Reliable safety message dissemination with minimum energy in VANETs

Road safety can be improved a lot with the help of Cooperative Collision Warning System, in which vehicles cooperate with each other for relaying safety messages to avoid accidents. Once a vehicle is in an abnormal status, which may lead to potential accidents, an emergency safety message will be generated and sent out to warn surrounding vehicles. In this paper, we address the routing problem of reliable dissemination of emergency safety messages in Vehicle Ad-Hoc Networks (VANETs). We aim to minimize the total transmission energy and reduce the transmission interference for delivering emergency safety messages to endangered vehicles while guaranteeing timeliness of safety messages and transmission reliability of inter-vehicle communications. The emergency safety message dissemination problem is formulated as a spanning tree optimization problem with both hop-count constraint and reliability-height constraint. A mixed integer programming model (MILP) is proposed for solving the studied problem optimally, which can be used as a benchmark for evaluating future fast heuristic algorithms. Simulations are conducted to validate our proposed MILP model.