Digital Multimedia Broadcasting

 

Digital Multimedia Broadcasting (DMB) is a digital radio transmission system for sending multimedia (radio, TV, and datacasting) to mobile devices such as mobile phones. This technology is an offshoot of DAB which was originally developed as a research project for the European Union (Eureka project number EU147). DMB was developed in South Korea under the national IT project and the world's first official DMB broadcast started in South Korea in 2005, although trials were available much earlier. It can operate via satellite (S-DMB) or terrestrial (T-DMB) transmission. DMB is based on the Eureka 147 Digital Audio Broadcasting (DAB) standard, and has some similarities with the main competing mobile TV standard, DVB-H.

Like DAB, T-DMB is made for transmissions on radio frequency bands band III (VHF) and L (UHF), for terrestrial. Because the United States and Canada still allocate the first band as for television broadcasting (VHF channels 7 to 13) and the United States reserves the L band for military applications, DMB is still unavailable in North America. Qualcomm's MediaFLO is a proprietary system used there instead. In Japan, 1seg is the standard, using ISDB.

T-DMB uses MPEG-4 Part 10 (H.264) for the video and MPEG-4 Part 3 BSAC or HE-AAC V2 for the audio. The audio and video is encapsulated in MPEG-2 TS. The stream is RS encoding and the parity word is 16 bytes length. There is convolutional interleaving made on this stream, then the stream is broadcast in data stream mode on DAB. In order to diminish the channel effects such as fading and shadowing, DMB modem uses OFDM-DQPSK modulation. A single-chip T-DMB receiver is also provided by an MPEG-2 transport stream demultiplexer. DMB has several applicable devices such as mobile phone, portable TV, PDA and telematics devices for automobiles.

T-DMB is an ETSI standard (TS 102 427 and TS 102 428).

Deployment

Currently, DMB is being put into use in a number of countries, although mainly used in South Korea.

South Korea

In 2005, South Korea started S-DMB and T-DMB service on May 1 and December 1, respectively. [1] [2]

As of December 2006, T-DMB service in South Korea consists of, 7 TV channels, 12 radio channels, and 8 data channels. These are broadcast on six multiplexes in the VHF band on TV channels 8 and 12 (6MHz faster).

As of April 2007, S-DMB service in South Korea consists of 15 TV channels and 19 radio channels and 3 data channels.

S-DMB service in South Korea is provided on a subscription basis through TU Media and is accessible throughout the country. T-DMB service is provided free of charge, but access is limited in selected regions.

Around one million receivers have been sold as of June 2006. Receivers are integrated in car navigation systems, mobile phones, portable media players, laptop computers and digital cameras.

South Korea has Full T-DMB serviced that include JSS(Jpeg Slide Show),DLS(Dynamic Label Segment),BWS, and TPEG in 2006

In Mid August 2007, Iriver, a multimedia and micro-technology company released their "NV", which utilizes South Korea's DMB service.

DMB in automobiles

T-DMB works flawlessly in 80km/h bus. Both TV and Radio works fine. Though DMB skips little bit in the tunnel. It recovers picture pretty fast.

Europe and some other countries

Some T-DMB trials are currently planned or available around Europe and other countries:

• Germany's 'Mobiles Fernsehen Deutschland' launched the commercial T-DMB service "Watcha" in June 2006, in time for the World Cup 2006, marketed together with Samsung's P900 DMB Phone, the first DMB Phone in Europe.
• France is currently running a trial in Paris.
• Indonesia is currently running a trial in Jakarta.
• NRK is currently running a trial in Trondheim, Norway.
• Italy ran a 6-month trial in some areas, they decided to cover more than 50% of the population before the end of 2007.
• China is planning to do DMB service during the 2008 Olympics.
• Ghana is currently running a trial in Accra on Onetouch mobile network.

See also

• 1seg
• China Multimedia Mobile Broadcasting (CMMB)
• Digital Audio Broadcasting (DAB)
• Digital Radio Mondiale (DRM)
• Digital Video Broadcasting (DVB)
• DVB-H
• ETSI Satellite Digital Radio (SDR)
• FMeXtra
• Handheld projector
• Internet radio device
• Multimedia Broadcast Multicast Service
• Satellite radio
• Satellite television
• WiMAX
• WorldDMB

External links

Official

• WorldDMB
• t-dmb.org
• T-DMB Official site of S. Korea
• ETSI T-DMB Specifications available at ETSI Publications Download Area (this will open ETSI document search engine, to find the latest version of the document enter a search string; free registration is required to download PDF)
  • TS 102 427
  • TS 102 428

Other

Related websites

• SK Telecom Satellite DMB service
• What's Satellite DMB service? (SK Telecom)
• News and information on the new digital broadcasting systems
• The Catalyst: e-zine on DAB in the Netherlands
• Mobiles Fernsehen Deutschland
• Litrature:Mobile TV:DVB-H,DMB,3G systems

Broadcast Video Formats
Analog broadcast	525 lines: NTSC • NTSC-J • PAL-M 625 lines: PAL • PAL-N • PALplus • SECAM Defunct systems: Pre-1940 • 405 lines • 819 lines • Baird-Nipkow • MAC • MUSE Multichannel audio: BTSC (MTS) • NICAM-728 • Zweiton (A2, IGR) • EIAJ Hidden signals: Captioning • Teletext • CGMS-A • GCR • PDC • VBI • VEIL • VITC • WSS • XDS
Digital broadcast	Interlaced: SDTV (480i, 576i) • HDTV (1080i) Progressive: LDTV (240p, 288p, 1seg) • EDTV (480p, 576p) • HDTV (720p, 1080p) Digital TV standards (MPEG-2):ATSC, DVB, ISDB, DMB-T/H Digital TV standards (MPEG-4 AVC):DMB-T/H,DVB,SBTVD,ISDB (1seg) Multichannel audio: AAC (5.1) • Musicam • PCM • LPCM Hidden signals: Captioning • Teletext • (CPCM/Broadcast flag)
Technical issues	14:9 • MPEG transport • Standards conversion • Video processing • VOD • HDTV blur

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