (currently based on DVB-S2/MPEG technologies adapted for terrestrial use). – Adaptations of HAMNET terminal devices. HAMNET is a mainly IP based broadband point- to-point network in the amateur service utilising spectrum mainly in allocations to the amateur service at 2.3 GHz and 5.7 GHz. There are already today a high number of users of the HAMNET applications in those countries where it is in use. – Amateur innovation in the 52-54 MHz frequency band could also pioneer the way for commercial applications in other parts of the low VHF band where many administrations are investigating how such spectrum might be used in an efficient and effective manner. HoT (HAMNET of Things) and Station to Remote Station are anticipated applications. Many of the applications mentioned above currently exist in amateur service microwave bands and a few Region 1 countries with experimental amateur VHF development spectrum. Their further development and adaptation to the frequency band 50-54 MHz requires the certainty of a sufficiently wide frequency allocation in Region 1. Digital communications is a highly innovative area and it is likely that additional applications will subsequently emerge. In Region 1 the sub-band 52-54 MHz is currently band planned by IARU as appropriate for ‘all-modes’ in those countries where it is already allocated (RR No. 5.169). Consistent with this current position is the service categories designated for amateur applications used in this document. The availability of 52-54 MHz would additionally encourage development of new technologies to support disaster relief in accordance with the IARU-ITU and Red Cross/Red Crescent Memorandum of Understandings4 on disaster relief operations, consistent with Article 25.9A of the Radio Regulations. Examples applications would be mobile video used for searching for survivors in earthquakes and easier establishment of medium capacity digital links over difficult propagation paths.

4 Copies of the MoUs are at: http://www.iaru.org/uploads/1/3/0/7/13073366/ituandiarumou.pdf and http://www.iaru.org/uploads/1/3/0/7/13073366/ifrcandiarumou.pdf. Rep. ITU-R M.2478-0 47

50 MHz amateur digital systems will thus either evolve from existing developments in other VHF/UHF bands, or will incorporate the use of new technologies and applications that will benefit from the physical characteristics of the frequency band in question.

A1.11 Power flux density On the understanding that a land mobile application in the band 52-54 MHz would in general utilise a 25 kHz channel (16 kHz {42 dBHz}receiver bandwidth as per Tables 3 and 9). A 17 dBW e.r.p. amateur emission in a 500 kHz (57 dBHz) channel would produce a power density of –40 dBW/Hz. In a receiver having a bandwidth of 16 kHz this would equate to an amateur emission of 2 dBW e.r.p. See Tables 3 and 9. This also assumes that the power from an amateur emission is spread evenly across the channel in use by the victim’s receiver. In any agreement covering this band a spectral density could be specified to adequately protect governmental systems. In any event amateurs shall always use the minimal power necessary to establish a reliable link. Typically this can be affected by modem software estimating the possible power reduction achievable knowing the actual signal to noise ratio.

A1.12 Station identification by call-sign Mitigation measures are addressed in section 9 of this Report. It is likely that systems transmitting in the 52-54 MHz frequency band will be software based using SDR techniques with digital modems. As for any amateur transmission a valid call-sign should be emitted at agreed/specified intervals. A beacon could also be broadcasted at agreed intervals enabling governmental stations to take appropriate action prior to harmful interference occurring. This would facilitate the identification of amateur stations which may be causing harmful interference. In addition an electronic or manual log of transmissions could be required.

A1.13 Listen before talk (transmit) Another mitigation measure (see also § 9 of this Report) is listen before talk. Amateur stations using 52-54 MHz would in general be operating on a secondary basis. Active transmitting stations should be required to implement a “listen before talk or transmit” scheme and be in a position to detect the use of spectrum by governmental users before commencing their transmissions. Recommendation ITU-R M.1825 gives guidance on how to perform sharing studies related to systems in the land mobile service. It establishes a list of parameters, that characterize a system to assist in sharing studies, provides information on the methodologies that can be used for sharing analyses involving the land mobile service and describes mitigation techniques that can improve spectrum sharing. It also contains a list of relevant ITU-R Recommendations, Reports and Handbooks. Listen before talk is a classic mitigation method since if a frequency is already occupied by an authorized service there is no point for another potential user to start transmitting especially if both potential users have been assigned alternative frequencies. In particular the following concepts can be implemented: Dynamic channel selection techniques – The radio system can potentially use one of a number of channels within a band for each transmission. The radio system listens on all of those channels to determine which ones are occupied and dynamically chooses the channel to be used accordingly. Such techniques include for example Dynamic Frequency Selection, or Detect and Avoid mechanisms (SPEC). Static channel selection techniques – Before transmitting, the radio system listens on predetermined sub-channel(s) to determine whether a channel is appropriate for transmission. Such techniques include, for example, listen before talk or other static detect and avoid mechanisms (SPEC). 48 Rep. ITU-R M.2478-0

A1.14 Band Availability Before transmitting in the band amateur stations should be required to check that the band is open and available to the amateur service in their country. Information should be provided on administrations’ web-pages and on web-pages of amateur societies recognized by the local administration.

Annex 2

Statistics – number of amateur stations and density

Using 2016 data collected from various sources, the number of amateur stations per square kilometre has been calculated for most CEPT countries in Table A2.1. This data may be further refined to develop user densities in urban and rural areas.

TABLE A2.1 CEPT Amateur statistics for May 2019

Licensees Country Licensees per km2 Albania 117 0.0041 Andorra 82 0.1752 Austria 6 467 0.0771 Belarus 1 400 0.0067 Belgium 5 261 0.1723 Bosnia and Herzegovina 3 500 0.0684 Bulgaria 6 960 0.0627 Croatia 1 657 0.0293 Cyprus 236 0.0255 Czech Republic 5 396 0.0684 Denmark 8 680 0.2022 Estonia 600 0.0132 Finland 7 229 0.0214 France 13 752 0.0214 Germany 74 698 0.2092 Greece 6 900 0.0523 Hungary 3 120 0.0335 Ireland 1 801 0.0256 Italy 25 000 0.0830 Latvia 340 0.0053 Lithuania 730 0.0112 Luxembourg 559 0.2162 Rep. ITU-R M.2478-0 49

TABLE A2.1 (end)

Licensees Country Licensees per km2 Malta 439 1.3892 Monaco 51 25.2475 Netherlands 12 637 0.3042 Norway 6 745 0.0208 Poland 13 098 0.0419 Portugal 5 677 0.0616 Romania 4 048 0.0170 San Marino 100 1.6393 Slovakia 1 500 0.0306 Slovenia 4 400 0.2171 Spain 30 756 0.0609 Sweden 13 000 0.0289 Switzerland 4 818 0.1167 The Russian Federation 37 500 0.0021 Ukraine 11 460 0.019 United Kingdom 84 694 0.3477

With the very high and very low values of countries such as Albania, Belarus, Latvia, Malta, Monaco and San Marino removed from the calculation, the average population density of amateur operators is 0.073 licensees/km2. Statistics for the Russian Federation and Ukraine are included for completeness and were not used in the calculations as the data was provided after the calculations were finalised.

Annex 3

An application-based approach to calculation of spectrum needs

This Annex describes an application based approach calculation of the amateur spectrum need, within the band 50-54 MHz. This approach can: – take account of the expected capabilities and usage scenarios, and – be readily implemented using common software tools such as a spreadsheet. The results from this calculation procedure need to be considered carefully given that the output might be sensitive to the input parameter values on the usage of advanced applications which can be drawn from a large range of possible values. This input parameter, on the other hand, could reflect the different situation in particular regions or countries. 50 Rep. ITU-R M.2478-0

A3.1 Principles for calculating spectrum needs This paragraph describes spectrum needs calculation principles relating to half-duplex applications and beacons, with clarification of terminology to reflect amateur usage and to set minimum operational conditions. In this case an application is considered to be equivalent to a transmission mode e.g. CW, SSB, FM etc. The characteristics of Amateur Service stations used in spectrum needs calculations are contained in Table 9 of this Report. NOTE – Repeaters and gateways are treated the same as the other applications except that the session duration is taken as 8 760 hours as the systems are required to operate at any time.

A3.2 Geographic Parameters Cell geometry and usage density: – D_A: Density of amateur radio users / km2. – Cell area (coverage area; a function of application, antenna height, TX power, S/N_min). This is assumed to a circular area of radius X km which is estimated to be the distance over which a contact may be made at an acceptable signal to noise ratio. Distance X is primarily dependent on application and is based on actual experience.

A3.3 Traffic Parameters The following frequency bands are generally available to the amateur service in CEPT countries, subject to local licensing conditions and are often incorporated into commercially available transceivers:

TABLE A3.1 Principal frequency bands used by the Amateur Service in Region 1

Frequency band Designator 1 1,800-2,000 kHz 160 2 3,500-3,800 kHz 80 3 5,351.5-5,366.5 kHz 60 4 7,000-7,200 kHz 40 5 10.100-10.150 MHz 30 6 14.000-14.350 MHz 20 7 18.068-18.168 MHz 17 8 21.000-21.450 MHz 15 9 24.890-24.990 MHz 12 10 28.000-29.700 MHz 10 11 50.000-52.000 MHz 6 12 144.000-146.000 MHz 2

– R_A_50_54: Based on experience, a simple estimation of the fraction of amateurs using the band 50– 54 MHz has been made based on an equal spread of amateur licensees across the 12 most popular currently available amateur service frequency allocations e.g. 8.3% per band. This has been rounded to 0.08. The estimation is based on the long term (1 year) usage patterns as actual usage of the band at any given time will be highly variable. Rep. ITU-R M.2478-0 51

– R_App: An estimation of the fraction of amateurs using one of the specified applications in the band 50–54 MHz. The estimation is based on the long term (1 year) usage patterns as an application’s actual usage at any given time will be highly variable. – T_session: Session duration. Taken to be the time in hours per day (averaged over 1 year) a station is active using a given application, either receiving or transmitting. – W: Observation window. Taken to be 1 year = 8 760 hours. – F_activity: Activity factor. Fraction of T_Session when transmitter is active, assumed to be 0.5 for typical Press-To-Talk usage. Assumed to be 1 for beacons which are always transmitting.

A3.4 Technology To accommodate a mix of analogue and digital applications all calculations are based on a simple channel bandwidth. However many transmission modes are not compatible with each other and cannot share spectrum, therefore a summation of spectrum is required for each individual application. Additionally, the calculated spectrum for each application is rounded up to the next integer multiple of the application channel bandwidth as a fractional bandwidth would not allow the application to function correctly.

A3.5 Calculations 1 Calculate the average number of amateurs or transmitters per km2 at any time in the year using the spectrum in the frequency band 50–54 MHz for a specific application: Nb_Amateurs_km2_Application = D_A * R_A_50_54 * R_App 2 Calculate the number of amateurs within one cell using a specific application within the band 50–54 MHz: Nb_Amateurs_Cell = Nb_Amateurs_km2_Application * cell_area 3 Calculate the spectrum within a cell for a specific application: BW_app = Nb_Amateurs_Cell * Channel bandwidth 4 Calculate the bandwidth for the specific application over the operating session time. This is required spectrum averaged over time and the result may be less than the specified channel bandwidth for the application: Occup_BW_app = BW_app * F_activity * T_session / W 5 A test is necessary: If Occup_BW_app < application channel bandwidth then: i) Occup_BW_app = application channel bandwidth ii) Else Occup_BW_app = Round up to next integer multiple of channel bandwidths e.g. 1.5 -> 2 6 Calculate the total required spectrum within the band 50 – 54 MHz: Occup_BW = Occup_BW_app1 + Occup_BW_app2 +… Occup_BW_app_n

A3.6 Results of application-based approach Results show that, based on the average amateur density in the CEPT area, the required spectrum exceeds 4 MHz and is considerably more in areas of high population density e.g. in the case of Germany with its high amateur population density estimated spectrum requirement exceeds 10 MHz. 52 Rep. ITU-R M.2478-0

An embedded Spread Sheet reflecting the calculation method is provided below in Figure A1. This shows that 4.162 MHz of spectrum is currently envisaged to meet the average Region 1 spectrum requirements of the amateur service in the frequency band 50-54 MHz, whilst 10.024 MHz would be required to meet the spectrum needs in a high density area such as Germany.

Work Sheet Spectrum Needs AI 1-1 v2.0.xlsx

Annex 4

Another analysis of amateur band occupancy

A significant number of frequency bands are allocated to the Amateur Service in accordance with Article 5 of the ITU Radio Regulations. In this regard there are specifications of their use.

Region 1 1 810–1 850 kHz AMATEUR 5.98 5.99 5.100 1 850–2 000 kHz FIXED MOBILE, except aeronautical mobile 5.92 5.96 5.103

The 1.8 MHz band (the 160-metre band) was earlier used by beginners for short-range voice-mode communications (AM and LSB) or by experienced radio amateurs for Morse Code communications. At present, communications are mainly carried in a narrow range of the telegraph band and around 1 900 kHz in the telephone band. Sometimes ‘round-table’ sessions are held in the 1 900-1 920 kHz frequency band. This band’s occupancy is very low. Usually this band is not used during competitions.

Region 1 18 068–18 168 kHz AMATEUR, AMATEUR-SATELLITE 5.154

The 18 MHz band (the 17-metre band). This band is used for operation of all types of emissions. Major propagation takes place during daytime and evenings. Many free ranges can be observed during listening. This band is not used during competitions.

Region 1 21 000-21 450 kHz AMATEUR, AMATEUR-SATELLITE

Rep. ITU-R M.2478-0 53

The 21 MHz band (the 15-metre band). This is one of the principal bands for DX communications and competitions. Major propagation takes place at morning time. It is actively used when propagation is sufficient however its occupancy is not very high.

Region 1 24 890–24 990 kHz AMATEUR, AMATEUR-SATELLITE

The 24 MHz band (the 12-metre band). This band is used for operation of all types of emissions. Propagation in this band is currently poor, but in principle DX communications are possible. Many free ranges can be observed during listening. This band is not used during competitions.

Region 1 28–29.7 MHz AMATEUR, AMATEUR-SATELLITE

The 28 MHz band (the 10-metre band). In this band propagation strongly depends on solar conditions. In the past it was used for voice-mode communications (USB, FM) by beginners as well as experienced radio amateurs. At present propagation bursts are extremely rare and many free ranges can be observed during listening.

Regions 2 and 3 50-54 MHz AMATEUR

As per Article 5 of the Radio Regulations, in Regions 2 and 3 the frequency band 50-54 MHz is allocated to the amateur service on a primary basis. As per the European ECA table, the frequency band 50-52 MHz is allocated to the amateur service on a secondary basis and is used in almost all European countries by amateur service stations in accordance with Article 4.4 of the Radio Regulations. At the same time, according to the website dxwatch.com, which records the conduct of amateur radio communications, including communications by radio amateurs in Regions 2 and 3, the actual occupancy of the subject band is quite low. Table A4.1 shows the number of amateur radio communications conducted in the 50-54 MHz band (wavelength 6 m), between 12.05.2018 and 14.05.2018. As seen from the sample provided, operations are mainly conducted in one radio frequency, 50.313 MHz, and more rarely, in the band 50.090-50.260 MHz. The numbers of amateur radio communications conducted in the 50-54 MHz band at other time periods are not significantly different from those shown in Table 9. 54 Rep. ITU-R M.2478-0

TABLE A4.1 Amateur radio communications conducted in the band of frequencies 50-54 MHz, according to the website dxwatch.com

Receiver station Transmitter station Frequency, Session date kHz IK5GQK (Italy) CT2HPM (Portugal) 50313 1349z 14 May IK5GQK (Italy) CT1ANO (Portugal) 50313 1346z 14 May AC2PB (USA) AE7KI (USA) 50313 1337z 14 May AC2PB (USA) W8OI (USA) 50313 1330z 14 May IK6DTB (Italy) 4U1ITU (ITU) 50096 1326z 14 May HA8VA (Hungary) HA8QRP (Hungary) 50091 1319z 14 May EA5CI (Spain) 4U1ITU (ITU) 50096 1316z 14 May 4U1ITU (ITU) 4U1ITU (ITU) 50096 1314z 14 May KK4XO (USA) AC2PB (USA) 50313 1256z 14 May KK4XO (USA) KD9VV (USA) 50313 1255z 14 May DK5EW (Germany) OY9JD (Denmark, Faroe 50130 1255z 14 May Islands) PC4N (Netherlands) PE1RF (Netherlands) 50314 1251z 14 May M0CGL (UK) OY9JD (Denmark, Faroe 50130 1251z 14 May Islands) VE1SKY (Canada) VE1PZ (Canada) 50313 1247z 14 May DF4PL (Germany) LX0SIX (Luxembourg) 50022 1246z 14 May KT4FW (USA) NF3R (USA) 50313 1235z 14 May VE1SKY (Canada) K8LEE (USA) 50313 1234z 14 May DK5EW (Germany) GS3PYE (UK) 50313 1231z 14 May VO1VCE (Canada) VO1FU/B (from China) 50073 1229z 14 May F1YJ (France) OY9JD (Denmark, Faroe 50130 1228z 14 May Islands) GM4FDM (UK) OY9JD (Denmark, Faroe 50130 1227z 14 May Islands) M0TLI (UK) OY9JD (Denmark, Faroe 50130 1223z 14 May Islands) K1TOL (USA) EUVIDEO (Belarus) 50000 1221z 14 May EI7HBB (Ireland) DF3XZ (Germany) 50099 1220z 14 May VE1SKY (Canada) K1TOL (USA) 50313 1219z 14 May VE1SKY (Canada) WA2GSX (USA) 50313 1219z 14 May F4AZF (France) OY9JD (Denmark, Faroe 50130 1218z 14 May Islands) VE1SKY (Canada) N3RG (USA) 50313 1218z 14 May PA1MR OY9JD (Denmark, Faroe 50130 1216z 14 May (Netherlands) Islands) LA4LN (Norway) EI4DQ (Ireland) 50313 1215z 14 May Rep. ITU-R M.2478-0 55

TABLE A4.1 (end)

Receiver station Transmitter station Frequency, Session date kHz PC2J (Netherlands) OY9JD (Denmark, Faroe 50130 1210z 14 May Islands) UN7TW JE1BMJ (Japan) 50313 0558z 14 May (Kazakhstan) VU2NKS (India) VU2NKS (India) 50313 0542z 14 May K7XC (USA) K7XC (USA) 50260 1744z 13 May 4Z4DP (Israel) 4Z70IARC (Israel) 50099.8 1616z 13 May LZ3BS (Bulgaria) 5B4AIF(Cyprus) 50314 1014z 13 May SV1QFF (Greece) F6HLC (France) 50133.2 0829z 13 May HA1VG (Hungary) G2KF (England) 50140 0759z 13 May HA1VG (Hungary) G2KF (England) 50140 0753z 13 May HA1VG (Hungary) G7RAV (England) 50092 0752z 13 May 2E0XXO (UK) IW1JTQ (Italy) 50170 0729z 13 May W9BWR (USA) AA0MZ (USA) 50313 1747z 12 May 4Z4DP (Israel) IW9GDC/B (Italy) 50006 1727z 12 May 4Z4DP (Israel) SV1SIX (Greece) 50040.1 1723z 12 May SV9CVY (Greece) K1TOL (USA) 50313 1518z 12 May SV9CVY (Greece) K1TOL (USA) 50313 1458z 12 May WB4JPG (USA) W1AIN (USA) 50125 1434z 12 May PU5BOY (Brazil) PU5BOY(Brazil) 50160 1344z 12 May SV9CVY (Greece) BD0AAI (China) 50313 1337z 12 May F1OOG (France) EA9ACD (Spain) 50160 1012z 12 Maу

Analysis of the occupancy of the frequency bands allocated to the Amateur Service shows that frequency bands allocated to the Amateur Service are not over-occupied at present and for that reason it is possible to meet the spectrum needs of the Amateur Service within the existing allocations. Therefore additional spectrum allocation to the Amateur Service in the 50-54 MHz band is not required.

