1、 Report ITU-R BS.2208(10/2010)Possible use of VHF band I for digitalsound broadcasting servicesBS SeriesBroadcasting service (sound)ii Rep. ITU-R BS.2208 Foreword The role of the Radiocommunication Sector is to ensure the rational, equitable, efficient and economical use of the radio-frequency spect
2、rum 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
3、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 stateme
4、nts 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 o
5、nline 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 servic
6、es 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 th
7、e Study Group 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 reproduced, by any means whatsoever, without written permission of ITU. Rep. ITU-R BS.2208 1 REPORT ITU-R BS.2208 Possible use of VHF
8、 Band I for digital sound broadcasting services (2010) TABLE OF CONTENTS Page 1 Introduction 1 2 Why consider the use of these bands for digital sound broadcasting? . 2 3 What digital broadcasting systems might be considered in Band I? 3 4 Band I . 4 4.1 The existing use of Band I in Region 1 4 4.2
9、The regulatory conditions for Band I in Region 1 5 4.3 Technical considerations related to Band I in Region 1 . 6 5 Conclusions and proposals . 7 Annex 1 Extract from the ST61 Plan: Assignments in Band I . 8 Annex 2 Extract from Article 5 of the ITU Radio Regulations for Band I . 9 Annex 3 Extracts
10、from the ST61 Agreement: Modification and notification procedures 11 Annex 1 to the Regional Agreement for the European broadcasting area Tables of distances to be used in the application of Article 4 of the Agreement . 13 1 Introduction Radio and television broadcasting is in the process of migrati
11、ng to digital modulation schemes to better exploit the possibilities offered by existing and new delivery platforms. Digital modulation offers significant advantages in being able to give: consistent quality which is less dependent on variations in the channel; more effective use of channel capacity
12、 through resilient coding and advanced compression techniques; easier access through automatic or assisted tuning; versatility by including audiovisual and data information in the same channel. 2 Rep. ITU-R BS.2208 Recognizing that analogue broadcasting technologies still find significant use and wi
13、ll continue to do so for some time to come, this Report will restrict itself to consideration of digital systems. While the Internet and associated systems are playing an increasingly important role in the delivery of sound broadcasting services, conventional terrestrial radio still plays a very imp
14、ortant part in delivering radio to its audiences. Demand for services outstrips the channel capacity and so there is pressure to increase that capacity. More efficient digital formats play a major part in this quest. However, this document examines the possibility of using digital formats in parts o
15、f the spectrum that are, have been, or can be made available for broadcasting but are not very much used at the moment. VHF Band I is taken to include frequencies between 47 MHz and 68 MHz. From a technical point of view, there is no reason why this should not be extended to include the OIRT Bands (
16、see Article 5 of the Radio Regulations (RR) used in certain countries for FM analogue broadcasting. While this band may not be available in all locations it is a valuable broadcasting resource where it is available and the technical arguments are the same as for the frequency bands immediately below
17、 it. 2 Why consider the use of these bands for digital sound broadcasting? Traditionally sound broadcasting has been carried out in the LF, MF, HF and VHF (Band II) bands. More recently, digital (DAB) sound services in VHF (Band III) have been broadcast in certain parts of the world. With the except
18、ion of the HF bands, where the unique propagation characteristics are vital to long distance international sound services, VHF Band II has become predominant among them. So much so that in many parts of the world the 88 to 108 MHz band has become crowded and there is little or no opportunity for new
19、 services to be introduced. For various reasons not least, better use of spectrum some countries are considering, or are in the process of introducing, digital sound broadcasting systems. At the present time the majority of such services are located in VHF Band III using the DAB system. It has not b
20、een possible to introduce DAB services into Band II because the band is already heavily used and the introduction of a single DAB multiplex would require eight existing services to be switched off to make space. Past experience has shown that it can take a long time for a new broadcasting format to
21、establish itself. FM in Band II was around for a very long time before it became the predominant sound broadcasting system, AM in the MF band was displaced from this predominant role. It is therefore to be expected that any radio service will have to be simultaneously broadcast in both the old, anal
22、ogue, and new, digital, formats until such time as the bulk of the audience has migrated. Obviously this will make a further demand on spectrum and further inhibit the ability to introduce new services. The restricted quality of sound broadcasting in the LF and MF bands means that it has fallen from
23、 favour with a large part of its traditional users; both broadcasters and audiences. Despite this there is still a large residual use. In certain parts of the world, including Europe, the LF and MF bands are still crowded. Even if channels were available, their perceived low analogue quality and wid
24、e area propagation characteristics make them unattractive to local and community broadcasters. There is a high demand for radio services to small, local and even community service areas. Such service areas are usually limited to a radius of less than a few kilometres covering just a small part of a
25、town or city. The cost of setting up such a local station, the ongoing running costs and quality of coverage are important issues to be considered. Use of digital modulation techniques would certainly provide the quality of coverage while requiring low transmitter power and hence low cost. The DAB s
26、ystem is good for covering large audiences. This is particularly true where a number of broadcasters have the same geographical coverage aspiration and where several high-power Rep. ITU-R BS.2208 3 transmitters can be synchronized into a large single frequency network. DAB is very good at national a
27、nd regional coverage. It is less good where the coverage aspirations of the participating broadcasters in a given multiplex are not the same which is frequently the case with small, local or community broadcasters. Conventional DAB only becomes efficient in its use of spectrum when multiple transmit
