DOCSLIB.ORG

Medium Wave DRM Field Test Results in Urban and Rural Environments David Guerra, Gorka Prieto, Igor Fernández, José M

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Medium Wave DRM Field Test Results in Urban and Rural Environments David Guerra, Gorka Prieto, Igor Fernández, José M Medium Wave DRM Field Test Results in Urban and Rural Environments David Guerra, Gorka Prieto, Igor Fernández, José M. Matías, Pablo Angueira, Juan Luis Ordiales Department of Electronics & Telecommunications Bilbao Engineering College (University of the Basque Country) Alameda Urkijo s/n. 48013 Bilbao. SPAIN Abstract This paper presents the results of the first Spanish field trial carried out to analyze a DRM (Digital Radio Mondiale) system in the medium-wave band. A 4-kW average power omni directional ground-wave experimental DRM transmission at a frequency of 1359 kHz was surveyed by means of a measurement vehicle for fixed and mobile reception. Several radial routes starting from the transmitter site provided rural and suburban behavior features of the system. Urban reception trials were performed in several dense and open streets of Madrid, within the expected coverage area. Field strength threshold values were determined for the tested transmission configurations and compared with the AM ground-wave ITU model predictions. Reliability versus distance from the transmitter is stated in this paper for different transmission configurations and the causes of dropouts for different reception conditions are explained. This analysis took into account subjective quality features of each configuration, providing practical planning parameter values. Keywords Digital AM, digital audio broadcasting, digital radio, DRM, medium wave. I. INTRODUCTION DRM (Digital Radio Mondiale) is the only universal non-proprietary digital radio system for broadcasting audio in the frequency bands below 30 MHz. It is designed to fit in with the existing AM broadcast band frequency plans, based on signals of 9 kHz or 10 kHz bandwidth. DRM radio system is capable of providing near-FM quality audio and it has the capacity to integrate data and text. In addition, DRM OFDM-based modulation along with guard interval techniques allows the implementation of single frequency networks (SFN) [1]. Several broadcasters, manufactures, research institutions and regulatory bodies integrate nowadays the international DRM consortium formed in 1998. In the different consortium working groups, technical, promotional and standardization tasks are carried out. One of the main results of this collaborative effort is the successful launch of commercial emissions in June 2003 by 16 of the leading international broadcasters. The actual, much longer, DRM services schedule can be found in [2]. The achievements of the status of ETSI Standard [3] and IEC International Standard [4], and the ITU procedural change [5] which allows the DRM use of the current analogue assignments in Regions 1 and 3, have also been important milestones. Despite the present availability of several DRM services and the achieved standardizations, an intense DRM analysis work is being performed. There is still a need for network parameter planning values measured on the field and also a need to analyze the behavior of the DRM system under several reception conditions. These tasks are mainly focusing on short-wave ionospheric long-range [6] transmissions [7] whereas there is a lack of testing of medium-wave ground wave propagated DRM signals. This medium frequency band propagation, traditionally of high importance in the AM radio broadcasting in Spain, has been chosen to carry out the DRM measurement campaign presented in this paper. First in this paper the objectives are explained. Then, the measurement campaign is presented by describing the broadcasting network, the reception and measuring systems, the campaign planning and the methodology used in these tests. After the measurement campaign description, the data processing method is detailed and the associated results are described in several graphs and tables. This results section is divided into subsections following the objectives initially proposed. Finally the most relevant conclusions are summarized. II. OBJECTIVES The main objective of this work has been to put under test the reception of DRM audio services in the medium-wave band broadcasted with different DRM transmission modes [3], under different reception conditions. This overall target was divided into the following specific objectives: • Study of the performance of different DRM transmission configurations in medium-wave reception. • Analysis of the DRM coverage range and field strength threshold in static reception for each analyzed mode comparatively with the corresponding AM range. • Study of the mobile DRM reception with different transmission modes and determine on the field the critical reception factors. III. MEASUREMENT CAMPAIGN Broadcasting Network The tested DRM broadcast features are shown in Table 1. The AM transmitter facilities used for the tests are located in Arganda del Rey which is 25 kilometers from downtown Madrid. The DRM standard [3] provides