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Digital Radio: Possibilities, Promises and Planning Murray Delahoy Principal Engineer Broadcast Spectrum Strategy. Digital Radio. Overview Introduction, systems and key technologies Survey of systems T-DAB, HD-Radio, DRM, Satellite Australian activities Resources, questions.
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Digital Radio: Possibilities, Promises and Planning Murray Delahoy Principal Engineer Broadcast Spectrum Strategy
Digital Radio Overview Introduction, systems and key technologies Survey of systems T-DAB, HD-Radio, DRM, Satellite Australian activities Resources, questions
Digital Radio What is Digital Radio? terrestrial - T-DAB, DRM, HD-Radio, DRM+, T-DMB, DVB-H satellite - Worldspace, S-DMB, Sirius, XM-Radio Why are we interested?
Digital Radio Key technologies perceptual audio coding Multi-level modulation COFDM SFN
Some recent international developments Digital Radio • T-DAB • Considerable take-up of T-DAB in UK (3.1 million units) • VHF Band III receiver prices falling (£35) • Other European, Canada and Asian countries have operating T-DAB services • But take-up is less impressive elsewhere • Germany is “re-purposing” its L-Band DAB network for T-DMB • Korean T-DMB is achieving rapid early growth (1 million units) • HD Radio (formerly known as IBOC or IBAC) • HD Radio standard well accepted in US • but so far only about 10% broadcasters are transmitting • consumer take up slow but seems to be gradually increasing • few receivers in the market (cheapest approx US$100) • DRM and DRM+ (…and no it isn’t Digital Rights Management!) • AM/FM/DAB/DRM LW/MW/SW/VHF Band III/L Band • 26 MHz short wave band for local broadcasting ?? • DRM+ extension to 54-72 or 88-108 MHz bands • consumer radios now available (€299)
Digital Radio HD-Radio proprietary system developed by iBiquity being promoted by US terrestrial radio broadcasters some non-US countries are broadcasting: Brazil, France, Philipines Modulation is COFDM MPEG-4 Perceptual Audio Coding AM and FM versions FM version: 96 kbit/s AM version: 36 kbit/s Digital blending Provides extra channel and/or data capacity Sharing issues 400 KHz FM spacing might be problematic AM spacing issues
Digital Radio HD-Radio – example of FM spectrum usage
Digital Radio HD-Radio – example of AM spectrum usage
Digital Radio T- DAB … what is it? 1.536 MHz spectrum blocks support approx. 1.2 Mbit/s MPEG-2 audio coding can provide 9x128kbit/s “FM radio” streams Can also carry data services Moves to allow improved audio coding Mobile video is possible T-DMB: 1 or 2 reasonable small screen video channels Signals must be multiplexed together at point of transmission or somewhere else? Coded Orthogonal Frequency Division Multiplexing (COFDM) 1536 1 kHz carriers By not transmitting during “guard interval” multipath and co-channel interference from other transmitters in a network can be rejected Single Frequency Network (SFN) concept
Digital Radio T-DAB … planning issues Spectrum availability VHF Band III (174-230 MHz or perhaps 240 MHz) sharing with TV needs to be considered L Band (1452-1492 MHz) Sharing issues terrestrial: fixed links, P-MP, Aeronautical Telemetry and DVB-H ? satellite: S-DAB 1467-1492 MHz (and possible terrestrial repeaters) Suitability of bands Building penetration losses Cost of L-Band deployments antenna performance
Digital Radio DRM and DRM+ DRM compatible with medium and short wave broadcast spectrum 8-20 kbit/s in a 9 kHz AM channel MPEG-4 audio coding - “comparable to FM quality” at 20 kbit/s COFDM with QPSK/16-QAM/64-QAM doesn’t require multiplexing of different program streams no significant receiver base yet DRM+ 50 or 100 kHz channels - “near CD quality” audio bands up to 108 MHz expected to be developed by 2009
Digital Radio DRM and DRM+
Digital Radio Satellite US systems in 2320-2345 MHz band Sirius (3 NGSO satellites + terrestrial repeaters) XM-Radio (2 GSO + terrestrial repeaters) car radios are the major market est. subscriber numbers: Sirius 6.2 million, XM-Radio 8.5 million Under RR 5.393 only US, Mexico and India can access 2310-2360 MHz for BSS(S) and complementary terrestrial repeaters Worldspace 1467-1492 MHz operating satellites: Asiaspace, Afrispace Asian beams cover SE Asia, India, NE Asia
Digital Radio Worldspace coverage
Digital Radio Australian activities Government policy statements: October 2005, April 2006 Staged approach Commence in state capital cities: 1 January 2009 T-DAB in VHF Band III (174-230 MHz) & L-Band(1452-1492 MHz) Capacity for national, commercial and some wide area community services Regional areas, other community and other radio services to be considered later Watching brief on other technologies – especially to address needs of regional areas Provision for future satellite use in L-Band
Digital Radio More information HD-Radio: http://www.ibiquity.com/hd_radio http://en.wikipedia.org/wiki/HD_Radio T-DAB: www.worlddab.org ETSI EN 300 401 v.1.3.3 EBU BPN003 Technical Bases for T-DAB Network Planning … DRM: www.drm.org http://www.drm.org/broadcastmanual/broadcastermanual.php http://en.wikipedia.org/wiki/Digital_Radio_Mondiale ACMA: www.acma.gov.au
Digital Radio Thank you Questions ?