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Adaptive AQM controllers for IP routers with a heuristic monitor on TCP flows
Author(s) -
Hong Yang,
Yang Oliver W. W.
Publication year - 2006
Publication title -
international journal of communication systems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.344
H-Index - 49
eISSN - 1099-1131
pISSN - 1074-5351
DOI - 10.1002/dac.742
Subject(s) - active queue management , computer science , queue , control theory (sociology) , network packet , robustness (evolution) , phase margin , transmission control protocol , heuristic , pid controller , random early detection , network congestion , controller (irrigation) , adaptive control , real time computing , computer network , bandwidth (computing) , control (management) , amplifier , control engineering , temperature control , biochemistry , chemistry , agronomy , operational amplifier , artificial intelligence , biology , engineering , gene
We propose adaptive proportional (P) and proportional‐integral (PI) controllers for Active Queue Management (AQM) in the Internet. We apply the classical control theory in the controller design and choose a proper phase margin to achieve good performance of AQM. We have identified a simple heuristic parameter that can monitor the changes of network environment. Our adaptive controllers would self‐tune only when the dramatic change in the network parameters drift the monitoring parameter outside its specified interval. When compared to P controller, a PI controller has the advantage of regulating the TCP source window size by adjusting the packet drop probability based on the knowledge of instantaneous queue size, thus steadying the queue size around a target buffer occupancy. We have verified our controllers by OPNET simulation, and shown that with an adaptive PI controller applied, the network is asymptotically stable with good robustness. Copyright © 2005 John Wiley & Sons, Ltd.