China Multimedia Mobile Broadcasting
Encyclopedia
China Mobile Multimedia Broadcasting (CMMB) is a mobile television and multimedia standard developed and specified in China
by the State Administration of Radio, Film, and Television
(SARFT). It is based on the Satellite and Terrestrial Interactive Multiservice Infrastructure (STiMi), developed by TiMiTech, a company formed by the Chinese Academy of Broadcasting Science. Announced in October 2006, it has been described as being similar to Europe's DVB-SH standard for digital video broadcast from both satellite
s and terrestrial repeaters to handheld devices.
It specifies usage of the 2.6 GHz frequency band and occupies 25 MHz bandwidth within which it provides 25 video and 30 radio channels with some additional data channels. Multiple companies have chips that support CMMB standard - Innofidei who was the first with a solution March 28, 2007,
Other manufacturers, such as Unique Broadband Systems, were quick to enter the race and grab a share of the handheld broadcasting market with their award winning hardware platform supporting both CMMB and DTMB (as well as others) standard waveforms based on their universal modulator hardware. While many other companies developed waveform specific hardware Unique broadband systems quickly cornered the Chinese market for CMMB and DTMB modulators.
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
by the State Administration of Radio, Film, and Television
State Administration of Radio, Film, and Television
The State Administration of Radio, Film, and Television is an executive branch under the State Council of the People's Republic of China...
(SARFT). It is based on the Satellite and Terrestrial Interactive Multiservice Infrastructure (STiMi), developed by TiMiTech, a company formed by the Chinese Academy of Broadcasting Science. Announced in October 2006, it has been described as being similar to Europe's DVB-SH standard for digital video broadcast from both satellite
Satellite
In the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavour. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon....
s and terrestrial repeaters to handheld devices.
It specifies usage of the 2.6 GHz frequency band and occupies 25 MHz bandwidth within which it provides 25 video and 30 radio channels with some additional data channels. Multiple companies have chips that support CMMB standard - Innofidei who was the first with a solution March 28, 2007,
Other manufacturers, such as Unique Broadband Systems, were quick to enter the race and grab a share of the handheld broadcasting market with their award winning hardware platform supporting both CMMB and DTMB (as well as others) standard waveforms based on their universal modulator hardware. While many other companies developed waveform specific hardware Unique broadband systems quickly cornered the Chinese market for CMMB and DTMB modulators.
RF Details
CMMB uses frequencies in the range 2635 - 2660 MHz (S-band) for satellite and "gap-filler" terrestrial broadcast, with additional terrestrial broadcast in the UHF band 470 – 862 MHz. The channel bandwidth can be either 2 or 8 MHz, depending on data rate.Coverage
China Satellite Mobile Broadcasting Corporation (CSMBC) , as of 2 June 2010, had completed CMMB network coverage in 317 prefecture-level cities.Versus DTMB
- The CMMB is not a Chinese national standard(GB), but the DTMB is GBGuobiaoGuóbiāo is usually the phonetic transcription of the word "National Standards" in Chinese.It could mean any of the standards issued by the Standardization Administration of China , the Chinese National Committee of the ISO and IEC....
20600-2006. - The CMMB uses QCIF or QVGA , so can not broadcast the HDTV(1080i/1080p), but the DTMB can do.
- The CMMB is intended for use on small screen devices (such as GPS,PDA,smartphone...) in a mobile scenario, while DTMB is intended for use on large screen devices (such as PC, LCD TV , PDP TV...) in a fixed scenario.
See also
- DTMB
- Digital Multimedia BroadcastingDigital Multimedia BroadcastingDigital Multimedia Broadcasting is a digital radio transmission technology developed in South Korea as part of the national IT project for sending multimedia such as TV, radio and datacasting to mobile devices such as mobile phones...
- DVB (Digital Video Broadcasting)
- DVB-TDVB-TDVB-T is an abbreviation for Digital Video Broadcasting — Terrestrial; it is the DVB European-based consortium standard for the broadcast transmission of digital terrestrial television that was first published in 1997 and first broadcast in the UK in 1998...
(Digital Video Broadcasting - Terrestrial) - DVB-HDVB-HDVB-H is one of three prevalent mobile TV formats. It is a technical specification for bringing broadcast services to mobile handsets. DVB-H was formally adopted as ETSI standard EN 302 304 in November 2004. The DVB-H specification can be downloaded from the official DVB-H website...
(Digital Video Broadcasting - Handheld) - International standardInternational standardInternational standards are standards developed by international standards organizations. International standards are available for consideration and use, worldwide...
External links
- IEEE Spectrum Article
- http://www.cmmb.org.cn/ (Chinese)
- http://www.uniquesys.com Unique Broadband Systems
- http://www.siano-ms.com Siano Mobile Silicon
- http://www.teamcast.com TEAMCAST
- http://www.elettronika.it ELETTRONIKA