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<table border=5>
<table border=5>
<tr><th rowspan=3>Transmission<br>
<tr><th rowspan=3>Transmission<br>
channel coding</th> <th>Modulation</th> <th>TC8PSK&#65292;QPSK&#65292;BPSK<br>
channel coding</th> <th>Modulation</th> <th>TC8PSK,QPSK,BPSK<br>
(Hierarchical transmission) </th></tr>
(Hierarchical transmission) </th></tr>
<th>Error correction coding</th> <th>Inner coding&#65306;Trellis [TC8PSK] and Convolution
<th>Error correction coding</th> <th>Inner coding:Trellis [TC8PSK] and Convolution
Outer coding :RS&#65288;204&#65292;188&#65289;
Outer coding :RS(204,188);
TMCC &#65306;Convolution coding&#65291;RS</th></tr>
TMCC:Convolution coding+RS</th></tr>
<th>Time domain multiplexing</th> <th>TMCC</th></tr>
<th>Time domain multiplexing</th> <th>TMCC</th></tr>
<tr><th colspan=2>Conditional Access</th> <th>Mutli-2</th></tr>
<tr><th colspan=2>Conditional Access</th> <th>Mutli-2</th></tr>

Revision as of 01:15, 5 February 2005

Integrated Services Digital Broadcasting (ISDB) is the digital television (DTV) and digital audio broadcasting (DAB) format. Japan has created to allow radio and television stations there to convert to digital.

File:ISDB-T.jpg
A picutre of ISDB-T (November/2004 at facility observation tour of NHK Osaka broadcasting station)

Introduction

ISDB maintained by the ARIB. The standards can be obtained for free at the DiBEG website, and can be obtained at ARIB.

The core standards of ISDB are ISDB-S (satellite television), ISDB-T(terrestrial) ,ISDB-C (cable) and 2.6GHz band mobile broadcasting which are all based on MPEG video and audio coding as well as the transport stream and are capable of high definition television (HDTV) as well. ISDB-T and ISDB-Tsb are for mobile reception in TV bands.

The concept was named for its similarity to ISDN, because both allow multiple channels of data to be transmitted together. This is also much like another digital radio system, Eureka 147, which calls each group of stations on a transmitter an ensemble; and also like the multi-channel digital TV standards ATSC and DVB-T. ISDB-T operates on unused TV channels, the approach taken by other countries for TV but never before for radio.

Video and Audio compresion

ISDB has adopted the MPEG video and Audio compression system. ATSC and DVB also adopted the MPEG system.

Transmission

These flavors differ mainly in the modulations used, due to the requirements of different frequency bands. The 12GHz band ISDB-S uses PSK modulation, 2.6 GHz band digital sound broadcasting uses CDM and ISDB-T (in VHF and/or UHF band) uses COFDM with PSK/QAM.

Interaction

Besides audio and video transmission, ISDB also defines data connections (Data broadcasting) with return the internet channel for several media (10Base-T/100Base-T, Telephone line modem, Mobile phone, Wireless LAN (IEEE 802.11) etc.) and protocols. This is for example used for interactive interfaces like Data broadcasting (ARIB STD B-24) and Electronic Program Guides (EPG). The features are described with Service Information (ARIB STD-B10).

Interfaces and Encryption

ISDB describes a lot of (network) interfaces, but most importantly the Common Interface for Conditional Access (ARIB STD-B25) with the Common Scrambling Algorithm (Multi-2) required for (de-)scrambling TV.

ISDB CAS system is operated by B-CAS company in Japan. And the CAS card is called as B-CAS card. Japanese ISDB signal is always encrypted by B-CAS system even if it is free TV programme. So it is called as "Pay per view system without a charge". The interface for mobile reception is under consideration.

ISDB supports the RMP (Rights management and protection). All DTV systems treat digital data content. The DVD and HD recorder, these are very popular products in the world, can make copy of content easily. So a lot of pirated content circulate in market. The Hollywood requested about the copy protection. The answer was RMP. The content have three modes that are “Copy once”, “Copy free” and “Copy never”. The contents, for example Movie program, can store to hard disc recorder, but it can not copy infinitely in case of “Copy once” mode.

Reciever

ISDB receiver has two types. One is TV (Television) set and another is STB (Set top box). The Aspect ratio of ISDB television set is 16:9. These television sets are called as Hi-vision TV. TV set has three types; these are CRT (Cathode ray tube), PDP (Plasma display panel) and LCD (Liquid crystal display). The LCD set is most popular Hi-Vision TV in Japanese market.

