高速公路环境下车联网同向协助下载方法研究

本文根据车联网协助下载的研究现状，针对高速公路环境下AP分布稀疏且通信范围有限所导致的用户通过WIFI接入互联网进行内容下载过程中高延迟低吞吐率的问题提出了一套同向车辆协助下载的方法。利用该方法，如果用户未能在AP通信范围内完成下载，AP选择其通信范围内与用户同向行驶的一组车辆携带用户所需数据，通过车速快于用户的车辆在赶超用户过程中完成数据转发。利用这种方法有效的提高用户获取数据的吞吐量，达到了延伸AP通信区的目的。仿真结果表明，使用同向协助下载方法可以使用户获取数据量提高二倍以上。

A Method of Same Direction Cooperative Downloading of VANET in Highway Scenarios

When the vehicles running on highway access internet and download data through WIFI,the throughput and delay are influenced by the problems of the sparse distribution and limitation of AP’s communication area.A kind of cooperative downloading method using the vehicles running the same direction with client is proposed.Using this method,if the client cannot finish its downloading in AP communication area,AP will pick up a group of vehicles with the same direction with the client to take the client’s unfinished data.When faster vehicles pass the client,data will be forward to it.Simulation results indicate the benefits of the proposed method in terms of reducing packets loss rate and increasing system throughput.