Digital Multimedia Broadcasting

DMB on a Samsung phone in South Korea

List of digital television broadcast standards

DVB standards (Europe)

DVB-S (satellite) DVB-S2

DVB-T (terrestrial) DVB-T2

DVB-C (cable) DVB-C2

DVB-H (handheld) DVB-SH (satellite)

ATSC standards (North America/Korea)

ATSC (terrestrial/cable)

ATSC-M/H (mobile/handheld)

ISDB standards (Japan/Latin America)

ISDB-S (satellite)

ISDB-T (terrestrial) 1seg (handheld)

ISDB-C (cable)

SBTVD/ISDB-Tb (Brazil)

DTMB standards (China)

DTMB-T/H (terrestrial/handheld)

CMMB (handheld)

DMB standards (Korean handheld)

T-DMB (terrestrial)

S-DMB (satellite)

MediaFLO

Codecs

Video MPEG-2 H.264/MPEG-4 AVC AVS

Audio MP2 MP3 AC-3 AAC HE-AAC

Frequency bands

VHF

UHF

SHF

v · d · e

Digital Multimedia Broadcasting (DMB) is a digital radio transmission technology developed in South Korea^[1][2][3] as part of the national IT project for sending multimedia such as TV, radio and datacasting to mobile devices such as mobile phones. This technology, sometimes known as mobile TV, should not be confused with Digital Audio Broadcasting which was developed as a research project for the European Union. DMB was originally developed in South Korea as the next generation digital technology to replace the FM radio.^[4] The world's first official mobile TV service started in South Korea in May 2005, although trials were available much earlier. It can operate via satellite (S-DMB) or terrestrial (T-DMB) transmission. DMB has also some similarities with the main competing mobile TV standard, DVB-H.^[5]

S-DMB

Main article: S-DMB

T-DMB

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 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, using UHF channel 55. 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 an MPEG transport stream (MPEG-TS). The stream is forward error corrected by Reed Solomon encoding and the parity word is 16 bytes long. 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 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). As of December 14, 2007, ITU formally approved T-DMB as the global standard, along with three other standards, like DVB-H, OneSeg, and MediaFLO.^[6]

Countries using DMB

Currently, DMB is being put into use in a number of countries, although mainly used in South Korea. Also see list of Countries using DAB/DMB.

South Korea

In 2005, South Korea became the world's first country to start S-DMB and T-DMB service on May 1 and December 1, respectively.^[7][8] As of December 2006^[update], 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 (6 MHz raster). In October 2007, South Korea added broadcasting channel MBCNET to the DMB channel. But in 2010, this channel changed tnN go. There was eight DMB video channels in Seoul and six in other metropolitan cities in 2009.

South Korea has had Full T-DMB services including JSS (Jpeg Slide Show), DLS (Dynamic Label Segment), BWS, and TPEG since 2006.

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^[update]. 14 million DMB receivers were sold including T-DMB and S-DMB in South Korea, and 40% of the new cell phones have the capability to see DMB.^[9]

Receivers are integrated in car navigation systems, mobile phones, portable media players, laptop computers and digital cameras. In Mid August 2007, Iriver, a multimedia and micro-technology company released their "NV", which utilizes South Korea's DMB service.

Other countries

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

• In Norway T-DMB services have been available since May 2009. MiniTV DMB service launched by the Norwegian Mobile TV Corporation (NMTV) is backed by the three largest broadcasters in Norway: the public broadcaster NRK, TV2 and Modern Times Group (MTG). The live channels can be viewed in and around Greater Oslo.^[10]
• Germany's Mobiles Fernsehen Deutschland (MFD) 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. It was stopped in April 2008 as MFD is now favouring DVB-H, the European standard.^[11]
• France on December 2007 chose T-DMB Audio in VHF band III and L band has the national standard for terrestrial digital radio.^[12]
• China in 2006 chose DAB as an industrial standard. Since 2007 DAB and T-DMB services broadcast in Beijing, Guangdong, Henan, Dalian, Yunnan, Liaoning, Hunan, Zhejiang, Anhui, and Shenzhen.^[13]
• In Mexico most cell phone carriers offer DMB broadcasting as part of their basic plans. As of 2008 the vast majority of Mexico receives DMB signals.
• Ghana is running a T-DMB service in Accra and Kumasi on mobile network since May 2008.^[14]
• The Netherlands: MFD, T-Systems and private investors are planning a DMB service under the name Mobiel TV Nederland. Callmax will also deploy a DMB service on the L-Band frequency in the Netherlands.^[15]
• Indonesia is currently running a trial in Jakarta.
• Italy and Vatican City: RAI^[16] and Vatican Radio^[17] are currently running a trial some areas.
• Canada has been running trials since 2006 in Ottawa, Toronto, Vancouver and Montreal, done by CBC/Radio-Canada.
• Malaysia has been running trials since 2008 in KL, done by TV3/MPB. Initially, the government was committed to deploying DVB-T for government-owned channels, however as of December 2009, RTM1 and 2, as well as all the radio channels, are available over Band III for DMB-T as in addition to DVB-T. Additionally, the TV3 DMB signal has moved to L Band. The TV3 DMB signals are still limited to the Damansara and Kuala Lumpur area, while the government owned DMB-T signals have a wider coverage and apparently covers most of the Klang Valley area. The government transmissions are part of a two year trial that is part of a test that also involves the DAB and DAB+ digital radio standard.
• Cambodia on August 2010 chose T-DMB as the national standard for terrsetrial digital broadcasting. TVK is currently running a trial.^[18]

