1seg - AbsoluteAstronomy.com

is a mobile terrestrial digital audio/video and data broadcasting service in Japan

Japan

Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

, Argentina

Argentina

Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...

, Brazil

Brazil

Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...

, Chile

Chile

Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...

and Peru

Peru

Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....

. Service began experimentally during 2005 and commercially on April 1, 2006. In Brazil, the broadcast started in late 2007 in just a few cities, with a slight difference from Japanese 1seg: a 30 frame/s transmission, while in Japan they use a 15 frame/s transmission. The first mobile phone handsets for 1seg were sold by KDDI

KDDI

is a Japanese telecommunications operator formed in October 2000 through the merger of DDI Corp., KDD Corp., and IDO Corp. It has its headquarters in the Garden Air Tower in Iidabashi, Chiyoda, Tokyo....

to consumers in autumn 2005.

ISDB-T, the terrestrial digital broadcast system used in Japan, Argentina, Brazil, Chile and Peru, is designed so that 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. Thus the name, "1seg" or "One Seg".

Technical information

The ISDB

ISDB

Integrated Services Digital Broadcasting is a Japanese standard for digital television and digital radio used by the country's radio and television stations. ISDB replaced the previously used MUSE "Hi-vision" analogue HDTV system...

-T system uses the UHF band at frequencies between 470 and 770 MHz (806 MHz in Brazil), giving a total bandwidth 300 MHz. The bandwidth is divided into fifty channels name channels 13 through 62. Each channel is 6 MHz wide consisting of a 5.57 MHz wide signalling band and a 430 kHz guard band to limit cross channel interference. Each of these channels is further divided into 13 segments, with each with 428 kHz of bandwidth. 1 seg uses a single of these segments to carry the 1seg transport stream.

1seg, like ISDB-T uses QPSK for modulation

Modulation

In electronics and telecommunications, modulation is the process of varying one or more properties of a high-frequency periodic waveform, called the carrier signal, with a modulating signal which typically contains information to be transmitted...

, with 2/3 forward error correction

Forward error correction

In telecommunication, information theory, and coding theory, forward error correction or channel coding is a technique used for controlling errors in data transmission over unreliable or noisy communication channels....

and 1/4 guard ratio. The total datarate is 416 kbit/s.

The television system uses a H.264/MPEG-4 AVC

H.264/MPEG-4 AVC

H.264/MPEG-4 Part 10 or AVC is a standard for video compression, and is currently one of the most commonly used formats for the recording, compression, and distribution of high definition video...

video stream and a HE-AAC

HE-AAC

High-Efficiency Advanced Audio Coding is a lossy data compression scheme for digital audio defined as a MPEG-4 Audio profile in ISO/IEC 14496-3. It is an extension of Low Complexity AAC optimized for low-bitrate applications such as streaming audio...

audio stream multiplexed into a MPEG transport stream. The maximum video resolution is 320x240 pixels, with a video bitrate of between 220 and 320 kbit/s. Audio conforms to HE-AAC

HE-AAC

profile, with a bitrate of 48 to 64 kbit/s. Additional data (EPG

Electronic program guide

Electronic program guides and interactive program guides provide users of television, radio, and other media applications with continuously updated menus displaying broadcast programming or scheduling information for current and upcoming programming...

, interactive services, etc) is transmitted using BML

Broadcast Markup Language

Broadcast Markup Language, or BML, is an XML-based standard developed by Japanese ARIB association as a data broadcasting specification for digital television broadcasting...

and occupies the remaining 10 to 100 kbit/s of bandwidth.

Conditional access and copy control are implemented in 1seg broadcasting by the use of Broadcast Flag

Broadcast flag

A broadcast flag is a set of status bits sent in the data stream of a digital television program that indicates whether or not the data stream can be recorded, or if there are any restrictions on recorded content...

-like structure contained in the "Copy Control Descriptor" within the broadcast. The broadcast contents themselves are not encrypted, but the Copy Control information forces the device to encrypt stored recordings and disallows making a copy of the recording.

Broadcast Markup Language

Broadcast Markup Language, or BML, is an XML-based standard developed by Japanese ARIB association as a data broadcasting specification for digital television broadcasting...

(BML), is a data-transmission service allowing text to be displayed on a 1seg TV screen.

The text contains news, sports, weather forecasts, "Earthquake Early Warning", etc. free of charge. Further information can be found through links to content on websites, frequently those belonging to the television station itself.

EPG (program guides) is not included, but transmitted in separate stream (EIT).