Annex 5

Amateur service sharing with (analogue television) broadcasting service

A5.1 Introduction WRC-19 agenda item 1.1 is to consider an allocation of the frequency band 50-54 MHz to the amateur service in Region 1, in accordance with Resolution 658 (WRC-15). The Resolution requests, to take into account the results of sharing studies with incumbent services. Section 8.2 and this annex deal with the compatibility between the amateur service and the broadcasting service prior to any switch- 56 Rep. ITU-R M.2478-0 off of the analogue broadcasting service in this frequency band. Section 8.3 of this Report provide the results of the study. Various mechanisms were studied which have been used by administrations in Regions 1 and 3 to regulate the amateur service in the 50-54 MHz frequency band where amateur stations have existed in relatively close geographical proximity to the service areas of analogue television broadcasting stations. In addition, ITU-R WP 6A has provided WP 5A with details of the current ITU-R Recommendations which detail the criteria necessary to assess sharing conditions and these have been used in formulating the sharing model detailed in § A5.2 below. To address part of the sharing scenario requested by WRC-19 agenda item 1.1, § A5.2 of this Annex details a sharing model that can be used or adapted to demonstrate how sharing between the amateur service and the remaining analogue television broadcasting applications in Region 1 in the band 50-54 MHz is feasible. Section A5.6 provides details of the scenario used for analyzing the sharing situation between the amateur service and analogue television in the broadcasting service in the Russian Federation. The sharing method calculates the difference in field strength between the wanted TV field and the field resulting from an amateur transmitter. Recommendation ITU-R SM.851-1 has been used in many forums to address sharing between the amateur service and the broadcasting service. In general this appears acceptable in the case of avoiding harmful interference to analogue broadcasting; however care must be exercised when addressing the polarization of amateur stations’ antennas which may be vertically or horizontally polarized depending on the location and application being utilized. The minimum median value of the field strength to be protected is specified as 46 dB µV/m in Table 1 of Recommendation ITU-R SM.851-1 (50% of time, 90% of locations). The required protection ratio is also given by Recommendation ITU-R SM.851-1, which is determined from Tables 3, 5 and Fig. 2 of the Recommendation and depends on the frequency separation between wanted and interfering emissions. The amateur signal strength is calculated using ITU-R recommendations and assumes the use of a four element Yagi antenna with the characteristics shown in the Fig. A5.1 below. The signal strength is further adjusted based on factors to adjust for differences in signal polarization, receiver antenna gain factors and losses due to obstructions between the amateur station and TV receiver.

A5.2 Method The minimum field strength for which protection against interference is provided in planning should never be lower than 46 dBµV/m (Table 1 of Recommendation ITU-R SM.851-1). Remaining analogue television transmitters in Region 1 generally utilise the SECAM System D/K standard with a channel centre frequency of 52.50 MHz, vision carrier frequency 49.75 MHz and sound carrier 56.25 MHz. Carrier offsets may be used. The method involves calculating the difference between the wanted TV signal's field and the field resulting from an amateur transmitter operating on a frequency within the TV channel some distance away from the edge of the TV service area. If the amateur signal is less than the minimum signal strength based on the minimum required TV signal field strength adjusted for the protection ratio, then no harmful interference will occur. Due to propagation phenomena it is estimated that European amateur stations such as those described in the paragraph below, which establishes the field strength from a specific type of amateur station less than 500 kHz from the 49.75 MHz video carrier of a television station will be transmitting for only 8.5% of daylight hours on 90 days within a year. In other parts of Region 1 especially in geographical areas nearer to the equator activity times may be greater. Rep. ITU-R M.2478-0 57

Other amateur applications including digital emissions with channel bandwidths of up to 500 kHz will employ a lower station e.r.p. generally not exceeding 20 dBW and will be separated from the 49.75 MHz vision carrier by between 1 and 4 MHz, thus requiring a lower protection ratio to protect the service area of the television broadcasting transmitter. Conversely the amateur emissions’ duty cycle is likely to be greater than the higher power amateur transmitters closer to the vision carrier.

FIGURE A5.1 Polar Diagram of assumed amateur transmitting antenna

A5.3 Variables for the unwanted amateur station signal E is the field strength (dB µV/m) of a typical amateur station which is located at a distance of d km from the service area of an analogue television transmitter. It assumes the amateur station antenna is pointing in the direction of the TV station and uses a state-of-the-art four element Yagi antenna design as shown in the figure above. The maximum gain is approximately 9 dBi which equates to 7 dBd. The value of E is determined using Recommendation ITU-R P.1546 curves for land paths for the case of 10% time and 50% locations, and h2 = 10 m and e.r.p. of 30 dBW. Pr is the radio frequency protection ratio. This value is determined from Recommendation ITU-R SM.851-1. For the situation given above with a carrier separation of around 400 kHz a Pr of 50 dB is required. 58 Rep. ITU-R M.2478-0

At is the amateur transmitting antenna factor. From the antenna diagram above, the side-lobe gain is –18 dBi which equates to –20 dBd. It is extremely likely that amateur operators will point their antennas away from the broadcasting transmitters which are geographically close to them because: – TV video signal levels in their receivers will be excessive and would interfere with the reception of weak signals and most importantly, – Administrations which have a large number of analogue television transmitters remaining in their territory have generally not authorized amateur emissions from their territory in the 50- 54 MHz frequency band. Since amateur operators outside such jurisdictions do not have the possibility of making amateur communications with such geographical areas it is unlikely that they will beam their emissions towards such territories. Ol is the Obstruction loss. Amateur radio stations are generally situated in domestic locations. They are not normally located on prime VHF sites and are often in heavily obstructed areas. Obtaining any degree of foreground Fresnel zone clearance is in many cases impossible. For the purposes of this study a 10 dB obstruction loss for amateur stations has been assumed at these frequencies. Cp is a receiving antenna polarization factor. Recommendation ITU-R P.1406 indicates that polarization changes due to scattering from various obstacles may be significant and that such scattering increases as the frequency is lowered reaching a maximum or about 18 dB at 35 MHz. As the standard deviation of the scattering is significant, a value of 10 dB is assumed for the cross polarization loss at 50 MHz for the purposes of this study. Ad is a television antenna receiving discrimination factor determined from Recommendation ITU-R BT.419 entitled Directivity and polarization discrimination of antennas in the reception of television broadcasting. Television receiving antennas nearest to amateur stations are likely to be pointed away from amateur stations whereas there will be additional geographical separation between television receiving antennas pointing towards the broadcasting transmitter and amateur stations in the model. 7 dB is permitted for this situation. Afs, the aggregate field strength of the amateur stations at a given distance from the edge of the TV station service area, is calculated from: Afs = E + At + Ol + Cp + Ad

A5.4 Variables for the wanted TV signal Tfs is the minimum TV Field strength of 46 dBµV/m. Pr is the required protection ratio, specified by the relevant ITU-R Recommendations depending on the type of TV service and the frequency separation between the wanted and unwanted signal. TVifs is the maximum field strength of the interfering signal calculated from the minimum wanted TV signal field strength adjusted by the specified protection ratio: TVifs = Tfs – Pr

A5.5 The calculation The difference in field strength is calculated between the wanted TV field with its protection factor (TVifs) and the field resulting from an amateur transmitter (Afs). If the amateur station(s) field strength (Afs) is equal to or less than the TV interference field strength (TVifs), then there should be no interference. If the Afs is greater than TVifs, interference is possible. E.g. for no interference: TVifs ≥ Afs Rep. ITU-R M.2478-0 59 which is calculated from: Tfs – Pr ≥ E + At + Ol+ Cp + Ad where all the variables are in dB.

A5.6 Sharing scenario This section addresses the results of calculations concerning sharing between the amateur service in neighbouring Region 1 countries adjacent to the Russian Federation and legacy analogue television transmitters utilising SECAM System D/K with a channel centre frequency of 52.50 MHz, vision carrier frequency 49.75 MHz and sound carrier 56.25 MHz. Carrier offsets may be used.

TABLE A5.1

System D 625 lines Channel Video-carrier Centre Colour-subcarrier Audio-carrier (MHz) (MHz) (MHz) (MHz) 2 49.75 52.50 54.18 56.25 3 59.25 62.00 63.68 65.75

It should be noted that the video carrier is outside the band being considered for an allocation to the amateur service in Region 1, the separation between the amateur transmitter and the vision carrier being greater than 400 kHz. Pr = 50 dB. This value was determined from Tables 3 and 5, and Fig. 2 of Recommendation ITU-R SM.851-1 based on video carrier protection. For a 50 km distance and one transmitting amateur station, the calculated figures for this sharing scenario are given below.

TABLE A5.2

Component Values E: Amateur signal level dB(µV/m) from stations 50 km from 27 TV service area boundary At: TX side-lobe gain (dBd) -20 Ol: obstruction loss (dB) -10 Cp: Antenna polarisation factor (dB) -10 Ad: TV RX antenna discrimination factor (dB) -7 Amateur field strength at edge of TV service area dB(µV/m) -20 Afs = E + At + Ol + Cp + Ad

Tfs: Wanted TV signal strength at service area boundary 46 dB(µV/m) Pr: Interference protection ratio (dB) 50 Permissible interference field strength at TV service area -4 boundary: TVifs = Et – Pr TVifs > or = Afs? Yes Interference from amateur stations? No

60 Rep. ITU-R M.2478-0

A5.7 An alternative approach Although the sharing study described in previous paragraphs suggests that sharing would be feasible between SECAM analogue television broadcasting and the amateur service in the frequency band 50-54 MHz a SEAMCAT study has been conducted to determine the probability of harmful interference occurring for several sharing situations for different configurations of the broadcasting and amateur services. Using Monte-Carlo simulators such as the CEPT/ETSI SEAMCAT software package allow various scenarios to be examined relatively quickly. The simulations conducted are thought to represent typical worst-case situations that might be encountered if the broadcasting service (analogue television) coexists with the amateur service in the 50-54 MHz frequency band. Report ITU-R SM.2028-1 is particularly relevant in this regard. Further details of the SEAMCAT analyses are contained in Annex 6 to this Report.

A5.8 Summary and conclusions This study shows that sharing is possible using the method described without any harmful interference occurring from an amateur transmitter with a power level (e.r.p. of 30 dBW) at a distance of 50 km from a television transmitters’ service area in the frequency band 50-54 MHz. This study details a method of ascertaining whether a rather basic sharing scenario will likely protect remaining analogue television broadcasting applications in Region 1 in the band 50-54 MHz, until this band is no longer used for broadcasting. The method calculates the difference in field strength between the wanted TV field with its protection factor (TVifs) and the field resulting from an amateur transmitter (Afs). If the amateur station(s) field strength (Afs) is equal to or less than the TV interference field strength (TVifs), then there should be no interference. If the Afs is greater than TVifs, interference is possible. In addition to the method described in §§ A5.1 to A5.5, a Monte-Carlo SEAMCAT simulation was conducted and discussed in § 8.4 and the results are contained in § 8.5 and Annex 6 to this Report. The predicted probability of interference between the amateur service and the TV broadcasting service is relatively low if typical operating conditions of both the TV service and amateur service are taken into account. In both rural and suburban environments the calculated mean signal strength (dRSS) of the TV signal is greater than the minimum receiver sensitivity of -48 dBm implying that the TV receivers display relatively interference free images when the amateur stations are not transmitting. Notwithstanding that the interference probability is low; any harmful interference which does occur could likely be handled through bilateral or multilateral agreements in place with neighbouring countries. It is believed that the foregoing has described scenarios to demonstrate that successful sharing is possible between the amateur service and broadcasting service in Region 1, in European countries which border those countries which have NOT so far implemented a full changeover to terrestrial digital television broadcasting in bands above 174 MHz.

Rep. ITU-R M.2478-0 61

Annex 6

A Monte-Carlo simulation study of compatibility between the analogue TV broadcast service and the amateur service

A6.1 Introduction and summary This Report presents the results of Monte-Carlo simulations using the SEAMCAT software tool to predict the probability of interference to residential analogue TV reception in suburban and rural environments by stations of the amateur service. The probability of interference is found to be low in the cases considered by this study.

A6.2 Study details This study considers two typical scenarios: – A major metropolitan area with a high powered TV broadcast transmitter. – A small rural township serviced by a relatively lower power transmitter. Two propagation models were used in the simulations, with the most appropriate model selected for each service: – For the TV broadcasting service ‘ITU-R P.1546-4 Land’ with the analogue broadcasting option selected and signal strength calculations are for between 10% and 50% of the time. ITU-R P.1546 calculations are only valid for field strengths exceeded for percentage times in the range from 1% to 50%. – For the amateur service the ‘Extended-Hata’ model was used. For the TV receiver, the required protection ratio of wanted to unwanted signal strengths (C/I) is 54 dB. The sensitivity of the TV receiver is –48 dBm (~1 mV into 50 Ohms) and the bandwidth of the TV signal is assumed to be 5 MHz. The TV receiving antenna used in the study is a low gain design which is ‘built in’ to SEAMCAT and it would be suitable for short to medium range reception of TV signals; however it is likely, and experience suggests, that receivers on the outskirts of the TV coverage area will use antennas with higher gains and more directional characteristics which will reduce the potential for interference from any directions other than the main lobe that will be pointing towards the TV broadcast transmitter antenna. The study assumes two amateur stations operating anywhere within a 50 km radius of the TV broadcast transmitter. The two amateur stations have a 100 W transmitter and use four-element Yagi antennas at 10 m elevation and are operating on a 5% duty cycle. The amateur transmitters may be communicating to receivers either inside or outside of the TV service area. All the parameters used by SEAMCAT are given in Table A6.3.

A6.3 The major metropolitan area study This study is modelled on the TV transmitter in Moscow found in the ITU BR database record 061000305, an extract of which is shown in Fig. A6.3. The TV broadcast transmitter is assumed to have an effective radiated power of 316 kW (85 dBm) into an omni-directional antenna with a numerical gain of 1 at an effective height of 385 metres and the radius of the TV service area is assumed to be 50 km. The predictions for the probability of interference made by SEAMCAT for the metropolitan area are shown in Table A6.1 and the simulation outline is shown in Fig. A6.1. 62 Rep. ITU-R M.2478-0

TABLE A6.1 Probability of interference for the major city calculated by SEAMCAT using the parameters given in Table A6.3. The C/I column is the calculated percentage of interference for the C/I protection criteria of 54 dB; Mean dRSS is the calculated mean signal strength of the desired TV signal and its standard deviation also shown

C/I % Mean dRSS dRSS StdDev Environment (54 dB) (dBm) (dBm) 0.14 -29.69 11.34 Suburban 0.81 -29.09 11.27 Rural

FIGURE A6.1 Simulation outline of the major metropolitan area (Moscow) study. This figure shows 601 positions of the 100 000 random positions that SEAMCAT simulates to predict the probability of interference

A6.4 The rural centre study This study is modelled on the TV transmitter in Zapadnaya Dvina Tver found in the ITU BR database record 096002674, an extract of which is shown in Figure A6.4. The other parameters used in the simulation, e.g. receiver antenna, sensitivity, amateur characteristics, etc., are the same as previously described in § A6.2 above. Rep. ITU-R M.2478-0 63

The TV broadcast transmitter is assumed to have an effective radiated power of 165 W (52.2 dBm) into an omni-directional antenna with a numerical gain of 1 at an effective height of 92 metres and the radius of the TV service area is assumed to be 5 km. Given the low transmitter power of 165 Watts (22.2 dBW) and relatively low antenna height (92 m), it is assumed that the broadcast station serves a small rural community or some other type of isolated compact settlement. The image from Google Earth (Figure A6.8) shows the town at the center of a largely forested area with a diameter of approximately 5 km. Table A6.2 shows the calculated probability of interference to residential TV reception by amateur operators and Fig. A6.2 shows the simulation outline.

TABLE A6.2 Probability of interference for the rural township calculated by SEAMCAT using the parameters given in Table A6.3. The C/I column is the calculated probability of interference; Mean dRSS is the calculated mean signal strength of the desired TV signal and its standard deviation also shown

C/I % Mean dRSS dRSS StdDev Environment (54 dB) (dBm) (dBm) 1.57 -41.06 9.99 Rural

FIGURE A6.2 Simulation outline of the rural township (Zapadnaya Dvina Tver) study. This Figure shows 601 positions of the 100 000 random positions that SEAMCAT simulates to predict the probability of interference

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FIGURE A6.3 Extract from ITU database giving details of the Moscow television transmitter used in the simulation in section A6.3 of this Report

FIGURE A6.4 Extract from ITU database giving details of the Zapadnaya Dvina Tver television transmitter used in the simulation in section A6.4 of this Report

Rep. ITU-R M.2478-0 65

TABLE A6.3 The main parameters used for the SEAMCAT studies given in this document. Any other parameters not specified were left as the program default values. SEAMCAT version 4.1.0 revision 2337 was used for this study.

Parameter Value Comments Frequency 52.5 MHz Same frequency is used for both the TV transmitter and amateur station Amateur transmitter power SSB: 50 dBm (100 W) PEP Typical of amateur equipment used around 52 MHz. See Fig. A2.2.7 for emission mask. Duty cycle of amateur SSB: 2.5% at 40 dBm and 2.5% 5% operation is 1.2 hours per day; most transmitter at 50 dBm amateurs would transmit less than this on average. Considering SSB; for smoothly read text, the mean power of the speech signal is 10 dB lower than the power of a reference sinusoidal signal (see Rec. ITU-R SM.326, Note 2 to Table 1). Amateur links antennas, SSB: 4 element Yagi, 9.4 dBi Typical amateur antennas. See Fig. RX & TX gain A2.2.5 for radiation pattern. Amateur antenna height, 10 m (above ground) A probable maximum amateur height due RX & TX to planning requirements. Number of active amateur 2 transmitters in service area Television broadcast 85 dBm (316 kW) The difference between e.r.p. and e.i.r.p. transmitter power 52.2 dBm (165) is small and is ignored here. Since e.r.p. Television broadcast Omni-directional vertical, 0 dBi is given antenna gain is assumed to be 0 transmitter antenna gain dBi Television transmitter height 385 m & 92 m TV receiver antenna height 5 m (above ground) TV receiver sensitivity –48 dBm (1 mV into 50 ohms) TV receiver antenna gain 0 dBi See Fig. A6.6 for radiation pattern. Pattern based on ITU-R BT.419 which is a built-in SEAMCAT option. TV signal bandwidth 5 MHz Interference criteria C/I = 53.97 dB, C/(N+1) = 47 dB (N+I)/N = 0.97 dB, I/N = –6 dB Noise floor –103 dBm Based on the fundamental calculation of noise power per Hertz (kTB), corrected for bandwidth (5 MHz) and receiver noise figure (4 dB): –103 dBm = –174 dBm/Hz + 10 log(BW) + NF Coverage radius 50 km TV transmitter to receiver Major city 5 km TV transmitter to receiver Rural town General environment Rural and suburban 66 Rep. ITU-R M.2478-0

TABLE A6.3 (end)

Parameter Value Comments Propagation model For amateur service: Extended- Suitable for elevated transmitters in a Hata cluttered, non-line-of-site environment between 30 MHz and 3 GHz up to a maximum range of 100 km

Broadcasting and other terrestrial TV service: ITU-R P.1546-4 services, typically considered in cases Land with high mounted transmitter antennas e.g. above 50-60 m

FIGURE A6.5 Radiation pattern of the 4 element Yagi used in this study. Side lobes have not been included as the random assignment of directions in the simulation covered all possibilities of direction by the main lobe

Rep. ITU-R M.2478-0 67

FIGURE A6.6 Radiation pattern of the TV receiver antenna

FIGURE A6.7 Emission mask of SSB transmission from the amateur station used in this study

68 Rep. ITU-R M.2478-0

FIGURE A6.8 A Google Earth image of Zapadnaya Dvina showing the extent of the settlement and rural nature of the surrounding environment. The township appears to have a diameter of roughly 5 km as shown by the lines drawn on the image. This is in accord with the assumed TV coverage area of 5 km radius

Rep. ITU-R M.2478-0 69

ANNEX 7

Amateur service stations interference to television receivers of the broadcasting service in the band 50-54 MHz

A7.1 Introduction As part of studies under WRC-19 agenda item 1.1, regarding electromagnetic compatibility (EMC) between amateur service stations in the 50 MHz band and broadcasting service stations, the telecom administration of the Russian Federation has performed EMC calculations for simulated sharing of the band 50-54 MHz by broadcasting service and amateur service stations.

