适用于语音业务的MANET机会路由机制

An opportunistic routing mechanism for real-time voice service in mobile ad hoc networks

传统路由机制需要在源和目的节点之间预先建立端到端路径,当链路质量较差时,频繁地建立路径会影响业务的服务质量。为支持实时语音业务,提出一种机会路由机制,该机制并不预先建立连接,而利用多个路由请求和路由应答消息建立转发列表,表中的节点利用与其他节点的相遇机会对数据包进行转发,并根据转发节点的优先级对转发数据包的数量进行限制。仿真结果表明:机会路由机制能够减小语音业务的端到端时延,提高分组投递率,可以在不稳定的信道为语音业务提供服务质量保证。

Pre-established end-to-end paths between the source and destination nodes are necessary in traditional routing protocols, and the quality of service will be affected by the frequent re-routings while the wireless channel is unstable. To support the real time voice service, an opportunistic routing mechanism is proposed in this paper. Without pre-established end-to-end paths, multiple Route Request （RREQ） and Route Reply （RREP） messages are exploited to construct the forwarding table, and nodes within the forwarding table have opportunities to forward the packets they overheard; moreover, the number of forwarded data packets can be restricted according to the priorities of forwarding nodes. Simulation results show that the proposed mechanism can effectively reduce the end-to-end delay and enhance the packet delivery ratio for the real-time voice service, thus the quality of service can be dramatically improved over the unstable wireless channel.