中文摘要：

现有机会路由算法采用与传统无线路由相似的转发机制,为每个节点指定全局度量值或下一跳节点集合。该文首先通过反例指出转发机制不能总获得最优的性能,进而提出从状态转移的角度研究机会路由过程,将不同已接收到的节点集合视为不同的状态,并将路由过程看作由不同状态组成的马尔科夫链。随后建立了相应的路由算法模型,该模型能够揭示路由过程的本质特征,可适用于多播与多冲突域场景。在此基础上提出了基于状态转移的最佳机会路由算法（Shortest Opportunistic Routing,SOR）,证明了其在多播与多冲突域场景下可获得最小期望传输次数（Expected Transmission Count,ETX）代价。仿真结果表明了SOR算法的有效性,其性能优于已有算法。SOR算法可应用于多跳无线网络的最优机会路由策略选择,计算给定拓扑下可获得的最小端到端ETX代价。

英文摘要：

Available Opportunistic Routing（OR） works adopted a relay scheme,which is derived from the traditional wireless routing algorithms.In such scheme,each node is assigned with a global metric or next-hop nodes set.In this paper,it is proved that the relay scheme can not always get the optimal performance by counterexample.The OR process is proposed to be regarded as a Markovian chain of different states from the perspective of state transition,where the states denote different set of nodes that have received the packet.Then the OR algorithms are modeled to help to investigate the intrinsic behavior of OR.It can be applied to the scenarios of multicast and multiple collision domains.Based on that,optimal algorithm named Shortest Opportunistic Routing（SOR） is proposed and proved,which can yield the least Expected Transmission Count（ETX） cost in both scenarios of multicast and multiple collision domain.Simulation results verify the superiority of SOR and show that the performance of SOR surpasses previous algorithms.The optimal OR strategy of wireless multi-hop networks can be selected and the minimal end-to-end ETX cost can be yielded by utilizing the proposed SOR.