28、ters can use the same channel to cover a large area. It can therefore be unattractive to local broadcasters who wish neither to reach, nor pay the transmission fees, to cover larger audiences. The DAB+ system partly addresses this by having more stations in the multiplex, thereby offering better spe
29、ctral efficiency without the need for single frequency networks. However, this implies that an even greater number of stations will have to be found which are seeking identical coverage. In turn this limits its attractiveness to small broadcasters who would be better served by a transmitter designed
30、 to match their unique coverage requirements. 3 What digital broadcasting systems might be considered in Band I? VHF Band I is currently little used and offers the possibility to find spectrum for new radio services. The most appropriate digital modulation scheme currently available for these bands
31、appears to be the DRM30/DRM+1family. The HD Radio specification does not include modes which allow it to work in the HF band or in VHF Band I. While HD Radio operation in these bands is a technical possibility, the EBU is not aware of any tests having been carried out. DRM was originally conceived a
32、s a digital medium for use in the LF, MF and HF bands below 30 MHz. Propagation conditions in the HF band can be hostile; much development effort was expended in making DRM work in these hostile conditions. DRM+ has been more recently developed, and standardized2 to facilitate a system offering the
33、benefits of DRM in the broadcast bands between 30 MHz and 174 MHz. It uses a wider-band multiplex. While DRM30 has been shown to work3in VHF Band I, a bigger multiplex offers a greater correlation bandwidth and hence better defence against flat fading. Further, higher bit rates are possible to give
34、better audio quality and/or more services in the multiplex. While able to offer line-of-sight services to small communities, VHF Band I might better be used to provide services to somewhat wider areas. This is perfectly feasible as evidenced by its traditional use for television. Band I is now littl
35、e used for television and so large parts of it are free in many parts of the world. It is worth noting that where parts of Band I have been used by administrations for other purposes there is little coordination. Different parts are used in different countries for different applications (see 5). How
36、ever, the band is wide and space is usually available in parts of the band, albeit different parts of the band in different parts of the world. Line-of-sight transmission and a relatively large amount of available spectrum offer the opportunity to use higher quality, wide channel modes with the DRM3
37、0 system. In VHF Band I, the DRM+ system is perhaps the better option as it can offer up to four high-quality audio services in a 100 kHz multiplex. The trade-off between the number of streams and the audio quality fewer streams higher quality should be noted. 1DRM30 is the DRM system initially desi
38、gned for use in the frequency bands below 30 MHz. DRM+ is the extension of this system for use in the frequency bands between 30 and 174 MHz. 2The DRM system specification was revised to incorporate an additional mode designed for the lower VHF band (i.e. broadcast frequencies between 30 MHz and 174
39、 MHz) allowing operation in Bands I and II (the FM band). This standard enhancement is called DRM+. A download version of the DRM system specification (ESTI ES 201 980 V3.1.1) is available on the ESTI website at http:/www.etsi.org. 3The technical feasibility of using Band I for DRM, and consequently
40、 for DRM+, has been proven by trials carried out by TDF in Rennes. 4 Rep. ITU-R BS.2208 DRM+ could be deployed in VHF Band II but this is at the moment saturated with FM services in many European countries. If there is a desire for usable spectrum for DRM+ at frequencies below 120 MHz in the short o
41、r medium term (or until it can be introduction in Band II), Band I would be a suitable candidate for its early introduction. 4 Band I Successful tests have been carried out in Band I4which demonstrate that this band is suitable for local broadcasting using both the DRM30 and DRM+ systems. 4.1 The ex
42、isting use of Band I in Region 1 VHF Band I is the frequency band from 47 to 68 MHz. In Region 1, this band is allocated to the broadcasting service on a primary basis in the ITU RR. In the European Broadcasting Area (EBA), the broadcast use is analogue television and FM sound broadcasting; SAB/SAP
43、applications are also included on a secondary basis. In some European countries, the broadcasting usage of that band has stopped. The ST61 Agreement for television and sound broadcasting in the European broadcasting area is the oldest broadcasting Plan. It is still in force after 45 years and shows
44、1 119 assignments currently registered in Band I in Region 1 (see Annex 1). Band I is not exclusive to broadcasting and there is sharing with land mobile and some other services (for example, the amateur service) in a number of countries. Parts of Band I are also allocated to the fixed service on a
45、secondary basis in certain countries. Within Band I there are several channel/frequency assignment arrangements. In Eastern Europe, in France and in Ireland, channels are 8 MHz wide and in other countries the channel width is 7 MHz. There is little consistency in the allocation of vision frequencies
46、 for a given channel within countries using either 7 or 8 MHz channels. There is, of course, no alignment of channel edges between countries using 7 MHz channels and those using 8 MHz channels. Despite being allocated to the broadcasting service in the ITU, a number of other diverse applications als
47、o have allocations in Band I through footnotes in the RR (see Annex 2). The trend in several European countries within CEPT has been to withdraw broadcasting activity from this band. For the long term, the CEPT plans do not consider this band for broadcasting any more, as shown in Table 1 which is a
48、n extract from the European Common Allocation Table (see ERO Report 25 for more details (www.ero.dk). 4The technical feasibility of using Band I for DRM, and consequently for DRM+, has been proven by trials carried out by TDF in Rennes and Successful trials of DRM+ in Band I were carried out in Pari
49、s in July 2009 by the Syndicat National des Radios Libres (SNRL) and was performed with the help of University of Applied Sciences, Kaiserslautern and Fraunhofer IIS, Erlangen. For more information, see: http:/www.drm.org/news/detail/news/drm-in-band-i-promoted-as-a-most-suitable-technology-to-complement-other-digital-radio-standards-in/. Rep. ITU-R BS.2208 5 TABLE 1 Allocation of Band I in the European Common Allocation Table (source ERO) Europe (ECA) 46.400-47.000 MHz Defence systems/PER/Wind profilers/Radio microphones and Assistive listening devic