A7.2 Working Assumptions The calculation of electromagnetic compatibility is based on the application of Recommendation ITU-R SM.851-1 and Recommendation ITU-R P.1546. The calculation assumptions used: – In the frequency band 50-54 MHz, the characteristics of amateur service stations are taken from Recommendation ITU-R M.1732-2 – Characteristics of systems operating in the amateur and amateur satellite services for use in sharing studies mobile service stations; – At is the factor that determines amateur service stations’ antenna selectivity. In calculations in accordance with Recommendation ITU-R P.1546, the amateur service station antenna's directivity is taken into account for each direction of transmission as the e.i.r.p. is re- calculated based on the antenna pattern radiation reductions. For non-directional antennas At is assumed to be 0 dB; – Ol is the propagation loss resulting from the limited size of the Fresnel zone. The calculation assumes 0 dB, since losses due to irregular terrain have already been addressed in the calculation, and the boundary of the TV broadcasting area is not in built-up areas; – Cp is a factor that accounts for polarization discrimination of the broadcasting service station and amateur service station antennas; – Here and hereinafter, TV stations’ reception area boundary locations affected by interference from amateur service stations are determined through calculations of the area with an interference level of 6 dBμV/m at a height of 10 metres with tropospheric interference (10% of the time) and –4 dBμV/m for continuous interference (50% of the time). The maximum interference is calculated by using the formula: Еint_max = Tfs-N-At-Ol-Cp-Ad-PR where Tfs is the minimum wanted field strength of the broadcasting service station in the frequency band 48.5-56.5 MHz, determined in accordance with Recommendation ITU-R SM.851-1.

TABLE A7.1 Calculation of the wanted field strength of an analogue television broadcasting station Wanted field strength, dBμV/m, on the boundary of the coverage area (in 50% of the time, 46 90% of the locations) Wanted field strength, dBμV/m, on the boundary of the coverage area (50% of the time, 48 50% of the locations), in accordance with Rec. ITU-R BT.417

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N is the number of amateur service stations operating simultaneously at a certain distance from the boundary of the TV station’s coverage area. This calculation addresses only one amateur service station operating. Ad is the factor that accounts for the selectivity of TV receiving antennas. A signal strength loss of 7 dB is assumed, as per Recommendation ITU-R BT.419. PR is the protection ratio for the signal of the analogue TV broadcasting station, calculated in accordance with Recommendation ITU-R SM.851; it equals 49 dB (for the amateur service station frequency of 50 MHz). For other amateur service station frequencies, the PR shall be adjusted by the difference between the protection ratio for the frequency of 50 MHz and the protection ratio of the frequency used by the amateur service station. If the field strength produced by the amateur service station on the boundary of the TV signal reception area exceeds the value of Eint_max, then the level of interference caused by the amateur service station is considered unacceptable. So, in order to detect amateur service stations’ interference into TV reception, one should identify overlaps between the broadcasting station’s reception area and the amateur service stations’ area of interference (for 10% of the time) exceeding the Eint_max level. Protection ratios for standard 625-line systems are shown in Fig. A7.1 and Table A7.2.

FIGURE A7.1 Protection ratios for analogue TV broadcasting systems

625-line systems

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TABLE A7.2 Protection ratios for analogue television broadcasting systems

Frequency difference between wanted and interfering carriers (MHz) Luminance range PAL SECAM MHz -1.25(1) -1.25(2) -0.5 0.0 0.5 1.0 2.0 3.0 3.6-4.8 5.7-6.0(3) 3.6-4.3(5) 5.7-6.3(3) (4) (4) dB 32 23 44 47 50 50 44 36 45 25 40 25 (1) H, I, K1, L television systems. (2) B, D, G, K television systems. (3) B, G television systems: the range is 5.3-6.0 MHz. (4) This value is valid until the end of the channel. (5) D/SECAM and K/SECAM: add 5 dB.

The calculation includes a scenario with the amateur service station located outside the ATV station’s reception area. The amateur service station parameters are shown in Table A7.3.

TABLE A7.3 Amateur service station parameters

Antenna height Antenna Station above ground Polarization e.i.r.p. directivity level Directional Amateur_service_1 15 m H 28 dBW (–6 to 12 dB) Amateur_service_2 2 m Non-directional V 17 dBW

Antenna attenuation diagram of an amateur station in the azimuth plane is shown in Fig. A7.2. 72 Rep. ITU-R M.2478-0

FIGURE A7.2 Antenna attenuation diagram of an amateur station in the azimuth plane (for a directional antenna)

Broadcasting service station parameters are shown in Table A7.4.

TABLE A7.4 Broadcasting service station parameters

Antenna height Station aboveground Antenna directivity Polarization e.i.r.p. level Sankt 253 m Non-directional Horizontal 50 dBW Petersburg Ruskeala 45 m Non-directional Horizontal 10 dBW

A7.3 Calculation results Based on the input data described, we plot the coverage areas of the broadcasting service stations and the amateur service stations using the CHIRplusBC software, in accordance with Recommendation ITU-R P.1546. A simulation of interference between amateur service stations located on the border of Russian Federation and actually operating TV stations in the Russian Federation is shown in Figs A7.3 to A7.11. Each Figure is based on a calculation of an amateur service station’s interfering field strength. Rep. ITU-R M.2478-0 73

The calculation includes the TV receiving antenna’s polarization isolation.

FIGURE A7.3 The area of interference from Amateur_service_1 to St. Petersburg ATV station

St. Petersburg station’s reliable reception area when the amateur service station operating;

The area of the amateur service station’s interference into TV signal reception from St. Petersburg ATV station; 74 Rep. ITU-R M.2478-0

FIGURE A7.4 The area of interference from Amateur_service_2 to St. Petersburg ATV station

St. Petersburg station’s reliable reception area when the amateur service station operating;

The area of the amateur service station’s interference into TV signal reception from St. Petersburg ATV station We plot the interference areas of the amateur service stations with an interference level of 6 dBμV/m during 10% of the time. Rep. ITU-R M.2478-0 75

FIGURE A7.5 Amateur_Service_Station_1’s interference area

St. Petersburg

Veliky Novgorod

Pskov

For Amateur_Service_Station_1, the interference distance in the direction of the territory of the Russian Federation is 129 km. 76 Rep. ITU-R M.2478-0

FIGURE A7.6 Amateur_Service_station_1’s area of interference to Ruskeala ATV station

Ruskeala station’s reliable reception area with the amateur service station operating;

The area of the amateur service station’s interference into TV signal reception from Ruskeala ATV station Rep. ITU-R M.2478-0 77

FIGURE A7.7 Amateur_service_station_2’s area of interference to Ruskeala ATV station

Ruskeala station’s reliable reception area with the Amateur service_2 station operating;

The area of the Amateur service_2 station’s interference into TV signal reception from Ruskeala ATV station 78 Rep. ITU-R M.2478-0

FIGURE A7.8 The area of interference from both amateur service stations to Ruskeala ATV station

Ruskeala station’s reliable reception area when Amateur service stations operating;

The area of the amateur service stations’ interference into TV signal reception from Ruskeala ATV station The aggregate interference field strength has been calculated using the power summation method. For evaluation of interference caused by amateur service stations to television receivers of the broadcasting service in the band 50-54 MHz interference field strengths at test points were also calculated. The results are shown in Table A7.5. Rep. ITU-R M.2478-0 79

TABLE A7.5

Field strength Distance values from Field strength Distance Distance Field from Test AS_1 at the values from Test from Test from Test strength Point to TV test points, AS_2 at the test point Point to Point to values from Station dBμV/m points, dBμV/m AS_1, km AS_2, km TV station Ruskeala, km (1% of the (1% of the time) time) TP1 10.07 3.02 10.82 48 54.3 36.6 TP2 9.52 9.77 5.10 48 41.9 49.1 TP3 0.36 12.76 14.29 88.2 43.2 32.6 TP4 0.28 13.37 14.85 90.7 42.4 32.0 TP5 11.51 24.42 22.52 47.8 33.0 26.4 TP6 10.25 22.63 24.54 48 31.0 25.3

Location of test points inside the TV station reception area boundary is shown in Fig. A7.9.

FIGURE A7.9

The minimum territorial isolation required to support compatibility of amateur service and broadcasting service stations is calculated. 80 Rep. ITU-R M.2478-0

FIGURE A7.10 Amateur_Service_Station_1’s interference area

For amateur_Service_Station_1, the interference distance in the direction of the territory of the Russian Federation is 175 km. Rep. ITU-R M.2478-0 81

FIGURE A7.11 Amateur_Service_Station_2’s interference area

For Amateur_Service_Station_2, the interference distance in the direction of the territory of the Russian Federation is 70 km.

A7.4 Findings and Proposals The study results show that the amateur service stations’ field strength values at the test points exceed the previously determined threshold that supports interference-free operation of the broadcasting service stations, which equals 6 dBμV/m. Values by which the field strength threshold is exceeded and the frequency and territorial separations required depend on the characteristics and relative location of the amateur service stations and TV broadcasting station. So, to compensate for the level of interference on the boundary of the TV broadcasting station’s reception area, additional restrictions should be imposed on amateur service stations’ e.r.p. in the direction of the boundary of the TV broadcasting station’s reception area, with the e.r.p. reduced to values below 0 dBW. The necessary protection distances vary from 70 km to 175 km. 82 Rep. ITU-R M.2478-0

Annex 8

Information concerning current and past sharing arrangements between the amateur service and other services in the 50-52 MHz frequency band

A8.1 Introduction This information Annex compiled by IARU details sharing arrangements which have been implemented by administrations when sharing currently takes place, or has been implemented in the past between the amateur service and other allocated services in-country, or in a neighbouring jurisdiction. The information provided in this Annex originates from administrations, IARU Member Societies or individual persons who were involved in introducing the sharing criteria.

A8.2 Sharing scenarios In the mid-1980s some countries in Region 1 were assessing whether VHF television should cease and spectrum should be transferred to the mobile service. It was at this time that a number of IARU Member Societies raised with their administrations the possibility of an allocation to the amateur service in the frequency band 50-54 MHz to align with the allocation in Regions 2 and 3. However because broadcasting in the frequency band 47-68 MHz (Broadcasting Band 1) ceased at different times two sharing scenarios arose: 1 When all broadcasting ceased within a territory but neighbouring countries were continuing with their Band 1 broadcasting. 2 Where administrations felt that they were able to introduce the amateur service within their own country in locations which were not impacted by their Band 1 transmitters or another service such as the mobile service or radiolocation service. This document describes the sharing formulation used in a number of countries and in part was initiated by sending a questionnaire to IARU Member Societies in CEPT countries. Information received for a number of countries is reproduced in the following paragraphs.

A8.3 Country information A8.3.1 Finland The frequency band 50-52 MHz is allocated to the amateur service on a national secondary basis in Finland. There are regional restrictions in border areas. Amateur radio transmitters must not be used in part of the Tohmajärvi Municipality in an area between Niirala, Pykälävaara, Tervavaara, Lusikkavaara and Ahvenvaara and the border between Finland and the Russian Federation. Rep. ITU-R M.2478-0 83

The maximum transmitter power in the elementary class is 30 W peak envelope power (PEP) or 120 when the carrier of the transmission is attenuated by at least 6 dB. The maximum transmitter power in the general class is 150 W PEP or 200 W when the carrier of the transmission is attenuated by at least 6 dB. For extended power amateur licences there are limits for the field intensity caused by the amateur station in the Russian area. The calculation model detailed in Recommendation ITU-R P.1546 is used for the calculation of the field intensity. The limit value of the field intensity is 6 dBuV/m and 10% of time. The same principles are applied to repeaters which are near Russia's border. In addition the permitted radiation direction for extended power licensees is 0-20 degrees and 150-360 degrees. However the radiation direction of the antenna can be 0-360 degrees when the elevation angle of the aerial is 15-90 degrees. A8.3.2 France Broadcasting Band 1 (47-68 MHz) was not used for television broadcasting in France. However in December 1997 when the amateur service in France was first authorised to use the band 50.20-51.20 MHz, sharing with mobile video links was implemented. In addition to frequency band limitations the following restrictions were applied to amateur stations: – Fixed or portable only (no mobile). – No repeaters. – No restriction on antenna type, but restrictions on the radiated power level. – Access and power levels defined by regions (French “departements”) as per the map below. 84 Rep. ITU-R M.2478-0

Authorized region with radiated power limited to 5 Watts

Authorized region with radiated power limited to 100 Watts

In the regions where use of the band was permitted further restrictions could apply. These restrictions ended in March 2013. A8.3.3 Germany In 1993 the frequency band 50.08–51.00 MHz was released on a national secondary basis in accordance with Article 4.4 of the Radio Regulations and could be used anywhere in Germany with the exception of proscribed protection zones, see Fig. A8.1. Amateur licensees within the defined protection zone were permitted to use the band whenever the TV station was not transmitting.

FIGURE A8.1 Pre 2014 German protection zones marked in red

Only Morse code telegraphy (A1A) and SSB telephony (J3E) were permitted. Power limit: 25 Watt e.r.p. Antenna polarization: horizontal. It should be noted that the limitation in power, emission modes and antenna polarization were based on governmental mobile requirements, NOT for the protection of analogue television broadcasting. In case of any reported interference to radiocommunication services and/or cable distribution networks (Cable TV) an amateur had to cease transmissions immediately. Interference from other radiocommunication services had to be accepted by amateurs. Amateur Rep. ITU-R M.2478-0 85 operators also had to be available by telephone in order that the administration could inform an amateur licensee to cease transmissions in case of interference. No mobile operation and no automatic stations were permitted. The broadcasting protection zones were removed after the closure of broadcasting stations using the lower Broadcasting Band 1 channel. In 2014 further changes were made. The frequency allocation was extended to 50.03–51.00 MHz. Additional emission classes were introduced and the power limit was changed to transmitter output power instead of e.r.p. The requirement to be available by telephone has also been dropped since no interference had been reported. A8.3.4 Hungary There are no longer any Band 1 television broadcasting stations in Hungary and no restrictions have been placed on the amateur service subsequent to the authorizing of the amateur service in 50-52 MHz other than secondary status e.g. no protection zones or other special provisions. The power limitation was and remains at 10 W e.r.p. A8.3.5 Norway In the past and today in accordance with RR Article 4.4 an amateur licensee is responsible for non- interference with other services, especially broadcasting in the band 50-52 MHz. In addition prior to the closure of Band 1 television transmitters the Administration of Norway recommended compliance with the 50-52 MHz IARU Band-Plan and required that amateur licensees operating in the band 50- 52 MHz comply with the following: – All emission classes as permitted in the band 144-146 MHz could be used. – The maximum transmitter power should not exceed 25 W and maximum e.r.p. 60 W. – Maximum antenna gain 6 dB and maximum antenna height 20 m. – Obtain a special licence for beacons. In areas where Band 1, channel 2 used for TV, amateur use of 50-52 MHz was not allowed within a given radius of TV-transmitters in the periods when the transmitter was active. The proscribed protection distances are indicated in the Table A8.1.

TABLE A8.1

TV transmitter power Sector Distance Transmitter (kW) (degrees) (km) Main Stations Greipstad 5 000 – 360 100 Gulen 5 000 – 110 120 110 – 200 120 200 – 360 Melhus 10 000 – 090 130 090 – 360 110 Steigen 10 000 – 110 110 110 – 360 140 Varanger 10 No transmission East of 27 deg or South of 31 deg Relay Stations Bødalen 1 000 – 360 20 86 Rep. ITU-R M.2478-0

TABLE A8.1 (end)

TV transmitter power Sector Distance Transmitter (kW) (degrees) (km) Øyer 5 000 – 360 15 Skarmodalen 2.5 000 – 360 25 Åbogan 20 000 – 360 25

Since all use of TV channel 2 in Norway ceased many years ago, the restrictions mentioned in the above table do not apply for today’s amateur use of the 50-52 MHz frequency allocation granted in accordance with RR Article 4.4. A8.3.6 Sweden Currently there are no geographical restrictions on the use of the band 50.0-52.0 MHz by the amateur service. However in 1989 (the start of 50 MHz activities in Sweden), no amateur transmissions were permitted during television broadcasting hours. A permit was required for each fixed location where 50 MHz amateur equipment was operated. Subsequently e.r.p. restrictions were introduced in an area around the television transmitters reflecting the actual protection requirements. Today the transmitter power limit in Sweden is 200 W PEP. Previously the maximum e.r.p. was 250 W e.r.p. at a specified distance from the TV transmitter and 50 W e.r.p. at a greater distance from the television transmitter. There have been no polarizations or antenna pointing restrictions on amateur licensees at any time. A8.3.7 United Kingdom Subsequent to WARC-1979 the first 50 MHz experimental permits provided to UK amateurs allowed operation outside television hours from February 1983. From February 1986 Class A amateur licensees were permitted to use 50.0-50.5 MHz and the “out of hours” time limits were withdrawn as Band 1 analogue television services had ceased in the UK. However sharing criteria was developed to protect the nearest operational Broadcasting Band 1 service area resulting from the Antwerp TV transmitter in Belgium: – Maximum power at all times shall be carrier 14 dBW e.r.p., PEP 20 dBW e.r.p. – Maximum transmitting antenna height to be 20 metres above ground level. – Antennas shall be horizontally polarised. – No mobile or 'temporary premises' operation allowed. – No Repeaters permitted. In June 1987 the 50 MHz band was also released to Class B licensees and the band was extended to 50-52 MHz. Restrictions were relaxed as Broadcasting Band 1 in Western Europe declined. Vertical polarization and mobile operation were permitted from April 1991. In July 1994, the e.r.p. limit and aerial height restriction were removed and a power of 400 Watts (26 dBW) watts permitted in 50-51 MHz with primary status for the Amateur Service on the basis of non-interference to other services outside the United Kingdom as per RR Article 4.4. The frequency band 51.0-52.0 MHz is allocated on a Secondary basis with a power limit of 100 W (20 dBW) for Full Licensees, available on the basis of non-interference to other services inside and outside of the UK, again in accordance with RR Article 4.4. Rep. ITU-R M.2478-0 87

A8.4 Summary This section provides information on various sharing mechanisms that have been introduced by CEPT administrations in Region 1 over the last 34 years to facilitate the allocation of the frequency band 50-52 MHz to the amateur service under the conditions of RR Article 4.4. It is believed that similar mechanisms would also be appropriate for the band 52-54 MHz to facilitate a globally harmonized frequency band allocated to the amateur service between 50 and 54 MHz throughout Region 1.

TABLE A8.2 Summary of operational restriction imposed on the amateur service in some countries when the broadcasting and amateur services shared all or part of the 50-52 MHz frequency band

Power Allowed Field strength Geographic Other Country restriction frequency limits restriction restrictions (maximum) range Finland 150 W PEP 6 dBµV/m and Operation not 50-52 MHz None (NOTE – This 10% of time on allowed in is the only border in some specified part areas country where locations for near the FIN/RUS restriction are stations border. still being operating higher applied) power stations Germany 25 W e.r.p. None Operation not 50.08-51 MHz Limited to allowed in some narrow band specified areas modes. Hungary 10 W e.r.p. Norway 60 W e.r.p. None 100-140 km zones 50-52 MHz Limitations on around specified antenna gain and main TV stations. height. 15-25 km zones around specified relay stations. Sweden 250 W e.r.p. None 50-52 MHz Operation only allowed after the TV station ceased transmission at night time. A permit was required for each fixed location where 50 MHz amateur equipment was operated. 88 Rep. ITU-R M.2478-0

TABLE A8.2 (end)

Power Allowed Field strength Geographic Other Country restriction frequency limits restriction restrictions (maximum) range United 100 W e.r.p. None None 50-50.5 MHz No Repeater or Kingdom mobile operation. Maximum antenna height of 20 m. Operation only allowed after the TV station ceased transmission at night time.

