摘要
随机早期检测 (Random Early Detection,RED)算法是主动队列管理 (Active Queue Managem ent,AQM)的有效实现算法 ,有关它性能的研究是近来网络研究的一个热点 .在某些网络配置和负载状态下 ,RED存在稳定性问题 .已有的关于 RED稳定性的研究用不同的方法 ,从不同的角度定性或定量地揭示了可能的原因 ,并给出了稳定运行的工作区间 ,但没有对等幅振荡的队列行为给出一个合理的解释 .在该文中 ,作者利用描述函数这一非线性控制理论中经典的分析方法 ,分析了 RED和 gentle- RED的工作特性 ,认为分组丢弃概率曲线中的非线性结构诱发的自激振荡是队列呈现周期运动的本质原因 ;虽然相比较而言 ,gentle- RED比 RED有更宽的稳定工作区间 ,但也是非常有限的 ,解决 AQM稳定性的理想途径是设计更为鲁棒的线性控制器 .
This paper analyzes the attributes of RED (Random Early Detection) and gentle-RED algorithms using the describing function approach, which is a classical analysis approach in nonlinear control theory. In fact, authors conclude that the essential reason that queue periodic motion is the self-oscillation caused by the nonlinear component in the packet dropping probability profile, this point is neglected by most of the existed schemes, and then deduce a more accurate criterion with which the stable operation region of RED scheme will be estimated, on the other hand, although gentle-RED is more powerful than RED to keep queues stable, this ability is very limited because it only extends the stable operation region with different nonlinear characteristic, but doesn't thoroughly eliminate it. The ideal solution should be to design more robust linear controller for AQM scheme.
出处
《计算机学报》
EI
CSCD
北大核心
2002年第12期1302-1307,共6页
Chinese Journal of Computers
基金
国家自然科学基金 ( 6 9972 0 40
6 0 1730 12 )
国家"九七三"重点基础研究发展规划项目 ( G19990 32 70 7)
国家"八六三"高技术研究发展计划项目 ( 2 0 0 1AA112 0 80 )资助
