单向ad-hoc移动网络路由协议UAOR

UAOR:A Routing Protocol for ad-hoc Mobile Network with Unidirectional Link

单向 ad- hoc移动网络是一种完全由移动主机构成的网络 ,传统的路由协议由于基于 DBF方式其路由更新开销大 ,对网络拓扑结构改变收敛慢 ,不适合 ad- hoc移动网络拓扑变化快和带宽有限等特点 .文中提出了一种支持单向 ad- hoc移动网络的路由协议 U AOR,它采用按需方式查找路由 ,并根据主机之间的邻接关系和距离矢量来选择相对最稳定且最短的路由 ,具有路由更新开销小 ,快速适应网络拓扑结构改变等特点 .

We proposed an on-demand routing protocol UAOR for ad-hoc mobile networks with unidirectional links. The major goal of on-demand is to minimize control traffic. UAOR consists of route discovery and route reconstruction phases. In route discovery, the nodes select routes depending on the affinity, which is inspired by ABR and the shortest path. Every node broadcasts hello message every t seconds so that the down-stream neighboring nodes can count the affinity. If the forwarding node has route to the destination, it appends route to the route request message and sends it to the destination without broadcasting. When the destination receives the route request, if in the destination's routing table there is a route to the source, the destination sends route reply to source directly by this route. Otherwise, the destination sends reply back to source similarly as the route request. When the source node obtains the route, it uses source route to send packet. We use hello message to achieve route reconstruction. When a link is broken (the downstream neighboring node dose not receive the hello message for T seconds), the downstream nodes carry the broken link in their hello message for only a T seconds. All nodes that received this hello message will rebroadcast broken links in their hello message for T seconds until to the source node. Every node broadcasts a broken link for only T seconds, then deletes it from hello message, which reduces the overheads of route reconstruction and ensures the source node know the failure of the route including the broken links. When a node or a group of nodes leave the network, their route table would update to avoid the failure routes. We also proved the correction of UAOR and analyzed the time and communication overheads of route reconstruction. We compared UAOR with UAHR and NUDL and found that UAOR has better performance than these two protocols.