NOTE – Primary allocation at national level. Australia Mode dependent None 120 km zones 50.0-50.3 MHz None but 100 W PEP around specified only in NSW, main TV stations. ACT, VIC and 60 km zones QLD, no around specified restrictions relay (translator) elsewhere. stations. No restriction in band 52-54 MHz

TABLE A8.3 Summary of restrictions imposed in two countries to protect the land mobile or other incumbent services in the 50-52 MHz frequency band

Power restriction Geographic Frequency Country Other restrictions (maximum) restriction restrictions France 5 W e.r.p., 100 W Operation not 50.2-51.2 MHz No repeaters. allowed in a small allowed in some only Fixed or portable number of regions “departments” only i.e. no mobile operation. Germany 25 W PEP 50.03-51.0 MHz

Rep. ITU-R M.2478-0 89

Annex 9

Background information on TV in Region 1

A9.1 Broadcasting plans In addition to the RR Article 5 allocation to the broadcasting service in Region 1 mentioned in noting d), the band continues to be subject to both the Final Acts of the European Broadcasting Conference (Stockholm, 1961 as revised in Geneva, 2006) (“ST61”) in the European Broadcasting Area and the Final Acts of the African Broadcasting Conference (Geneva, 1989 as revised in Geneva, 2006) (“GE89”) in the African Broadcasting Area and neighbouring countries. The ITU-R eQry database also shows that there are a total of 353 broadcasting assignments recorded in the ST61 and GE89 plans still using the frequency range 50-54 MHz in 41 administrations. The MIFR contains 555 broadcasting transmitters in that band in Region 1. This information is shown in Table A9.1 below:

TABLE A9.1

Date IFIC no. ST61 GE89 Region 1 MIFR Region 1 24/10/2016 2831 292 56 555 TV entries falling into or overlapping with frequency range 50 MHz-54 MHz. The information submitted to the BR for recording in the MIFR may not necessarily include all broadcasting stations in operation thus it may not reflect the actual use of the frequency band.

A9.2 The 2016 Situation In the European Regional Telecommunications Organization (RTO), CEPT administrations have been urged to remove their unused assignments to the broadcasting service in the band 50-54 MHz in view of agenda item 1.1 of WRC-19. This action will be in line with an earlier decision to protect assignments according to the Stockholm Agreement 1961 Plan. The CEPT over a number of decades has developed a European Common Allocation (ECA) table, which is reviewed annually. Footnote ECA3 states 'CEPT administrations are urged to take all practical steps to clear the band 47-68 MHz of assignments to the broadcasting service. The broadcasting assignments according to Stockholm Agreement 1961 shall be protected.' At a recent CEPT meeting administrations agreed that it could be useful if the totality of Broadcasting Band 1 could be addressed in accordance with ECA3 and unused assignments listed in the MIFR suppressed. ECA3 will therefore be reviewed at future meetings when the ECA is addressed. The closure of analogue television in the 47–68 MHz frequency band relates directly to the introduction of digital television. In 2009, the European Commission promoted a coordinated approach to the freeing up and future use of the radio spectrum because it wanted to ensure that EU citizens could enjoy the benefits of digital television. For that to happen, Member States (and other CEPT countries) closed analogue transmissions and moved to digital broadcasting. The switch-off of analogue terrestrial TV transmission was completed by 2009 in Germany, Finland, Luxembourg, Sweden and the Netherlands. The 2012 EU target for switch-off was met by almost all Member States of the European Union. The MIFR does not reflect this result. The current situation is that in Western Europe the 47-68 MHz frequency band is no longer used for terrestrial television broadcasting to the general public. 90 Rep. ITU-R M.2478-0

A9.3 Digital Terrestrial Television Broadcasting in Band 1: 47-68 MHz The Chester July 1997 Multilateral Coordination Agreement (MCA) attended by 34 CEPT administrations representing Member countries of the ITU was convened under the terms of Article 6 of the ITU Radio Regulations and dealt with the technical criteria as well as coordination principles and procedures for the introduction of Digital Terrestrial Television Broadcasting (DTTB). Article 4 of the Multilateral Co-ordination Agreement states that coordination procedures only deal with the frequency bands in which DTTB is envisaged, i.e. 174 to 230 MHz and 470 to 862 MHz. In the other bands the procedures of the 1961 Stockholm Agreement (ST61) would apply, without additional procedures. Furthermore, the joint CEPT ERC/EBU Report on Planning and Introduction of Terrestrial Digital Television (DVB-T) in Europe, Izmir, December 1997 states in section D2-2 “Due to long distance propagation effects and the high man-made-noise level, Band I is not considered suitable for DVB-T”. During consultations carried out by ITU Secretary General in 2000/2001 an overwhelming majority of the countries of the European Broadcasting Area indicated their support for the proposed revision of ST61. In addition, Member States from the planning area of the Regional Agreement for VHF/UHF television broadcasting (GE89) in the African Broadcasting Area (ABA) and neighbouring countries also expressed the wish to convene a Regional Radiocommunication Conference (RRC) for the same purposes. The ITU Council, at its sessions in 2001 and 2002, adopted Resolutions 1185 and 1180, by which it agreed to the convening of a RRC on the planning of terrestrial broadcasting in the VHF/UHF bands, for the combined planning area covering the European Broadcasting Area (EBA), the African Broadcasting Area, and the countries outside the African Broadcasting Area which are parties to the Regional Broadcasting Agreement, Geneva, 1989. The Plenipotentiary Conference, Marrakesh, 2002, also considered this issue and decided to extend the planning area to the territories of the following countries that are not or only partially covered by the planning areas of both the ST61 and GE89 Agreements: Armenia, Azerbaijan, Georgia, Kazakhstan, Kyrgyzstan, Russian Federation (the part of the territory to the west from longitude 170° E), Tajikistan, Turkmenistan and Uzbekistan (see Resolution 117 (Marrakesh, 2002)). In summary, the planning area comprised those parts of Region 1 that are situated west of the meridian 170° East and north of the parallel 40° South, as well as the whole territory of the Islamic Republic of Iran. The expectation that the band 47–68 MHz will not be utilized for DTTB in Region 1 continues in the ITU-R documentation, especially Report ITU-R BT.2387-0 (07/2015) which contains information from administrations on the current and future use of various frequency bands, including 50-54 MHz for broadcasting. None of the responding administrations identified VHF1 spectrum for their current or future DTTB services. However it is likely that several countries in Region 2 may adopt or have adopted the ATSC DTTB standard in spectrum allocated to the Broadcasting Service above 54 MHz. In May 2019 the Russian Federation stated that it was considering the use of the frequency band 50-54 MHz for digital broadcasting, so potential use of that band for such a purpose could not be ruled out. The frequency band 48-56 MHz is also being considered by some administrations as a candidate band for deploying digital TV and multimedia broadcasting systems. There are proposals to expand the use of DVB-T2 for bands below 174 MHz and to implement enhanced sound and multimedia broadcasting systems in the lower portion of the VHF band, including frequencies from 50 MHz to 54 MHz. Rep. ITU-R M.2478-0 91

A9.4 Analogue Television Broadcasting in Band 1: 47-68 MHz Report ITU-R BT.2387-0 (07/2015) clearly indicates that low VHF spectrum is not generally considered by administrations to be suitable for DTTB. As national Analogue Switch Off (ASO) programmes are completed, the number of analogue television stations diminishes in those countries where DTTB has been fully implemented. However there are a large number of analogue stations assigned frequencies in the VHF band below 100 MHz which are still in operation, for example 2 091 in Brazil above 54 MHz and 3 683 in the Russian Federation, some of which will be in the 47-54 MHz frequency band. It therefore appears that analogue television in VHF1 spectrum remains a cost effective means of reaching viewers in remote areas of large countries. Another important consideration is that many of the remaining analogue broadcasting stations in Region 1 were planned using the criteria and Plan assignments detailed in ST61 and GE89. On the assumption that those countries which have completed their ASO have decommissioned their analogue transmitters that the interference environment for those stations which remain operational has as a result significantly improved and the combined interference potential of several hundred amateur stations spread across the countries of central and western Europe is likely to be significantly less than the situation when the band was utilized solely for television broadcasting. Nevertheless, it may in some situations be necessary to develop mechanisms to limit the possibility of harmful interference being caused by the amateur service to broadcasting reception in the 50-54 MHz frequency band in Region 1, until such time that the broadcasting stations cease operations.

Annex 10

A Monte-Carlo simulation of sharing with the mobile service

This Annex contains the results of a Monte-Carlo simulations performed using the SEAMCAT software tool to assess the possibility of co-channel sharing in the frequency band around 52 MHz between a proposed governmental tactical communications system and the amateur service. The results indicate that under the most likely circumstances the probability of co-channel interference is low and contained within a very limited area. A protection distance of 40 km, to separate the tactical and amateur stations, could be applied if required though under most circumstances the interference would be transitory due to the very different operational characteristics of the tactical system and amateur service.

A10.1 Introduction There is a need to undertake appropriate sharing studies between various services and the amateur service for WRC-19 agenda item 1.1 which is considering the possibility of a new amateur service allocation in the 50-54 MHz frequency band. This contribution presents a sharing study between a proposed government tactical communications system and the amateur service for a number of scenarios in the 50-54 MHz frequency band.

A10.2 Background Recommendation ITU-R M.1634 notes under considering: “c) that deterministic interference calculations may not give a complete picture of the severity of the interference, for example, in terms of percentage of time; 92 Rep. ITU-R M.2478-0

d) that deterministic calculations are simple but may result in important decisions being made which overlook potentially useful sharing opportunities; e) that probabilistic interference calculations can provide significantly improved insights that enable more informed decisions regarding use of radio spectrum;” Recommendation ITU-R M.1634 further states that the software tool known as SEAMCAT is an appropriate method for undertaking the recommended probabilistic sharing studies. SEAMCAT was developed by the group of European Conference of Postal and Telecommunications Administrations (CEPT), European Telecommunications Standardization Institute (ETSI) members and international scientific bodies. SEAMCAT is publicly available along with relevant reference and user documentation at: http://www.cept.org. This Annex presents the results of SEAMCAT simulations covering a number of scenarios that are thought to represent a worst case situation when considering contemporary technology of the amateur service and a proposed government tactical communication system that may be used in the 50-54 MHz frequency band.

A10.3 The study scenarios and basic system parameters This SEAMCAT simulation study covers six situations in a rural environment with both the ‘victim’ (tactical system) and the ‘interfering’ (amateur station) links operating on the same frequency of 52 MHz: – Base station transmitting to vehicle receiver. – Base station transmitting to handset receiver. – Vehicle transmitting to base station receiver. – Vehicle transmitting to handset receiver. – Handset transmitting to base station receiver. – Handset transmitting to vehicle receiver. Each simulation was run for 20 000 individual random positions with the amateur transmitter free to operate anywhere within a 40 km radius of a tactical transmitter. All the relevant SEAMCAT parameters are given in Table A10.1.

TABLE A10.1 The main parameters used for the SEAMCAT studies given in this document. Any other parameters not specified were left as the program default values. SEAMCAT version 4.1.0 revision 2337 was used for this study

Parameter Value Comments Amateur transmitter power SSB: 50 dBm (100 W) PEP Typical of amateur equipment used around 52 MHz. The emission mask is shown in Fig. A10.2. Duty cycle of amateur transmitter SSB: 2.5% at 40 dBm and 2.5% 5% operation is 1.2 hours per day; at 50 dBm most amateurs would transmit less than this on average. Considering SSB; for smoothly read text, the mean power of the speech signal is 10 dB lower than the power of a reference sinusoidal signal (see Rec. ITU-R SM.326, Note 2 to Table 1). Rep. ITU-R M.2478-0 93

TABLE A10.1 (end)

Parameter Value Comments Amateur links antennas, RX & 4 element Yagi, 9.4 dBi gain Typical amateur antennas. See TX Figure A10.1 for radiation pattern. Amateur antenna height, RX & 10 m (above ground) A probable maximum amateur TX height due to planning requirements. Number of active amateur 1 transmitters in service area Base station transmitter power 47 dBm (50 W) Vehicle transmitter power 47 dBm (50 W) Handset transmitter power 37 dBm (5 W) Tactical base station antenna Omni-directional vertical, 2.15 See Fig. A10.3 for radiation pattern. dBi gain, 8 m high Vehicle antenna Omni-directional vertical, –3 See Fig. A10.3 for radiation pattern. dBi gain, 2 m high Handset station antenna Omni-directional vertical, –10 See Figure A10.3 for radiation dBi gain, 1.5 m high pattern. Tactical service receiver –112 dBm (0.56 uV into 50 sensitivity ohms) Mobile link bandwidth and 16 kHz modes Mobile service interference C/I = 16.97 dB 10 dB SINAD and –6 dB I/N criteria C/(N+I) = 10 dB specified (N+I)/N = 0.97 dB I/N = –6 dB Mobile service noise floor –126.9 dBm Based on the fundamental calculation of noise power per Hertz (kTB), corrected for bandwidth (16 kHz) and receiver noise figure (4 dB): –129 dBm = –174 dBm/Hz + 10log(BW) + NF Coverage radius 40 km for amateur 1 to 40 km for tactical system General environment Rural, over land Propagation model Extended-Hata Suitable for elevated transmitters in a cluttered, non-line-of-site environment between 30 MHz and 3 GHz up to a maximum range of 100 km

The transmission mode of the amateur station is single sideband suppressed carrier (SSB) using a 100 W Peak-Envelope-Power (PEP) transmitter operating with a duty cycle of 5% which represents 1.2 hours of transmission per day. The amateur transmit and receive antennas have a gain of 9.4 dBi and are located 10 m above ground (Fig. A10.1). The emission mask of the amateur signal is shown in Fig. A10.2. 94 Rep. ITU-R M.2478-0

FIGURE A10.1 Radiation pattern of the 4 element Yagi used in this study. Side lobes have not been included as the random assignment of directions in the simulation covered all possibilities of direction by the main lobe.

FIGURE A10.2 Emission mask for the SSB transmissions made by the amateur station transmitter used in this study.

Rep. ITU-R M.2478-0 95

FIGURE A10.3 Radiation pattern of the 2.15 dBi antenna used in this study. The other omni-directional antennas have the same pattern but use different gains in place of 2.15 dBi as shown here.

The ‘victim’ (tactical) system specifications used for the SEAMCAT studies are shown in Tables A10.2 through A10.5.

TABLE A10.2 Main tactical System parameters System type Governmental tactical Frequency range 30-88 MHz (52 MHz used) Receiver bandwidth 16 kHz Protection criteria I/N = –6 dB Thermal noise density –169 dBm/Hz Receiver sensitivity –112 dBm for 10 dB SINAD Deployment environment Rural, over land

TABLE A10.3 Vehicular parameters Antenna height 2 m Antenna polarization Linear Vertical Antenna gain –3 dBi Antenna radiation pattern Omnidirectional Transmitter power 50 W

96 Rep. ITU-R M.2478-0

TABLE A10.4 Handset parameters Antenna height 1.5 m Antenna polarization Linear Vertical Antenna gain –10 dBi Antenna radiation pattern Omnidirectional Transmitter power 5 W

TABLE A10.5 Base station parameters Antenna height 8 m Antenna polarization Linear Vertical Antenna gain 2.15 dBi Antenna radiation pattern Omnidirectional Transmitter Power 50 W

Using the parameters specified for the Protection Criteria of I/N = –6 dB and 10 dB SINAD the equivalent SEAMCAT Noise Floor and Interference Criteria were calculated and a given in Table A10.6.

TABLE A10.6 SEAMCAT noise floor and interference criteria used for this study Noise floor –126.9 dBm = –169 + 10 log10(16000) C/I 16.97 dB C/(N+I) 10 dB (N+I)/N 0.97 dB I/N –6 dB

A10.4 Operational considerations Tactical systems are likely to be deployed rapidly in response to various situations, operate for a relatively short period of time (hours to days) and then be stood down or moved to another area. The vehicular and handset assets are likely to be highly mobile and move continuously or intermittently throughout the service area, not remaining in any given position for an extended period of time. The handset devices carried by the user have a limited range and the user is highly likely to remain in close proximity to the host vehicle at all times otherwise communication may be lost. Stations of the amateur service are relatively sparse, static and located in homes or temporary field sites. In general they are highly visible and their location or proximity is known because of national licensing requirements and all transmissions are clearly identified by the call-sign of the transmitting station. Amateur stations operate intermittently and much more time is spent listening than transmitting. A typical amateur operator is only likely to be operational for an hour or two each day, or a few hours a week. Rep. ITU-R M.2478-0 97

A final factor to consider is that most amateur antennas likely to be used around 52 MHz are horizontally polarized versus the vertical polarization of the tactical system. This cross-polarization is not taken into account in this study but its presence in the actual usage of the band under consideration would reduce the interfering signal strength in the range 6 to 185 dB which would further decrease the probability of interference.

A10.5 Estimating the service range of the tactical links The first step undertaken in this study was to estimate the likely service range of the tactical system from the parameters provided. In particular, the specified receiver sensitivity of –112 dBm for a 10 dB SINAD sets the lower limit for the required signal strength and defines the maximum likely operational range. SEAMCAT simulations were run for the six scenarios over a variety of coverage radii and the predicted mean desired signal strength (dRSS) and standard deviations were recorded and compared to the minimum required signal strength. The radius of the service area was taken to be that given by the mean desired signal strength minus two standard deviations. This implies that approximately 97% of all possible paths in the service area will be above the minimum signal strength of –112 dBm. dRSS is the predicted mean desired signal strength i.e. of the tactical service, in a service area with the radius shown. If the value dRSS – 2.StdDev falls below approximately –112 dBm the link does not meet its required performance criteria. The results of these calculations are shown in Table A10.7.

TABLE A10.7 Predicted ranges of tactical devices in various configurations based on the minimum acceptable signal strength of 112 dBm for a 10 dB SINAD.

Radius dRSS StdDev dRSS – 2.StdDev Link (km) (dBm) (dBm) (dBM) Base to vehicle 40 –88.56 12.21 –112.98 Base to handset 15 –87.42 11.87 –111.16 Vehicle to base 40 –88.57 12.1 –112.77 Vehicle to handset 3 –86.93 12.73 –112.39 Handset to base 7.5 –87.02 11.96 –110.94 Handset to vehicle 1 –91.19 10.64 –112.47

The service ranges show significant variation due to the differences in transmitter power, antenna gain and antenna elevation and these ranges will dictate the use and positioning of the individual tactical system assets. This SEAMCAT study uses the above predicted transmission ranges as the basis for assessing the compatibility of the tactical and amateur service communication links.

A10.6 Range of the amateur service links assumed in this study The second part of this study assumes there is one active amateur transmitter (‘interfering’ transmitter) in a radius of 40 km around a tactical system transmitter and both systems are operating on the same frequency. As the amateur service does not have a defined service area, transmissions from the amateur stations are to other amateur station receivers which may be either inside or outside

5 The adjustment factor resulting from the antenna polarization discrimination for horizontally polarised broadcasting emissions with respect to vertically polarised mobile emissions is –18 dB, from section 4.1 of Recommendation ITU-R SM.851-1. 98 Rep. ITU-R M.2478-0 of the tactical service area. In this case it is assumed that the amateur receiver can be within a radius of 40 km of any position that the amateur transmitter may occupy. This implies that in some cases the tactical system assets may be very close to an amateur station, or relatively far away in other cases and this is to be expected as the tactical system is not a fixed installation and may be deployed in any position relative to an amateur station. Figure A10.4 shows this study scenario. In this study the test areas for each service completely overlap and in normal practice an amateur station would not transmit on an occupied frequency, so the situations presented in this simulation would not usually occur in practice as the amateur station would be aware that a tactical station was already using the frequency.

FIGURE A10.4 The SEAMCAT simulation for the Base-to-Handset scenario which has a 15 km service range, with the relative positions of the tactical and amateur stations free to move within the entire 40 km radius amateur transmitter area. The figure shows just 401 positions of the 20 000 random positions actually used to calculate the interference statistics

A10.7 Results of the simulations This study assumes that the amateur transmitter is within a 40 km radius of a tactical system transmitter, operating on the same frequency and with the tactical receiver operating anywhere within Rep. ITU-R M.2478-0 99 its defined service area. Table A10.8 shows the predicted average probability of interference for the scenarios and it can be seen that the probability of interference is generally small and the tactical links generally function without interference for more than 95% of the time for the given 10 dB C/I protection criteria. Those scenarios that do have a higher probability of interference (vehicle-to-base and handset-to-base) are all mobile situations that are highly likely to be transient as the relative distance between the tactical assets and amateur station changes. The Table also shows that the I/N criteria is not a good indicator of compatibility for this type of application as the position of the victim and interfering systems are likely to be constantly moving and that while the I/N criteria may be exceeded the ultimate Signal to Noise Ratio is acceptable.

