系数自调整的PD-RED算法  

PD-RED algorithm with self-adjusting coefficients

作　　者：毛银宁 姚旭寅[2] 张小贝[1] 李伟杰[2] 杨融[2] Mao Yinning;Yao Xuyin;Zhang Xiaobei;Li Weijie;Yang Rong(Communication&Information Engineering Institute,Shanghai University,Shanghai 200444,China;Electronic Integration Dept.,Shanghai Aircraft Design&Research Institute,Shanghai 201315,China)

机构地区：[1]上海大学通信与信息工程学院,上海200444 [2]上海飞机设计研究院电子集成部,上海201315

出　　处：《计算机应用研究》2022年第6期1683-1688,共6页Application Research of Computers

基　　金：上海飞机设计研究院课题项目(MJZ-2016-S-45)。

摘　　要：随着技术发展,民机上的网络环境渐渐趋于日常生活中的网络环境。为了避免拥塞,需要对飞机上的链路数据进行主动队列管理。在比例微分控制的随机早期检测(random early detection based on proportional deri-vative control principle,PD-RED)算法基础上,提出一种系数自调整的PD-RED(improved PD-RED,IPD-RED)算法。在IPD-RED算法中,引入比例系数和微分系数的调整函数来减小参数选取对算法的影响。考虑队列偏差,将其归一化处理后,作为调整函数的参数来使系数动态变化,根据系数变化规律设计函数。实验通过改变上下门限值组合、路由节点间延时和端节点数量来分析算法改善效果,通过改变比例系数和微分系数的初值来探究初值对算法性能的影响。NS2仿真结果表明,IPD-RED算法使平均队列长度更接近期望值,提高了吞吐量,减小了丢包率。初值影响表明,一定范围内增大比例系数可使平均队列长度更快更接近期望值且减小丢包率,但会使延时和振荡增加。微分系数的动态范围很大,对几个网络性能参数的影响很小。实际应用中适当选取系数初值,可使算法更好地适配飞机上的业务。With the development of technology,the network environment on civil aircraft gradually tends to it in daily life.In order to avoid congestion,link data on aircraft needs active queue management.This paper proposed an IPD-RED algorithm with self-adjusting coefficients,which based on the PD-RED algorithm.IPD-RED algorithm introduced the adjustment functions of proportional coefficient and derivative coefficient to reduce the influence of parameter selection on the algorithm.Considering the queue deviation after normalization,the adjustment function used it as the parameter in order to make the coefficient change dynamically.IPD-RED designed the adjustment function according to the law of coefficient change.The experiment analyzed the improvement effect of the algorithm by changing the combination of upper and lower threshold values,the delay between routing nodes and the number of end nodes,and explored the impact of the initial value on the performance of the algorithm by changing the initial value of proportional coefficient and derivative coefficient.NS2 simulation results show that IPD-RED algorithm makes the average queue length closer to the expected value,improves the throughput and reduces the packet loss rate.The influence of initial value shows that increasing the proportional coefficient in a certain range can make the average queue length faster and closer to the expected value and reduce the packet loss rate,but it increases the delay and oscillation.The dynamic range of the derivative coefficient is very large and has little effect on several network performance parameters.In practical application,the appropriate selection of the initial value of the coefficient can make the algorithm better adapt to the business on the aircraft.

关 键 词：主动队列管理 早期检测 调整函数 IPD-RED 

分 类 号：TP393[自动化与计算机技术—计算机应用技术]