Integrated-layer packet radio study for AHS

The design issues and the performance evaluation of packet radio communication systems for automated highway systems (AHS) are presented. The main focus is on the analysis and interaction between the physical and the link-access layers of a packet radio system that can accommodate communication between vehicles and roadside infrastructure as well as between vehicles. We discuss the information flow requirements of AVCS (advanced vehicle control systems) and ATMIS (advanced traffic management and information systems) services and we present preliminary results from the performance evaluation of four multiple access schemes (slotted-ALOHA, reservation-ALOHA, TDMA, and CDMA).