DMB in automobiles

See also: Software-defined radio and Car audio

T-DMB works flawlessly in vehicles traveling up to 120 km/h.^{[citation needed]} In tunnels or underground areas, both TV and Radio broadcast is still available, though DMB may skip occasionally. Fortunately, the broadcast recovers quickly. In South Korea, some long distance buses adopted T-DMB instead of satellite TV such as Sky TV. It works quite well even though the resolution is less than satellite TV.^{[citation needed]}

See also

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

References

1. ^ "Korea's Terrestrial DMB: Germany to begin broadcast this May". ZDNet Korea. http://www.zdnet.co.kr/ArticleView.asp?artice_id=00000039146251. Retrieved 2010-06-17. 
2. ^ "picturephoning.com: DMB". Textually.org. http://www.textually.org/picturephoning/archives/cat_dmb.htm. Retrieved 2010-06-17. 
3. ^ "South Korea : Social Media 답변 내용 : 악어새 - 리포트월드". Reportworld.co.kr. http://www.reportworld.co.kr/cbqna/cb_answer_view.html?no=40590. Retrieved 2010-06-17. 
4. ^ "The Introduction of DMB in Korea". Ericemoon.googlepages.com. http://ericemoon.googlepages.com/IntroductionofDMBinKorea.pdf. Retrieved 2010-06-17. 
5. ^ "T-DMB". Eng.t-dmb.org. http://eng.t-dmb.org/. Retrieved 2010-06-17. 
6. ^ "ITU approves Mobile TV Standards". Koreatimes.co.kr. http://www.koreatimes.co.kr/www/news/biz/2007/12/123_15630.html. Retrieved 2010-06-17. 
7. ^ "AsiaMedia :: KOREA: Cell phone-based broadcasting starts". Asiamedia.ucla.edu. http://www.asiamedia.ucla.edu/article.asp?parentid=23866. Retrieved 2010-06-17. 
8. ^ "AsiaMedia :: KOREA: KBS to start terrestrial mobile television services next month". Asiamedia.ucla.edu. 2005-11-22. http://www.asiamedia.ucla.edu/article.asp?parentid=34172. Retrieved 2010-06-17. 
9. ^ DMB users shout in the metro coming home, Daily economics
10. ^ "Norway launches mobile TV via DMB". Broadbandtvnews.com. 2009-05-18. http://www.broadbandtvnews.com/?p=18236. Retrieved 2010-06-17. 
11. ^ Broadband TV news: MFD hands back German T-DMB licence, May 1, 2008
12. ^ "Country Information for DAB, DAB+ and DMB -France (WorldDMB)". Worlddab.org. 2008-01-18. http://www.worlddab.org/country_information/france. Retrieved 2010-06-17. 
13. ^ "Country Information for DAB, DAB+ and DMB -China (WorldDMB)". Worlddab.org. http://www.worlddab.org/country_information/china. Retrieved 2010-06-17. 
14. ^ "Country Information for DAB, DAB+ and DMB -Ghana (WorldDMB)". Worlddab.org. http://www.worlddab.org/country_information/ghana. Retrieved 2010-06-17. 
15. ^ Emerce Digitale omroep gaat concurrentie aan met KPN MobielTV, Februari 12, 2009
16. ^ "RAIWay". RAIWay. http://www.raiway.rai.it/index.php?lang=IT&cat=73&showNE=57&PHPSESSID=014e6bb9. Retrieved 2010-06-17. 
17. ^ Webteam. "Web TV and T-DMB programmes". Vatican Radio. http://www.radiovaticana.org/sv1/web_tv.asp. Retrieved 2010-06-17. 
18. ^ http://news.naver.com/main/read.nhn?mode=LSD&mid=sec&sid1=001&oid=001&aid=0004620658

External links

• WorldDMB
• T-DMB Official site of S. Korea
• TS 102 427 specification
• TS 102 428 specification
• Differences between T-DMB and DAB+ explained