traffic message channel (RDS) (TMC)
Digital traffic radio is a special information service for road users. The TMC service (Traffic Message Channel), which is used to transmit general traffic news and congestion reports, can be used to filter out individual traffic information that is relevant for the individual road user. In doing so, the TMC receivers take into account the location and direction of travel of the corresponding road user, who can use this information for his or her individual route planning.
Only traffic information is transmitted via digital traffic radio; the TMC system is limited to a maximum of 65,000 traffic points.
An extension of the TMC service is offered by T-Mobile Traffic with its fee-based TMCpro, which uses this traffic service to transmit up-to-date highway traffic reports and precise congestion descriptions. To achieve this goal, TMCpro makes greater use of traffic sensors on freeway bridges. In addition, traffic data from mobile congestion reporting systems, i.e. floating car data( FCD), data from stationary acquisition systems( SES), induction loops and data from traffic information centers are incorporated into the traffic messages.
The TMC data is transmitted by public broadcasters between the data for the radio text( RDS), whereby the nationwide traffic messages are broadcast in a regionalized manner. The road user receives as only messages from the regional area in which he is currently located and a certain overlap area. The TMCpro data is encrypted, and special encoders are required for reception.
The next generation of TMC is called TPEGautomotive and is broadcast via digital audio broadcasting( DAB).