LCD set share as measured by JEITA is about 60 percent in November 2004. PDP set occupied high end market that is over 50 inch size. PDP and CRT set share are about 20 percent respectively. The CRT set is low end TV for Hi-Vision now.

STB is sometimes referred to as digital tuner. ISDB STB of high end has several interfaces,

Services

ISDB provides HDTV and Multi-SDTV services with one channel.


ISDB-S

History

Japan started digital broadcasting using DVB-S standard by PerfecTV in October/1996 and DirecTV in December/1997 with communication satellite. But, the DVB-S did not satisfy the requirements of Japanese broadcasters, i.e. NHK and commercial broadcasting stations (NTV, TBS, Fuji TV, TV Asahi, TV Tokyo and WOWOW). Consequently, ARIB developed the ISDB-S standards. The requirements were HDTV, interactive services, network accesses and effective frequency utilization etc. The DVB-S can transmit bit stream of 34 Mbps with a transponder of satellite. It means the transponder can send a HDTV channel. But, broadcasting satellite had only 4 vacant transponders. ARIB and NHK developed ISDB-S, which can transmit about 51 Mbps with a transponder. It means ISDB-S is 1.5 times efficient than DVB-S. And one transponder can transmit two HDTV channels and other independent sound and data. Satellite digital broadcasting (BS digital) was started by NHK and commercial broadcasting stations at 1st December 2000. Now SkyperfecTV!, that is successor of Skyport TV, Sky D, CS burn, Platone, EP, DirecTV, J Sky B and PerfecTV!, adopted ISDB-S system at the east longitude 110 degree wide band communication satellite.

Technical specification

Summary of ISDB-S(Satellite digital broadcasting)

Transmission
channel coding		 Modulation TC8PSK,QPSK,BPSK
(Hierarchical transmission)
Error correction coding Inner coding:Trellis [TC8PSK] and Convolution

Outer coding :RS(204,188);

TMCC:Convolution coding+RS
Time domain multiplexing TMCC
Conditional Access Mutli-2
Data broadcasting ARIB STD B-24(BML, ECMA script)
Service information ARIB STD B-10
Multiplexing MPEG-2 Systems
Audio coding MPEG-2 Audio（AAC）
Video coding MPEG-2 Video

Channel

Frequncy and channel specification of Japanese Satellite using ISDB-S

Method BS digital broadcasting Wide band CS digital broadcasting
Frequency band 11.7-12.2 GHz 12.2-12.75 GHz
Transmission bit rate 51Mbps (TC8PSK) 40Mpbs (QPSK)
Transmission band width 34.5MHz* 34.5 MHz
  • Compatible to 27MHz band satellite transponder for analog FM broadcasting.

ISDB-T

History

The HDTV was invented in NHKSTRL. The research of HDTV was started in 1960s. In 1973, standard was proposed to ITU-R (CCIR). In 1980 era, Television camera, High definition cathode-ray tube, Video tape recorder and editing equipment etc, have developed. In 1982, NHK developed MUSE (Multiple sub-nyquist sampling Encoding), the first HDTV video compression and transmission system. MUSE adopted digital video compression system, but for transmission (frequency modulation) is adopted after DA converted digital signal. In 1987, NHK made demonstration of MUSE in the Washington D.C and NAB. The demonstration made great impact to U.S. As the result of this impact, U.S. made ATSC, the first terrestrial digital HDTV. And European also developed their system that is DVB. Japan have started R&D of digital system in 1980s. That is ISDB. Japan started terrestrial digital broadcasting using ISDB-T standard by NHK and commercial broadcasting stations at 1st December 2003.

Feature

ISDB-T is characterized by below features,

  • ISDB-T can transmit a HDTV channel and a mobile phone channel with a channel of 6MHz bandwidth.
  • ISDB-T can change to two or three SDTV channels instead of one HDTV channel.
  • Combination of these services can be changed anytime.
  • ISDB-T provides interactive services with data broadcasting.
  • ISDB-T provides EPG (Electronic Program Guides)
  • ISDB-T supports the internet access that work in collaboration with the data broadcasting. And the internet access is also provided on mobile phone.
  • ISDB-T provides SFN (Single frequency Network) and on-channel repeater technology. SFN makes utilization of frequency resource.
  • ISDB-T provides robustness to impulse noises that come down from motor cycles and power lines in urban city.
  • ISDB-T can receive HDTV on moving vehicle over 100 km/h. And DVB-T can receive SDTV on moving vehicle. But ATSC can not receive on moving vehicle.
  • ISDB-T can receive on mobile phone over 400 km/h.

