1、 Recommendation ITU-R BS.1348-3(06/2014)Service requirements for digital sound broadcasting at frequencies below 30 MHzBS SeriesBroadcasting service (sound)ii Rec. ITU-R BS.1348-3 Foreword The role of the Radiocommunication Sector is to ensure the rational, equitable, efficient and economical use of
2、 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 Re
3、gional 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 su
4、bmission 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
5、 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 service (television) F Fixed service M Mobile, radiodetermination, am
6、ateur 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
7、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, 2014 ITU 2014 All rights reserved. No part of this publication may
8、be reproduced, by any means whatsoever, without written permission of ITU. Rec. ITU-R BS.1348-3 1 RECOMMENDATION ITU-R BS.1348-3 Service requirements for digital sound broadcasting at frequencies below 30 MHz*(Question ITU-R 217/10) (1998-2001-2011-2014) Scope This Recommendation describes the desir
9、able technical and operational characteristics and capabilities when the digital sound broadcasting systems is used for the terrestrial digital sound broadcasting to vehicular, portable and fixed receivers in the frequency below 30 MHz. Keywords Service Requirement, Digital Sound Broadcasting, LF, M
10、F, HF. The ITU Radiocommunication Assembly, considering a) that there is an increasing requirement worldwide for suitable means of broadcasting high-quality monophonic or stereophonic sound to vehicular, portable and fixed receivers; b) the limitations of the existing LF, MF and HF sound broadcastin
11、g services abilities to fulfil such requirements; c) that the present congestion in some countries on the utilization of the LF, MF and HF bands causes a high level of interference and limits the number of programmes which can be transmitted; d) that technical developments in source and channel codi
12、ng, modulation and advanced digital signal processing, have demonstrated the technical feasibility and maturity of digital sound-broadcasting systems in other bands; e) that a large series of demonstrations and field trials in various parts of the world have confirmed the technical feasibility and e
13、conomic viability from a system design point of view of digital sound broadcasting systems in other bands; f) that an advanced digital sound broadcasting system can provide better coverage and better spectrum and power efficiency as well as better performance in multipath environments than conventio
14、nal analogue systems; g) that a digital broadcasting system can be designed which may be employed in both terrestrial and satellite applications using closely related emission signal parameters, thus allowing common elements in the receiver design; h) that sound broadcasting has always used similar
15、modulation techniques, such as AM or FM and similar, if not identical, frequency bands throughout the world, leading to a receiver that could be used worldwide, for the benefit of the listener; i) that extensive sound broadcasting services, both public and private, which provide sound programmes to
16、listeners, exist throughout the world, *This Recommendation should be brought to the attention of the International Electrotechnical Commission (IEC). 2 Rec. ITU-R BS.1348-3 recommends 1 that when digital sound-broadcasting services from terrestrial transmitters, intended for vehicular, portable and
17、 fixed reception, are introduced into the LF, MF and HF bands, the digital system employed should have the following technical and operational characteristics and capabilities as well as the service requirements in Annex 1: be capable of providing high-quality monophonic or stereophonic sound to veh
18、icular, portable and fixed receivers; provide better spectrum and power efficiency than conventional analogue systems; provide significantly improved performance in a multipath environment; allow for a trade-off between extent of coverage and service quality for a given emission power; be capable of
19、 allowing, with a common receiver, the use of all means of programme delivery (e.g. mono, stereo, dual mono); be capable of providing facilities for programme-related data; be capable of providing additional data services; allow the manufacturing of low-cost receivers through mass production; 2 that
20、 a receiver designed for digital signals should also be capable of conventional analogue reception with maximum commonality of technology and parts, invites the ITU membership and radio receiver manufacturers to consider 1 economically viable, portable, multiband, multistandard radio receivers desig
21、ned to work, through manual or preferably automatic selection, with all the different analogue and digital radio broadcasting systems 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 d
22、ecoding, navigation, management capability, etc.; 3 a simple indicator of the received RF field level and of the bit error rate. Rec. ITU-R BS.1348-3 3 Annex 1 Service requirements for digital sound broadcasting and their relative importance Systems features Importance 1 System standard requirement
23、a. digital receiver should work worldwide. A 2 Capability for a gradual transition from analogue to digital a. Simulcast (analogue and digital share a single channel). A b. Multicast (analogue and digital occupy separate channels). 3 Data casting a. Audio and data (i.e. data casting capability). B b
24、. Provision of access control and scrambling. C 4 Audio performance requirements a. Improve audio quality over that of equivalent analogue systems. A b. Multi-language or dual mono. B c. Stereo capability. B d. Dynamic bit rate division between audio and data (opportunistic data). B e. Bit rate sele
25、ctable in small steps and higher bit rate supported than achievable at the date of introduction. B 5 Spectral efficiency a. Single frequency from geographically separated or co-sited transmitters. B b. Comply with ITU RF channel bandwidth and spacing. A c. Interference potential no more than equival
26、ent amplitude modulation. A d. Interference susceptibility no more than equivalent amplitude modulation. A 6 Services reliability a. Improve reception reliability. A b. Significantly reduced susceptibility to fading effects. A c. 1) Automatic frequency switching of receiver. 2) Inaudible automatic f
27、requency switching of receiver. A C d. Vehicular, portable and fixed reception. A e. Rapid tuning. A f. Graceful degradation. B g. Maintain coverage area. A h. Good indoor reception. A 7 Service information for tuning selection a. Simplified selection of services by using programme related data to s
28、elect broadcaster and programme content. B 8 Transmission system considerationsa. Use of existing modern transmitters capable of digital and analogue. A b. Power savings when covering the same service area with the same service reliability. C c. Spurious and out of band emissions adhere to ITU regul
29、ations. A 9 Receiver considerations a. System complexity should not preclude low cost receivers. A b. System complexity should allow low power consumption battery operated receivers. B 10 Variable trade off a. Possibility to select system parameters depending on broadcaster requirement. B Relative importance of the system features: A = mandatory B = highly desirable C = desirable
