基于内容及留存时间的VANETs转发策略

A VANETs Forwarding Strategy Based on Content and Retention Time

随着车载通信需求的增加,车载自组织网络将成为现代智能交通系统的一个重要组成部分。基于命名数据网络,对车载自组织网络中请求的转发策略进行了研究,提出了一种基于内容关系度及留存时间的转发策略。车辆动态地更新自身的内容记录表,及时去除移出通信范围的车辆,保证内容关系度的准确性,请求车辆根据位置、速度等信息计算邻居车辆的留存时间,由内容关系度与留存时间综合决定选择请求的转发节点,提高请求成功率和通信的稳定性。同时,为了进一步提高请求的成功率,在提出的转发策略中引入了内容缓存机制,车辆根据关系程度阈值判断是否需要缓存收到的内容。仿真结果表明,提出的转发策略能有效地提高网络中车辆请求的成功率,同时降低了成功请求的路径长度,减少了请求时延。

With the increasing demand for vehicle communication, vehicular ad hoc networks (VANETs) will become an important part of modern intelligent transportation system.Based on the named data networking,the forwarding strategies in VANETs is studied, and a forwarding strategy based on content concern degree and retention time is proposed.The vehicle dynamically updates its own content record table and removes the neighbor vehicles that beyond the communication range to ensure the accuracy of content concern degree.According to the speeds and locations of neighbor vehicles,the request vehicle calculates the corresponding retention time.Considering neighbor vehicles’ content concern degree and retention time,the request vehicle chooses the forwarding node that improves the success rate of the request and the stability of the communication.For the further improvement, the content caching mechanism is introduced in the proposed forwarding strategy.The vehicles received content decides whether the content should be cached according to the content concern degree threshold.The simulation shows that the proposed forwarding strategy can effectively improve the success rate of vehicle requests in the network,reduce the path length of the successful request and decrease the request delay.