Analytical design of PI controller for AQM with robustness adjustability

Abstract

Based on a linearized TCP/AQM model, a new proportional integral (PI) controller design approach is proposed. This analytical approach applies H_∞ optimization and internal model control (IMC) theory to design active queue management (AQM) routers that support transmission control protocol (TCP) flows. The most important feature of the proposed scheme lies in that it can be explicitly tuned with a single parameter for the trade-off between performance and stability of the AQM control system. It is thus flexible and easy to use in design. The proposed method and the designed PI controller are verified and compared with other existing AQM schemes using ns-2 simulator. The results show the advantages of the new PI controller design approach for AQM routers supporting TCP flows.

References

1. Hollot C V Misra V Towsley D et al.Analysis and design of controllers for AQM routerssupporting TCP flowsIEEE Transactions onAutomatic Control 2002 47(6)945959. doi:10.1109/TAC.2002.1008360
2. Floyd S Jacobson V Random early detection gatewaysfor congestion avoidanceIEEE/ACM Transactionson Networking 1993 1(4)397413. doi:10.1109/90.251892
3. May M Bolot J Diot C et al.Reasons not to deploy REDIn: Proceedings of IWQoS 1999 260262
4. Feng W Kandlur D Saha D et al.Self-configuring RED gatewayIn: Proceedings of IEEE INFOCOM 1999 313201328
5. Christiansen M Jeffay K Ott D et al.Tuning RED for web trafficIn: Proceedings of ACM/SIGCOMM 2000 139150
6. Park E C Lim H Park K J et al.Analysis and design of the virtual rate controlalgorithm for stabilizing queues in TCP networksComputer Networks 2004 44(1)1741. doi:10.1016/S1389‐1286(03)00321‐9
7. Ott T J Lakshman T V Wong L H SRED: Stabilized REDProceedingsof IEEE INFOCOM.PiscatawayIEEE Press 1999 313461355
8. Lin D Morris R Dynamics of Random Early DetectionProceedings of ACM/SIGCOMMNew YorkACM 1997 127137
9. Feng W Kandlur D Saha D et al.Stochastic fair blue: a queue management algorithmfor enforcing fairnessProceedings of IEEEINFOCOMPiscatawayIEEE Press 2001 315201529
10. Ren F Y Lin C Ying X H et al.A robust active queue management algorithm basedon sliding mode variable structure controlIn: Proceedings of IEEE INFOCOMPiscatawayIEEE Press 2002 11320
11. Misra V Gong W B Towsley D Fluid-based analysis of a network of AQM routers supportingTCP flows with an application to REDProceedingsof ACM/SIGCOMMNew YorkACM 2000 30(4)151160
12. Hollot C V Misra V Towsley D et al.A control theoretic analysis of REDIn: Proceedings of IEEE INFOCOM. Piscataway: IEEE Press 2001 15101519
13. Morari M Zafiriou E Robust process control.Englewood Cliffs.NJPrentice Hall 1989
14. Lee Y Lee M Park S et al.PID controller tuning for desired closed-loop responsefor SI/SO systemAICHE Journal 1998 44106115. doi:10.1002/aic.690440112
15. Zhang W D Xu X M Xi Y G A new two-degree-of-freedom level control schemeISA Transactions 2002 41(3)333342. doi:10.1016/S0019‐0578(07)60092‐5