针对车载无线网络环境中由于多信道传输需要进行信道切换导致控制信道起始处的同步冲突问题，文中利用车辆节点估算信道占用率并计算发送概率，能够达到动态调整信道拥塞程度并有效缓解冲突的目的。首先对控制信道的传输机制进行规划，为安全消息和业务信道预约消息等设置不同优先级，然后进行自适应信道负载分散。当信道负载较重时发送概率减少，部分节点需要重新竞争信道，从而起到缓解冲突的作用。仿真结果表明，该算法能够提高数据包的成功转发率，降低传输延时，有效缓解由信道切换带来的同步冲突。%Multi-channel transmission will lead to channel switch in VANET,which causes the synchronized collisions at the start of con-trol channel. Propose a method to relieve this collision effectively and adjust the degree of channel congestion dynamically by estimating channel utilization and computing the transmission probability with vehicles. Firstly,the mechanism of control channel transmission has planned. The priority of safety-related messages is higher than reservation message of service channel and so on. Then the channel load will be distributed self-adaptively. When the load is heavy,the transmission probability reduces as well,part of vehicles need re-competi-tion of control channel,for the purpose of collision mitigation. Simulation results show that this method can improve the rate of package forwards,reducing the transmission delay and relieving the synchronized collisions caused by channel switch effectively.
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