 | This article needs additional citations for verification. (March 2023) |
 1seg logo in Japan | |
| Company type | Incentive |
|---|---|
| Founded | 2005 Japan |
| Headquarters | Japan |
| List of digital television broadcast standards |
|---|
| DVB standards (countries) |
| ATSC standards (countries) |
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| ISDB standards (countries) |
| DTMB standards (countries) |
| DMB standard (countries) |
| Codecs |
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| Terrestrial Frequency bands |
| Satellite Frequency bands |
1seg (ワンセグ, wansegu) is a mobile terrestrial digital audio/video and data broadcasting service in Japan, Argentina, Brazil, Chile, Uruguay, Paraguay, Peru and the Philippines. Service began experimentally during 2005 and commercially on April 1, 2006. It is designed as a component of ISDB-T, the terrestrial digital broadcast system used in those countries, as each channel is divided into 13 segments, with a further segment separating it from the next channel; an HDTV broadcast signal occupies 12 segments, leaving the remaining (13th) segment for mobile receivers, hence the name, "1seg" or "One Seg".
Its use in Brazil was established in late 2007 (starting in just a few cities), with a slight difference from the Japanese counterpart: it is broadcast under a 30 frame/s transmission setting (Japanese broadcasts are under the 15 frame/s transmission setting).