Chicago – The Radio Data System is a data bearer that uses the 57 kHz subcarrier on FM Radio broadcasts. The data is genrated by an RDS encoder, which produces groups of RDS information and adds them to the subcarrier. In ist most basic form – providing on RDS-capable receivers an unambiguos readout of the station name and the ability to follow from transmitter to transmitter seamlessly – it has been in use since about 1986 in Europe, and now is in widespread use arround the world.