自组织网络中MAC层退避算法的分析

Study and Comparison of Back off Algorithm in Ad Hoc Networks

二进制指数退避BEB(Binary Exponential Back—off)算法机制在重负载的情况下会表现出低的包成功发送率和吞吐率问题。对BEB算法进行分析,并从吞吐量和退避窗口方面与一种基于区分机制的退避DB(Distinct Back—off)算法进行比较,仿真结果表明,这种基于区分机制的退避算法在包成功发送率和吞吐率方面与BEB算法相比均有不同程度的改善。在已有算法基础上提出了一种新的退避算法思想,通过与一种自适应调整接入速率算法相结合,进行最佳发送速率的选择,能更好地改善网络的性能。

BEB algorithm in heavy network traffic would show low the success rate of sending packets and the throughput problems. BEB and DB algorithms of Ad Hoc MAC layer were analyzed,modeled and simulated to compare＇their performance （throughput and backoff window）, the DB algorithm can effectively improve the success rate of sending packets and the throughput in heavy network traffic,compared with the BEB algorithm. On the basis of these two algorithms,a new back-off algorithm was proposed for enhancing the network performance,the best rate was selected based on the decision which obtained through one kind of auto-adapted adjustment turning on speed algorithm to combine access.