TABLE A10.8 Predicted co-channel average interference probability for each study scenario assuming the tactical assets are operating within their operating ranges and with the amateur station transmitting anywhere within a 40 km radius of a tactical transmitter

Radius C/(N+I)% I/N% Link C/I% (17 dB) (km) (10 dB) (–6 dB) Base-to-vehicle 40 2.73 1.78 14.16 Base-to-handset 15 1.11 0.66 6.43 Vehicle-to-base 40 8.73 5.47 38.11 Vehicle-to-handset 3 1.19 0.66 6.45 Handset-to-base 7.5 10.1 6.25 44.65 Handset-to-vehicle 1 3.82 2.44 17.53

A10.8 Conclusion Using Monte-Carlo simulators such as SEAMCAT allow various scenarios to be examined relatively quickly. The simulations discussed above are thought to represent typical worst case situations that might be encountered if a tactical service and amateur service coexist in the 50-54 MHz band. Notwithstanding that the co-channel interference probability is low in some cases and moderate in others it would appear that any interference which is likely to occur would be transient, probably be in the same jurisdiction as the tactical system and could be handled by national provisions in place for the use of the radio spectrum, which might include bilateral or multilateral agreements in place with neighbouring countries.

Annex 11

Minimum Coupling Loss sharing study between amateur radio stations and governmental mobile systems

This Annex aims to evaluate to which extent an amateur radio transmitter would interfere with mobile radio equipment. This investigation is undertaken for different scenarios with a distinct set of parameters for each scenario, such as: antenna heights, topological conditions and emission masks of the amateur radio transmitter. The simulations are based on a minimum coupling loss approach. 100 Rep. ITU-R M.2478-0

A11.1 Propagation model Radio wave propagation is calculated for 3 different propagation scenarios representing flat as well as hilly terrain respectively mountainous environment. Detailed representation of the scenarios are shown in Attachment 2 to this Annex. Propagation effects are calculated according to the model of Recommendation ITU-R P.2001-2 (4). The results are subject to statistical fluctuations6. The calculated losses show values for a probability of 10% respectively 50% of all possible cases. At low probabilities, propagation effects such as tropospheric scattering become more important making the propagation loss decreasing. In ECC Recommendation T/R 25-08 “Planning criteria and coordination of frequencies for land mobile systems in the range 29.7-470 MHz” indicative coordination thresholds are calculated based on 10% propagation probability. However, in the following both the probability values of 10% and 50% are considered. Therefore the calculated values on a probability parameter of 50% indicate a somewhat optimistic interference scenario. No clutter loss is considered. As stated in Recommendation ITU-R P.2001-2, section 1.1, the model is believed to be most accurate for distances from about 3 km to 1 000 km. At shorter distances, the effect of clutter will tend to dominate unless the antenna heights are high enough to give an unobstructed path. It can be seen in section Appendix 4 to this Annex that the interference ranges are often significantly longer than 3 km. The antennas heights are 8 m or more for all type of amateur radio stations and for the base station victim receiver. Only the vehicular and the handset receiver antenna heights are below 8 m. The considered radio stations often operate in rural environment, where the clutter height can be assumed to be below 8 m. Therefore the calculation is somewhat conservative for short interference distances (d < 3 km) in the cases of handset and vehicular victim radio receivers.

A11.2 Global approach In order to evaluate the interference ranges of amateur radio transmitters for different propagation scenarios, the following calculation method is executed in four consecutive steps: 1 The required protection level is evaluated with a protection criterion of I/N = –6 dB based on ambient noise figure according to Recommendation ITU-R P.372-13 (5). 2 The radiated power for co- and adjacent channels is calculated. 3 The minimum required path attenuation is calculated to meet the required protection level. 4 The interference range is evaluated by means of the calculated minimum path attenuation and evaluated path attenuation for six different propagation scenarios, respectively path profiles.

A11.3 Protection criterion and ambient noise figure For mobile radios, a protection criterion of I/N = –6 dB is specified. According to Recommendation ITU-R P.372-13 (5), natural background noise (dominated by galactic noise) corresponds to a noise figure of F = 15 dB at a frequency of 50 MHz. The maximum acceptable interference power for the mobile Service 푃푝푟표푡푒푐푡,is calculated as follows: 퐼 푃 = 푁 + 퐹푠 + 10 log(퐵푊) − 푝푟표푡푒푐푡 0 푁

6 With spherical diffraction, attenuation effects occur which depend on the gradient of the local dielectric characteristics of the environment. These are considered in the model as statistical parameters. Rep. ITU-R M.2478-0 101

where 푁0 is the thermal noise power at a temperature of 20°C, BW is the receiver bandwidth and Fs = 16.2 dB is the noise figure of the added ambient noise and receiver noise. Accordingly, the maximum acceptable interference power for mobile service application is calculated as follows: 푑퐵푚 −ퟏퟐퟏ. ퟖ 풅푩풎 = −174 + 16.2푑퐵 + 10log (16 푘퐻푧) − 6 푑퐵 퐻푧 The values for the ambient noise figure F defined in Recommendation ITU-R P.372-13 (5) relate to measurements with a vertical dipole or monopole antenna. In the given case, the victim antennas (mobile service) also show isotropic directivity in the azimuth, though with a gain which differs from the Recommendation's notional ideal antennas. However, because the ambient interference is substantially higher than the level of the receiver's internal noise, the gain of the victim antenna needs not be considered for calculation of ambient noise. It should also be noted that the assumed ambient noise figure of 15 dB for antennas with increased directivity in the horizontal direction has been set somewhat too high. If corresponding antennas (with increased directivity in the elevation) are used at the victim receiver, the computed interference ranges represent a minimum, as in this case galactic noise actually reduces receiver sensitivity by less than the determined 16.2 dB.

A11.4 Radiated power for co- and adjacent channels

The calculated transmit interference power 푃퐸 of amateur radio transmitters is determined on the basis of two different emission masks: Option 1 mask and Option 2 mask (Appendix 1 to this Annex). In the SSB interference study, consideration is given to the fact that the bandwidth of the receiver affected by the interference (16 kHz) is greater than that of the interference signal (3.0 kHz). The calculated interference powers at the transmitter output of the interference source, corrected for bandwidth, are shown in Appendix 3 to this Annex.

A11.5 Determination of minimum path attenuation The minimum path losses which are necessary to guarantee that the reception level of the interference signal remains below the value of the protection value are determined. Then, the minimum distance between the interfering transmitters and the victim receiver can be determined from the computed path loss curves.

The minimum path losses 퐴푆 is calculated as:

퐴푆 = 푃퐴푚푎푡 + 퐺퐴푚푎푡 + 퐵푊퐶표푟푟 − 푃표푙푚𝑖푠 − 푃푝푟표푡푒푐푡 where:

푃퐴푚푎푡: is the emission power of the amateur station, in dBm;

퐺퐴푚푎푡: is the Amateur station antenna gain, in dBi;

퐵푊퐶표푟푟: is a correction for calculation of power density, due to the fact that interferer and victim operate with a different signal bandwidth, it applies only if the interferer bandwidth is greater than the victim bandwidth 퐵푊퐶표푟푟 = 10 ∗ log (BWMob/ BWAmat), in dB;

푃표푙푚𝑖푠: is the polarization mismatch considered to be 3 dB for the SSB mode and 0 dB for FM and wideband modes. Because the ambient noise figure is higher than the receiver noise figure, the gain of the receiving antenna is not taken into account. 102 Rep. ITU-R M.2478-0

A11.6 MCL Results Achieved results are depicted in § 5.2.

Attachment 1 to Annex 11

Amateur radio transmission mask

The out of band emission masks of amateur equipment are defined in Recommendation ITU-R SM.1541-6 Annex 9 and are represented in Figs A11.1 and A11.2 for narrowband and wideband applications. Those masks are somewhat conservative definitions. Often, amateur radio transmitters exhibit smaller adjacent channel emissions than represented in Recommendation ITU-R SM.1541-6. In order to take this fact into account, an additional spectrum mask (Option 2) is defined for the compatibility studies to be carried out. This is plotted graphically in Figs A11.3, A11.4 and A11.5.

FIGURE A11.1 OoB emissions of amateur stations in operation above 30 MHz in the normal or narrowband applications as defined in Rec. ITU-R SM.1539-1 0

10 dB 10 RBW = 1 kHz

r

e

w

o

p 20

n

a

e

m

o 31 + 10 log P dB (P = 1), RBW = 1 kHz

t 30

e

v

i

t

a

l

e

r

) 40

B 38 + 10 log P (P = 1), RBW = 10 kHz

d

(

n

o

i

t

a 50

u

n

e

t t 58 dB - limit case forP  500 W

A

60 120% BN 225% BN 58 dB - limit case forP  500 W, RBW = 10 kHz

70 0 50 100 150 200 250

Frequency offset from the centre of the emission in percentage of necessary bandwidthBN

SM.1541-37 Rep. ITU-R M.2478-0 103

FIGURE A11.2 OoB emissions of amateur stations in operation above 30 MHz for wideband applications as defined in Rec. ITU-R SM.1539-1

For ‘spurious emissions’, the values specified in the ETSI standard EN 301 783 V.2.1.1 (1), as shown in Table A11.1, are used. The appropriate measurement bandwidths are specified in the respective standards as 100 kHz.

TABLE A11.1 Limit values for spurious emissions according to ETSI EN 301 783 V.2.1.1

It is not evident from ETSI standard EN 301 783 (1) how mobile SSB transmitters differ from other transmitters or when an item of equipment is classified as ‘mobile SSB equipment’. However, it is evident that ‘mobile SSB equipment’ with a transmitter power of more than 1 W causes ‘spurious emissions’ which are above the limit of other transmitters. It must also be assumed that in SSB operation the ‘spurious emissions’ decrease as the frequency spacing in relation to the carrier frequency increases. This is the nature of intermodulation 104 Rep. ITU-R M.2478-0 interference. Accordingly, one could assume that interference with very large frequency spacing in relation to the carrier frequency is well below the limit value.

FIGURE A11.3 Emission masks (e.i.r.p.) with reduced adjacent channel power for narrowband operation Emission mask (e.i.r.p.) at 3.0 kHz bandwidth and 9.4 dBi antenna 60 gain

50

40 ) 30

20

10 Option 1 0 Option 2 0 5 10 15 20

-10 power density power density (dBm/kHz -20

-30

-40 frequency (kHz)

FIGURE A11.4 Emission masks (e.i.r.p.) with reduced adjacent channel power for FM operation

FM emission mask (e.i.r.p.) at 16.0 kHz bandwidth and 2.5 dBi antenna 40 gain

30

20 ) 10

0 0 10 20 30 40 50 60 -10 option 1 -20 option_2

-30 power density power density (dBm/kHz -40

-50

-60 frequency (kHz)

Rep. ITU-R M.2478-0 105

FIGURE A11.5 Emission masks (e.i.r.p.) with reduced adjacent channel

Emission mask (e.i.r.p.) at 300 kHz bandwidth and 4 dBi antenna 30 gain

20

10

) 0 0 100 200 300 400 500 600 700 800 -10

-20 Option 1 Option 2 -30

-40 Power density(dBm/kHz

-50

-60

-70 frequency (kHz)

Attachment 2 to Annex 11

Propagation scenarios for MCL calculations

To determine path loss, the following model cases are calculated using the propagation model according Recommendation ITU-R P.2001: Scenario 1 • Flat terrain propagation condition • Probability in time = 10% • Interferer antenna height = 1 000 m, 20 m and 10 m • Victim antenna height= 1.5 m, 2 m, 8 m Scenario 2 • Flat terrain propagation condition • Probability in time = 50% • Interferer antenna height = 1 000 m, 20 m, 10 m • Victim antenna height = 1.5 m, 2 m, 8 m 106 Rep. ITU-R M.2478-0

Scenario 3 • Hilly terrain propagation condition for the propagation between the two Swiss cities Yverdon and Laufenburg • Probability in time = 50% • Interferer antenna height = 10 m • Victim antenna height 1.5 m Propagation effects are calculated according to the model of Recommendation ITU-R P.2001-2 (4). The results are subject to statistical fluctuations7. The calculated losses show values for a probability of 10% respectively 50% of all possible cases. At low probabilities, propagation effects such as tropospheric scattering become more important making the propagation loss decreasing. In ECC Recommendation T/R 25-08 “Planning criteria and coordination of frequencies for land mobile systems in the range 29.7-470 MHz” indicative coordination thresholds are calculated based on 10% propagation probability. However, in the following the probability values of 10% and 50% are considered. Therefore the calculated values on a probability parameter of 50% indicate a somewhat optimistic interference scenario. No clutter loss is considered. As stated in Recommendation ITU-R P.2001-2, section 1.1, the model is believed to be most accurate for distances from about 3 km to 1 000 km. At shorter distances, the effect of clutter will tend to dominate unless the antenna heights are high enough to give an unobstructed path. It can be seen in Attachment 4 to this Annex, that the interference ranges are often significantly longer than 3 km. The antennas heights are 8 m or more for all type of amateur radio stations and for the base station victim receiver. Only the vehicular and the handset receiver antenna heights are below 8 m. The considered radio stations often operate in rural environment, where the clutter height can be assumed to be below 8 m. Therefore the calculation is somewhat conservative for short interference distances (d < 3 km) in the cases of handset and vehicular victim radio receivers. Some path loss curves for the three above mentioned scenarios are shown in Figs A11.6 to A11.8. It is interesting to note, that in hilly terrain situations, the attenuation may be lower than in flat terrain situations, even in case of multiple bullington diffraction.

7 With spherical diffraction, attenuation effects occur which depend on the gradient of the local dielectric characteristics of the environment. These are considered in the model as statistical parameters. Rep. ITU-R M.2478-0 107

FIGURE A11.6 Path loss on flat terrain for time probability = 10% and the following antenna height parameters: red curve: Transmitter height = 1 000 m, receiver height = 8 m yellow curve: Transmitter height = 1 000 m, receiver height = 1.5 m blue curve: Transmitter height = 10 m, receiver height = 8 m green curve: Transmitter height = 10 m, receiver height = 1.5 m

180

170

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120

anttenuation [dB]anttenuation

110

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90

80 0 50 100 150 200 250 300 350 400 450 500 distance [km]

108 Rep. ITU-R M.2478-0

FIGURE A11.7 Path loss on flat terrain for time probability = 50% and the following antenna height parameters: red curve: Transmitter height = 1 000 m, receiver height = 8 m yellow curve: Transmitter height = 1 000 m, receiver height = 1.5 m blue curve: Transmitter height = 10 m, receiver height = 8 m green curve: Transmitter height = 10 m, receiver height = 1.5 m

180

170

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130

attenuation [dB]attenuation 120

110

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80 0 50 100 150 200 250 300 350 400 450 500 distanc [km]

Rep. ITU-R M.2478-0 109

FIGURE A11.8 Path loss and terrain profile for the scenarion Yverdon – Laufenburg. Receiver antenna height = 8 m, transmitter antenna height = 10 m, propagation time probability = 50%

160

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60 0 20 40 60 80 100 120 140 distance [km]

1400

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profile height [m]height profile 600

400 0 20 40 60 80 100 120 140 distance [km]

Attachment 3 to Annex 11

Radiated Power for Co-adjacent and spurious domain

The values calculated in Tables A11.2, A11.3 and A11.4 are based on emission power densities shown in Figs A11.3, A11.4 and A11.5. 110 Rep. ITU-R M.2478-0

TABLE A11.2 Bandwidth-corrected co – channel, adjacent channel and spurious domain interference from a SSB amateur radio transmitter to a mobile receiver with 16 kHz Bandwidth Interference emissions Power PE e.i.r.p. for mask Power PE e.i.r.p. for mask Option Option 1 (dBm) 2 (dBm) Same channel 50 dBm + 9.4 dBi 50 dBm + 9.4 dBi = 59.4 dBm = 59.4 dBm 1st adjacent channel –35.8 dBm/kHz + 10log(16) –35.8 dBm/kHz + 10log(16) = –23.8 dBm = –23.8 dBm BWRX = 16 kHz 2nd adjacent channel –35.8 dBm/kHz + 10log(16) –35.8 dBm/kHz + 10log(16) = –23.8 dBm = –23.8 dBm BWRX = 16 kHz Spurious -(43 dBc + 17 dBW) = –35.8 dBm/kHz + 10log(16) –35.8 dBm/kHz + 10log(16) –60 dB = –23.8 dBm = –23.8 dBm Measurement BW = 100 kHz BWRX = 16 kHz

TABLE A11.3 Bandwidth-corrected co – channel, adjacent channel and spurious domain interference from a wideband amateur radio transmitter to a mobile receiver with 16 kHz Bandwidth Interference emissions Power PE e.i.r.p. for mask option 1 Power PE e.i.r.p. for mask option 2 (dBm) (dBm) Same channel 26.2 dBm/kHz + 10log(16) 26.2 dBm/kHz + 10log(16) = 38.2 dBm = 38.2 dBm 1st adjacent channel 26.2 dBm/kHz + 10log(16) 26.2 dBm/kHz + 10log(16) = 38.2 dBm = 38.2 dBm 2nd – 6th channel 26.2 dBm/kHz + 10log(16) 26.2 dBm/kHz + 10log(16) = 38.2 dBm = 38.2 dBm

7th – 12th channel 16.2 dBm/kHz + 10log(16) = 28.2 dBm 1.2 dBm/kHz + 10log(16) = 13.2 dBm

Spurious 16th – 30th –48.8 dBm/kHz + 10log(16 kHz) –48.8 dBm/kHz + 10log(16 kHz) channel = –36.8 dBm = –36.8 dBm

Rep. ITU-R M.2478-0 111

TABLE A11.4 Bandwidth-corrected co – channel, adjacent channel and spurious domain interference from a FM amateur radio transmitter to a mobile receiver with 16 kHz Bandwidth Interference emissions Power PE e.i.r.p. for mask Option 1 Power PE e.i.r.p. for mask Option 2 (dBm) (dBm) Same channel 43 dBm + 2.5 dBi 43 dBm + 2.5 dBi = 45.5 dBm = 45.5 dBm 1st adjacent channel 23.5 dBm/kHz + 10*log(2.2) 8.5 dBm/kHz + 10*log(2.2) = 26.9 dBm = 11.9 dBm BWRX = 16 kHz 2nd adjacent channel –56.6/kHz + 10(16) –56.6 dBm/kHz + 10(16) = –44.6 dBm = –44.6 dBm BWRX = 16 kHz Spurious 60 dB –56.6 dBm/kHz + 10log(16) –56.6 dBm/kHz + 10log(16) =-44.6 dBm = –44.6 dBm BWRX = 16 kHz

Attachment 4 to Annex 11

Minimum required path loss

The values for the minimum required path loss for co- and adjacent channel scenarios considering the different type of amateur applications are shown in Tables A11.5, A11.6 and A11.7.