several configurable transmission parameters that allow many different DRM transmission modes with different robustness against noise, multipath and interference. The more robust the mode, the less maximum subjective audio quality can be achieved due to a lower useful bit rate available. In order to evaluate the influence of each parameter the modes in Table 2 were chosen for the tests. The OFDM configurations A and B of the DRM standard are the only ones that fulfill the ITU constraints of medium-wave signal bandwidth in Spain [9]. A broader explanation of the number of carriers, guard interval, protection and interleaving algorithms, and Main Service Channel (MSC), Service Description Channel (SDC) modulations is out of the scope of this article and can be found in detail in [3]. The first column of Table 2 is a reference code included for the sake of briefness when referring to a combination of parameters in the rest of this paper. The DRM modes in Table 2 are ordered from less to more robust as can be deduced from the corresponding useful bit rate which decreases from the top to the bottom of the table. The maximum subjective audio quality provided by each DRM mode depends on the audio coding parameters, which are in turn determined by the available useful bit rate. Thus it is possible to compare the maximum subjective audio quality that the modes in Table 2 can provide. Reception and Measurement System The measurement vehicle was equipped as shown in Figure 1 where three sections are distinguished: The acquisition and distribution system, the measurement system and the control system. The acquisition system was composed of the fully characterized short monopole active antenna R&S HE010 mounted on top of the van with a specific ground plane. The signal received by the antenna was distributed to the measurement equipment by means of a splitter system formed by two power dividers. A first divider fed the received signal on the one hand to a DRM monitoring receiver and on the other hand to the second divider that in turn fed the received signal to a second measurement block. The DRM monitoring receiver was composed of an AR7030 analogue front- end modified to be capable of tuning the received DRM signal an down convert it to a 12 kHz IF channel. A SB Extigy sound card sampled this IF signal into a PC which ran the professional Windows based Fraunhofer Software Radio DRM demodulator. The second measurement block was made up of a Vector Signal Analyzer which provided RF spectrum captures and a Field Meter to measure the RF power level field strength in the DRM signal bandwidth. The last section was based on a laptop computer running a control software over a GNU/Linux platform which had the tasks of configuring and controlling the rest of the equipment, calculate some on-the-run statistics, coordinate the time/position/trip measuring, and conveniently store all the captured and calculated data. Ancillary data were provided by a GPS receiver and a trigger system which was generated every wheel turn. The control section was completed with a GSM remote control system for the DRM modulator located in Arganda which allowed the quick on-board changing of the DRM transmission mode via GPRS (General Packet Radio System) data calls between two identical GPRS modules, one located in the van, the other in the transmitter site. This remote control system for the modulator allows the analysis of all the proposed DRM modes with the same propagation conditions i.e. in the same point and consecutively. Measurement Methodology The measurement campaign included measurements in static locations and mobile measurements along routes which were planned following environmental criteria. The distinction made between static and mobile reception is based on the two kinds of radio listeners: the “on board” ones and the “on foot” ones and it reflects the most difficult reception conditions featured by mobile reception mainly due to fast signal variations. Radial Routes The first set of measurements was captured along radial routes from the transmitter, as shown in Figure 2, featuring mainly rural and suburban environments and thus, locations where man-made noise level was expected to remain quite low. The sporadic presence of power plants, high-voltage power lines and urban cores in certain locations of these mainly rural-suburban routes is an exception to the aforementioned lack of noise and must be taken into account in the subsequent data analysis. Modes 1, 4 and 5E were measured in 42 static locations and along a total number of 2200 km in order to determine their coverage ranges. The less robust mode 1E was not measured in these routes as its expected coverage range was too low. Madrid Routes The second set of measurements was planned in the urban environment of Madrid as shown in Figure 3. The routes and static locations were selected to represent from wide avenues to the densest urban environment in Madrid. Distance from the transmitter and the direction of the route (radial and circular) with respect to the transmitter were also taken into account. Modes 1, 4 and 5E were tested in 19 static locations, along 470 km overall.
