1、 Recommendation ITU-R BS.774-4(06/2014)Service requirements for digital sound broadcasting to vehicular, portable and fixed receivers using terrestrial transmitters in the VHF/UHF bandsBS SeriesBroadcasting service (sound)ii Rec. ITU-R BS.774-4 Foreword The role of the Radiocommunication Sector is t
2、o 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 functio
3、ns 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 referen
4、ced 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
5、-R patent information database can also be found. Series of ITU-R Recommendations (Also available online at http:/www.itu.int/publ/R-REC/en) Series Title BO Satellite delivery BR Recording for production, archival and play-out; film for television BS Broadcasting service (sound) BT Broadcasting serv
6、ice (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
7、 fixed service systems SM Spectrum management SNG Satellite news gathering TF Time signals and frequency standards emissions V Vocabulary and related subjects Note: This ITU-R Recommendation was approved in English under the procedure detailed in Resolution ITU-R 1. Electronic Publication Geneva, 20
8、14 ITU 2014 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without written permission of ITU. Rec. ITU-R BS.774-4 1 RECOMMENDATION ITU-R BS.774-4 Service requirements for digital sound broadcasting to vehicular, portable and fixed receivers using terrest
9、rial transmitters in the VHF/UHF bands* (Question ITU-R 107/10) (1992-1994-1995-2011-2014) Scope This Recommendation describes the desirable technical and operational characteristics and capabilities when the digital sound broadcasting systems is used for the terrestrial digital sound broadcasting t
10、o vehicular, portable and fixed receivers in the VHF and UHF bands. Keywords Service Requirement, Digital Sound Broadcasting, Terrestrial Transmission, UHF/VHF Bands. The ITU Radiocommunication Assembly, considering a) that there is an increasing requirement worldwide for suitable means of broadcast
11、ing high-quality stereophonic sound of two or more channels with subjective quality indistinguishable from high-quality consumer digital recorded media (“CD quality”) to vehicular, portable and fixed receivers; b) the limitations of the existing VHF/FM sound broadcasting services to fulfil such requ
12、irements, particularly for vehicular and portable reception; c) that the present congestion in some countries in the utilization of the VHF/FM frequency band causes a generally increasing level of interference and limits the number of programmes which can be transmitted; d) that technical developmen
13、ts in source and channel coding, modulation and advanced digital signal processing, have demonstrated the technical feasibility and maturity of digital sound broadcasting systems; e) that a large series of demonstrations and field trials in various parts of the world have confirmed the technical fea
14、sibility and economic viability from a system design point of view of digital sound broadcasting systems; f) that an advanced digital sound broadcasting system can provide better spectrum and power efficiency as well as better performance in multipath environments than conventional analogue systems;
15、 g) that the complementary use of terrestrial and satellite systems can result in better power and spectrum efficiency through the implementation of hybrid and mixed terrestrial/satellite digital sound broadcasting service; h) that a digital broadcasting system can be employed in both terrestrial an
16、d satellite applications using closely related emission signal parameters, thus allowing common receiver design with common processing VLSI circuits; *This Recommendation should be brought to the attention of the International Electrotechnical Commission (IEC). 2 Rec. ITU-R BS.774-4 i) that sound br
17、oadcasting has always used similar modulation techniques throughout the world, such as AM or FM and similar, if not identical, frequency bands, leading to a receiver that could be used worldwide, for the benefit of the listener; j) that extensive sound broadcasting services, both public and private,
18、 exist throughout the world that provide sound programmes to listeners, recommends that when digital sound broadcasting services from terrestrial transmitters, intended for vehicular, portable and fixed reception, are introduced into the VHF and UHF bands, digital sound broadcasting systems to be us
19、ed should have the following technical and operational characteristics and capabilities: 1) be capable of providing high-quality stereophonic sound of two or more channels with subjective quality indistinguishable from high-quality consumer digital recorded media (“CD quality”) to vehicular, portabl
20、e and fixed receivers; 2) better spectrum and power efficiency than conventional analogue FM systems; 3) significantly improved performance in a multipath and shadowing environment through the use of frequency and time diversity and co-channel space diversity at the transmitting end when needed; 4)
21、be capable of utilizing common signal processing in receivers for any terrestrial and satellite broadcasting applications; 5) allow configuration/reconfiguration in order to transmit sound programmes with lower bit rates to trade-off quality and the number of sound programmes available; 6) allow for
22、 a trade-off between extent of coverage for a given emission power, service quality and the number of sound programmes and data services; 7) be capable of allowing, with a common receiver, the use of all means of programme delivery, such as: local, sub-national and national terrestrial VHF/UHF netwo
23、rk services; mixed/hybrid use of terrestrial and national/supra-national UHF satellite service; cable distribution networks; 8) be capable of providing enhanced facilities for programme-related data (e.g. service identification, programme labelling, programme delivery control, copyright control, con
24、ditional access, dynamic programme linking, services for visually and hearing-impaired, etc.); 9) allow for flexible assignment of services within a given multiplex; 10) a system multiplex structure capable of complying with the layered ISO open system interconnect model and permitting interfacing t
25、o information technology equipment and communications networks; 11) be capable of providing value-added services with different data capacities (e.g. traffic message channels, business data, paging, still picture/graphics, future integrated services digital broadcasting (ISDB), low bit-rate video/mu
26、ltiplex, etc.); 12) allow the manufacturing of low cost receivers and antennas through mass production, invites the ITU membership and radio receiver manufacturers to consider 1 economically viable, portable, multiband, multistandard radio receivers designed to work, through manual or preferably aut
27、omatic selection, with all the different analogue and digital radio broadcasting systems currently in use in all the relevant frequency bands; Rec. ITU-R BS.774-4 3 2 digital radio receivers allowing downloading of upgrades for some of their specific functionalities such as decoding, navigation, man
28、agement capability etc.; 3 a simple indicator of the received RF field level and of the bit error rate. NOTE 1 An example of a digital sound broadcasting system (Digital System A) that meets the above technical and operational requirements and capabilities is described in Annex 1 to Recommendation I
29、TU-R BS.1114. NOTE 2 System and service characteristics as well as radio-frequency aspects of digital sound broadcasting systems are considered in detail in the ITU-R Special Publication on Terrestrial and Satellite Digital Sound Broadcasting to Vehicular, Portable and Fixed Receivers in the VHF/UHF bands. NOTE 3 There is a closely related Recommendation ITU-R BO.789 for satellite sound broadcasting.
