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).

Volkswagen on-board computer with focus on the Radio Data System

 Radio Navigation System

The radio navigation system combines navigation with multimedia entertainment.

See also:
Navigation system

Image of the radio navigation system in the on-board computer of a VW Passat

Rain sensor

Volkswagen's rain sensor automatically controls the wipe frequency of the wiper according the intensity of the rain. The sensor at the base of the interior mirror consists of several infrared LEDs and one central photodiode. The light emitted by the LEDs is reflected by the windscreen to the photosensor. The more water droplets are on the windscreen, the less light is received by the sensor. This information is passed on to an electronic control unit that adjusts the wiping frequency of the wiper accordingly. The sensor’s sensitivity can also be adapted using a selector switch.

The rain sensor is designed so that neither minor damage, dirt nor ageing of the windscreen can have a negative impact on its function. The driver can focus all their attention on what's happening on the road without having to change the wiping frequency. This is a major benefit, particularly in the event of sudden obstructions of view, such as when overtaking a lorry on a wet surface.