车联网中基于贝叶斯决策的垂直切换方法研究

车辆需要在车联网的异构无线网络环境下进行垂直切换，针对垂直切换技术普遍不能支持 WAVE， WiMAX和3G cellular间的垂直切换这一问题，提出了一种基于贝叶斯决策的垂直切换算法。首先，根据接入网络的信号强度、传输速率、误码率和网络阻塞率以及车辆终端的速度和运动趋势建立多条件相关的切换概率分布，计算出切换先验概率；然后通过贝叶斯决策算法计算后验概率并进行决策分类，从而选取最优网络接入。仿真实验结果表明，该算法不仅有效地实现WAVE，WiMAX和3G cellular无线接入技术之间的垂直切换，而且避免了乒乓效应，保证了网络及时更新。

IoV vertical handoff research based on Bayesian decision

Vehicles need vertical handoffs in the heterogeneous wireless network environment of IoV, but current vertical switching technologies generally cannot support vertical handoff among WAVE, WiMAX and 3G cellular. In order to overcome this problem, a vertical handoff method with Bayesian decision was proposed. Firstly, according to the signal strength, transmission rate, bit error rate, blocking probability, vehicle speed and movement trend, the handoff probability distribution of Multi-condition was established and the handoff prior probability was calculated. Secondly, Bayesian decision method was used to obtain the handoff posterior probability and to classify decisions, which made vehicles access the best network. Simulation results show that the proposed method can not only achieve the vertical handoff among WAVE, WiMAX and 3G cellular, but also avoid the ping-pong effect and ensure the network update rate.