1、 Recommendation ITU-R BS.1514-2(03/2011)System for digital sound broadcasting inthe broadcasting bands below 30 MHzBS SeriesBroadcasting service (sound)ii Rec. ITU-R BS.1514-2 Foreword The role of the Radiocommunication Sector is to ensure the rational, equitable, efficient and economical use of the
2、 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 Region
3、al 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 submis
4、sion 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 Rec
5、ommendations (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 service (television) F Fixed service M Mobile, radiodetermination, amateu
6、r 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 SNG Satellite news gath
7、ering 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, 2011 ITU 2011 All rights reserved. No part of this publication may be r
8、eproduced, by any means whatsoever, without written permission of ITU. Rec. ITU-R BS.1514-2 1 RECOMMENDATION ITU-R BS.1514-2 System for digital sound broadcasting in the broadcasting bands below 30 MHz (Question ITU-R 60/6) (2001-2002-2011) Scope This Recommendation describes the characteristics of
9、various digital terrestrial sound broadcasting systems currently in use, in the LF, MF and HF bands and encourages radio receiver manufacturers to develop portable, multiband, multi-standard digital radio receivers designed to receive emissions not only in the medium and short-wave bands but also in
10、 other bands intended for direct reception of sound broadcasts by the general public. The ITU Radiocommunication Assembly, considering a) that there is an increasing requirement worldwide for suitable means of broadcasting high-quality monophonic or stereophonic sound programmes to vehicular, portab
11、le and fixed receivers; b) that listeners to LF, MF, and HF broadcasts do not yet have an opportunity to benefit from the use of digital sound broadcasting; c) that digital terrestrial sound broadcasting in these bands offers the potential for new and improved services to listeners; d) that listener
12、s would benefit from the existence of a single worldwide standard for terrestrial broadcasting of digital sound signals; e) that the present congestion of terrestrial sound broadcasting bands below 30 MHz in some countries causes a high level of interference and limits the number of programmes which
13、 can be transmitted; f) that broadcasters rely heavily upon the use of these bands because of their favourable propagation conditions, particularly for wide-area coverage requirements; g) that to facilitate the transition from analogue to digital sound broadcasting in a manner that ensures continuit
14、y of service, a simulcast (combined analogue and digital) solution may be necessary in addition to digital-only solutions; h) that Recommendation ITU-R BS.1348 on service requirements for digital sound broadcasting in these bands specifies a series of requirements that are focusing system developers
15、 in several countries to overcome the current deficiencies in audio quality and signal robustness and to provide new services; j) that subsequent to an ITU-R Call for Proposals asking for system descriptions and laboratory and field test results, two ITU-R Sector Members submitted documentation on t
16、wo different digital terrestrial sound broadcasting systems for use in frequency bands below 30 MHz; k) that concise functional design specifications of the two proposals mentioned in considering j) appear in Annexes 1 and 2, with more extensive details referenced in Appendix 1; l) that each of the
17、system proponents has submitted laboratory and field test results, referenced in Appendix 1 for prototype equipment, and that condensed versions of these test results, matched to evaluation criteria defined in Annex 3 are presented in Annexes 4 and 5, 2 Rec. ITU-R BS.1514-2 further considering a) th
18、at other digital radio systems are now in use in different parts of the world, for radio services in various frequency bands, and that different systems sometimes require different IF filters to provide enhanced functionalities, e.g. to enable reception of analogue-digital simulcasts and stereo tran
19、smissions; b) that such a multiplicity of systems and applications might confuse the end users; it may also lead to the availability of radio receivers on the market, designed to only receive some digital radio systems; c) that it would be in the best interest of consumers, particularly of those who
