【摘要】 针对在使用方向性天线的AdHoc网络中没有合理利用远距离传输优势的问题,提出了一种支持远距离通信的方向性MAC协议.在该方向性MAC协议中,中间节点会利用一种远距离定向算法帮助发送节点获取位于两跳远的目的节点的定向信息从而建立远距离链路,这种链路的建立有助于解决局部拥塞,同时降低传输延时.本文中根据MAC层能否获得信号接收功率信息提出了两种LRO算法:基本LRO算法不使用信号接收功率信息,仅利用几何关系获得近似的远距离节点定向信息;而LRO-PI(LRO with power in for mation)算法在利用信号接收功率信息后可以进行更加准确的远距离节点定向.性能分析表明,在合理地选择相关参数后,LRO算法有着很高的定位准确性.并且仿真结果表明远距离链路的建立可以有效地提高网络的吞吐量,并且降低端到端延时.更多还原

【Abstract】 To address the problem that long-range communication capability in ad hoc networks using directional antenna is not generally utilized,a directional media access control (DMAC) protocol with long-range communication (LRC) capability in ad hoc networks is proposed.In the LRC-DMAC,the intermediate node uses a long-range orientation (LRO) algorithm to help the transmitter obtain the directional information of the receiver which is two hops away.Consequently,the long-range link between such two hops nodes can be set up.According to whether the received power information is available or not,we propose two types of LRO algorithm:without the received power information,a basic LRO obtains the approximate directional information of the long-range receiver by a geometric relationship;however,the LRO-PI can calculate the accurate directional information of the long-range receiver using the received power.Performance analysis indicates that the LRO algorithm achieves high accuracy when the relevant parameters are properly chosen.Simulation results show that the establishment of long-range links can effectively improve the network throughput and reduce the end-to-end delay.更多还原