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"1seg" is a digital terrestrial broadcasting services for movable bodies such as mobile telephones, PC and a car navigation system with receiver ability. The services started on April 1st, 2006. Originally it was called "one segment broadcast" as technical naming, offically named as "1 Seg" in September, 2005 by association of ground digital broadcasting promotion.
A Japanese terrestrial digital broadcasting format divides one channel into 13 "segments" (division). Among these 13 division, 12 segments are used for television transmission and 1 segment for movable bodies. It bundles up 4 or 12 segments to transmit picture, sound, and data of TV . All 12 remaining segments, except one for 1seg, are necessary to send out much information by high vision broadcast (HDTV), but normal broadcast (SDTV) needs only 4 segments so usually three different programs with one channel can be broadcast at the same time.
Because it is small, a band can transmit only a low resolution picture of 320*240 pixels QVGA size, but a description of information by BML is possible, and a data broadcasting part makes use of a characteristic of a handheld unit, and expectation gathers when it is possible for new trials such as cooperation with an E-mail and a schedule book, position information with GPS that a handheld unit has.
For the moment, it is broadcast Simultaneously, it is considered to broadcast other contents in the future.
A Japanese terrestrial digital broadcasting format divides one channel into 13 "segments" (division). Among these 13 division, 12 segments are used for television transmission and 1 segment for movable bodies. It bundles up 4 or 12 segments to transmit picture, sound, and data of TV . All 12 remaining segments, except one for 1seg, are necessary to send out much information by high vision broadcast (HDTV), but normal broadcast (SDTV) needs only 4 segments so usually three different programs with one channel can be broadcast at the same time.
Because it is small, a band can transmit only a low resolution picture of 320*240 pixels QVGA size, but a description of information by BML is possible, and a data broadcasting part makes use of a characteristic of a handheld unit, and expectation gathers when it is possible for new trials such as cooperation with an E-mail and a schedule book, position information with GPS that a handheld unit has.
For the moment, it is broadcast Simultaneously, it is considered to broadcast other contents in the future.
[Figure 1. The Concept of 1SEG Service]
The 1SEG can provide interactive and convergence service using mobile network and internet.
For example, user can get the a weather forecast, a disaster information and find various program information using E.PG or BML
For example, user can get the a weather forecast, a disaster information and find various program information using E.PG or BML
[Figure 2. The Service Type of 1SEG]
Users can enjoy 1SEG services through various kinds of handheld terminals such as mobile phones, in-car devices, laptops computers and dedicated mobile TV.
1) Mobile Phone with 1SEG
A mobile phone with a 1SEG is expected to lead the receiver market, as it is very convenient for users to carry
it anytime and anywhere.
◎ Various convenient functions are added to 1SEG mobile phones..
* External memory (Compact-Flash)
* TV-out : sending 1SEG signals to normal TV
◎ Digital Camera and MP3 player functions are also combined.
A mobile phone with a 1SEG is expected to lead the receiver market, as it is very convenient for users to carry
it anytime and anywhere.
◎ Various convenient functions are added to 1SEG mobile phones..
* External memory (Compact-Flash)
* TV-out : sending 1SEG signals to normal TV
◎ Digital Camera and MP3 player functions are also combined.
[Figure 3. au by KDDI W33A(made by Sanyo)]
[Figure 4. FOMA P901iTV by Panasonic]
2) Vehicle DMB Receiver
◎ Use of cigar-jack power. No battery limitation
◎ A navigation function embedded receivers have been released in early 2006. (Sanyo Gorilla)
◎ The combination of BML and EPEG will provide various service for vehicle
◎ Use of cigar-jack power. No battery limitation
◎ A navigation function embedded receivers have been released in early 2006. (Sanyo Gorilla)
◎ The combination of BML and EPEG will provide various service for vehicle
[Figure 5. FOMA P901iTV by Panasonic]
3) Laptop and USB Receiverr
Laptops with a 1SEG function and USB-type 1SEG receivers have been released. With USB-type 1SEG)
receivers, users can enjoy 1SEG services through their own laptop and desktop PCS.
Laptops with a 1SEG function and USB-type 1SEG receivers have been released. With USB-type 1SEG)
receivers, users can enjoy 1SEG services through their own laptop and desktop PCS.
 [Figure 6. Logitec LDT-1S100U] |
 [Figure 7. Buffalo DH-ONE/U2] |
4) 1SEG Dedicated receiver
1SEG function can be equipped in various handheld devices with LCD screen and audio system. Digital camera,
PMP(Portable Multimedia Player), PDA equipped with 1SEG function have been released. As 1SEG market grows other
handheld devices such as portable DVD player, portable game player and so on, can be equipped with 1SEG functions.
1SEG function can be equipped in various handheld devices with LCD screen and audio system. Digital camera,
PMP(Portable Multimedia Player), PDA equipped with 1SEG function have been released. As 1SEG market grows other
handheld devices such as portable DVD player, portable game player and so on, can be equipped with 1SEG functions.
[Figure 8. Papyrus (PW-TC900) made by SHARP]
[Figure 9. V Series (with PMP) made by Toshiba]
[Figure 10. DVD LX-97 made by Panasonic]
1SEG uses MPEG-4 AVC (Advanced Video Coding), MPEG2-AAC(Bit-Sliced Arithmetic Coding) and BML(Broadcasting Markup Language)as the encoders for video, audio and contents-related data services. All of these encoded results are multiplexed into MPEG-2 TS packets.
[Figure 11. ISDB-T System Overview]
In 1SEG System. It can broadcast audio, video and data using various technology in under table.
| Technology used in 1SEG | |
| Modulation Skill | QPSK, 16QAM |
| Encode Rate | 1/2, 2/3 |
| Video Codec | AVC/H.264 |
| Audio Codec | MPEG2 AAC |
| # of pixels | 320×240 pixels or 320×180 pixels(QVGA) |
| Data Broadcast | BML(Broadcast Markup Language) |
1. The Association for Promotion of Digital Broadcasting D-PA : http://www.d-pa.org/
2. Digital Broadcasting Expert Group : http://www.dibeg.org/
3. Association of Radio Industries and Business : http://www.arib.or.jp
4. 1SEG Technical Information : http://www.geocities.jp/bokunimowakaru/std-1seg.html
2. Digital Broadcasting Expert Group : http://www.dibeg.org/
3. Association of Radio Industries and Business : http://www.arib.or.jp
4. 1SEG Technical Information : http://www.geocities.jp/bokunimowakaru/std-1seg.html
