Multiple access and spatial collision resolution for IVHS packet radio networks

The spectrum efficiency of cellular radio data networks is maximized by increasing the cell throughput and decreasing the cluster sizes. However, smaller cluster sizes lead to higher cochannel interference and hence lower throughput. A multiple access and collision resolution scheme that accounts for the spatial aspects of cochannel interference is introduced and analyzed for roadside base station to vehicle packet communications in intelligent vehicle highway systems (IVHS). In a wireless network with base stations having full knowledge of neighboring station activity, cochannel interference and destructive collisions are diminished by using discontinuous transmissions and coordination: a base station is silenced (or power-controlled) by a neighboring station in order to improve the latter's chance of successful transmission and decrease retransmission attempts. Interaction among base stations makes efficient use of channel resources for both low- and high-intensity traffic.