Annex A: UHF Technical Compatibility Issues Prepared for Ofcom by Ægis as part of the ‘Preparatory study for UHF spectrum award’ 19 December 2006 Ægis Systems Limited Annex A: UHF Technical Compatibility Issues Table of Contents 1 RADIO PLANNING AND INTERFERENCE ISSUES .....................................5 1.1 The wanted signal .............................................................................................. 5 1.2 Interference mechanisms.................................................................................. 7 1.2.1 Co-channel interference....................................................................................... 7 1.2.1.1 Location variability........................................................................................... 8 1.2.1.2 Temporal variability ......................................................................................... 8 1.2.1.3 Modelling......................................................................................................... 9 1.2.2 Adjacent channel interference.............................................................................. 11 1.2.2.1 Hole punching ................................................................................................. 12 1.2.3 Image channel relationships ................................................................................ 13 1.2.4 Non-linear effects ................................................................................................. 13 1.2.5 Receiving antenna discrimination ........................................................................ 15 2 DTT ................................................................................................16 2.1 Wanted signal assumptions.............................................................................. 16 2.2 Interfering signal assumptions......................................................................... 18 2.2.1 Co-channel DVB-T/DVB-H interference............................................................... 18 2.2.2 Adjacent channel DVB-T/DVB-H interference ..................................................... 18 2.2.3 Non-adjacent channel interference ...................................................................... 19 2.2.4 Image channel...................................................................................................... 19 2.2.5 Response to other interfering signals................................................................... 19 2.2.6 Summary of receiver interference response ........................................................ 19 2.3 Planning of DTT networks................................................................................. 20 2.3.1 Constraints on use of specific channels............................................................... 21 2.3.1.1 Unavailability to DTT of specific mid-band channels ...................................... 34 2.4 Interference issues............................................................................................. 37 2.4.1 Protection of other DTT services.......................................................................... 37 2.4.2 Co-channel interference to other services ........................................................... 37 2.4.3 Adjacent -channel interference to other services................................................. 37 3 MOBILE TV ......................................................................................38 Annex A: UHF Technical Compatibility Issues i Ægis Systems Limited Annex A: UHF Technical Compatibility Issues 3.1 Wanted signal assumptions.............................................................................. 38 3.2 Interfering signal assumptions......................................................................... 40 3.2.1 Adjacent channel interference.............................................................................. 40 3.2.2 Non-linear effects ................................................................................................. 41 3.3 Planning considerations for mobile TV ........................................................... 42 3.3.1 Network implications ............................................................................................ 42 3.3.2 Restrictions on use of specific channels .............................................................. 42 3.4 Interference to and from other services .......................................................... 43 3.4.1 Co-channel outgoing interference....................................................................... 43 3.4.2 Incoming Co-channel interference from DTT....................................................... 45 3.4.3 Adjacent channel interference to DTT.................................................................. 46 3.4.4 Adjacent channel interference to Cellular / BWA services................................... 53 4 CELLULAR / BROADBAND WIRELESS ..................................................54 4.1 UMTS 500 ............................................................................................................ 54 4.1.1 UMTS 500 parameters......................................................................................... 57 4.1.1.1 UMTS 500 Base station .................................................................................. 57 4.1.1.2 UMTS 500 Mobile terminal.............................................................................. 59 4.2 Wi-MAX (802.16) ................................................................................................. 61 4.3 Interference to and from other services .......................................................... 61 4.3.1 Co-channel outgoing interference....................................................................... 61 5 LOCAL TV........................................................................................64 5.1 Interference to and from other services .......................................................... 64 5.1.1 Co-channel outgoing interference........................................................................ 64 5.1.2 Adjacent-channel outgoing interference .............................................................. 64 6 PMSE .............................................................................................66 6.1 Wanted signal..................................................................................................... 66 6.2 Interference to and from other services .......................................................... 66 6.2.1 Incoming interference from DTT & Local DTT ..................................................... 66 6.2.2 Incoming interference from other services........................................................... 67 6.2.3 Co-channel outgoing interference from PMSE ................................................... 68 6.2.4 Adjacent channel Interference to other Cellular / BWA........................................ 70 ii Annex A: UHF Technical Compatibility Issues Ægis Systems Limited Annex A: UHF Technical Compatibility Issues 7 MUTUAL INTERFERENCE CONSIDERATIONS .........................................71 7.1 Co-channel separation distance matrix........................................................... 73 7.2 Adjacent -channel separation distance matrix ............................................... 74 8 THE IMPACT OF INTRA-SERVICE FREQUENCY SEPARATION....................75 8.1 Net filter discrimination ..................................................................................... 77 8.1.1 ITU-R WP8F report .............................................................................................. 78 8.2 Modelling approaches ....................................................................................... 79 8.2.1 DVB-T transmitter adjacent to CDMA BS receiver .............................................. 79 8.2.2 Monte Carlo modelling ......................................................................................... 81 8.2.3 Conclusions.......................................................................................................... 86 9 PROTECTION OF RADIO ASTRONOMICAL USE OF CHANNEL 38...............88 9.1 Modelling............................................................................................................. 88 9.2 Estimate of required separation distance ....................................................... 90 9.3 Site-specific prediction...................................................................................... 90 9.4 Commentary ....................................................................................................... 93 10 SUMMARY AND CONCLUSIONS ...........................................................94 10.1 ‘Hole punching’ in PSB and COM multiplexes by new services ................... 94 10.2 The impact of RRC constraints on network design........................................ 94 10.3 The implications of free-roaming BWA/Cellular transmit terminals............. 95 11 GLOSSARY.......................................................................................96 12 REFERENCES ...................................................................................98 Annex A: UHF Technical Compatibility Issues iii Ægis Systems Limited Annex A: UHF Technical Compatibility Issues The work forming the basis of this annex has been driven by the underlying objective of the study to seek to develop a service and technology neutral award process.