INTEGRATED VEHICULAR POSITIONING AND COMMUNICATIONS SYSTEM

摘要

A wireless vehicular positioning and communications system that combines inter-vehicular ranging and a self-organizing TDMA MAC protocol to both achive more accurate positioning than is possible with GPS positioning and provide a deterministic channel for inter-vehicle communication. The band used for the system is divided into time slots, with each vehicle being able to obtain a time slot autonomously. Within a time slot, there is a ranging signal which occupies the full bandwidth; following the ranging signal, the band is divided into sub-bands. Some of the sub-bands are used to send packets according to the TDMA MAC protocol, and thus provide the deterministic channel; others are used for a non-deterministic channel which may be used for packets following the Internet Protocols. The system also uses mesh networking to permit vehicles to obtain advance warning of abnormal conditions in other vehicles.