VANET-Cellular环境下安全消息广播中继选择方法研究

The broadcast of safety message based on opportunistic network always lead to high latency when the target area is far from the source node.In this circumstance, the QoS of the safety message dissemination will have no insurance. The rapid popularity and development of cellular network provides a new method for the broadcast of safety message. Based on the VANET-cellular architecture, a selection method of safety message broadcast relay was proposed by us. We first introduce a relay metric for relay selection by jointly considering cellular signal strength and its variation, link stability, physical-layer channel conditions and geographical locations. Then, using the relay metric,a unique relay vehicle is selected to forward the safety message to server by cellular network. The server will send the safety message to the target area afterward. Simulations and mathematical analysis demonstrate that the proposed method can minimize the broadcast message redundancy,improve the network resource utilization, rapidly and reliably transmit the safety message. What’s more, the encouraging results are not excessively dependent on the density of traffic and widely deployment of infrastructures.