Date Added: Sep 2010
The authors consider the problem of designing cooperative driver assistance and collision warning systems in vehicular networks. In this problem each car has a small size state information message that should be received by its neighbourhood within a short lifetime of L timeslots. Because of the safety nature of the application, communication reliability (success probability) and delay are of critical importance. In a repetition-based MAC scheme, each car retransmits its safety message w times in a time frame of L timeslots. Based on the proposed opportunistic network coding in this paper, given the local feedback information and already heard messages, each node tries to find the best message combining strategy such that the number of nodes that can instantly decode an uncoded packet is maximized.