主动队列管理(active queue management,简称AQM)是一个非常活跃的研究领域,作为对终端系统上拥塞控制的一种补充,中间节点的AQM策略在保证较高吞吐量的基础上可以有效地控制队列长度,基于TCP/AQM控制论模型,使用H∝最优控制理论,以解析的方法设计了新型PID控制器。该控制器的特点是:控制器由单参数调节,可以方便地实现系统标称性能和鲁棒性能的折衷,通过NS仿真并与其他算法相比较,验证了所设计的控制器的性能。结果显示,所设计的PID控制器性能优于其他算法。
Active queue management (AQM) is a very active research area in networking. As a complementary mechanism to the congestion control of end-to-end systems, AQM, used on the intermediate nodes, can provide high throughputs for routers and control the queue length effectively at the same time. Based on a model of TCP and AQM, a new PID controller is designed analytically using H∝ optimal control theory in this paper. The specialty of this controller is that a single parameter tuning method is proposed, through which the nominal performance and robust performance can be adjusted monotonically to achieve the trade-off. The performance of the controller is verified and compared with other methods using NS simulations. The result shows the advantages of the proposed PID controller.