Abstract: In order to realize the low latency and high reliability transmission of safety application messages, this paper designs a network selection algorithm based on DSRC/LTE for the transmission of safety application message. From the quality of service (QoS) demand of safety application messages, the designed algorithm considers various parameters such as end-to-end delay, packet loss rate and transmission speed. The algorithm firstly uses the analytic hierarchy process (AHP) to compute the weight of each parameter in the safety application message transmission QoS, then analyzes the ability to support the safety application message transmission QoS of each candidate network, finally calculates the satisfaction of the safety application message transmission QoS. The simulation of the designed algorithm is implemented on the platform VeinsLTE, in which the relationship of traffic simulation and network simulation is bidirectional coupling and they can interact in real-time, and the performance is verified on it too. The simulation results show that the designed algorithm can allocate the network resource reasonably according to the different QoS needs of safety application messages. On one hand, compared with the QoS-oriented TDMA protocol, when using the QoS-oriented TDMA protocol and the designed algorithm simultaneously, in the high speed scenario and the urban scenario respectively, the reception probability of the safety application message has improved by 13.7% and 10.4%, and the transmission delay of the safety application message has reduced by 8.6% and 11.5%. On the other hand, compared with the matching game network selection algorithm in the high speed scenario and the urban scenario respectively, the reception probability of the safety application message in the designed algorithm has improved by 11.6% and 7.5%, and the transmission delay of the safety application message in the designed algorithm has reduced by 13.2% and 15.3%.

Key words:  Internet of vehicles (IoV), safety application message, heterogeneous network, network selection

摘要： 为了实现异构车联网中安全应用消息的低时延高可靠传输，针对基于DSRC/LTE的异构车联网，设计了一种面向安全应用消息传输的网络选择算法。该算法从安全应用消息传输服务质量（quality of service, QoS）需求出发，综合考虑了安全应用消息传输QoS的多项参数指标，包括端到端时延、丢包率、传输速率。算法首先利用层次分析法计算出安全应用消息传输QoS各个参数的权重值，然后分析了各个候选网络支持安全应用消息传输QoS的能力，最后确定了安全应用消息传输QoS的满意度。采用双向耦合、实时交互的车联网仿真平台VeinsLTE对面向安全应用消息传输QoS的网络选择算法进行了仿真实现和性能验证。仿真结果表明，面向安全应用消息传输的网络选择算法可以根据安全应用消息传输的不同QoS需求，合理地分配网络资源。一方面，与仅使用已经实现的QoS-oriented TDMA协议相比，同时使用QoS-oriented TDMA协议和面向安全应用消息传输的网络选择算法的异构车联网，在高速场景和市区场景中安全应用消息的接收概率分别提高了13.7%和10.4%，传输时延分别减少了8.6%和11.5%。另一方面，面向安全应用消息传输的网络选择算法在高速场景和市区场景中，与匹配博弈网络选择算法相比，安全应用消息的接收概率分别提高了11.6%和7.5%，传输时延分别减少了13.2%和15.3%。

关键词: 车联网, 安全应用消息, 异构网络, 网络选择