Multiple-program arrangement

On June 23, 2008, broadcaster Tokyo MX

Tokyo Metropolitan Television

thumb|Tokyo Metropolitan Television old headquarters : Telecom Center Building is the only commercial television station in Tokyo, Japan that exclusively serves the city. It competes with Nippon Television, TV Asahi, Tokyo Broadcasting System, TV Tokyo, and Fuji Television, all of which are...

officially began using technology to simultaneously broadcast two programs on a single divided segment. Most 1seg receivers manufactured after September 2008 are compatible with this technology. Multiple-program arrangement in 1seg is named as .

NHK Educational TV

NHK Educational TV

is the second television service of NHK . It is a sister service of NHK General TV, showing programs of a more educational, cultural or intellectual nature, periodically also showing anime...

(from 1 April 2009) and (from 1 December 2009) are also started for several number of programs.

Popularity

Until the end of March 2008, Japanese regulation required that the programs on 1seg were fundamentally the same as those broadcast on the equivalent HDTV channel. On April 1 the regulation was revised, and experimental programs by 1seg or third parties have begun airing on several stations.

On January 16, 2008, JEITA

Japan Electronics and Information Technology Industries Association

The is a Japanese trade organization for the electronics and IT industries. It was formed in 2000 from two earlier organizations, the Electronic Industries Association of Japan and the Japan Electronic Industries Development Association.-See also:...

released their monthly shipping survey showing approx. 4.806 million mobile phone

Mobile phone

A mobile phone is a device which can make and receive telephone calls over a radio link whilst moving around a wide geographic area. It does so by connecting to a cellular network provided by a mobile network operator...

s were sold in Japan

Japan

in November 2007. Of these, approx. 3.054 million phones, 63.5% of the total, can receive 1seg broadcasts.

In the fiscal year of 2007, on average 45% of mobile phones had 1seg reception capability out of the 22.284 million units sold. The percent increased from 26.8% in April 2007 to 64.2% at end of fiscal year March 2008.

Receivers

Electronic dictionary

An electronic dictionary is a dictionary whose data exists in digital form and can be accessed through a number of different media. Electronic dictionaries can be found in several forms, including:*as dedicated handheld devices...

Sharp Papyrus PW-TC900

Sharp Papyrus PW-TC920

Sharp Papyrus PW-TC930

Sharp Papyrus PW-TC980

PC connect type

Pixela PC

Monster TV 1D PC card

PC card

In computing, PC Card is the form factor of a peripheral interface designed for laptop computers. The PC Card standard was defined and developed by the Personal Computer Memory Card International Association which itself was created by a number of computer industry companies in the United States...

Type II 1seg receiver by SKNET

Cowon

Cowon Systems, Inc. is a South Korean electronics company. Established in 1995, the company's initial focus was software development. In 2000, with the introduction of the CW100, Cowon expanded their business to the portable digital audio player industry....

D2TV

and more.

Car navigation system

Sanyo One-seg & car navigation system

and more.

Handheld game console

A handheld game console is a lightweight, portable electronic device with a built-in screen, game controls and speakers. Handheld game consoles are run on machines of small size allowing people to carry them and play them at any time or place...

1seg PSP-2000 Tuner

Nintendo DS

The is a portable game console produced by Nintendo, first released on November 21, 2004. A distinctive feature of the system is the presence of two separate LCD screens, the lower of which is a touchscreen, encompassed within a clamshell design, similar to the Game Boy Advance SP...

(via an add-on called "DS Telebi")

Portable devices
Set top box
Others

Sony

, commonly referred to as Sony, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan and the world's fifth largest media conglomerate measured by revenues....

Walkman

Walkman is a Sony brand tradename originally used for portable audio cassette, and now used to market Sony's portable audio and video players as well as a line of Sony Ericsson mobile phones...

NW-A919

Kodak 3-inch OLED TV

and more.

Mobile Phones

Today, almost all mobile phones sold in Japan allow the user to watch 1seg.

External links

One-Seg service for Mobile DevicesPDF file, Digital Broadcasting Experts Group (DiBEG)
Digital Broadcasting Experts Group (DiBEG) promote ISDB-T
ISDB-T, Application, Present and Future, PDF File
Mobile phone
Mobile phone
A mobile phone is a device which can make and receive telephone calls over a radio link whilst moving around a wide geographic area. It does so by connecting to a cellular network provided by a mobile network operator...

and PHS
PHS
-General:*Pallister-Hall syndrome, a genetic disorder*Peninsula Humane Society, an animal welfare organization in San Mateo County, California* Pennsylvania Horticultural Society promotes horticulture-related events and community activities, headquartered in Philadelphia, Pennsylvania.*Personal...

operators which provide 1seg phone receivers.
ACCESS Ginga Edition for 1Seg in Brazil

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