Packet-switched roadside base station to vehicle communication for intelligent vehicle/highway systems

Optimum frequency reuse patterns for roadside base station to vehicle communications in intelligent vehicle/highway systems (IVHS) are determined based on optimal delay/throughput and packet erasure rates for BPSK transmission over narrowband dispersive Rician channel with ISI and (Rayleigh-faded) co-channel interference. For fixed cluster size and fixed total system bandwidth, a reuse pattern of 2 for continuously transmitting (hence interfering) base stations gives minimum average delay and maximum spectrum efficiency: this is a denser pattern than suggested for highway cellular telephony networks. Spectrum efficiency is enhanced by using a dynamic cluster size which depends on the distance from the base station, taking advantage of the IVHS environment where vehicle position may be known