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Information about 1seg

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1seg (Katakana: ワンセグ) is a mobile terrestrial digital audio/video and data broadcasting service in Japan. Service began experimentally during 2005 and officially on April 1, 2006. First mobile phone handsets for 1seg were sold by KDDI to consumers in autumn 2005.

Terrestrial digital broadcast in Japan (ISDB-T) is designed so that each channel is divided into 13 segments (plus one segment for separating channels). HDTV broadcast occupies 12 segments, and the remaining (13th) one segment is used for mobile receivers. Thus the name, '1seg'.

Technical information

1seg broadcasting uses H.264/MPEG-4 AVC video and HE-AAC audio encapsulated in MPEG-2 Transport Stream. 1seg, like ISDB-T also uses QPSK for modulation, 2/3 FEC and 1/4 guard ratio. Total bit-rate is 416 kbit/s. Maximum video resolution is 320x240 pixels, video bitrate is 220-320 kbit/s. Audio conforms to HE-AAC profile, with bitrate of 48-64 kbit/s. Additional data broadcasting using BML (EPG, interactive services, etc) occupies the remaining 10-100 kbit/s.

Conditonal access and copy control is not implemented in 1seg broadcast, however each receiver device manufacturer can limit recording function. For example, W33SA receiver only allows recording 1seg broadcasts to internal memory, and disallows copy or move to external miniSD card.

Broadcast Markup Language

By the BML or Broadcast Markup Language, Data Coding and Transmission methodorogy allows text display on the 1seg TV screen.

The text contains news, sports, weather forecast, program guides, "Earthquake Early Warning" and etc. at free as well as TV programs. Further information is obtainable with jump to Television station's or other Internet Website with communication fee for internet.

Criticism

Almost a year after the 1seg trial started, the purpose of the service is still unclear. Mobile reception is difficult, especially in a moving vehicle/train, as the signal quality deteriorates quickly even at speeds around 20 km/h (12 mph). This leaves the majority of the target audience for this service unable to receive it. In-car reception requires use of diversity antenna and increases receiver complexity and price.

Handheld 1seg receivers generally do not work well at all in moving cars or trains, even when held by a window because the signal drops out every few seconds. There is minimal or no reception in trains that are underground, or go inside buildings, such as most of the commuter trains in Tokyo. In addition, long distance trains, especially the shinkansen, move from one service area to another in a matter of minutes, making it impossible to view a program to completion before having to scan for a new set of channels and find whatever local channel may be broadcasting the program in question.

Handheld 1seg receivers work well inside homes, although it may be necessary to be near a window and/or adjust the antenna for reception. However, a home user can watch HDTV on a large screen TV instead of a 320x180 small screen 1seg.

Even though 1seg signals are not encrypted, some receiver manufacturers have chosen to apply DRM to recorded files, preventing users from viewing or editing the recording in third party software.[1]

Receivers

In July 2007, over 10,000,000 mobile phones can receive 1seg.[2]

See also

  • DMB - South Korea & Europe
  • DVB-H
  • ISDB-T

References

External links


[ edit ] 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)
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 | MPEG-4: SBTVD
Multichannel audio: AAC (5.1) | Musicam | PCM | LPCM
Hidden signals: Captioning | Teletext | (CPCM/Broadcast flag) | AFD | EPG
Digital cinema: UHDV (2540p, 4320p) | DCI | 22.2 audio
Technical issues: | MPEG transport | Standards conversion | Video processing | VOD
Katakana
カタカ?

Sister systems Hiragana, Hentaigana
Unicode range U+30A0–U+30FF
ISO 15924 Kana

Note: This page may contain IPA phonetic symbols in Unicode.
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April 1 is the 1st day of the year (2nd in leap years) in the Gregorian calendar. There are 0 days remaining. April 1 is most notable in the Western world for being April Fools' Day.
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20th century - 21st century - 22nd century
1970s  1980s  1990s  - 2000s -  2010s  2020s  2030s
2003 2004 2005 - 2006 - 2007 2008 2009

2006 by topic:
News by month
Jan - Feb - Mar - Apr - May - Jun
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KDDI Corporation

