基于避免拥塞的优先级退避算法

High priority backoff algorithm based on congestion avoidance

引入了拒绝帧,在网络状况极度拥塞时,采取拒绝发送方请求的方法来疏解网络压力。根据发送节点的数据属性随机变化来影响退避参数CW,优先处理高优先级业务。最后,应用NS-2平台进行了仿真试验,比较了负载情况下各种优先级数据流的吞吐量以及分组重传频次。结果表明:优先级二进制退避算法(Prioritized binary exponential backoff,PBEB)是提高优先级业务接入成功概率的一种有效方法。

A high priority backoff algorithm is proposed for congestion avoidance, which introduces the concept of rejected frames. If the network is under extreme congestion, it rejects the sender request to alleviate the network pressure. According to the random variation of data attribute of the sending nodes, the algorithm influences the CW parameters to deal with high priority service. Experiment is carried out in NS-2 simulation platform to compare various priority data flow throughputs and packet retransmission frequency. Results show that Prioritized Binary Exponential Backoff （PBEB） is an effective method to improve the successful access probability of high priority service.