20、 need to also use their radio receivers when travelling, if receivers were available on the market that can receive all the digital radio systems currently in use or proposed; d) that some interactive media, such as the Internet, allow upgrading of the software used to decode and present audio progr
21、ammes and it would be useful if this feature were also available in digital radio receivers; this would also allow taking into account specific requirements of the hearing-impaired and elderly users, recommends 1 that in the HF bands between 3 and 30 MHz: the system characteristics outlined in Annex
22、 1, with more extensive details referenced in Appendix 1, which meet the service requirements of Recommendation ITU-R BS.1348, and answer affirmatively Question ITU-R 60/6, comprise the single common digital sound broadcasting system that should be used in the broadcasting bands under Article 12 of
23、the Radio Regulations provisions; any implementation of digital sound broadcasting in these bands should embody the system characteristics in Annex 1; 2 that in the broadcasting bands below 3 MHz: the system characteristics outlined in Annexes 1 and 2, with more extensive details referenced in Appen
24、dix 1, which meet the service requirements of Recommendation ITU-R BS.1348, and answer affirmatively Question ITU-R 60/6, comprise the digital sound broadcasting systems that should be used in these broadcasting bands; and any implementation of digital sound broadcasting in these bands should embody
25、 the system characteristics in Annex 1 or Annex 2; administrations that wish to implement systems for digital sound broadcasting in the broadcasting bands below 3 MHz, meeting some or all of the requirements stated in Recommendation ITU-R BS.1348, should use Table 1 to evaluate the respective merits
26、 of the systems that they are selecting, invites radio receiver manufacturers to develop 1 economically viable, portable, multiband, multi-standard radio receivers designed to receive, through manual or preferably automatic selection, all the different analogue and digital radio broadcasting systems
27、 currently in use in all the relevant frequency bands; 2 digital radio receivers allowing downloading of upgrades for some of their specific functionalities such as decoding, navigation, management capability, etc. NOTE 1 The revision of this Recommendation, once adopted and approved, should be brou
28、ght to the attention of ISO/IEC/TC 100, as appropriate. Rec. ITU-R BS.1514-2 3 TABLE 1 Compliance table of ITU requirements for DRM and IBOC systems Systems features Importance In the design Test status Expected completion DRM IBOC DRM IBOC DRM IBOC MW SW MW MW SW MW 1 System standard requirement a)
29、 Digital receiver should work worldwide A Yes Yes FUL FUL NYT 07/2002 2 Capability for a gradual transition from analogue to digital a) Simulcast (analogue and digital share a single channel) A Yes Yes (allows gradual transition between analogue and digital) FUL UND FUL 07/02 b) Multicast (analogue
30、and digital occupy separate channels) A Yes (where administration allows such operation) Yes (where administration allows such operation) FUL FUL NYT 3 Data casting a) Audio and data i.e. data casting capability B Yes Yes FUL FUL FUL b) Provision of access control and scrambling C Yes (open issue) Y
31、es (open issue) NYT NYT UND 03/03 03/03 07/02 4) Audio performance requirements a) Improve audio quality over that of equivalent analogue systems A Yes Yes FUL FUL FUL b) Multilanguage or dual mono B Yes No NYT NYT 07/02 07/02 4 Rec. ITU-R BS.1514-2 TABLE 1 (continued) Systems features Importance In
32、 the design Test status Expected completion DRM IBOC DRM IBOC DRM IBOC MW SW MW MW SW MW c) Stereo capability B Yes (pseudo stereo in 9 or 10 kHz) Yes FUL FUL FUL d) Dynamic bit rate division between audio and data (opportunistic data) B Yes Yes FUL FUL FUL e) Bit rate selectable in small steps and
33、higher bit rate supported than achievable at the date of introduction B Yes Yes FUL FUL FUL 5 Spectral efficiency a) Single frequency from geographically-separated or cosited transmitters B Yes Yes FUL FUL NYT 12/02 b) Comply with ITU RF channel bandwidth and spacing A Yes Yes (all digital) FUL FUL
34、UND 03/02 c) Interference potential no more than equivalent amplitude modulation A Yes Yes FUL FUL FUL d) Interference susceptibility no more than equivalent amplitude modulation A Yes Yes FUL FUL FUL 6 Service reliability a) Improve reception reliability A Yes Yes FUL FUL FUL b) Significantly reduc
35、ed susceptibility to fading effects A Yes Yes FUL FUL FUL c) automatic frequency switching of receiver A Yes Yes NYT NYT NYT 12/02 12/02 07/02 inaudible automatic frequency switching of receiver C Yes Yes NYT NYT NYT 12/02 12/02 07/02 Rec. ITU-R BS.1514-2 5 TABLE 1 (continued) Systems features Impor