Load more

Recommended publications
  • Signal Issue 37
    Signal Issue 37 Tricks of the Trade Dave Porter G4OYX and Alan Beech G1BXG By 25th September 1965, Radio 390 was on the air and 31st December 2015 marks the fiftieth anniversary of the start of the offshore station Radio Scotland. The only remaining station to launch with RCA 10 kW Ampliphase transmitters was Radio 270 from 4th June 1966, on-air some three months later than originally planned. Member’s contribution understood that, whilst CE was used to these T-K arrangements, mainly for Government contracts, the need After reading the last three ToTT, VMARS Member Tony to effect a quick turn-around with minimal delays was not Rock G3KTR/AD1X contacted the author (DP) with the quite their norm. With time slipping by, the decision was following information on the 1965 build of Radio Scotland. made to leave the USA without the systems being totally commissioned and to complete en-route. Also, during this Tony writes; I read with interest the article you and Alan trip, it was discovered that one of the planned operating put together on Ampliphase transmitters. In the mid-1960s frequencies, namely 650 kHz, was actually occupied in the I was working out of the RCA Broadcast & UK by a certain high-power station on 647 kHz, the Communications Division at Sunbury-on-Thames. At this 150 kW BBC Third Programme. It was understood that an time RCA had sold several transmitters to offshore ‘pirate’ early ‘recce’ by the Americans to the UK to check for ‘spare radio stations. While Marconi and other European channels’ resulted in a monitoring time when the Third companies could be subjected to sanctions by the Programme was not scheduled on air.
    [Show full text]
  • Implementation Considerations for the Introduction and Transition to Digital Terrestrial Sound and Multimedia Broadcasting
    Report ITU-R BS.2384-0 (07/2015) Implementation considerations for the introduction and transition to digital terrestrial sound and multimedia broadcasting BS Series Broadcasting service (sound) ii Rep. ITU-R BS.2384-0 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 Annex 1 of 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.
    [Show full text]
  • Consultation Document Spectrum Allocation Strategy for Other Radio
    FOREWORD Botswana Telecommunications Authority (BTA) is mandated by the Telecommunication Act, 1996 [No. 15 of 1996] to ensure the rational use of the radio frequency spectrum in Botswana. The BTA assisted by the Teleplan AS from Norway in association with ICT Consultants (Pty) Ltd from Botswana, is in the process of developing a comprehensive Spectrum Management Strategy. The spectrum management strategy has the following components: • Review the current national radio frequency plan; • Develop a spectrum allocation strategy for various radio services; • Develop a spectrum licensing policy for various frequency bands; and • Develop a spectrum pricing policy In January 2007, the BTA issued a consultation document for radio services dealing with preliminary views and recommendations relating to high demand spectrum . A workshop was held on 14 – 15 February 2007, during which the consultation document was presented and comments/input received from stakeholders. The consultation process for the high demand spectrum has been finalised and the BTA has already communicated it to the industry stakeholders. This consultation document contains information and recommendations on other radio services that were not included in the first round of consultation. The document summarises the key findings from technology reviews, analysis of regional radio regulations, frequency plans (national, regional and international) and available radio equipment. Page 1 of 80 The Authority wishes to invite the industry stakeholders, (the operators, service providers,
    [Show full text]
  • Long-Wave and Medium-Wave Propagation
    ~EMGINEERING TRAINING SUPPLEMENT No. 10 LONG-WAVE AND MEDIUM-WAVE PROPAGATION BRITISH BROADCASTING CORPORATION LONDON 1957 ENGINEERING TRAINING SUPPLEMENT No. 10 LONG-WAVE AND MEDIUM-WAVE PROPAGATION Prepared by the Engineering Training Department from an original manuscript by H. E. FARROW, Grad.1.E.E. Issued by THE BBC ENGINEERING TRAINING DEPARTMENT 1957 ACKNOWLEDGMENTS Fig. 2 is based upon a curve given by H. P. Williams in 'Antenna Theory and Design', published by Sir Isaac Pitrnan and Sons Ltd. Figs. 5, 6, 7, 8 and 9 are based upon curves prepared by the C.C.I.R. CONTENTS ACKNOWLEDGMENTS... ... INTRODUCTION ... ... ... AERIALS ... ... ... ... GROUND-WAVEPROPAGATION ... GEOLOGICALCORRELATION ... PROPAGATIONCURVES ... ... RECOVERYAND LOSS EFFECTS ... MIXED-PATHPROPAGATION ... SYNCHRONISED. GROUP WORKING LOW-POWERINSTALLATIONS ... IONOSPHERICREFLECTION ... FADING ... ... ... ... REDUCTIONOF SERVICEAREA BY SKYWAVE ... LONG-RANGEINTERFERENCE BY SKYWAVE ... APPENDIXI ... ... ... ... ... REFERENCES ... ... ... ... ... LONG-WAVE AND MEDIUM-WAVE PROPAGATION The general purpose of this Supplement is to explain the main features of propagation at low and medium frequencies i.e. 30-3000 kc/s, and in particular in the bands used for broadcasting viz. 150-285 kc/s and 525-1605 kc/s. In these bands, the signal at the receiver may have two components: they are (a) a ground wave, i.e. one that follows ground contours (b) an ionspheric wave (sky wave) which is reflected from an ionised layer under certain conditions. In the vicinity of the transmitter, the ground wave is the predominant component, and for domestic broadcasting, the service ideally would be provided by the ground wave only. In fact the limit to the service area is often set by interference from the sky wave.
