Ad hoc网络中一种生命周期约束的自适应退避算法

在IEEE 802.11标准定义的BEB退避算法基础上,提出一种生命周期约束的自适应退避算法LCAB,以生命周期代替最大重传次数作为分组丢弃的依据,并根据网络忙闲程度自适应地调整节点执行退避过程的权限,以最大化系统归一化有效吞吐量,适合于ad hoc网络中有严格时延要求的VoIP等实时性业务.构建Markov链模型分析LCAB算法性能,得到系统归一化有效吞吐量表达式.仿真结果表明,理论分析与仿真结果一致,且LCAB算法的归一化有效吞吐量优于BEB算法.

Life cycle constrained backoff algorithm for ad hoc network

Based on researching binary exponential backoff algorithm which defined in IEEE 802.11 standard,a life cycle constrained adaptive backoff algorithm(LCAB) was proposed.LCAB used life cycle instead of maximum retransmission times as the reference of packet dropping,and controlled process of backoff adaptively according to degree of network congestion.It fitted for real-time traffic such as VoIP which used widely in ad hoc network.A Markov model was introduced to analyze the performance of LCAB,and the normalized effective throughput of LCAB was obtained.The results show that the theoretic analysis is in accordance with the simulation,and the throughput of LCAB is better than that of BEB.