RDS radio system

Details RDS radio system RDS radio system

1991-08-08

1993-08-24

Eisenzopf, Reinhard J.

Telecommunications

Transmitter and receiver at separate stations

4551861, 455345, 340993, H04B 7100, H04O 302

Patent

active

052396819

DESCRIPTION:

BRIEF SUMMARY
The Radio Data System RDS was developed under the auspices of the European Broadcasting Union (EBU) who publish its specification, "Specifications of the radio data system RDS for VHF/FM sound broadcasting" EBU Document 3244-E, 1984. The main objective of this system is to facilitate the realisation of automatic tuning features in new receivers by using the Programme (i.e., program) Identification (PI) code, Alternative Frequency (AF) codes, and, where appropriate, Other Network (ON) features of RDS. The various codes are carried by a digital data channel accompanying the broadcast program.
The data is broadcast in what are known as "groups". A group is a 104-bit message comprising four 26-bit blocks called block 1 to block 4. Within a block 16 bits carry information and 10 bits are used for error protection. Various different types of group have been proposed and the EBU specification give details of types 0 to 6, all with A and B variants. Every group always carries PI(TN) i.e. the PI code of the transmitting network in block 1. Block 2 contains various bits and groups of bits including the group type code, and TP(TN), i.e. the traffic program flag for the transmitting network bits which signifies whether the group is A type or B type.
The usage of blocks 3 and 4 is determined by the group type, indicated by the group type code in block 2. In type 0A groups, for example, block 3 carries two alternative frequency codes AF identifying channels which carry the same program, to facilitate rapid switching of channels, especially in car radios, in order to stay tuned to the selected program. Block 4 carries a program programme service name PS, two bytes at a time, for display on a suitably equipped receiver. In type 0B groups block 4 is as in type 0A except that block 3 repeats the PI code of block 1--when there is no AF information to transmit. Type B groups in general have block 4 as the corresponding type A group but have PI in block 3 instead of whatever is carried by block 3 in the type A group. A type B group can be used when the A-type is not required to increase the mean rate at which PI(TN) is transmitted.
One of the more sophisticated uses of RDS is to transmit information regarding other networks (ON) as well as the transmitting network (TN) to enable receivers to maintain updated information on other networks. One requirement is then to transmit alternative frequencies for the other networks, i.e. AF(ON). The EBU specification proposes to provide this facility in the type 3A group which is shown in the accompanying FIG. 1 which is derived directly from FIG. 10 of the EBU specification.
The following symbols are used in FIG. 1:


______________________________________ PI(TN) PI code for the transmitting network CW Checkword for a block GT Group type code, 4 bits B A or B type bit TP Traffic program flag PTY Program type code, 5 bits AC Address code, 3 bits UC Usage code, 2 bits AF(ON) Alternative frequency code for other network PI(ON) PI code for other network PIN(ON) Program item number for ther network TA Traffic announcement flag ______________________________________
The usage code UC specifies the contents of block 4, as indicated in block 4. It will be seen that UC=00 means that block 4 carries a PI(ON) code while UC=11 means that block 4 carries two AF(ON) codes. Block 3 also carries AF(ON) codes. Since PI(ON) is not always present there has to be some way of associating the AF(ON) codes with the correct PI(ON) code. This is effected by means of the address code AC is block 2. The AF(ON) information in any group pertains to the PI(ON) information in a group with the same address code.
This proposal suffers from a number of disadvantages. Firstly the address code is only 3 bits which limits the transmission of other networks information to 8 networks. This is completely inadequate in developed societies with many different radio networks. Furthermore the PI(ON) data may not be reliably available at the time the fourth block is received, in which case the receiver doe

REFERENCES:
patent: 4907159 (1990-03-01), Mauge et al.

Affiliated with

Also associated with

Rating

RDS radio system does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with RDS radio system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and RDS radio system will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-836310