    [Show full text]
  • WBU Radio Guide
    FOREWORD The purpose of the Digital Radio Guide is to help engineers and managers in the radio broadcast community understand options for digital radio systems available in 2019. The guide covers systems used for transmission in different media, but not for programme production. The in-depth technical descriptions of the systems are available from the proponent organisations and their websites listed in the appendices. The choice of the appropriate system is the responsibility of the broadcaster or national regulator who should take into account the various technical, commercial and legal factors relevant to the application. We are grateful to the many organisations and consortia whose systems and services are featured in the guide for providing the updates for this latest edition. In particular, our thanks go to the following organisations: European Broadcasting Union (EBU) North American Broadcasters Association (NABA) Digital Radio Mondiale (DRM) HD Radio WorldDAB Forum Amal Punchihewa Former Vice-Chairman World Broadcasting Unions - Technical Committee April 2019 2 TABLE OF CONTENTS INTRODUCTION .......................................................................................................................................... 5 WHAT IS DIGITAL RADIO? ....................................................................................................................... 7 WHY DIGITAL RADIO? .............................................................................................................................. 9 TERRESTRIAL
    [Show full text]
  • Chapter 1 Background of the Project
    CHAPTER 1 BACKGROUND OF THE PROJECT CHAPTER 1 BACKGROUND OF THE PROJECT Currently, the radio transmitting station of MRTV is obliged to operate the transmitter at about half load of their capacities. This is due to such backgrounds as superannuation of equipments, shortage of spare parts, and increase of operation and maintenance cost. As the result, the broadcasting service area has contracted quickly each year (For the current service area, refer to Appendix-6(4) “Estimation of Project Effects”). Especially, transmission to the remote area cannot be fully performed in satisfactory and the means of information distribution towards the nomads is being lost. In order to cope with such situation, the Government of Mongolia selected three (3) stations (Ulaanbaatar, Altai, and Murun) among the existing seven (7) radio transmitting stations as for the Project objective location. The Government of Mongolia expects to restore the ratio of service area to the whole country up to 93% by installing a new 50kW transmitting system to Ulaanbaatar Transmitting Station, and 10kW transmitting system to Altai and Murun Transmitting Stations. In order to procure and install the above-mentioned equipments, the Government of Mongolia requested the Government of Japan for the assistance through Japanese Grant Aid. 1 - 1 CHAPTER 2 CONTENTS OF THE PROJECT CHAPTER 2 CONTENTS OF THE PROJECT 2-1 Basic Concept of the Project At the existing radio transmitting stations, some transmitters have been forced to stop operation due to technical failures, and, in other cases, superannuation of transmitters are advancing near the life limit of the transmitters. Furthermore, it was obliged to reduce the power output to nearly half of normal operation due to shortage of the spare parts and increase of operation and maintenance cost.
    [Show full text]
  • The AM Signalling System, AMSS
    RADIO BROADCASTING TheAMSS AM Signalling System: — does your radio know what it’s listening to? Andrew Murphy and Ranulph Poole BBC Research & Development, UK The AM Signalling System (AMSS) adds a small amount of digital information to existing analogue AM broadcasts on short-, medium- and long-wave, giving similar functionality to that provided by the Radio Data System (RDS) on the FM bands. The system has been designed within the Digital Radio Mondiale (DRM) consortium, primarily to ease the transition from analogue to digital broadcasting. A suitably-equipped receiver will allow selection of the AM service by name as well as the choice of re-tuning to other frequencies carrying analogue or digital versions of the same or a related service. Several AMSS transmissions are already on air and some, if not all, of the first consumer DRM receivers will incorporate AMSS decoding. If you’re listening to an AM broadcast on the short-, medium- or long-wave bands, the answer to the question in the title has traditionally been a resounding “no”. Currently, the only way for a listener to identify an AM broadcast is to wait for a station’s ident or jingle to be played. Without an up-to-date copy of the World TV and Radio Handbook or Passport to World Band Radio to hand, or an Internet connection available, it can be difficult to identify an AM station from the plethora available. With increasing numbers of broadcasters switching on Digital Radio Mondiale (DRM) [1] broadcasts, the DRM consortium started to think about how the transition for broadcasters and listeners from AM to DRM could be eased.
