车载自组网拥塞自适应路由

Congestion adaptive routing in vehicular Ad hoc networks

车载自组网通过节点间的多跳数据包转发为智能交通应用提供支持。节点数目多和分布密度不均匀的特点易使其在网络局部产生通信拥塞,造成数据包传递延迟增大甚至丢失。针对典型的城市应用场合,提出了一种新的拥塞适应路由协议,通过监测信道状态来估计各节点可用带宽,从而获得拥塞程度指标;同时利用邻居道路口通告和数据包捎带机制,发布网络通信拥塞程度信息;并结合道路车流信息和通信拥塞状态,给出了自适应路径选择模型。仿真实验表明,协议回避了网络中的拥塞区域,提高了数据包递送率,降低了递送延迟。

In VANET,packets can be delivered via multi-hops relay to support a wide range of application in intelligent transportation system.However most current VANET routing protocols may suffer from the increased delay or packet drops while the traffic congestions become more probable due to the large amount and uneven density of nodes.A new congestion adaptive protocol for urban vehicular networks was presented.To get the metric of congestion degree,the available bandwidth was estimated by monitoring the channel utilization.Furthermore,the congestion information was distributed by neighbor-intersection notifications and data packets piggybacking.Finally,the adaptive route was selected by using the model that takes into account both the vehicle densities and the congestion metrics.The results of simulation show that the routing protocol can avoid congestion region,improve the packet delivery ratio and decrease the average delay.