移动Ad Hoc网络中一种支持QoS的多址接入协议

基于随机竞争和冲突解决的思想,为多跳移动Ad Hoc网络提出了一种支持服务质量(QoS)的多址接入(QMA)协议.将业务负载划分为时延敏感的实时业务和非时延敏感的数据业务.按照该协议,节点在发送业务分组前利用预报突发进行竞争接入,节点按照业务分组时延情况确定预报突发的长度,所发预报突发能持续到最后的节点优先获得接入.同时,具有实时业务的节点可以按照其优先级在更早的竞争微时隙中开始发送预报突发,因而可以比发送数据业务的节点更优先接入信道.最后利用OPNET仿真评估了QMA协议的多址性能,通过与带冲突避免的载波侦听(CSMA/CA)协议比较表明,QMA协议可以提供较高的吞吐量和较低的消息丢失率,并能为实时业务提供较低的时延,从而实现了对多媒体业务的QoS支持. 

Multiple access protocol with QoS support for mobile Ad Hoc networks

Based on the concept of random contention and collision resolution,a QoS-based multiple access(QMA) protocol for Ad Hoc networks was proposed to support multimedia service and multi-hop architecture.The traffic was divided into two groups with different requirements on delay,namely real-time traffic and data(or non real-time) traffic.According to the protocol,nodes contend to access channel,and the node broadcasting the most forecast bursts(FBs) get right to access the channel according to its packet delay and the earliest deadline first(EDF) principle.Meanwhile,the nodes with real-time traffic have higher priority to access channel than those with data traffic by broadcasting FBs in earlier contention slots.Through simulations in OPNET modeler,it is shown that the QMA protocol outperforms the carrier sensing multiple access with collision avoidance(CSMA/CA) protocol in terms of throughput,message discard rate and average packet delay,and the QMA protocol can provide differentiated QoS guarantees for traffic in multi-hop networks.