    [Show full text]
  • What Are Your Comments on These Proposals?
    Name: Susannah Simons/Tom Everest Representing: BBC What are your comments on these proposals? Executive Summary Broadcasting is changing. The growth of digital television and digital radio, the increased availability of services on demand, and the blurring of boundaries between platforms and content-providers are having a profound effect on how audiences listen to and watch our services. In the midst of this maelstrom, listening to radio is thriving, even as listeners explore new ways to find the programmes, networks and services that they want to hear. In this response to Ofcom’s consultation about aspects of the future of radio, the BBC argues that radio – as a discrete platform, not just as audio services delivered over other technologies – has and will continue to have a vital place in society. We argue that universal access to radio will continue to be important and that the provision of localness should be entrusted to all parts of the radio market, not just the BBC and community radio. Underpinning all of these arguments is our contention that discussions concerning the future of radio should involve all stakeholders in the industry: audiences, broadcasters, manufacturers, regulators, and Government. We consider that it is impossible to review all of the issues thoroughly without approaching them together and so propose a common review of both the technology and frequency issues and the commercial pressures facing the industry. Whilst we recognise that Ofcom has identified a need to make certain decisions now, we suggest that the current state of the technology and receiver markets make predictions about future listening habits unreliable.
    [Show full text]
  • Radio and Tv Broadcast Antennas
    BROADCAST ANTENNAS RADIO AND TV Summary 1 Front Cover 2 Summary 3 Introduction 4 Channels & Frequencies 5 Circular Polarization Tuned MY-Heliax FM Radio MY-Ciclone MY-Syren 6 Circular Polarization Broadband MY-TetraQ MY-TetraQ2 MY-TetraQ3 7 Circular Polarization High Power Panel MY-4DC 8 Vertical Polarization Dipole MY- Yinx- FM MY-FMPL MY-FMPL2 9 Vertical Polarization MY-GM MY-GM2Y MY-GM3Y 10 Vertical Polarization High Power Panel MY-BII Panel 11 Radio FM Splitters 12 Radio FM Filters 13 Radio FM Combiners 14 MY-1130 DAB MY-1150 MY-1180/90 15 MY-1140 MY-1170 MY-1160 16 DAB Splitters 17 DAB Filters 18 DAB Combiners 19 MY-BI Panel TV B I 20 MY-BIII 2D Panel TV BIII MY-BIII 4D Panel 21 2D BIII D Panel BIII yagi 22 Splitters BIII Filters BIII 23 Combiners BIII 24 MY-BIV/V 4 D Panel CI UHF BIV/V TV MY-BIV/V 4 D Panel 25 MY-YINX-N UHF 26 Splitters UHF 27 Filters UHF 28 Combiner UHF 29 MY-DVB Panel DVB 30 Splitters DVB 31 Filters DVB 32 Combiner DVB 33 Accessories Rigid Line Accesories Adapters Coaxial Connectors Directional Couplers 34 Address 2 Summary MOYANO is since 1960 the pioneer Company in the Spanish Radio Frequencies technology, basing its development in the design and construction of Antennas, Power devices and Telecommunication Towers. MOYANO is today the company that offers to their clients the best solutions in technology and Infrastructure for Broadcast Networks. The technological development based in the applied engineering facility is fully supported by a production group as well as installtion and maintenance division.
