China Mobile Multimedia Broadcasting (CMMB) is a mobile television and multimedia standard developed and specified in
China
China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...
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
A satellite or an artificial satellite is an object, typically a spacecraft, placed into orbit around a celestial body. They have a variety of uses, including communication relay, weather forecasting, navigation ( GPS), broadcasting, scient ...
s and terrestrial repeaters to handheld devices.
It specifies usage of the S-band/U-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 28 March 2007.
Other manufacturers, such as Unique Broadband Systems, were quick to enter the race and grab a share of the handheld broadcasting market with thei
hardware platformsupporting both CMMB and DTMB (as well as others) standard waveforms.
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
GB 20600-2006.
* The CMMB uses
QCIF or
QVGA
A display resolution standard is a commonly used width and height dimension (display resolution) of an electronic visual display device, measured in pixels. This information is used for electronic devices such as a computer monitor. Certain com ...
, so can not broadcast the HDTV (1080i/1080p), but the DTMB can.
* The CMMB is intended for use on small screen devices (such as GPS, PDA, or 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 Broadcasting
Digital multimedia broadcasting (DMB) is a digital radio transmission technology developed in South Korea as part of the national information technology, IT project for sending multimedia such as TV, radio and datacasting to mobile devices s ...
*
DVB (Digital Video Broadcasting)
*
DVB-T
DVB-T, short for Digital Video Broadcasting – Terrestrial, 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 Singapore in Fe ...
(Digital Video Broadcasting - Terrestrial)
*
DVB-H
DVB-H (digital video broadcasting - handheld) 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 2 ...
(Digital Video Broadcasting - Handheld)
*
International standard
An international standard is a technical standard developed by one or more international standards organizations. International standards are available for consideration and use worldwide. The most prominent such organization is the International O ...
References
External links
IEEE Spectrum Article*https://archive.today/20130116033332/http://www.cbc.cn/ (Chinese)
Unique Broadband Systems
{{Authority control
Digital television
Chinese inventions
2006 introductions
2006 establishments in China