Key Design Issues for Efficient Broadcasting of Traffic Information Services

Traffic information and other telematics services can efficiently be transmitted by using broadcast networks. This paper describes a versatile service distribution platform that has been tailored to an automotive setting, i.e. for the use of services in cars and navigation systems. The overall architecture and particularly the transmission protocol are streamlined for minimizing the transmission overhead such that a large number of services can be sent in parallel. A flexible conditional access system allows encrypting individual services with a minimum of subscription management overhead and without requiring any return channel. The platform is currently being deployed and tested in Germany and is scheduled to start regular operation in 2008.