    [Show full text]
  • Historical Survey of Fading at Medium and High Radio Frequencies
    PB161634 *#©. 133 jjoulder laboratories HISTORICAL SURVEY OF FADING AT MEDIUM AND HIGH RADIO FREQUENCIES BY *- ROGER &. SALAIS4AN U. S. DEPARTMENT OF COMMERCE NATIONAL BUREAU OF STANDARDS THE NATIONAL BUREAU OF STANDARDS Functions and Activities The functions of the National Bureau of Standards are set forth in the Act of Congress, March 3, 1901, as amended by Congress in Public Law 619, 1950. These include the development and maintenance of the na- tional standards of measurement and the provision of means and methods for making measurements consistent with these standards; the determination of physical constants and properties of materials; the development of methods and instruments for testing materials, devices, and structures; advisory services to government agen- cies on scientific and technical problems; invention and development of devices to serve special needs of the Government; and the development of standard practices, codes, and specifications. The work includes basic and applied research, development, engineering, instrumentation, testing, evaluation, calibration services, and various consultation and information services. Research projects are also performed for other government agencies when the work relates to and supplements the basic program of the Bureau or when the Bureau's unique competence is required. The scope of activities is suggested by the listing of divisions and sections on the inside of the back cover. Publications The results of the Bureau's research are published either in the Bureau's own series of publications or in the journals of professional and scientific societies. The Bureau itself publishes three periodicals avail- able from the Government Printing Office: The Journal of Research, published in four separate sections, presents complete scientific and technical papers; the Technical News Bulletin presents summary and pre- liminary reports on work in progress; and Basic Radio Propagation Predictions provides data for determining the best frequencies to use for radio communications throughout the world.
    [Show full text]
  • Digital Multimedia Broadcasting Trainer (Model : DMB-5000)
    Digital Multimedia Broadcasting Trainer (model : DMB-5000) 1. Features We announce the developments of DAB / DMB Trainer System, DMB-5000 and DMB-5040. Which comply Eureka-147 and T-DMB standard completely, and can be used in training of DAB / DMB receiver development. The System consisted of DMB-5040, receiver board, DMB-5000, the T-DMB transitter, and DMS-6000, the Manager Software for DMB-5000. DMB-5000, the DMB signal generator, generate Band 3 (174~250MHz) RF signal. With USB interface adopted, this equipment can be connected to a PC and can transfer contents and control data. The DMS-6000, Manager Software for DMB-5000, runs on a PC and performs controls over DMB-5000 and can transfer contents data from a PC to the transmitter. DMB-5040, the T-DMB receiver board, can receive the T-DMB signal and can produce sound for audio services, or can capture the stream of TV channels. Using this board, students can examine various functionality such as; control of tuner, baseband chip, switchs, and display devices of the DMB-5040 receiver board. The development environment for the traniner system is a Linux system running on a PC. Using Linux system, students can edit, compile, download to DMB-5000 board, and execute their test program of DMB receiver. The contents for generation of DMB signal can be stored in Flash Memory of the transmitter or a hard disc of a PC. Using these contents, the software of DMB-5000 or DMS-6000 Manager Software can generate ETI stream, which can be used for DMB signal generation in real time.
    [Show full text]
  • Introduction to Digital Radio Spectrum
    Introduction to Digital Radio Spectrum Summary Radio Spectrum is a vital resource for broadcasters to distribute services to listeners. It allows for a signal to be reached at almost all points in a covered area, including in building and even when a receiver is moving, for instance in a car. It is a quick way to distribute a signal and compared to other forms of media (e.g. newspapers, cable), is an inexpensive way of distributing information. It is flexible, for instance parameters of signal can be adjusted according conditions and requirements. The most important spectrum for digital radio is Band III, which consists of the frequencies from 174 to 230 MHz. Understanding and measuring Spectrum and Radio Waves Radio waves are an electromagnetic radiation like the light, sound or infra light and generated by natural sources such as lightning. They can also be generated artificially for radio communication, industry use or e.g. cooking (microwave ovens). Radio Waves propagate in free air but in other materials. They go through buildings and can be reflected, absorbed or modified. Different frequencies have different propagation characteristics. Propagation is important feature for communication but for interference issues too. Only one signal can be delivered on the same frequency in the same area and time, otherwise the signals will collide and successful transmission will not be possible. Wave length is measured in distance units like meters or kilometres and frequency in units called Hertz. Radio Spectrum is a group of electromagnetic waves with wavelengths from 0.1 millimetres to 100 kilometres. Their frequency is inversely proportional to their wavelength and corresponding values are from the 3000 GHz to 3 kHz.
    [Show full text]