Digital Radio: Possibilities, Promises and

Planning

Murray DelahoyPrincipal 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• 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

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 ?