Radio Spectrum for Digital Audio Broadcasting

Transcription

1 For Information on 3 March 2005 RSAC Paper 5/2005 Radio Spectrum for Digital Audio Broadcasting Purpose This paper updates Members on the latest development on Digital Audio Broadcasting ( DAB ) services and discusses the existing and potential radio spectrum for DAB services in Hong Kong. Background 2. In 1997, the Office of the Telecommunications Authority ( OFTA ) informed members of the latest development on DAB (Please refer to RSAC Paper No. 2/1997 titled Radio Spectrum for Digital Audio Broadcasting ). Since then, there have been significant developments of DAB services worldwide. At present, the prevailing DAB standards include: (a) Digital Radio Mondiale ( DRM ) This standard has been adopted by the International Telecommunication Union ( ITU ) and the European Telecommunications Standards Institute ( ETSI ); (b) Eureka 147 This standard has been adopted by the ITU and ETSI. There is also a variant of Eureka 147 known as Digital Multimedia Broadcasting ( DMB ) under consideration by the ETSI. DMB supports multimedia applications for a mix of video, sound and data. (c) In-Band-On-Channel ( IBOC ) This standard was developed in the US and has been adopted by the US and ITU for DAB; and (d) Integrated Services Digital Broadcasting Terrestrial ( ISDB-T ) This standard has been adopted by the Association of Radio Industries and Businesses ( ARIB ) for use in Japan. Frequency Bands for DAB Services and the Latest Developments 3. The frequency bands which can be used for DAB services together with the supporting DAB standards are described below: 1

2 (a) HF Band and below (frequencies < 30 MHz) The DRM and IBOC standards support DAB services in the frequency bands below 30MHz. Both standards allow the coexistence of the existing analogue sound service and new digital sound service. Due to the low frequencies, the channel bandwidth is usually very narrow. Both standards do not support high quality sound service. However, low frequency band is good for long distance and wide coverage applications. (b) VHF/FM Band ( MHz) The band is being used for analogue FM broadcast worldwide. IBOC supports DAB services in the band by inserting additional digital carriers in the sidebands of an existing FM channel, making it possible for the simultaneous transmission of a new digital sound programme together with an existing FM sound programme. In order to implement IBOC, the overall channel bandwidth should not be less than 400 khz. (c) Band III ( MHz) Eureka 147 supports the provision of DAB services in this band. The propagation characteristics are similar to those of the existing VHF/FM band and it is possible to make use of the same FM transmitting sites to provide Band III DAB services with more or less the same coverage. The cost of a Band III Eureka 147 receiver is much cheaper than that of an L Band receiver. ISDB-T also supports DAB services in this band. (d) L-Band ( MHz) The ITU has allocated the L-Band for Eureka 147 DAB services. According to the frequency plan, a total of 23 frequency channels are defined for satellite and terrestrial DAB services based on Eureka 147. (e) S Band ( MHz and MHz) According to the ITU Radio Regulations, broadcasting satellite service (sound) may operate in the band MHz for US, India and Mexico and the band MHz for Korea, India, Japan, Pakistan and Thailand. 2

3 Implementation of DAB Services in Other Countries 4. A number of countries have already implemented DAB services and a brief summary of the deployment of different DAB standards is given in Annex 1. The latest DAB development and adoption of different DAB standards is given below: (a) According to the DRM Consortium, some 65 broadcasters in the Europe and the US have already implemented the DRM system for provision of simulcast services to supplement and improve the existing analogue sound broadcasting service. The supply of DRM receivers is limited and the price is high. As most of the famous manufacturers have announced to support DRM, it is expected many different types of DRM receivers with affordable prices will soon be available in the market. (b) IBOC standard is only adopted in the US and has been implemented in the VHF/FM and MF/AM bands to provide simulcast services. (c) A number of European countries, including the UK, Germany, Denmark and some Asian economies including Taiwan, Singapore and South Korea have launched Eureka 147 DAB services in Band III. There are many types of receivers available in the European market now and the price comes down quickly in recent years. It is expected that DAB services in Band III with the use of Eureka 147 will become more and more popular. (d) Canada, German and Australia have already launched Eureka 147 DAB services in the L-Band. However, the service is not popular because of the high receiver cost. (e) The Mainland China is conducting trial of DMB system in Band III in Foshan of Guangdong and has a plan to install DMB receivers on public transportation, such as bus and trains. It aims to provide video broadcast services. In South Korea, a trial of satellite based DMB services in the S Band is being conducted. South Korea aims to offer commercial video broadcast service in May