36、tance In the design Test status Expected completion DRM IBOC DRM IBOC DRM IBOC MW SW MW MW SW MW d) Vehicular, portable and fixed reception A Yes Yes FUL FUL FUL 07/02 e) Rapid tuning A Yes Yes FUL FUL FUL f) Graceful degradation B Yes (Various modes + UEP)Yes (hybrid mode) UND UND FUL g) Maintain c
37、overage area A Yes Yes FUL UND FUL 07/02 h) Good indoor reception A Yes Yes FUL FUL FUL 7 Service information for tuning selection a) Simplified selection of services by using programme-related data to select broadcaster and programme content B Yes (provided in the standard) Yes NYT NYT NYT 12/02 12
38、/02 07/02 8 Transmission system considerations a) Use of existing modern transmitters capable of digital and analogue A Yes Yes FUL FUL FUL b) Power savings when covering the same service area with the same service reliability C Yes Yes FUL FUL FUL c) Spurious and out-of-band emissions adhere to ITU
39、 regulations A Yes Yes FUL FUL FUL 9 Receiver considerations a) System complexity should not preclude low cost receivers A Yes (chipset under development, proven DSP- based) Yes (chipset demonstrated CES2002) UND UND FUL 12/02 12/02 6 Rec. ITU-R BS.1514-2 TABLE 1 (end) Systems features Importance In
40、 the design Test status Expected completion DRM IBOC DRM IBOC DRM IBOC MW SW MW MW SW MW b) System complexity should allow low power consumption battery operated receivers B Yes (chipset technology allows it) Yes UND UND UND 06/03 06/03 06/03 10 Variable trade-off a) Possibility to select system par
41、ameters depending on broadcaster requirement B Yes Yes FUL FUL FUL Neither system A nor system B has finalized testing in LW. However, the results obtained in MW are probably representative for LW. The only possible bottleneck could be the antenna RF bandwidth. DSP: Digital signal processing FUL: Fu
42、lly tested, therefore nothing is needed to be placed in the expected completion date NYT: Not yet tested UEP: Unequal error protection UND: Under way Rec. ITU-R BS.1514-2 7 Annex 1 Summary description of the Digital Radio Mondiale (DRM) system 1 Key features of the system design for the markets to b
43、e served by the DRM system The DRM system, is a flexible digital sound broadcasting (DSB) system for use in the terrestrial broadcasting bands below 30 MHz. It is important to recognize that the consumer radio receiver of the near future will need to be capable of decoding any or all of several terr
44、estrial transmissions; that is, narrow-band digital (for 30 MHz RF), and analogue for the LF, MF, HF bands and the VHF/FM band. The DRM system will be an important component within the receiver. It is unlikely that a consumer radio receiver designed to receive terrestrial transmissions with a digita
45、l capability would exclude the analogue capability. In the consumer radio receiver, the DRM system will provide the capability to receive digital radio (sound, program related data, other data, and still pictures) in all the broadcasting bands below 30 MHz. It can function in an independent manner,
46、but, as stated above, will more likely be part of a more comprehensive receiver much like the majority of todays receivers that include AM and FM band analogue reception capability. The DRM system is designed to be used in either 9 or 10 kHz channels or multiples of these channel bandwidths. Differe
47、nces in detail on how much of the available bit stream for these channels is used for audio, for error protection and correction, and for data depend on the allocated band (LF, MF, or HF) and on the intended use (for example, ground wave, short distance sky wave or long distance sky wave). In other
48、words, there are modal trade-offs available so that the system can match the diverse needs of broadcasters worldwide. As indicated in the next section, when regulatory procedures are in place to use channels of greater bandwidth than 9/10 kHz, the DRM systems audio quality and total bit stream capab
49、ility can be greatly improved. The DRM system employs advanced audio coding (AAC), supplemented by spectral band replication (SBR) as its main digital encoding. SBR improves perceived audio quality by a technique of higher baseband frequency enhancement using information from the lower frequencies as cues. OFDM/QAM is used for the channel coding and modulation, along with time interleaving and forward error correction (FEC) using multi-level coding (MLC) based on a convolutional code. Pilot reference symbols are used to de
