在大规模移动自组织网中,利用节点位置信息辅助建立路由被认为是一种有效提高无线网络路由可扩展性的方法.提出了一种可扩展与高效的、适用于移动自组织网络的路由算法——分簇覆盖的节点位置信息辅助路由算法(CLAR).CLAR使用如最小簇改变(LCC)算法,建立并保持的单跳分簇结构为拓扑.已有文献证明,LCC是更新成本最小的保持簇头节点密度均一的分簇算法.CLAR利用网络节点的位置信息提高无线网络路由的网络层性能,由目标节点的位置信息预测并构造一个较小的、形状为等腰三角形、矩形或圆形的区域.该区域需保证覆盖目标节点可能存在的位置,且根据源节点与目标节点间的相对位置决定该区域适宜的形状,从而限制源节点在一个较小的"请求域"内寻找可用路由,而不是在网络内盲目寻找.仿真实验结果表明,与其他路由算法相比较,CLAR路由算法在路由建立所需时长、路由代价、平均时延及数据包冲突等参数上表现优良.同时,算法保持了低平均时延、高数据包到达率、低控制开销及低路由寻找次数等优势.
Using location information to assist routing is often proposed as an efficient means to achieve scalability in large mobile ad hoc networks (MANET). This paper proposes an algorithm, named as Cluster-Based Location Aided Routing (CLAR), a scalable and efficient routing algorithm for MANET. CLAR runs on top of a one-hop cluster cover of the MANET, which can be created and maintained by, for instance, the Least Cluster Change (LCC) algorithm. It has been proven that LCC can maintain a cluster cover with a constant density of clusterheads with the minimal update cost. CLAR then utilizes nodes' location information to improve the network layer performance of routing. The location information of destination node is used to predict a smaller isosceles triangle, rectangle, or circle request zone, which is selected according to the relative location of the source and the destination, that covers the estimated region where the destination may locate. Instead of searching the route in the entire network blindly, CLAR confines the route searching space into a much smaller estimated range. Simulation results have shown that CLAR outperforms other protocols significantly in route set up time, routing overhead, mean delay and packet collision, and simultaneously maintains low average end-to-end delay, high success delivery ratio, low control overhead, as well as low route discovery frequency.