4 DAB Development in Hong Kong 5. As stated in the Consultation Paper on Digital Terrestrial Broadcasting in Hong Kong 1 issued in 2000 and the Second Consultation on Digital Terrestrial Broadcasting in Hong Kong 2 issued in 2003, the Government adopts a market-led approach to the development of DAB in Hong Kong. While allowing the existing sound broadcasters to continue their AM/FM analogue services under their respective licence conditions, the Government welcomes applications for DAB service trials by using L-band frequencies or, subject to spectrum availability, Band III frequencies. 6. The development of DAB and availability of frequency bands for implementation of DAB in Hong Kong are described below: a) HF Band and below (frequencies < 30 MHz) Radio Television Hong Kong ( RTHK ) conducted a trial of DRM in Golden Hill by sharing the existing AM channel at 783 khz (MF band) for simultaneous transmission in March The result revealed that the indoor coverage of DRM was constrained by the maximum allowable transmitter power of the AM service in Hong Kong and the radio wave propagation characteristics in the MF band. So far OFTA is not aware of any plan from the existing broadcasters for deploying DRM in Hong Kong. (b) VHF/FM Band ( MHz) The VHF/FM band in Hong Kong has already been fully occupied for provision of FM broadcast service. As the channel bandwidth of the Hong Kong VHF/FM plan is 200 khz, implementation of IBOC, which requires a minimum bandwidth of 400 khz, in this band is not feasible. (c) Band III ( MHz) Except the band MHz which is vacant, most of the frequencies in the band MHz have been assigned for fixed and land mobile services in Hong Kong. A brief summary of the frequency allocation in Band III in Hong Kong is summarized in 1 The first consultation paper on Digital Terrestrial Broadcasting in Hong Kong issued in 2000 could be downloaded from 2 The second consultation paper on Digital Terrestrial Broadcasting in Hong Kong issued in 2003 could be downloaded from 4

5 Annex 2. OFTA has conducted an initial study and found that some frequency channels could be made available for DAB in Band III but frequency coordination with the Mainland authority is required. OFTA has been coordinating with the Mainland Authorities since It is expected that a firmed frequency plan in Band III for DAB can be formulated in (d) L-Band ( MHz) Hong Kong has conducted a trial of Eureka 147 system in the L-band in 1998 and confirmed that Eureka 147 in L-band could provide acceptable DAB services in Hong Kong. At present the frequencies in MHz, as shown in Annex 3, are reserved for DAB services in Hong Kong. (e) S Band ( MHz and MHz) The band MHz has been allocated for the third generation ( 3G ) mobile service in China and hence cannot be used for DAB service in Hong Kong. The band MHz has been reserved for 3G expansion worldwide. Hence, for the time being, these bands will not be considered for DAB service in Hong Kong. Way Forward 7. According to the worldwide DAB development, the use of Band III for DAB services is becoming popular. To meet the possible demand, OFTA has initiated action to coordinate with the Mainland authorities for frequency channels in the Band III for DAB services. OFTA will keep Members informed of the proposed frequency plan for Band III DAB in future RSAC meetings. Office of the Telecommunications Authority February

6 Annex 1 Summary of the DAB Systems in Overseas Countries Eureka 147 DRM IBOC ISDB-T Band III L-Band Below 30 MHz Australia Australia Belgium Canada Canada Denmark Finland German Singapore South Korea * Taiwan UK France German New Zealand German Luxembourg Netherlands Portual Russia Sri Lanka UK MF/AM VHF/FM UHF Japan US US * South Korea aims to launch its DMB service in S-Band in May

7 Annex 2 Frequency Allocation in Band III Frequency Band (MHz) Allocation in ITU Region 3 FIXED MOBILE BROADCASTING Existing Allocation in Hong Kong FIXED LAND MOBILE (Note 1, 2) TO BE PLANNED FIXED MOBILE BROADCASTING AERONAUTICAL RADIONAVIGATION Radiolocation FIXED MOBILE (Note 3 and 4) Note: 1. The band MHz is currently used mostly for fixed and mobile radiocommunications services. 2. The band MHz and MHz have been included in the Telecommunications (Telecommunications Apparatus) (Exemption from Licensing) Order. 3. There are a few Outside Broadcasting links being used by the radio sound broadcasters in the band MHz. 4. The band MHz is currently used by mobile radio systems. 7

8 Frequency Channels for Eureka 147 DAB System in L-Band Annex 3 Block Number Frequency (MHz) Block Number Frequency (MHz) LA LM * LB LN * LC LO * LD LP * LE LQ LF LR LG LS LH LT LI * LU LJ * LV LK * LW LL * Notes: The frequencies marked with an asterisk are vacant and readily available for DAB services in Hong Kong. Some of the remaining frequencies may be made available for DAB services when there is a need. 8