The increasing number of VHF/FM programme frequencies made conventional tuning difficult. RDS has been on the market since 1987 and is now a standard function in many receiver classes.
More than 40 years after the technology was created, almost all FM radios use RDS. Highly integrated receiver ICs often include both the FM receiver and RDS decoder, with more than one billion FM/RDS radio ICs manufactured each year.
RDS made FM radios user-friendly
RDS development started in the European Broadcasting Union. The goal was to make radio receivers easier to use, especially car radios operating across transmitter networks with Alternative Frequencies.
Programme Identification and Programme Service name allow a receiver to know which audio programme is being received. A microprocessor-controlled tuner can retune in milliseconds, mute audio during the switch, and choose the best available frequency carrying the same programme.
Travel information is supported by the TP and TA flags. RDS is also used for the Traffic Message Channel, widely used by navigation systems for dynamic re-routing.
EON and dynamic features
Enhanced Other Networks lets a receiver receive additional information about other programmes from the same broadcaster. A listener can be switched automatically to travel information even when the currently tuned service is not carrying it.
Many receivers support dynamic features such as Programme Type, RadioText, Clock Time, and RadioText Plus. RT+ can identify elements inside text such as music title, artist name, and a programme service home page.
RDS2
Since 2018, IEC 62106 has included the RDS2 option. RDS2 adds three further subcarriers structured like the basic RDS subcarrier, significantly increasing data capacity while preserving the established RDS service model.