Radio Data System (RDS) 

RDS stands for Radio Data System and is a radio broadcasting corporation service. As well as the audio broadcast programme, information is transmitted in the form of encrypted digital signals which can be analysed by RDS-ready radios. This makes it possible to transmit additional services such as broadcaster name (PSN), radio text (RT) or the labelling of traffic programmes (TP) or traffic disruption (e.g. traffic jams, accidents, road closures via TMC). Transmission of alternative frequencies (AF) in RDS permits adjustment to the frequency of the current broadcast programme with the best reception.  When a signal becomes weaker, the radio switches automatically to an improved broadcast frequency of the same station.
Traffic Announcement (TA) conveys traffic reports at a preset volume, even when other sources (CD, SD or other media) are being played or the radio is switched off. Within a broadcasting network, the system also automatically switches from a station not broadcasting traffic news to the relevant traffic news station (EON, Enhanced Other Network).
The radio station operators are responsible for the accuracy of RDS information. RDS is already in use throughout Europe. However, in other parts of the world (e.g. North America, China), RDS is playing an increasingly important role in conjunction with broadcaster name (PSN) and traffic information (TMC).