PID controller for active queue management

Acting on the intermediate nodes, Active Queue Management (AQM) either keeps the high throughput for routers or effectively controls the queue lengths, so that arrives the object, to control end-to-end delay for QoS guarantees. C. Hollot, et al. (2001) designed the PI controller for AQM with the frequency approach in classical control theory, but it seems to be unscientific to tune the controller parameters through trial-errors, moreover the transient performance of the PI controller is not, perfect, such as the adjusting time is very long, etc. In this paper, the differential component is introduced to enhance the responsibility, and an approach for tuning controller parameters is put forward based on the explicit gain and phase margins. The simulation results show that the integrated performance of PID controller designed with the new approach is obviously superior to that of the PI controller.