Ad hoc网络路由抖动与路由维护

针对路由抖动对Ad hoc网络服务质量的影响,提出了2种基于AODV的多路由维护方案。方案一(AODV-CRM)是由源节点进行全路由维护,维护由源、宿节点之间的所有没有公共中继节点的可用路由。方案二(AODV-SRM)是根据网络拓扑自主选择路由维护方式,如果源节点有多条到达宿节点的路由,则由源节点维护到宿节点的备用路由;否则,沿源宿方向递归查询,直至某一节点有到宿节点的多条(子)路由,由其维护备用(子)路由。本文首先从理论上定性地分析了路由抖动对原协议和改进协议的影响。通过NS-2工具仿真验证,两种备份协议在抗抖动性能上都优于原协议,AODV-SRM的控制信息开销低于AODV-CRM。

Route maintenance against route flapping in Ad hoc networks

Since route flapping weakens the quality of service in Ad hoc networks, this paper proposes two protocols of multiple route maintenance based on Ad hoc On Demand Distance Vector (AODV). In the first protocol, called AODV-CRM protocol, the complete routes from the origination are maintained. It gets all available routes between the origination and the destination, and any two of these routes share no common middle nodes. The second protocol, called AODV-SRM protocol, chooses a route maintenance method according to network topology. If there are multiple routes between the origination and the destination, the backup routes are maintained. Otherwise, a recursive method is applied from the origination to the destination until one node gets multiple sub-routes to the destination. We first analyze the performance of the two protocols against route flapping; then carry out simulations by NS-2. Results show that the two proposed protocols with backup routes perform better against route flapping than the existing protocols. The control message cost of AODV-SRM is less than that of AODV-CRM.