Overview of ARIB Standards (STD-B31)
|STD Number||ARIB STD-B31|
|Standard Name||Transmission System for Digital Terrestrial Television Broadcasting|
This standard intends to specify transmission schemes about digital terrestrial television broadcasting, among standard television broadcasting and so on which broadcasting stations broadcast, and applies to digital terrestrial television broadcasting using frequency of UHF and VHF band.
In this standard, according to “Technical conditions on digital terrestrial television broadcasting system” among “Technical conditions on digital broadcasting system” which is the report in parts dated on 24 May 1999 by Telecommunication Technology Council of the Ministry of Post and Telecommunications (present Information Communication Technology Council of the Ministry of Internal Affairs and Communications), which discussed on the request for advice of the Minister of Post and Telecommunications (present the Minister of Internal Affairs and Communications) No.74 “Technical conditions on digital broadcasting system (the request for advice dated on 27 June 1994), based on the items provided in “Standard transmission systems on digital broadcasting among standard television broadcasting and the like (Ordinance of MPT No.102, 1999) (Note)” and “Notification of MPT (Notification of MPT No.864, 1999) ”, and in addition to them, the items which are agreed that it is desirable to be provided on operations are recorded.
Guidelines under various conditions about program transmission and equipment of transmission which are recommended in practical operations are described as Attachment, and concrete example of elemental technique are described as Appendix.
Abbreviation for Integrated Services Digital Broadcasting – Terrestrial
Digital Terrestrial Television Broadcasting, ISDB-T is the system that the transmission band of 1 channel is divided into 13 bands (OFDM segments) and transmission parameters and information to be transmitted are set by each segment. Therefore, various services such as HDTV broadcasting, multichannel standard television, data, etc. can be combined and broadcasted in 1 channel. Also, by setting transmission parameter of a part of the segments to be resistant to interference, besides receiving at home, the service suitable for receiving in a car and receiving by a mobile phone are possible.
On the other hand, digital terrestrial sound broadcasting uses one OFDM segment or three OFDM segments which consist of the same structure. In this case, it is denoted as ISDB-TSB in the sense of Sound Broadcasting.
Abbreviation for Orthogonal Frequency Division Multiplex
OFDM is one of the systems that transmit digitized information. Comparing the conventional method which all information is modulated fast by one carrier, OFDM transmits by dividing information to thousands carriers. Looking at each carrier, as the time to transmit a mass of digital data of 1 and 0 becomes thousands times, the transmission characteristics which is resistant to multi-path interference is acquired.
Because of the mechanism that multiple carriers do not interfere each other (orthogonal multiplex), this is called OFDM.
Abbreviation for Single Frequency Network
This is the network technology that plural adjacent stations use the same frequency, by using the merit actively that OFDM is resistant to multi-path interference. Comparing conventional network that frequency is converted at each relay station, service area can be covered by less frequencies.
|IFFT (Inverse Fast Fourier Transform)||
Inverse operation to FFT which transforms time signal to frequency component.
In OFDM, this means batch processing that digital modulated data by thousands carrier frequencies are converted to time signal (transmission signal).
Abbreviation for Auxiliary Channel
This is specified as the channel for information-added on broadcasting (information-added on transmission control of modulated wave, or alarm information of earthquake), and transmission delay of signal in main line is from about 0.1 to about 1 second in channel coding part and decoding part for digital terrestrial broadcasting. On the other hand, it is the merit in AC transmission channel that transmission capacity is small as it is from several kbps to hundreds kbps, but transmission delay is short.
|Program Specific Information (PSI)||
A part which is standardized by ISO/IEC13818-1 among transmission control signals is PSI.
PSI data consists of four kinds of table (PAT, CAT, PMT, NIT) and is transmitted by section form.
|Transport Stream||Data structure that is defined in ISO/IEC13818-1.|
|transport_ stream_id||Proper identifier to transport stream in original network|
2. Amendment History
|Ver.||Amendment or Enactment Date||Amendment summary|
According to the amendment of Notification of MIC, normative Notification is changed. Also, misprints are corrected and notation is unified.
As for this standard version 2.2, an English translation version will be published.
According to the amendment of Ordinance and Notification accompanied by the amendment of Broadcasting Act, normative Ordinance and Notification are modified and added, and references of Ordinance and Notification are clarified.
Also, notation and terms are unified to the other standards related to this standard, and Attachment: Operational guidelines are modified and clarified.
|2.0||03.28.2011||Reconsideration of the table of transmission parameters for 6MHz bandwidth system in order to keep consistency with ITU-R Recommendation, and addition of Annex for the table of transmission parameters of 7 and 8MHz bandwidth systems and the table of information rate.|
|1.9||07.15.2010||According to the amendment of Notification, change of the name of area concerning detail information of earthquake alarm, and addition of the provision of tolerant deviation of transmitting frequency concerning very small power station.|
|1.8||12.16.2009||Addition of the provision concerning transmission system of earthquake alarm information using AC signal.|
|1.7||09.26.2007||Amendment on the provision of tolerant deviation of transmission frequency and transmission spectrum mask, according to the amendment of Ordinance Regulating Radio Equipment concerning a relay station of digital terrestrial television broadcasting|
|1.6||11.30.2005||Amendment according to Ordinance Regulating Radio Equipment concerning spurious.|
|1.5||07.29.2003||Clarification of the transmission parameters subject for index of exchanging transmission parameters|
Addition of the provision of interface (I/F) between broadcasting TS involving AC data in AC transmission and AC transmission carrier, and the provision to secure compatibility between manufacturers of equipment
·“Operational guidelines for AC data transmission” is added as Attachment, Chapter 6.
·Syntax of ISDB-T_information and syntax of modulation_control_configuration_information concerning AC data multiplex are amended in Attachment, Chapter 5 “Signal transmission to STL/TTL” 5.5 “Information-added which is necessary when broadcasting TS is transmitted”.
·An exceptional operational rule is added to the provision of 3.2.1 “Multiplexing method for PAT, NIT, CAT in scalable transmission” in Attachment, Chapter 3 “Operational guidelines for scalable transmission”.
·A part of (4) “Structure of network_synchronization_information” in Attachment, Chapter 5 ” Signal transmission method to STL/TTL”, 5.5.3 “Multiplexing to invalid layer of IIP (ISDB-T Information Packet)” is reconsidered.
|1.2||01.24.2002||“Video coding system” is newly added as 3.4 to “Chapter 3: Operational guidelines for scalable transmission” in “Attachment: Operational guidelines for digital terrestrial television broadcasting”.|
|1.1||11.15.2001||The provision of “Signal transmission method to STL/TTL” as Chapter 5 is added in “Attachment: Operational guidelines for digital terrestrial television broadcasting”.|