Adoption

ISDB-T entered in commercial transmission in Japan in December 2003. It possesses a market of 100 million television sets. ISDB-T has 2 million subscribers at end of December 2004.

Brazil, which currently uses an analogue TV system (PAL-M) slightly different from any other country's, is also considering ISDB-T for its DTTV format. Otherwise, no other countries are considering ISDB, although it does seem to have an advantage over ATSC and DVB-T in reception tests. ABERT/SET group in Brazil did system comparison tests of DTTV under supervision of the CPqD foundation. The comparison tests were done by under direction of a work group of SET (the Brazilian Engineers Society of Television) and ABERT (the Brazilian Association of the broadcaster of Radio and Television). The ABERT/SET group selected ISDB-T as the best in the digital broadcasting systems that were ATSC, DVB-T and ISDB-T. ISDB-T is pointed out as most flexible of all for better answering the necessities of mobility and portability. It is most efficient for mobile and portable reception.

Technical specification

Segment struture

Seg.13 Seg.11 Seg.9 Seg.7 Seg.5 Seg.3 Seg.1 Seg.2 Seg.4 Seg.6 Seg.8 Seg.10 Seg.12


Summary of ISDB-T

Transmission
channel coding		 Modulation 64QAM-OFDM,

16QAM-OFDM,
QPSK-OFDM,
DQPSK-OFDM

(Hierarchical transmission)
Error correction coding Inner coding,

Convolution 7/8,3/4,2/3,1/2

Outer coding :RS(204,188)
Guard interval 1/16,1/8,1/4
Interleaving Time, Frequency, bit, byte
Frequency domain multiplexing BST-OFDM (Segmented structure OFDM)
Conditional Access Mutli-2
Data broadcasting ARIB STD B-24(BML, ECMA script)
Service information ARIB STD B-10
Multiplexing MPEG-2 Systems
Audio coding MPEG-2 Audio (AAC)
Video coding MPEG-2 Video MPEG-4 AVC /H.264*
  • H.264 used in one segment broadcasting for Mobile phone.


Channel

Specification of Japanese terrestrial digital broadcasting using ISDB-T

Method terrestrial digital broadcasting
Frequency band VHF/UHF,Super high band
Transmission bit rate 19Mbps(64QAM)
Transmission band width 5.6MHz*
  • Compatible to 6MHz band terrestrial analog TV broadcasting.

2.6GHz Satellite Sound digital broadcasting

MobaHo! is the name of services. MobaHo! uses Mobible satellite digital audio broadcasting specifiecation. MobaHo! services in at 20st October 2004.

ISDB-Tsb

ISDB-Tsb is terrestrial digital sound broadcasting specification. The technical specification is same as ISDB-T. ISDB-Tsb support Concaticanted transmission of OFDM siginal.

ISDB-C

ISDB-C is cable digital broadcasting specification. The technical specification is developed by JCTEA.

Standards

ARIB and JCTEA developed below standards. Some part of standards are regisitated on ITU-R and ITU-T

I
Channel Communication Satellite television digital broadcasting Broadcasting

/Communication
Satellite
television

digital
broadcasting		 Terrestrial television digital broadcasting Satellite Sound digital broadcasting Terrestrial Sound digital broadcasting Cable

television

digital broadcasting
Nick name - ISDB-S ISDB-T 2.6GHz mobile broadcastingISDB-Tsb 64QAM,

Trans-modulation

(ISDB-C)
Transmission DVB-S ARIB

STD-B20,

ITU-R BO.1408		 ARIB

STD-B31,

ITU-R BT.1306-1		 ARIB STD-B41 ARIB STD-B29, ITU-R BS.1114 ITU-T J.83 Annex C, J.183
Receiver ARIB STD-B16 ARIB STD-B21 ARIB STD-B42 ARIB STD-B30 JCTEA STD-004, STD-007
Server type broadcasting - ARIB STD-B38 -
Conditional access - ARIB STD-B25 (Muti-2) JCTEA STD-001
Service information - ARIB STD-B10 JCTEA STD-003
Data broadcasting - ARIB STD-B24 (BML), ARIB STD-B23 (EE or MHP like) -
Video/Audio compression and multiplexing MPEG-2 ARIB STD-B32 (MPEG) -
Technical report - ARIB TR-B13 ARIB TR-B14 - - -


See also

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