RDS

From Freeradio

RDS stands for Radio Data System, and is what allows RDS radios to display the name of the FM station being received.

The RDS data is transmitted on a 57 kHz sub-carrier, using Double Side Band Suppressed Carrier (DSBSC) to send the digital data. In addition to transmitting the station name, RDS is also capable of transmitting alternative frequencies used by a station (allowing RDS radios to automatically re-tune to the strongest frequency), and transmitting a "flag" to tell the radio when traffic news is being broadcast.

Since about 2000, a growing number of pirates - mostly the larger pirate stations - have been transmitting RDS data. Some of them have used scrolling RDS, to advertise club events etc organised by the stations.

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External links:

RDS info on the Radio & Telly web site [1]