中文摘要：

车辆自组织网络（Vehicular Ad Hoc Network,VANET）能够提高人们出行的安全性和舒适性,成为学术界和工业界的研究热点.然而由于NET特殊的应用场景,如拓扑高动态、节点高密度、信道质量的不稳定等特性,导致网络中数据的可靠性难以得到保证.我们在传统自组织网络的研究成果基础上,提出了基于TDMA（Time Division Multiple Access）的分布式协作MAC（Media Access Control）协议,称之为C-T-MAC（Cooperative TDMA MAC）.C-T-MAC算法引入了协作通信的概念.源节点与目的节点传输失败后,选定的协作节点选择网络中一个空闲的时隙向目的节点转发数据,完成协作通信过程.仿真结果表明,C-T-MAC算法提高了网络的吞吐量和数据传输的可靠性.

英文摘要：

Vehicular Ad Hoc Network can improve traffic safety and efficiency, and it attracts close attention from academia and industry. However, the features in special VANETs scenario, such as highly dynamic topology, high traffic density, unstable links, and so on, cause that it is hard to maintain the reliable data dissemination. Based on the existing MAC layer protocol research results of Ad Hoc network,associating with the special scenarios of VANET, a novel distributed TDMA algorithm named C-T-MAC is designed, and it introduces the concept of cooperative communication. When the transmission between source node and destination node fails, destination node could accept the help of neighbor nodes in idle time slot. Through this can increase the network throughput and the reliability of data. At last, the proposed algorithm in NS- 2 simulation platform is verified. The simulation results show that the algorithm can improve the reliability of information and the utilization of slot in a certain extent.