Public (TYO: 9433
Founded 1984
Headquarters Tokyo, Japan

Key people Tadashi Onodera, President & Chairman
Industry Telecommunications
Products Telephone, Internet, Mobile Phone (CDMA Network)
Revenue $43.
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High-definition television (HDTV) is a digital television broadcasting system with a significantly higher resolution than traditional formats (NTSC, SECAM, PAL). While some early analog HDTV formats were broadcast in Europe and Japan, HDTV is usually broadcast digitally,
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H.264 is a standard for video compression. It is also known as MPEG-4 Part 10, or AVC (for Advanced Video Coding). It was written by the ITU-T Video Coding Experts Group (VCEG) together with the ISO/IEC Moving Picture Experts Group (MPEG) as
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High Efficiency AAC (HE-AAC) is a lossy data compression scheme for digital audio. It is an extension of Low Complexity AAC (AAC LC) optimized for low-bitrate applications such as streaming audio.
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MPEG-2 is a standard for "the generic coding of moving pictures and associated audio information".[1] It describes a combination of lossy video compression and lossy audio compression (audio data compression) methods which permit storage and transmission of movies using
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Transport stream (TS, TP, or MPEG-TS) is a communications protocol for audio, video, and data which is specified in MPEG-2 Part 1, Systems (ISO/IEC standard 13818-1 [1] ).
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FEC is an acronym which can have the following meanings:
  • Fast Ethernet Channel (a method for bundling ethernet channels)
  • Family Entertainment Center
  • Federación Ecuatoriana de Ciclismo
  • Farnell Electronic Components (a distributor in the United Kingdom)

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Broadcast Markup Language, or BML, is an XML-based standard developed by Japanese ARIB association as a data broadcasting specification for digital television broadcasting.
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Electronic Program(me) Guide (EPG) or also an Interactive Program(me) Guide (IPG) or Electronic Service Guide (ESG), is an on-screen guide to scheduled broadcast television programs, allowing a viewer to navigate, select, and discover content by
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BML is a TLA that could mean:
  • Battle management language
  • Broadcast Markup Language
  • Bean markup language
  • Bank of Maldives Limited
  • Belfast and Moosehead Lake Railroad (AAR reporting marks BML)
  • Better Markup Language

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Broadcast Markup Language, or BML, is an XML-based standard developed by Japanese ARIB association as a data broadcasting specification for digital television broadcasting.
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television station is a type of broadcast station that broadcasts both audio and video to television receivers in a particular area. Traditionally, TV stations made their broadcasts by sending specially-encoded radio signals over the air, called terrestrial television.
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Internet is a worldwide, publicly accessible series of interconnected computer networks that transmit data by packet switching using the standard Internet Protocol (IP). It is a "network of networks" that consists of millions of smaller domestic, academic, business, and government
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A website (alternatively, Web site or web site) is a collection of Web pages, images, videos or other digital assets that is hosted on one or several Web server(s), usually accessible via the Internet, cell phone or a LAN.
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diversity scheme refers to a method for improving the reliability of a message signal by utilizing two or more communication channels with different characteristics. Diversity plays an important role in combating fading and co-channel interference and avoiding error bursts.
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antenna is a transducer designed to transmit or receive radio waves which are a class of electromagnetic waves. In other words, antennas convert radio frequency electrical currents into electromagnetic waves and vice versa.
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Tokyo Metropolis (東京都 Tōkyō-to)

Capital n/a
Region Kantō
Island Honshū
Governor Shintaro Ishihara
Area 2,187.
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Digital rights management (DRM) is an umbrella term that refers to access control technologies used by publishers and other copyright holders to limit usage of digital media or devices.
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Nintendo DS (sometimes abbreviated NDS or DS) is a handheld game console developed and manufactured by Nintendo, which was released in 2004 in Canada, U.S., and Japan.
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In computing, PC Card (originally PCMCIA) is the form factor of a peripheral interface designed for laptop computers. It was originally for memory expansion, but the existence of a usable general standard for notebook peripherals led to many kinds of devices being made
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Digital Multimedia Broadcasting (DMB) is a digital radio transmission system for sending multimedia (radio, TV, and datacasting) to mobile devices such as mobile phones.
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DVB-H (Digital Video Broadcasting - Handheld) is a technical specification for bringing broadcast services to handheld receivers. DVB-H was formally adopted as ETSI standard EN 302 304 in November 2004.
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A video format describes how one device sends video pictures to another device, such as the way that a DVD player sends pictures to a television, or a computer to a monitor.
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This article needs copy editing for grammar, style, cohesion, tone and/or spelling.
You can assist by [ editing it] now. A how-to guide is available, as is general .
This article has been tagged since October 2007.
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NTSC-J is an analog television system and video display standard for the region of Japan.

Technical definition

It is based on 'regular' NTSC, but is slightly different.
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PAL-M is the TV system used in Brazil since February 19, 1972. At that time, Brazil was the first country in South America with broadcasting in color. Rede Bandeirantes passed to PAL-M that year, while other television stations - like Rede Globo and Tupi - made a progressive and
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