基于移动状态的车载自组织网络路由算法

传统的AODV协议应用于车载自组织网络,尽管分组投递率比较高,但在数据分组需要发送时才建立路由,网络延迟较大。而DSDV中通过周期性的路由更新机制,网络延迟小,但需维护大量不必要的路由,并且拓扑结构变化使许多路由无效,导致分组投递率非常低。为了综合满足VANET分组投递率和网络延迟的要求,将AODV和DSDV两种路由建立机制相互融合,形成混合式路由协议。首先,根据车辆节点的位置、速度和方向等移动状态周期性地选择稳定且距离适中的链路,形成网络主干并更新路由;其次,当数据分组目的节点路由不存在时,发起路由发现过程建立路由,在路由请求报文前进和路由应答报文回溯过程中求出路由过期时间。仿真实验表明,尽管路由开销有所增大,分组投递率略低于AODV,但是网络延迟显著降低。

A moving state based routing algorithm invehicular ad hoc networks

The traditional AODV protocol is applied in vehicular ad hoc networks. Although the packet delivery ratio is relatively high, the network latency is high due to the routinggeneration after demand. DSDV makes use of periodic routingupdating mechanism and has low network latency, but many unnecessary routes need to be maintained and the change of topology leads to many invalid routes, which causes low packet delivery ratio. To meet the requirements of the packet delivery ratio and the network latency inVANET, The organic combination of tow routing mechanisms for AODV and DSDV forms a hybrid routing protocol. Firstly, the stable and moderate range links are periodically selected as the backbone network according to nodes’ location, speed and direction and updating routes. Secondly,the routing discovery process is carried out to establish the routewhen the route of destination does not exist, and the route expiration time is computed in the forward process of routing request packet and in the backward process of routing reply packet. Simulation results show that, although the routing overhead increases and the packet delivery ratio is slightly lower than that of AODV, the network latency is significantly reduced.