GB/T 15770-1995 in English

《GB/T 15770-1995广播数据系统（RDS）技术规范》由TC239（全国广播电影电视标准化技术委员会）归口，主管部门为国家广播电视总局。
本标准规定了广播数据系统（Radio Data System:RDS)的调制特性、基带编码、消息格式、寻址和编码及有关协议。本标准适用于我国87.0MHz～108.0MHz调频声音广播的RDS信号传送、接收、测试和RDS设备研制。

Specification of the radio data system

1 Scope

This standard specifies the modulation characteristics, baseband coding, message format, addressing and coding as well as relevant protocols of the radio data system (RDS).

This standard is applicable to RDS signal transmission, reception, testing and RDS equipment development of 87.0MHz to 108.0MHz FM sound broadcasts in China.

2 Normative references

The following standards contain provisions which, through reference in this standard, constitute provisions of this standard. At the time of publication, all editions listed are valid. All standards are subject to revision, and parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below.

GB 1988-89 Information processing - 7-bit coded character set for information interchange
GB 2311-90 Information processing - ISO 7-bit and 8-bit coded character sets - Code extension techniques
GB 2312-80 Code of Chinese graphic character set for information interchange - Primary set
GB 4311.1-84 FM broadcasting - Monophonic
GB 4311.2-84 FM broadcasting - Stereophonic
GB 8565.2-88 Information processing - Coded character sets for text communication - Part 2: Graphic characters

3 Terms

3.1 program identification, PI
code message that enables the receiver to distinguish between countries, areas in which the same program is transmitted. One important application of this information would be to enable the receiver to search automatically for an alternative frequency in case of bad reception of the program to which the receiver is tuned. See Annex A for its coding mode

3.2 program service name, PS name
text consisting of not more than four double-byte characters or eight single-byte characters, which is displayed by RDS receivers in order to inform the listener what program service is being broadcast by the station to which the receiver is tuned. See Annex B for its coding mode

3.3 program type, PTY
program type identification number to be transmitted with each program item, which is intended to specify the program type within 31 possibilities. The receiver receives and records this type of program according to this identification code. See Annex C for its coding mode

3.4 traffic-program identification, TP identification
on/off switching signal to indicate, by means of a special lamp on the receiver, that this is a program on which announcements are usually made for motorists

3.5 traffic-announcement identification, TA identification
on/off switching signal to indicate whether an announcement for motorists is on the air. The signal could be used in receivers to switch automatically to the traffic announcement and restore the initial operating mode after the end of the traffic announcement

3.6 list of alternative frequencies, list of AF
list of alternative frequencies give information on the various transmitters broadcasting the same program in the same or adjacent reception areas, and enable receivers equipped with a memory to reduce the time for switching to another transmitter. This is particularly useful for mobile reception

3.7 decoder identification, DI
switching signal indicating which of 16 possible operating modes (or combinations thereof) is appropriate for use with the broadcast signals

3.8 music/speech switch, M/S switch
two-state signal to provide information on whether music or speech is being broadcast. The listener adjusts the receiver volume according to this signal to achieve the best effect

3.9 program-item number, PIN
scheduled program start date and time announced by the broadcasting station, and the receiver uses this signal to select the program to be listened to in advance

3.10 radiotext, RT
text transmissions coded in accordance with Annex B, which may be displayed on the receivers equipped with suitable display facilities

3.11 enhanced other network information, EON information
information used to update the PI, PIN, PTY, TP, TA, and AF of the program service other than the tuned program service A receiver having EON function can listen to both tuned programs and traffic announcements of other programs that are cross-referenced through the EON function

3.12 transparent data channel, TDC
data channel with 32 subchannels, which may be used to send single-byte or double-byte graphic characters (including mosaic graphics), or for transmission of computer programs and similar data not for display

3.13 in-house application, IH application
data to be encoded only within the broadcasting organization, the applications of which may be decided by each broadcasting organization itself

Foreword i
1 Scope
2 Normative references
3 Terms
3.1 program identification, PI
3.2 program service name, PS name
3.3 program type, PTY
3.4 traffic-program identification, TP identification
3.5 traffic-announcement identification, TA identification
3.6 list of alternative frequencies, list of AF
3.7 decoder identification, DI
3.8 music/speech switch, M/S switch
3.9 program-item number, PIN
3.10 radiotext, RT
3.11 enhanced other network information, EON information
3.12 transparent data channel, TDC
3.13 in-house application, IH application
3.14 clock time and date, CT and date
3.15 radio paging, RP
3.16 emergency warning systems, EWS
3.17 traffic message channel, TMC
3.18 location and navigation, LN
4 Modulation characteristics of the data channel (physical layer)
4.1 Subcarrier frequency
4.2 Subcarrier phase
4.3 Subcarrier level
4.4 Method of modulation
4.5 Data rate and clock frequency
4.6 Differential coding
4.7 Data channel spectrum shaping
5 Baseband coding (data-link layer)
5.1 Baseband coding structure
5.2 Order of bit transmission
5.3 Error protection
5.4 Synchronization of blocks and groups
6 Message format (session and presentation layers)
6.1 Addressing
6.2 Coding of information
Annex A (Normative) Program identification codes and extended country codes
Annex B (Normative) Character sets for program service name, radiotext and radio paging
Annex C (Informative) Program type codes
Annex D (Informative) Conversion between CT and date conventions
Annex E (Informative) Offset words to be used for group and block synchronization
Annex F (Informative) Theory and implementation of the modified shortened cyclic code
Annex G (Informative) Implementation of group and block synchronization using the modified shortened cyclic code
Annex H (Informative) RDS logo