TABLE A11.5 Minimum path loss necessary to protect the mobile radio receiver from amateur service wideband transmitter interference Interference scenario Necessary path loss AS1 for mask Necessary path loss AS2 for mask Option 1 (dB) Option 2 (dB) Same channel – 6th channel 38.2 dBm + 121.8 dBm = 160 dB 38.2 dBm + 121.8 dBm = 160 dB

7th – 12th channel 28.2 dBm + 121.8 dBm = 150 dB 13.2 dBm + 121.8 dBm = 135 dB

16th – 30th channel –36.8 dBm + 121.8 dBm = 85 dB –36.8 dBm + 121.8 dBm = 85 dB

112 Rep. ITU-R M.2478-0

TABLE A11.6 Minimum path loss necessary to protect the mobile radio receiver from amateur service SSB transmitter interference Interference scenario Necessary path loss AS1 for mask Necessary path loss AS2 for mask Option 1 (dB) Option 2 (dB) Same channel 59.4 dBm + 121.8 dBm – 3 dB 59.4 dBm + 121.8 dBm – 3 dB = 178.2 dB = 178.2 dB 1st adjacent channel –23.8 dBm + 121.8 dBm = 98 dB –23.8 dBm + 121.8 dBm = 98 dB 2nd adjacent channel –23.8 dBm + 121.8 dBm = 98 dB –23.8 dBm + 121.8 dBm = 98 dB Spurious –23.8 dBm + 121.8 dBm = 98 dB –23.8 dBm + 121.8 dBm = 98 dB

TABLE A11.7 Minimum path loss necessary to protect the mobile radio receiver from amateur service FM transmitter interference Interference scenario Necessary path loss AS1 for mask Necessary path loss AS2 for mask Option 1 (dB) Option 2 (dB) Same channel 45.5 dBm + 121.8 dBm = 167.3 dB = 45.5 dBm + 121.8 dB = 167.3 dB 1st adjacent channel 26.9 dBm + 121.8 dB = 148.7 dB 11.9 dBm + 121.8 dB = 133.6 dB 2nd adjacent channel –44.6 dBm + 121.8 dB = 77.2 dB –44.6 dBm + 121.8 dB = 77.2 dB Spurious –44.6 dBm + 121.8 dB = 77.2 dB –44.6 dBm + 121.8 dB = 77.2 dB

Annex 12

Radio Interference coverage mapping

This annex considers plotting the interference created by an amateur station on a real geographic map in order to better visualise and interpret the propagation phenomena. To do so, we place an amateur station in a given geographical location, and then compute the amount of interference created by this station in the adjacent geographical location area. Maximum allowed emission powers, and maximum antenna gains are taken into account for amateur stations. The antenna patterns are considered to be omnidirectional in order to evaluate the impact in all the direction. Regarding the mobile (victim), only the base station is considered as it has the maximum antenna gain and the higher height. A propagation probability Tpc = 50% is considered, indicating that during 50% of time the interference level could be higher than the evaluated ones. As stated in § 2.3, this represents somehow an optimistic interference scenario. Even with this optimistic value, in the results section it will be observed that large areas are interfered, this will obviously be worsen with a Tpc = 10%. Note that only co-channel operation is taken into account. The maximum level of interference computed in § A11.3 remains valid for this section. Rep. ITU-R M.2478-0 113

Below are summarized the parameters that are used for the production of radio interference coverage maps: – SSB mode: Emission power = 50 dBm, Antenna gain = 9.4 dBi, Antenna height = 10 m, omnidirectional, polarization horizontal, bandwidth = 3 kHz; – FM mode: Emission power = 43 dBm, Antenna gain = 2.5 dBi, Antenna height = 10 m, omnidirectional, polarization vertical, bandwidth = 16 kHz; – Wideband Digital: Emission power = 47 dBm, Antenna gain = 4 dBi, Antenna height = 10 m, omnidirectional, polarization vertical, bandwidth = 300 kHz; – Mobile Base Station: omnidirectional, Antenna height = 8 m, bandwidth = 16 kHz.

A12.1 Determination of the interference level The interference level created by the amateur station is computed each 0.02° point in latitude/longitude, using the same approach described in § 3.3, i.e.:

퐼 = 푃퐴푚푎푡 + 퐺퐴푚푎푡 + 퐵푤퐶표푟푟푒푐푡푖표푛 − 퐿푃푟표푝푔푎푡푎𝑖표푛 − 푃표푙푚𝑖푠 dBm where 퐿푃푟표푝푔푎푡푎𝑖표푛 is the propagation loss computed using Recommendation ITU-R P.2001-2, and the numerical terrain profile SRTM (Shuttle Radar Topography Mission, 90 metres resolution, provided by NASA8). Because the ambient noise figure is higher than the receiver noise figure, the gain of the receiving antenna is not taken into account.

A12.2 Simulation results Simulations were conducted for different terrain nature in order to observe and to appreciate the different propagation phenomena, namely: – Yverdon-Les-Bains (Switzerland, Latitude: 46.7833° Longitude: 6.65°); – Aachen (Germany, Latitude: 50.77664°, Longitude: 6.08342°); – Faux d’Enson (Switzerland, Latitude: 47.363056°, Longitude: 6.958889°). – Vallon-En-Sully (France, Latitude: 46.5333°, Longitude: 2.6°). For each coverage map, a colour map level is always depicted near the figures. The unit of the colour map is in dBm. All levels in red are the ones with received interfering power higher than –60 dBm. Geographical areas not coloured are the areas where the received interfering power is less than the maximum acceptable interfering power (–121.8 dBm). Please note that due to the symmetry of Recommendation ITU-R P.2001 the propagation model, an interfered point would at it turn create interference to the transmitter point if the roles would be inverted.

A12.3 Results for Yverdon-Les-Bains Switzerland Results for Yverdon-Les-Bains are depicted in Figs A12.1, A12.2 and A12.3. For the SSB mode, we can observe that areas situated, on average, at 240 km can be interfered. In some cases, given the terrain profile, and due to occurrence of some propagation phenomena, this distance can achieve more than 350 km as depicted before in the MCL studies. In Fig. A12.4, we depicted the terrain profile from Yverdon (Switzerland) to Milan (Italy). In the SSB mode, Milan is one of the interfered cities, when considering Fig. 4, with this scenario ti can be

8 https://www2.jpl.nasa.gov/srtm/. 114 Rep. ITU-R M.2478-0 checked that different types of propagation phenomena like spherical diffraction line of sight but also Bullington diffraction intervene with different weights. The separation distances are smaller for the FM Mode and the Wideband Digital mode: they are of 200 km on average for FM mode and less than that for the Wideband digital. This is mainly first due to the fact that the e.i.r.p. values are lower than for SSB mode. More than that, for the wideband digital mode, the bandwidth factor cuts the power seen by the smaller bandwidth of the Mobile Base Station. Once again the obtained distances match the one computed in the MCL assessment previously presented in this Annex. However, even if smaller distances are achieved with the Wideband Digital Mode, one should note that it creates interference on large portion of the frequency spectrum dedicated to the Mobile, as already explained in the MCL section.

FIGURE A12.1 Interference caused by an amateur station located at Yverdon (Switzerland) emitting with SSB mode on a Mobile Base station. Coloured areas are the interfered areas

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FIGURE A12.2 Interference caused by an amateur station located at Yverdon (Switzerland) emitting with FM mode on a Mobile Base station. Coloured areas are the interfered areas

FIGURE A12.3 Interference caused by an amateur station located at Yverdon (Switzerland) emitting with Wideband digital mode on a Mobile Base station. Coloured areas are the interfered areas

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FIGURE A12.4 Path from Yverdon to Milan, Top: Different path losses for Tpc = 50%, Bottom: Path profile, Polarization Horizontal

A12.4 Results for Aachen (Germany) Results for Aachen (Germany) are depicted in Figs A12.5, A12.6 and A12.7. In this scenario, the city of Aachen is at about 260 m Altitude where in the neighbouring area studied, the maximum altitude encountered is around Willingen with more than 700 m altitude. The variation in the path profile does not depict a large fluctuation. For SSB mode, only part of Germany and the Netherlands are interfered, while the whole Belgium and Luxembourg suffer from interference. The North east border of France is also touched. Maximum separation distance can achieve 270 km. In this case, it can be clearly observed that the interfered areas shrunken for the FM and Wideband digital modes. The maximum required distances are about 190 km (Amsterdam) for the FM mode and 160 km for Wideband Digital mode (Oud-Beijerland). Rep. ITU-R M.2478-0 117

FIGURE A12.5 Interference caused by an amateur station located at Aachen (Germany) emitting with SSB mode. Coloured areas are the interfered area

FIGURE A12.6 Interference caused by an amateur station located at Aachen Germany emitting with FM mode. Coloured areas are the interfered area

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FIGURE A12.7 Interference caused by an amateur station located at Aachen (Germany) emitting with Wideband digital mode. Coloured area are the interfered area

A12.5 Results for Faux d’Enson (Swiss/French border) Results for Faux d’Enson (Swiss/French border) are depicted in Figs A12.8, A12.9 and A12.10. Faux d’Enson is at 927 m altitude, such altitude allows it to have a wide radio coverage. For instance, using SSB mode, an amateur station could interfere up to Paris (380 km far), with severe levels of interference up to 150 km around. Parts of France, Switzerland, Germany Luxembourg, Liechtenstein and Austria are interfered. Again, for FM and wideband digital these areas are shrunken as depicted in the Figures below. For convenience of the reader and for understanding the different phenomena, in Fig. A12.11 is plotted the path profile from Faux d’Enson to Paris and the different propagation losses. Rep. ITU-R M.2478-0 119

FIGURE A12.8 Interference caused by an amateur station located at Faux d’Enson (Swiss/French border) emitting with SSB mode. Coloured areas are the interfered area

FIGURE A12.9 Interference caused by an amateur station located Faux d’Enson (Swiss/French border) emitting with FM mode. Coloured areas are the interfered area

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FIGURE A12.10 Interference caused by an amateur station located at Faux d’Enson (Swiss/French border) emitting with Wideband digital mode. Coloured area are the interfered area

FIGURE A12.11 Faux d'Enson to Paris path. Top: Different propagation losses, bottom: path profile

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A12.6 Results for Vallon-En-Sully (France) The final area studied in this Annex is cantered in Vallon-En-Sully in the centre of France. Vallon- En-Sully is at 208 m altitude. For the SSB mode, we can observe that interference up to 300 km can be encountered up to Paris. Again, for FM mode this interference range is shrunken to 200 km and to 140 km. Being in the centre of the country, only interference in France is encountered.

FIGURE A12.12 Interference caused by an amateur station located at Vallon En Sully (France) emitting with SSB mode. Colored areas are the interfered area

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FIGURE A12.13 Interference caused by an amateur station located at Vallon En Sully (France) emitting with FM mode. Colored areas are the interfered area

FIGURE A12.14 Interference caused by an amateur station located at Vallon En Sully (France) emitting with WBD mode. Colored areas are the interfered area

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Annex 13

Amateur service vs. Mobile service Monte-Carlo study details

The Monte-Carlo approach used in this annex consists in localising a mobile station in a given area with a fixed operational frequency, and then spread a certain number of amateurs station around it. Those amateurs are scattered within a certain range according to propagation effects and attributed different frequency channels (thus different incident power to the victim) and different azimuths. The aggregated interference to the mobile is than computed. This process is repeated a certain number of times and a cumulative distribution function is deduced.

A13.1 Determination of the interference level The interference level created by the amateur stations surrounding the mobile is computed according to the following equation: 푁 퐴푚푎 푃퐴푚푎,𝑖+퐺퐴푚푎,푖+퐵푤퐶표푟푟푒푐푡푖표푛−퐿푃푟표푝,푖−푃표푙푚푖푠 퐼 = 10 ∗ log10(∑𝑖=1 10 ) dBm (1) where:

푁퐴푚푎: total number of amateur station surrounding the mobile victim

푃퐴푚푎,𝑖: is the emission power of the ith amateur station, in dBm

퐺퐴푚푎,𝑖: ith amateur station antenna gain, in the direction of the mobile station in dBi

퐵푊퐶표푟푟: correction factor for calculation of power density, due to the fact that interferer and victim operate with a different signal bandwidth, it applies only if the interferer bandwidth is greater than the victim bandwidth 퐵푊퐶표푟푟 = 10 ∗ log (BWMob/BWAmat), in dB

푃표푙푚𝑖푠: polarization mismatch considered to be 3 dB for the SSB mode and 0 dB for FM and wideband modes

퐿푃푟표푝,𝑖: propagation Loss from the ith amateur station to the mobile victim, in dB. Because the ambient noise figure is higher than the receiver noise figure, the gain of the receiving antenna is not taken into account.

A13.2 Amateur service characteristics The amateur service transmitter parameters are extracted from Table 9 of this Report.

A13.3 Propagation Model Radio wave propagation is calculated according to the model of Recommendation ITU-R P.2001-2. No clutter loss is considered. As stated in Recommendation ITU-R P.2001-2, section 1.1, the model is believed to be most accurate for distances from about 3 km to 1000 km. At shorter distances, the effect of clutter will tend to dominate unless the antenna heights are high enough to give an unobstructed path. It can be seen later, that the interference ranges are often significantly longer than 3 km. The antennas heights are 8 m or more for all type of amateur radio stations and for the base station victim receiver. The considered radio stations often operate in rural environment, where the clutter height can be assumed to be below 8 m. 124 Rep. ITU-R M.2478-0

Regarding the terrain profile, our simulations are based on and the numerical terrain profile SRTM (Shuttle Radar Topography Mission, 90 meters resolution, provided by NASA9). Note that the terrain profile is deduced for each path between each amateur station and the victim mobile station. Note that the percentage of time used in the simulations is not fixed, but randomly chosen from 1-99%, since dealing with a Monte Carlo simulation, and that the amateur see the mobile in different propagation conditions.

A13.4 Protection criterion and ambient noise figure For mobile radios, a protection criterion of I/N = – 6 dB is specified. According to Recommendation ITU-R P.372-13 and ITU-R M.1808, natural background noise (dominated by galactic noise) corresponds to a noise figure of F = 15 dB at a frequency of 50 MHz. The maximum acceptable interference power for the mobile Service 푃푝푟표푡푒푐푡,is calculated as follows: 퐼 푃 = 푁 + 퐹푠 + 10 log(퐵푊) − 푝푟표푡푒푐푡 0 푁 where 푁0 is the thermal noise power at a temperature of 20°C, BW is the receiver bandwidth and Fs = 16.2 dB is the noise figure of the added ambient noise and receiver noise. Accordingly, the maximum acceptable interference power for mobile service application is calculated as follows: 푑퐵푚 −ퟏퟐퟏ. ퟖ 풅푩풎 = −174 + 16.2푑퐵 + 10log (16 푘퐻푧) − 6 푑퐵 퐻푧 The values for the ambient noise figure F defined in Recommendation ITU-R P.372-13 relate to measurements with a vertical dipole or monopole antenna. In the given case, the victim antennas (mobile service) also show isotropic directivity in the azimuth, though with a gain which differs from the Recommendation's notional ideal antennas. However, because the ambient interference is substantially higher than the level of the receiver's internal noise, the gain of the victim antenna needs not be considered for calculation of ambient noise. It should also be noted that the assumed ambient noise figure of 15 dB for antennas with increased directivity in the horizontal direction has been set somewhat too high. If corresponding antennas (with increased directivity in the elevation) are used at the victim receiver, the computed interference ranges represent a minimum, as in this case galactic noise actually reduces receiver sensitivity by less than the determined 16.2 dB.

A13.5 Amateurs Emission masks/Mobile reception mask Amateurs masks are designed as per Recommendations ITU-R SM.1541-6 Annex 9, ITU-R SM.329- 12 and ETSI EN 301 783. A second option (option 2) is also studied by adding 15 dB attenuation for the first floor OoB emission. The Mobile reception mask is considered to be perfect (rejecting all interference coming out of the 16 kHz mobile bandwidth).

A13.6 SSB Case According the IARU frequency plan for the 50-52 MHz band, the SSB operating range is 50.105-50.250 MHz. The following algorithm is adopted:

9 https://www2.jpl.nasa.gov/srtm/. Rep. ITU-R M.2478-0 125

A13.6.1 Proposed algorithm and used parameters – Step 1: Attribute a fixed operating frequency to the mobile (victim), in our simulation the centre frequency of SSB range is used, namely, f_m = 50.1783 MHz. This frequency will be fix all over the Monte-Carlo runs. – Step 2: Localise the mobile, in our simulations Vallon-En-Sully in France (46.5333°, 2.6°) has been chosen. This localisation is fixe all over the Monte-Carlo runs. – Step 3: Precise the area of simulation, carry out coverage simulation to determine the geographical area from where amateurs could create potential interference to the mobile. Using google map measurement tool, insert a circle cantered at the mobile position which could cover the largest possible interference area, than, deduce its radius. For Vallon-En- Sully example, a circle of 200 km can be inserted in the interference area. The simulation will be carried out inside this 200 km circle.

FIGURE A13.1 Simulation area for a mobile centered in Vallon-En-Sully, SSB case (red circle)

– Step 4: Deduce the number of active channels (busy channels) this area, this is the number of active amateur without channel redundancy. It is computed thanks to the algorithm described in § 3.7 of this Report. When using a radius of 200 km for the SSB mode, it is found that 19 amateurs are active within this area. 126 Rep. ITU-R M.2478-0

FIGURE A13.2 Number of active amateurs within 200 km using SSB mode

Global variables Density of amateurs (average over all Europe) 0,073 km-2 Fraction of amateurs using the band 0,08 Session duration (hours/year) based on 2 hours a day 730 Observation window (hours/year) 8760 Fraction of time transmitting within a single session (= 0.5 if PTT considered) 0,5 SSB Application Variables Variable Name App 1 Contact range at usable SNR 200 Fraction of amateurs using specific application who are using the band (must all add up to 1) R_App 0,6 Channel bandwidth (analog) 3 Number N/A

Calculations Density of amateurs (average over all Europe) D_A 0,073 Cell size==service area (assuming circular area) Cell size (area) 125663,71 Fraction of amateurs using the band R_A_50_54 0,08 Session duration (hours/year) based on 2 hours a day (All time busy for repeaters, beacons and infrastructure) T_session 730 Fraction of time transmitting within a single session F_activity 0,5 Observation window (hours/year) W 8760 Number of amateurs or transmitters per km2 per application 0,003504 Number of amateurs in cell using specific application Nb_Amateur_Cell 440,32563 Spectrum required within cell for application - not averaged over time BW_app 1320,9769 Bandwidth occupied as function of time for application Occup_BW_app 55,040703 Number of integer channels required (i.e. Occup_BW_app/Channel Bandwidth) 19 – Step 5: Scatter randomly 19 amateurs stations inside the circle of 200 km.

FIGURE A13.3 Example of one shot scattering of 19 amateurs (circles) around one mobile station (diamond) inside a circle of 200 km

– Step 6: Attribute to each amateur a frequency channel. To do so it is required to create a frequency plan for the SSB channel. In the band 50.105-50.250 MHz, we need to center channels each 3 kHz. Meaning: (50.1065 50.1095 50.1125 50.1155 50.1185 50.1215 50.1245 …). Than choose random 19 random channels from these 48 channels. Rep. ITU-R M.2478-0 127

FIGURE A13.4 Random attribution among the 48 channels

Ch1 Ch2 Ch3 Ch4 Ch5 Ch6 Ch7 … Ch44 Ch45 Ch46 Ch47 Ch48 – Step 7: Attribute to each amateur a random azimuth (from the north); the amateur antenna used in the simulation is the one depicted in Fig. A13.1. – Step 8: Compute the aggregate interference to the mobile according to equation (1). – Step 9: Get back to Step 5 and repeat the process 10 000 times. – Step 10: Create the CDF of all stored interference in dBm.

A13.6.2 Simulation results for SSB The obtained simulation results for the SSB case are depicted in Fig. A13.5 (Option 1). The protection criterion of –121.8 dBm is exceeded for 86.5% of the time for the option 1 mask, and 86.16% of the time for option 2 mask.

FIGURE A13.5 Inverse cumulative CDF for the SSB case

In order to assess the impact of the number of amateurs on the interference created to the mobile, we carried out a bunch of simulation when varying the number of active amateurs within the vicinity of the mobile. The results are depicted in Figure 13.6. It can be logically observed that amount of interference reduces according to the number of active amateur stations. For 14 amateurs the probability of interference is of 75.45%, for 10 users it is 62.77%, 38.18% for 5 users, 17.21% for 2 user and only 8.49% for one user. 128 Rep. ITU-R M.2478-0

FIGURE A13.6 Impact of the amateur number on the interference under mask Option 2

It is also considered a scenario where a protection distance was imposed on the amateurs. This protection distance is centered at the mobile position. In that case the amateurs are scattered inside a crown delimited by the protection distance diameter and the simulation radius diameter.

FIGURE A13.7 Example of amateurs scattering when considering a protection distance of 90 km

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One should note that the application of a separation distance could be very difficult given that the land mobile has to operate in unknown places without notice. Table A13.1 depicts a summary of the obtained results.

TABLE A13.1 Summary of the interference probability for different users and different considered protection distances, Option mask 2

Number of users inside 200 km circle area

1 2 5 10 14 19

None 8.49% 17.21% 38.18% 62.77% 75.45% 86.5%

10 7.46% 14.35% 31.99% 55.04% 68.47% 80.2% 30 6.35% 11.58% 26.77% 47.78% 61.62% 73.73% 50 5.06% 9.05% 22.86% 41.76% 53.84% 65.82% 70 4.1% 8.57% 19.36% 36.75% 48.12% 58.94% 90 3.59% 6.77% 16.6% 31.56% 42.58% 52.8%

Protection distance Protection 100 3.54% 6.57% 15.33% 29.10% 40.28% 51.1%

A13.7 FM case According the IARU frequency band plan for the 50-52 MHz band, the FM operating range is 51.210-51.390 MHz. A13.7.1 Proposed algorithm and used parameters The same algorithm adopted for the SSB case is used for the FM, except that: – The Mobile is still localized in Vallon En Sully; its centre frequency is f_m = 51.3 MHz. – Regarding the simulation area, coverage processing shows that a circle of 120 km is required for the FM case. Please note that distance is not inherent to the amateur contact range distance, which depends only on the amateurs’ characteristics and the propagation conditions. The simulation radius depends on the amateur’s emission characteristics, but also on the land mobile reception characteristics and of course, on the propagation conditions. 130 Rep. ITU-R M.2478-0

FIGURE A13.8 Simulation area for the FM case (red circle)

– According to doc PTD(18)017, only one amateur is active within this area. – A discrete frequency plan for amateurs is created within the 51.210-51.390 MHz band, namely 7 channels centred at (51.2225 51.2475 51.2725 51.2975 51.3225 51.3475 51.3725). – The amateur antenna is an omnidirectional antenna with 2.5 dBi gain.

