California Partners for Advanced Transportation Technology

This report documents a single-channel architecture offering two-way communication between vehicles and a fixed communication infrastructure. Part I discusses the technical advantages and disadvantages of a dedicated Intelligent Vehicle Highway Systems (IVHS) communications infrastructure versus the use of a hybrid system involving several existing communication networks. Aspects such as spectrum efficiency, message capacity, and network performance are described. Part II proposes a network architecture that offers several transmission services essential to IVHS communications, using only a single (30kHz) radio channel. This narrow bandwidth can accommodate datacasting, packet-switched transmission to and from the vehicle, collection of traffic data from probe vehicles and emergency messages. The proposed architecture may not have enough capacity to support a mature IVHS system, but it provides a scalable method to provide spectrum-efficient wireless access to packet data communications services.