中文摘要：

车用自组织网络（VANET）的一个重要特点是车辆终端具有高速移动性．传统的无线局域网MAC协议适用于节点固定的网络，对移动性的支持不够．基于时隙ALOHA和预约ALOHA提出一种在高速车辆运动环境下，适合节点移动的SR-ALOHA协议，采用动态切换协议的方法适应速率变化带来的通信链路时断时续．仿真结果表明，在速率变化的环境下协议具有较高的吞吐表现、较低的端到端传输延时．

英文摘要：

An important feature of Vehicular A_d-hoc Network was high mobility of terminals. The traditional medium access control protocols that were fit for networks composed with stationary nodes had not enough support with the mobility of nodes. Based on Slotted AL~）HA and Reservation ALOHA, an adaptive MAC protocol SR-ALOHA was proposed to be used in high mobility vehicular environment, which had a dynamic switch of protocols for the intermittent connections. Simulation result showed that SR-ALOHA had a higher perforrnsnee of throughput and less end-to-end delay.