A13.7.2 Simulation results The obtained simulation results for the FM case are depicted in Fig. A13.9 (Options 1 and 2). The protection criterion of –121.8 dBm is exceeded for 37.25% of the time for the Option 1 mask, and 28.31% of the time for Option 2 mask. Rep. ITU-R M.2478-0 131

FIGURE A13.9 Inverse cumulative CDF for the FM case, for both Options mask 1 and 2

Simulations were also carried-out when applying a varying protection distance. The inverse CDF of the received interference is depicted in Fig. A13.10. The corresponding probabilities to exceed the interference threshold are summarized in Table 5.

FIGURE A13.10 Inverse CDF of the received interference for different protection distances, FM case, Option mask 2

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TABLE A13.2 Probability of interference according to the applied protection distance, FM case, mask Option 2, only one amateur is active within the 120 km circle area Protection distance (km) None 10 30 50 70 90 Probability of interference 28.31% 23.7% 16.54% 13.53% 11.35% 9.85%

In Table A13.3, a case is considered where the simulation radius is reduced to 70 km. This distance corresponds to the communication range given by the amateurs for the FM mode. Please note again, that this distance is different from the interference range.

TABLE A13.3 Probability of interference according to the applied protection distance, FM case, mask Option 2, only one amateur is active within the 70 km circle area Protection distance (km) None 10 30 50 Probability of interference 37.57% 30.08% 22.9% 17.68%

A13.8 Wideband Digital A13.8.1 Considered scenario In this case, a simulation area of 70 km is considered (see Fig. A13.11), as provided by the interference coverage simulation. In the absence of the antenna pattern for the 4 dBi directional antenna, a 2.5 dBi omni-directional antenna is used. The simulation scenario in this case is different from the two previous ones. One amateur station active in the 70 km circle area is considered, then the probability of interference created into the mobile station is computed, in the case where the mobile station is active within a channel situated in band, 1st floor OoB, 2nd floor OoB, 3rd floor OoB or Spurious domain of the amateur emission. Rep. ITU-R M.2478-0 133

FIGURE A13.11 Simulation area for the WB digital case (red circle)

A13.8.2 Simulation results The obtained results are summarized in Table A13.4.

Table A13.4 Simulation results for the WB digital case 1st floor OoB 11th to Inband up to 2nd floor OoB 21th to 3rd floor OoB 26th to 20th channel, Spurious 10th channel 25th channel 50th channel M1|M2 None 93.65% 78.90%|50.13% 10.81% 3.15% 0.85% 10 km 91.14% 73.15%|37.45% 0.40% 0.01% 0% 30 km 86.37% 55.98%|11.85% 0.04% 0% 0% 50 km 75.92% 38.80%|2.72% 0.01% 0% 0%

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Annex 14

Sharing with the radiolocation service (WPR)

A14.1 Background In the frequency band 46-68 MHz, RR No. 5.162A provides an additional allocation to the radiolocation service on a secondary basis in a number of countries and limited to the use of wind profiler radars. 5.162A Additional allocation: in Germany, Austria, Belgium, Bosnia and Herzegovina, China, Vatican, Denmark, Spain, Estonia, the Russian Federation, Finland, France, Ireland, Iceland, Italy, Latvia, The Former Yugoslav Republic of Macedonia, Liechtenstein, Lithuania, Luxembourg, Monaco, Montenegro, Norway, the Netherlands, Poland, Portugal, the Czech Rep., the United Kingdom, Serbia, Slovenia, Sweden and Switzerland the band 46-68 MHz is also allocated to the radiolocation service on a secondary basis. This use is limited to the operation of wind profiler radars in accordance with Resolution 217 (WRC-97). (WRC-12) The relevant Wind profiler radars parameters for sharing studies with amateur service are described in Table A14.1.

TABLE A14.1

System parameter Range of values Pulse peak power (kW) 5 – 60 Average transmitted power (kW) 0.5 – 5 Main beam antenna gain (dBi) 30 – 34 Antenna beamwidth (degree) 4 – 6 Main pointing elevation angle (degree) 90 (zenith) Tilt angle from main pointing (degree) 11 – 16 Antenna side-lobe suppression between 0 and 5° compared to horizon (dB) 33 (minimum) – 40 (Median) Antenna height (m) 1 Pulse width (µs) 1 – 10 Necessary bandwidth (MHz) 0.2 – 2.2 Occupied bandwidth (MHz) 0.5 – 5 Protection criteria (I/N)(dB) –6 Noise figure (dB) 3 Maximum interference level in necessary bandwidth (dBW) –154 (for 0.2 MHz bandwidth) –144 (for 2 MHz bandwidth)

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A14.2 WPR location and parameters

FIGURE A14.1 Identified VHF WPR systems in Europe (red = in 50-54 MHz, green = out of band)

TABLE A14.2 WPR locations parameters

Power WMO Site Latitude Longitude Freq. Power Pk Antenna Beam Avg Sitename mean No , N , E (MHz) (kW) gain width mins (kW) Kühlungsborn (OSWIN) 54.1183 11.7690 53.50 4.5 90.0 30.0 6.0 (Germany) South Uist (UK) 03019, 03020, 57.3536 –7.3752 64.00 4 .0 40.0 29.0 4.5 15/30 03021, 03022 Abersywyth (NERC- 3501 52.4245 –4.0055 46.50 2.5 100 (typ.) 35 .0 3.0 30 MST) (UK) 160.0 (max.) Clermont-Ferrand 7453 45.7125 3.0903 45.00 0.8 5.0 30.0 5.5 (France) Lannemezan (France) 7626 43.1290 0.3660 45.00 0.8 5.0 30.0 5.5 15 Kiruna (Esrange) 2043 67.8865 21.1065 52.00 72.0 29.0 6.7 30 (Sweden) Andenes MAARSY- 1012 69.2980 16.0420 53.50 40.0 800.0 33.5 3.6 MST (Norway) SOUSY Svalbard Radar 78.1530 16.0300 53.50 0.2 2.0 30.0 5 (Norway) Rome (Ciampino) (Italy) 16239 41.8080 12.5850 65.50 ? ? ?

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TABLE A14.3 WPR parameters used for study

System parameter Range of values Pulse peak power (kW) 2 – 800 Average transmitted power (kW) 0.2 – 72 Main beam antenna gain (dBi) 29 – 35 Antenna beamwidth (degrees) 3 – 7 Main pointing elevation angle (degrees) 90 (zenith) Tilt angle from main pointing (degrees) 11 – 16 Antenna side-lobe suppression between 0 and 5° compared to horizon (dB) 33 (minimum) – 40 (Median) Pulse width (µs) 1 – 10 Necessary bandwidth (MHz) 0.2 – 2.2 Occupied bandwidth (MHz) 0.5 – 5 Protection criteria (I/N)(dB) –6 Noise figure (dB) 3 Maximum interference level in necessary bandwidth (dBW) –154 (for 0.2 MHz bandwidth)

A14.3 In-band separation distances At a preliminary stage, it is proposed to assess separation distance between amateur service stations and WPR taking into account the following elements: – Amateur service stations typical e.i.r.p. ranging 2 to 26 dBW (see ITU-R M.1732 for both analogue and digital systems). – Amateur service stations typical bandwidth ranging 2.7 to 16 kHz (see ITU-R M.1732 for both analogue and digital systems). – WPR victim scenario. – Hata (rural) propagation model (at 52 MHz) (median case): Rep. ITU-R M.2478-0 137

It should be noted that the case of the Amateur systems antenna height of 1 000 m is not considered since it is not within the validity range of the E-Hata model. It should also be noted that considering the WPR antenna height of 1 m, such 1 000 m height would lead to a visibility distance of around 115 km (hence free space).

A14.4 Separation distances FM (F3E) case (only extreme distances are provided)

WPR Amateur Amateur Amateur WPR BW WPR antenna side Maximum Required Separation Amateur antenna Power Bandwidth bandwidth factor antenna lobe interference Isolation distance gain (dBi) height (dBW) (kHz) (MHz) (dB) gain (dBi) suppression level (dBW) (dB) (km) (m) (dB) 13 2.5 16 10 2 0 30 40 -143.96572 149.466 60 13 2.5 16 10 0.2 0 34 33 -153.96572 170.466 158 13 2.5 16 20 2 0 30 40 -143.96572 149.466 79 13 2.5 16 20 0.2 0 34 33 -153.96572 170.466 196 For the FM (F3E) case, the separation distances would be ranging: – 60 to 158 km (Amateur antenna height of 10 m). – 79 to 196 km (Amateur antenna height of 20 m). Wideband (omni) case (only extreme distances are provided)

WPR Amateur Amateur Amateur WPR BW WPR antenna side Maximum Required Separation Amateur antenna Power Bandwidth bandwidth factor antenna lobe interference Isolation distance gain (dBi) height (dBW) (kHz) (MHz) (dB) gain (dBi) suppression level (dBW) (dB) (km) (m) (dB) 17 2.5 300 10 2 0 30 40 -143.96572 153.466 73 17 2.5 300 10 0.2 1.7609 34 33 -153.96572 172.705 173 17 2.5 300 20 2 0 30 40 -143.96572 153.466 95 17 2.5 300 20 0.2 1.7609 34 33 -153.96572 172.705 214 138 Rep. ITU-R M.2478-0

For the Wideband (omni) case, the separation distances would be ranging: – 73 to 173 km (Amateur antenna height of 10 m). – 95 to 214 km (Amateur antenna height of 20 m). Wideband (directional) case

WPR Amateur Amateur Amateur WPR BW WPR antenna side Maximum Required Separation Amateur antenna Power Bandwidth bandwidth factor antenna lobe interference Isolation distance gain (dBi) height (dBW) (kHz) (MHz) (dB) gain (dBi) suppression level (dBW) (dB) (km) (m) (dB) 17 4 300 10 2 0 30 40 -143.96572 154.966 79 17 4 300 10 0.2 1.7609 34 33 -153.96572 174.205 184 17 4 300 20 2 0 30 40 -143.96572 154.966 102 17 4 300 20 0.2 1.7609 34 33 -153.96572 174.205 227 For the Wideband (directional) case, the separation distances would be ranging, when considering the Amateur station main beam: – 79 (case 1) to 184 km (case 2) (Amateur antenna height of 10 m). – 102 (case 3) to 227 km (case 4) (Amateur antenna height of 20 m). The following Figure provides, for the cases 1 to 4 above, the variation in separation distances vs azimuth taking into account the Amateur system relative gain according to the antenna pattern:

Rep. ITU-R M.2478-0 139

SSB (J3E) (directional) case

WPR Amateur Amateur Amateur WPR BW WPR antenna side Maximum Required Separation Amateur antenna Power Bandwidth bandwidth factor antenna lobe interference Isolation distance gain (dBi) height (dBW) (kHz) (MHz) (dB) gain (dBi) suppression level (dBW) (dB) (km) (m) (dB) 10 9.4 3 10 2 0 30 40 -143.96572 153.366 73 10 9.4 3 10 0.2 0 34 33 -153.96572 174.366 186 20 9.4 3 10 2 0 30 40 -143.96572 163.366 116 20 9.4 3 10 0.2 0 34 33 -153.96572 184.366 276 10 9.4 3 100 2 0 30 40 -143.96572 153.366 173 10 9.4 3 100 0.2 0 34 33 -153.96572 174.366 300 20 9.4 3 100 2 0 30 40 -143.96572 163.366 246 20 9.4 3 100 0.2 0 34 33 -153.96572 184.366 300 For the SSB (J3E) (directional) case, the separation distances would be ranging, when considering the Amateur station main beam: – 73 (case 5) to 186 km (Amateur antenna height of 10 m and 10 dBW Power). – 116 to 276 (case 6) km (Amateur antenna height of 10 m and 20 dBW Power). – 173 (case 7) to above 300 km (Amateur antenna height of 100 m and 10 dBW Power). – 246 to above 300 km (case 8) (Amateur antenna height of 100 m and 20 dBW Power). The following Figure provides, for the cases 5 to 8 above, the variation in separation distances vs azimuth taking into account the Amateur system relative gain according to the antenna pattern: 350

300

250

200

150

100 Separationidstance (km) 50

0

0 5

15 10 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95

170 100 105 110 115 120 125 130 135 140 145 150 155 160 165 175 180 Azimuth (°)

Case 5 Case 6 Case 7 Case _8

A14.5 Conclusions The above calculations show that typical separation distance between Amateur service systems and Wind profiler would range from 29 to distances above 300 km, confirming the need for specific protection measures. Taking into account the limited numbers of systems in or immediately adjacent to the frequency band 50-54 MHz range (and probably the expected low number of amateur systems in the vicinity of WPR 140 Rep. ITU-R M.2478-0 installations), sharing could probably be considered on a case-by-case basis e.g. coordination zones established in affected geographical areas. It has to be noted that this approach, currently, could only be possible and efficient if amateur and radiolocation services are of equal status within the 50-54 MHz band.

Annex 15

Spectrum needs evaluation based on spectrum monitoring

A15.1 Spectrum needs evaluation In Document 5A/599 it is indicated that the spectrum need can be calculated for different countries but the overall requirement should be based on at least average use, knowing that in the high population density areas, additional spectrum would be required when emergencies, public service, special events, contests and favorable anomalous propagation conditions occur. Therefore the spectrum need is calculated for average and high population density areas, taking into account everyday usage situations as well as exceptional usage situations where additional spectrum is required. Accordingly the spectrum needs are calculated for the following usage situations. – Situation A: Average use case, which represents situations of standard daily use and occurs with a probability of 98% in time. – Situation B: Where additional spectrum is required. This situation occurs e.g. during contests and special events. It is assumed, that contests and special events do not occur during more than 7 days a year. This corresponds to situation which occur with probability of less than 2% in time. Both usage situations are considered in calculations for European countries with a typical as well as with maximum amateur station density. The spectrum needs evaluation based on the application based approach, as presented in section 3.5 of the main body text, considers different parameters which need to be defined respectively derived. The derivation of the parameters for active amateur stations density and session duration is not straightforward but are of central importance. For this study, they are obtained through an analysis of IARU 2017 50 MHz contest log data together with the analysis of spectrum monitoring data as well as application of correction factors regarding the forecasted growth of the amateur radio community and propagation conditions. To obtain figures for future spectrum use and future conditions, the following data and procedures are used: – The number of active amateur stations for the Case A situation in a typical European country is evaluated based on spectrum monitoring results obtained through a measurement campaign which has taken place in the period of April to July 2018. It turns out, that for Case A the spectrum occupancy is well below 1%. – The session duration for an active amateur station in a Case A scenario is assumed to be 2h a day in average when about 3% of the existing amateur licenses are daily accessing the band 50-52 MHz. – The session duration for Case B is calculated based on the maximum duration of a two way contact during the IARU 2017 50 MHz contest. Therefore the evaluated figure for the session duration during contests may represent an overestimation. Rep. ITU-R M.2478-0 141

– The number of active amateur station for the case B is evaluated based through an analysis of IARU 2017 50 MHz contest log data. The spectrum monitoring results of the IARU 2018 50 MHz contest showed a lower activity than the activity of the IARU 2017 50 MHz contest (evaluated based on contest log data). This may be caused by significantly worse propagation conditions during the 2018 contest compared to the 2017 contest. Therefore, the monitoring data of the IARU 2018 50 MHz contest are disregarded for the spectrum needs analysis. When assuming a session duration as described above, it was found that the evaluated number of active amateur stations was 68% of the existing amateur licenses. – For the evaluation of the future need, the growth of the number for amateur licenses is linearly extrapolated to the year 2038. – It is shown, that the current spectrum use in the frequency band 50-52 MHz for the average, everyday use case is very low, while during contests a strong increase of the use can be observed, but only for narrow band modes. However, the use of the spectrum in the 50.5-52 MHz frequency band by all other modes like FM, RTTY, digital communication, etc. is always very low. Accordingly, for the determination of future requirements, the ratios of the case B are considered for narrowband applications, while for FM, repeaters, Infrastructure and Wideband modes the circumstances of daily use (case A) are considered. – It is shown, that the number of active amateur stations during the IARU 2017 50 MHz contest was significantly higher, than during the ‘big opening’ on the 28.05.2018. Therefore no data from this ‘big opening’ but only from the IARU 2017 50 MHz contest is considered for Case B spectrum needs evaluation. – Because future maximum solar activity may stimulate a more intense use of the band 50-52 MHz, the calculation for future spectrum needs considers in average 50% additional amateur activity due to high solar activity. – Figures for high amateur station populations are obtained based on data for average amateur population density corrected trough linear interpolation.

A15.2 Current amateur station activity and spectrum needs for the average use case According to the calculations in Attachment 1 to this Annex, the calculated minimum required bandwidth for a country with an average density of amateur stations are as depicted in Table A15.1.

TABLE A15.1 Current minimum required bandwidth for average populated European country during an average day, when only existing Amateur Radio applications are considered

Frequency Required bandwidth for average use Applications range case rounded up to multiple integers of (MHz) the application bandwidths

Existing applications Narrow band 50.0 – 50.5 3 kHz and Telegraphy

FM, Repeaters, 50.5 – 52.0 25 kHz Digital, etc.

An additional 3 kHz channel for the beacon HB9SIX operation is required. 142 Rep. ITU-R M.2478-0

When applying the formulas of the application based approach the value of the current amateur station density, which was active during the period of the spectrum monitoring campaign, can be calculated as shown below:

퐵푊푂퐶퐶푇표푏푠 1 퐴퐷푆푀 = 푇푆푒푠푠𝑖표푛푇푇푋퐵푊푎푝푝퐴푐푒푙푙퐹퐵푎푛푑퐹푎푝푝 푀푆_푀 2.57 푘퐻푧∙8760ℎ 1 = = 0.00311 730ℎ∙0.5∙3푘퐻푧∙196349.54푘푚2∙0.08∙0.6 0.7 where: 2 ADS_M density of amateur stations / km active during spectrum monitoring

BWocc bandwidth occupied as function of time for application

Tobs observation window (hours/year)

TSession session duration (hours/year) based on 2 hours a day

TTX fraction of time transmitting within a single session

BWapp channel bandwidth (analogue)

Acell cell sizeservice area (assuming circular area)

FBand fraction of amateurs using the band

Fapp fraction of amateurs using specific application who are using the band

MS_M_ minimum fraction. When calculating the spectrum needs for current average use the following parameters are taken into account. – Observation window, W for SSB, and FM 8 760 h – Observation window, W for Repeaters 8 760 h

– Session duration, Tsession for SSB, FM and WB 730 h

– Session duration, Tsession for Repeaters 8 760 h

– Fraction of time transmitting within a single session, Factivity 0.5 – Number of amateurs km2 0.002417 – Fraction of Amateurs using SSB, FM, Repeaters, 0.6, 0.05, 0.2. When using above mentioned parameters with application based approach, the following spectrum requirements numbers are obtained: – SSB 3 kHz – FM 25 kHz – Repeaters 50 kHz. An additional 3 kHz channel for the beacon operation may be required as explained in Attachment 1 to this Annex.

