车载自组网中的分布式TDMA方法没有利用节点的空闲TDMA时隙,未能充分利用无线信道资源,基于此,提出了一种利用空闲TDMA时隙的MAC层数据重发方法,当节点发送数据失败时,附近节点利用空闲的TDMA时隙重新发送传输失败的数据。理论分析和仿真结果表明,所提方法显著提高了分布式TDMA方法的数据发送成功概率和网络吞吐量。此外,通过仿真比较所提方法与IEEE802.11p的性能,结果表明,由于以确定的方式访问信道,所提方法能够及时稳定地传输车载自组网中的实时安全信息。
The distributed TDMA approach for VANET dose not take advantage of idle slots, failing to effectively utilize radio resources. A retransmission method for medium access control was proposed for utilizing idle slots. In the method, neighboring nodes utilized idle slots for retransmitting a packet which failed to reach the target receiver. Theoretical analysis and simulation results show that the proposed method significantly increases the probability of successful packet transmission and the network throughput. In addition, a comparison between the proposed method and IEEE 802.11 p was presented via extensive simulation, and the results prove that, due to its ability to access channel determinately, the method can disseminate real-time safety information timely and stably.