VANET中基于合作式的ADHOC MAC协议

由于车载网VANETs(Vehicular Ad hoc Networks)在道路安全、车流量管理和娱乐应用具有广阔的前景,VANETs的数据传输技术成为研究的焦点。然而,VANETs的拓扑动态变化、车辆快速移动加速了车间通信链路的断裂,降低了链路的可靠性。为此,提出合作式通信机制以提高通信链路的可靠性,并缓解因车辆移动引起的无线道路的恶化。基于ADHOC MAC 方案,提出合作式的ADHOC MAC方案 ,记为CAH-MAC。在CAH-MAC中,一旦发现数据包未能成功传输到目的节点,邻居节点使用未占用的时隙提供合作模式重传数据。通过理论分析,得出合作模式的概率。理论分析和仿真表明,CAH-MAC提高了成功传输数据包的概率,提升了系统吞吐量。

Cooperative Ad hoc medium access control in VANETs

Data transmission technology in VANETs(Vehicular ad-hoc networks) is more attention due VANETs providing road safety, vehicle traffic management and infotainment. However, the changed topology and fast moving vehicle accelerate the fracture of communication link between vehicles, and reduce the reliability of communication links. Therefore, cooperative communication is proposed in order to improve the reliability of communication links, thus mitigating wireless channel impairments due to the vehicle mobility. In this paper, we present a cooperative scheme for medium access control (MAC) in VANETs, referred to as Cooperative ADHOC MAC (CAH-MAC). In CAH-MAC, neighboring nodes cooperate by utilizing unreserved time slots, for retransmission of a packet which failed to reach the target receiver due to a poor channel condition. Through mathematical analysis and simulation, we show that our scheme increases the probability of successful packet transmission and hence the network throughput in various networking scenarios.