A15.3 Future spectrum needs for the average use case in a country with average amateur license density The future spectrum needs are calculated based on application based approach as shown in § 3.5 of the main body text, except the parameter for the amateur station density. The parameter value for the amateur station density used for the following calculation is based on the value applied for the calculation of the current spectrum need, but corrected with a forecasted growth of Amateur Station density within the following 20 years and an increase of Amateur station activity due to maximum solar activity periods expected in the next years. Rep. ITU-R M.2478-0 143

In 2017 there were 4 829 amateur licences, while in 2003 there were 4 501 amateur licenses counted in Switzerland. This represents a growth of 7.3% within 14 years. Accordingly for 20 years a 10.4% growth of amateur station density is considered to calculate the future spectrum needs. The solar activity in 2017 is at the level of about 30% compared to the activity maximum of the past solar activity cycle. It is assumed, that during a period with maximum solar activity the activity of the amateur stations increases by 50% in average. The above mentioned growth of the number of amateur stations and the increase of amateur activity of 50% is considered in the spectrum needs calculation, by correcting the amateur station density number according to the following method

퐴퐷푓푢푡푢푟푒 = 퐴퐷푆푀퐺푛푏푠푡푎푡𝑖표푛푠 퐺푎푐푡𝑖푣𝑖푡푦

퐴퐷푓푢푡푢푟푒 = 0.00311 ∙ 1.104 ∙ 1.5 = 0.00516 where: 2 ADfuture_SSB forecasted density of amateur stations / km 2 ADS_M density of amateur stations / km active during spectrum monitoring

Gnb_stations growth of the number of amateur licenses within 20 years

Gactivity increase of amateur activity due to periods of high solar activity. When calculating the spectrum needs for current average use the following parameters are taken into account. – Observation window, W for SSB, FM and WB 8 760 h – Observation window, W for Repeaters and Infrastructure 8 760 h

– Session duration, Tsession for SSB, FM and WB 730 h

– Session duration, Tsession for Repeaters and Infrastructure 8 760 h

– Fraction of time transmitting within a single session, Factivity 0.5 – Number of amateurs km2 0.004003 – Fraction of Amateurs using SSB, FM, WB, Repeaters, Infrastr. 0.6, 0.05, 0.05, 0.2, 0.1. When using the above mentioned parameters with application based approach, the following spectrum requirements numbers are obtained for Switzerland when considering the future amateur service applications “wide band mode” and “infrastructure”: – SSB 9 kHz – FM 25 kHz – Repeaters 100 kHz – Wide band modes 500 kHz – Infrastructure 500 kHz. An additional 3 kHz channel for the beacon operation may be required as shown in Attachment 1 to this Annex. It can be concluded, that the available spectrum in Switzerland in the Frequency band 50 – 52 MHz would also not be saturated in future when wide band mode operation is taken into account and when average use cases are considered. It may be concluded, that the situation may be very similar in other European countries, where the Amateur Service has assignments in the 50 – 52 MHz frequency range. 144 Rep. ITU-R M.2478-0

A15.4 Current amateur station activity and spectrum needs during a SSB contest in a country with average amateur license density In Switzerland the density of amateur stations in the year 2017 is 0.117 licenses per km2 as calculated below. This number is well above the European average. 푛푏_푙𝑖푐푒푛푐푒푠 4829 푙𝑖푐푒푛푐푒푠 퐴퐷2017 = = = 0.117 2 퐴푆푤𝑖푡푧푒푟푙푎푛푑 41285 푘푚 where 2 AD2017 density of amateur licenses / km in Switzerland in the year 2017 Nb_license number of amateur licenses in Switzerland in the year 2017

ASwitzerland area of Switzerland. To analyse a situation, where additional spectrum is required, statistics of the 2017 IARU 50 MHz contest are analysed to obtain amateur station density parameter values for the spectrum needs calculation. Information provided by IARU show that during the contest 147 different stations were identified as operating from Switzerland. In IARU contest log statistics the number of two way contacts per hour are analysed. During high activity periods, more than 80 two way contacts are counted per hour. Accordingly it can be concluded that during the contest, a single two – way – contact takes not more than 45 seconds (single session duration). In assuming an average session duration of 45 seconds, a large margin is considered. This is also confirmed by the measurement results of the four month spectrum monitoring campaign. There were 54’709 two way contacts from Swiss stations within a period of a single day. Accordingly the average number of contacts per Swiss amateur station is 372. The total session duration during the contest is 372 * 45 seconds = 4.65 hours. When assuming that there were 10 Swiss stations participating to the contest, but were not logged at all in the contest, then the total number of Swiss stations is assumed to be 157. Therefore, the number of amateur stations or transmitters per km2 per SSB application is 0.0038 amateur stations or transmitters per km2 per application corresponding to a density of active licenses of 0.0794 stations / km2 as calculations show below. 157 푠푡푎푡𝑖표푛푠 푠푡푎푡𝑖표푛푠 퐴퐷 2 = = 0.00380 푘푚 ,푎푝푝_푆푆퐵_푐표푛푡푒푠푡 41285 푘푚2 푘푚2,푎푝푝

퐴퐷푘푚2,푎푝푝_푆퐵퐵_푐표푛푡푒푠푡 푎푐푡𝑖푣푒 푙𝑖푐푒푛푠푒푠 2 퐴퐷푘푚 _푐표푛푡푒푠푡 = = 0.0794 2 퐹퐵푎푛푑퐹푎푝푝 푘푚 where: 2 ADkm2,app,SSB_contest density of SSB amateur stations / km during spectrum contest 2 ADkm2,_contest density of amateur stations / km during spectrum contest

BWocc bandwidth occupied as function of time for application

FBand fraction of amateurs using the band

Fapp fraction of amateurs using SSB in the band. The value of active licenses is below the number of density of licenses / km2. It can be concluded that 68% of amateur licences operating at 50 MHz frequency range are active during an exceptional event, which seems to be a high value, but can be considered as a reasonable one. In the following the spectrum needs calculation, according to the methodology shown in § 3.5 of the main body text, is done using the following parameters:

– Session duration, Tsession: 4.65 h

– Fraction of time transmitting within a single session, Factivity 0.5 – Observation window, W 24 h – Number of amateurs km2 0.0794. Rep. ITU-R M.2478-0 145

When using the above mentioned parameter values with the spectrum needs calculation methodology of § 3.5 of the main body text, 219 kHz spectrum is required for the SSB contest. This figure is based on contest log data analysis of the IARU 50 MHz 2017 contest. During the IARU 50 MHz 2018 contest, the spectrum occupancy was measured and it turned out, that the measured spectrum use in 2018 contest was much lower than the calculated one (based on log data analysis) for 2017. But it should be noted, that the propagation conditions during the 2018 MHz contest were significantly worse than in 2017. Therefore the results of the occupancy measurements results of the 2018 contest cannot be considered as representative and are disregarded for the spectrum needs calculations. It can be concluded, that the available spectrum in the Frequency band 50 – 52 MHz assigned for radio amateur service is by far not saturated in Switzerland during SSB contest situation. Even for countries with twice the amateur license density of Switzerland, the band would not be saturated.

A15.5 Future amateur spectrum needs for the case where additional spectrum is required in a country with average amateur license density As shown in the previous section, it can be assumed that in current situations where exceptional high amateur station activity is expected, a density of 0.0794 stations / km2 active stations can be assumed in Switzerland. 8% of them are accessing the 50-52 MHz frequency band. To obtain a forecasted density figure, which considers a growth of 10.4% the following calculation method is applied: 푠푡푎푡𝑖표푛푠 퐴퐷 2 = 퐴퐷 ∙ 1.104 = 0.08740 푘푚 _푓푢푡푢푟푒 푘푚2_푐표푛푡푒푠푡 푘푚2 The spectrum needs methodology of section 3.5 of the main body text is used to calculate the required spectrum using the following parameters:

– Session duration, Tsession for SSB 4.65 h – Observation window, W for SSB 24 h – Observation window, W for FM and WB 8 760 h – Observation window, W for Repeaters and Infrastructure 8 760 h

– Session duration, Tsession for FM and WB 730 h

– Session duration, Tsession for Repeaters and Infrastructure 8 760 h

– Fraction of time transmitting within a single session, Factivity 0.5 – Number of amateurs km2 0.08740 – Fraction of Amateurs using SSB, FM, WB, Repeaters, Infrastr. 0.6, 0.05, 0.05, 0.2, 0.1. When calculating with those parameters, the following requirement results are obtained: – SSB 240 kHz – FM 25 kHz – WB modes 500 kHz – Repeaters 100 kHz (No contest use but only average day use) – Infrastructure 500 kHz (No contest use but only average day use). It can be seen, that the applications “repeaters” and “infrastructure” need the major part of spectrum during very high activity situations (where additional spectrum is required). This is mainly due to their very high operation DC which never goes below 50%. However, it is unclear whether those applications are really relevant for very high activity situations like amateur contests. 146 Rep. ITU-R M.2478-0

A15.6 Future amateur spectrum needs in a country with high amateur license density According Table A2.1 the highest density of amateur radio stations in Europe is 0.3477, when the extreme values of countries such as Albania, Belarus, Latvia, Malta, Monaco and San Marino are not considered. This density is 2.98 times higher than the density considered in calculations for a typical European country. Accordingly, the densities for the active radio amateur stations used in the calculations above, need to be multiplied with the factor 2.98, such that a density of active 50 MHz stations for the average use case is considered to be 0.0154 and for the contest situation 0.26 stations / km2. When calculating with those parameters, the following requirement results are obtained for the average use case: – SSB 21 kHz – FM 25 kHz – Repeaters 200 kHz – WB modes 500 kHz – Infrastructure 500 kHz. When calculating for the use case, where addition spectrum is required (e.g. in contest situations), the following figures are obtained: – SSB 477 kHz – FM 25 kHz – Repeaters 200 kHz – WB modes 500 kHz (No contest use but only average day use) – Infrastructure 500 kHz (No contest use but only average day use). As earlier noted, in assuming an average session duration of 45 seconds, a large margin is considered. This is also confirmed by the measurement results of the four month spectrum monitoring campaign. Accordingly the calculated needs for the SSB contest may be overestimated.

A15.7 Spectrum needs summary The spectrum needs are calculated for two different usage situations: – Case A: Average use case which occurs with a probability of 98% in time. – Case B: Where additional spectrum is required. This situation occurs e.g. during contests and special events. It is assumed, that contests and special events do not occur during more than 7 days a year. This corresponds to situations which occur with probability of less than 2% in time. In Table A15.2 different spectrum use options are shown. For each option the required spectrum and the percentage of time during which the spectrum needs are fulfilled is indicated. Rep. ITU-R M.2478-0 147

TABLE A15.2 Spectrum use options

Amateur Required Spectrum Usage Option Applications population Spectrum needs in % situation density (MHz) of time average 0.534 1 Case A SSB, FM, WB 98% high 0.546 average 0.765 2 Case B SSB, FM, WB 2% high 1.002 average 0.634 3 Case A SSB, FM, WB, Repeaters 98% high 0.746 average 0.865 4 Case B SSB, FM, WB, Repeaters 2% high 1.202 SSB, FM, WB, Repeaters, average 1.034 5 Case A 98% Infrastructure high 1.246 SSB, FM, WB, Repeaters, average 1.365 6 Case B 2% Infrastructure high 1.702

Attachment 1 to Annex 15

Spectrum Monitoring and Spectrum Occupancy Results

In a spectrum monitoring campaign, the spectrum occupancy has been measured in an average populated European country in the period April – July 2018. The spectrum occupancy measurement system which was used for this study counts the number of emissions which last minimum 1 second but not longer than 45 seconds within a bandwidth of 5 kHz. Accordingly the result of the measurements are a certain number of counts in a certain bandwidth. As an example, a monitored signal with 2.7 kHz bandwidth and a duration of 130 seconds causes at least 3 counts but not more than 6 counts. A signal with 16 kHz bandwidth and 130 seconds duration causes at least 16 counts but not more than 20 counts. Accordingly 1 count represents the full or partly occupancy of a 5 KHz channel during 45 seconds. Obviously the results of the described method represent always an overestimate but never an underestimate of the spectrum occupancy. Only emissions are counted which originate within the Swiss borders. The monitoring measurements are based on the following existing amateur region 1 band plan as shown in Table A15.3. 148 Rep. ITU-R M.2478-0

TABLE A15.3

The occupancy measurement is based on a 5 kHz resolution bandwidth. The measured occupancy of the band 50.0-50.1 MHz may be underestimated in a certain sense, because simultaneous transmissions of telegraphy stations within a 4 kHz bandwidth are counted as a single band 1 kHz frequency band occupation. On the other hand, the occupancy of the 50.5-52 MHz may be overestimated, because a single 12.5 kHz signal emission may be counted as an occupation of three channels. However, in view of the very weak band usage, this overestimation does not change the conclusion that the band usage is negligible.

During the period of April – July 2018 the number of counts as shown in Table A15.4 are obtained on average for the different frequency sub-bands and scenarios: Rep. ITU-R M.2478-0 149

TABLE A15.4 Spectrum monitoring results (number of counts)

Frequency Number Scenario Application (MHz) of counts 50.0-50.1 Telegraphy 107.8 All Narrowband modes 50.1-50.5 967.9 (Telegraphy, SSB etc.) Average day Digital communications FM Repeaters in / out 50.5-52.0 263.1 FM FAX, RTTY, etc. 50.0-50.1 Telegraphy 884

All Narrowband modes 50.1-50.5 3499 Exceptional (Telegraphy, SSB etc.) propagation conditions Digital communications FM Repeaters in / out 50.5-52.0 49 (Opening 28.05.18) FM FAX, RTTY, etc. 50.0-50.1 Telegraphy 1358 All Narrowband modes IARU 50.1-50.5 8775 50 MHz (Telegraphy, SSB etc.) Contest Digital communications FM Repeaters in / out 50.5-52.0 25 Max (16.07.18, FM 17.07.18) FAX, RTTY, etc.

The occupancy (%) for the different applications is calculated as follows:

푁푏 푐표푢푛푡푠푇푒푙푒𝑔푟푎푝ℎ푦 푇 ∑ 푛 100 푛=1 24∙푇 푂푐푐푇푒푙푒푔푟푎푝ℎ푦(%) = (50′100푘퐻푧−50′000푘퐻푧) 1 푘퐻푧

푁푏푐표푢푛푡푠 푇 ∑ 푁푎푟푟표푤푏푎푛푑 푛 100 푛=1 24∙푇 푂푐푐푁푎푟푟표푤 퐵푎푛푑(%) = (50′500푘퐻푧−50′100푘퐻푧) 5 푘퐻푧

푁푏푐표푢푛푡푠 푇 ∑ 푎푙푙 푚표푑푒푠 푛 100 1 24∙푇 푂푐푐푎푙푙 푚표푑푒푠(%) = (52′000푘퐻푧−50′500푘퐻푧) 15 푘퐻푧 where:

OccTelegraphy: occupation of the frequency band 50.0-50.1 MHz

OccNarrowband: occupation of the frequency band 50.1-50.5 MHz

Occall modesy: occupation of the frequency band 50.5-52.0 MHz

Nb_countsTelegraphy: number of measured emissions within the band 50.0-50.1 MHz

Nb_countsNarrowband: number of measured emissions within the band 50.1-50.5 MHz

Nb_countsall modes: number of measured emissions within the band 50.5-52.0 MHz

Tn: duration of a single emission (rounded up to integer multiples of 45 seconds) 150 Rep. ITU-R M.2478-0

T: 3 600 seconds.

TABLE A15.5 Spectrum occupancy

Maximum Frequency Occupancy Scenario Application (MHz) (45 s) (rounded up) 50.0-50.1 Telegraphy 0.0561% All Narrowband modes 50.1-50.5 0.630% (Telegraphy, SSB etc.) Average day Digital communications 50.5-52.0 FM Repeaters in / out 0.137% FM FAX, RTTY, etc. 50.0-50.1 Telegraphy 0.460% All Narrowband modes 50.1-50.5 2.28% Exceptional (Telegraphy, SSB etc.) propagation conditions Digital (Opening communications 28.05.18) 50.5-52.0 FM Repeaters in / out 0.0255% FM FAX, RTTY, etc. 50.0-50.1 Telegraphy 0.707% IARU All Narrowband modes 50.1 – 50.5 5.71% 50 MHz (Telegraphy, SSB etc.) Contest Digital communications Max(16.07.18, 50.5 – 52.0 FM Repeaters in / out 0.013% 17.07.18) FM FAX, RTTY, etc.

A graphical representation of the occupancy for some sample days is shown in Figs A15.1 to A15.6. Rep. ITU-R M.2478-0 151

FIGURE A15.1 Spectrum occupancy measured during the 19.5.2018

19.Mai 2018 100 90 80 70 60 50 40 30 20 10

0

50.1 50.4

50.09 50.11 50.12 50.13 50.14 50.15 50.16 50.17 50.29 50.32 50.72 51.83 51.84 51.95

50.305 51.805 50.835 51.045 51.155 51.235 51.375 51.975 50.195

FIGURE A15.2 Spectrum occupancy measured during the 28.5.2018

28. May 2018 100 90 80 70 60 50 40 Ergebnis 30 20 10

0

50.31 50.06 50.09 50.12 50.15 50.18 50.22 50.85

50.195 50.415 50.105 50.135 50.165 50.295 50.325 50.345 50.655 51.115 51.305 51.375 51.505 50.075 152 Rep. ITU-R M.2478-0

FIGURE A15.3 Spectrum occupancy measured during the 13.5.2018

13. Mai 2018 100 90 80 70 60 50 40 30 20 10 0

FIGURE A15.4 Spectrum occupancy measured during the 17.6.2018

IARU Contest 17. June 2018 100 90 80 70 60 50 40 Ergebnis 30 20 10

0

50.4

50.06 50.09 50.12 50.15 50.18 50.21 50.32 51.36

50.105 50.135 50.165 50.195 50.225 50.275 50.305 50.855 51.875 50.075 Rep. ITU-R M.2478-0 153

FIGURE A15.5 Spectrum occupancy measured during the 30.6.2018

30. June 2018 100

90

80

70

60

50

40

30

20

10

0

FIGURE A15.6 Spectrum occupancy measured during the 24.6.2018

24. July 2018 100 90 80 70 60 50 40 30 20 10 0

It can be noted, that the use of digital modes, FM and repeaters in the 50 MHz spectrum is obviously not very popular, as the spectrum is nearly unused by those application during most of the times. When using the occupancy measurement data, to calculate the occupied bandwidth and comparing those results to results of two existing spectrum needs studies, it can be concluded that both studies make very probably an overestimate of the required spectrum. A summary of the comparison is shown in Table A15.6. 154 Rep. ITU-R M.2478-0

TABLE A15.6 Comparison of calculated spectrum requirements and occupied bandwidth for existing applications

on Current average occupied bandwidth in a Future spectrum Future spectrum Frequency typical European needs (MHz) needs (MHz) Applications range country according according (MHz) measured during Study 1 Study 2 a four-month period in spring 2018

Spectrum usage situati 0.003 MHz* Narrow band & 0.009 MHz 0.087 MHz 50.0 – 50.5 av av Telegraphy (0.0561 kHz 0.021 MHz 0.25 MHz Existing + 2.52 kHz) high high Applications FM, Repeaters, 0.025 MHz* 0.125 MHz 0.975 MHz 50.5 – 52.0 av av Digital, etc. (1.69 kHz) 0.225 MHzhigh 2.7 MHzhigh New Wide Band, 1.0 MHz 3.0 MHz > 50.5 n.a. av av applications Infrastructure 1.0 MHzhigh 7.0 MHzhigh

During average (98% of time) days 0.219 MHz* Narrow band & 0.24 MHz 50.0 – 50.5 (Contest 2017) av n.a. Telegraphy 0.477 MHzhigh Existing Applications 0.025 MHz* FM, Repeaters, 0.125 MHz 50.5 – 52.0 (0.033 kHz) av n.a. Digital, etc. 0.225 MHz high New Wide Band, 1.0 MHz > 50.5 n.a. av n.a. Applications Infrastructure 1.0 MHzhigh

During exceptional contests (during 2% of time) and conditions

All 1.365 MHzav 4.062 MHzav All modes - n.a. applications 1.702 MHzhigh 9.95 MHzhigh

Total max. * To integer multiples of channel band width rounded up values. ** Result of 2017 amateur contest is representative because propagation conditions during the 2018 contest were rather poor for typical amateur communication activities.

The occupied bandwidth measurement results for FM, Repeaters, Digital modes etc. are rounded up to a single 15 kHz channel. It should be noted that the spectrum needs according to Study 1 are based on parameter values which are calculated based on a combination of the IARU 50 MHz 2017 contest log data analysis and spectrum monitoring results. It may be possible, that the contest of 2018 was less crowded that that one in 2017.