Integral sliding-mode robust observer-based congestion control for wireless access networks

Abstract

Designing a robust active queue management (RAQM) is mandatory to avoid congestion in networks with wireless access links, because transmission control protocol (TCP) can detect congestion after its occurrence in a communication network and wireless links suffer from bottleneck capacity variations caused by fading and packet error rate (PER) in the acknowledgement packets. Furthermore, the average window size cannot be measured explicitly from the output signal and input and state delay are imposed to a network, which complicate the RAQM design problem in nonlinear models. So, the main contribution of this study is to design a robust observer based control procedure based on integral sliding mode protocol to estimate the average window size, to control congestion in a TCP/RAQM network and to compensate input and state delay. Simulation results via professional simulator NS-2 and SIMULINK confirm that the procedure can effectively estimate the window size and can robustly avoid congestion.

KEYWORDS:

• Congestion control
• integral sliding mode
• robust active queue management (RAQM)
• robust observer-based control (ROBC)
• transmission control protocol (TCP)
• wireless access network

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Notes on contributors

Ladan Khoshnevisan

Ladan Khoshnevisan received her B.S. degree from the University of Science and Technology, Tehran, Iran in 2008, and her M.Sc. and Ph.D. degrees from Tarbiat Modares University and University of Tehran, Tehran, Iran in 2010 and 2017, respectively, all in electrical engineering. She was an International Visiting Ph.D. Student at the Department of Applied Mathematics, Faculty of Mathematics, University of Waterloo, Waterloo, Canada. Her research interests include robust and adaptive control systems, congestion and flow control in computer networks, bifurcation and system analysis, fault detection and isolation, fault tolerant control and fractional order systems.

Farzad R. Salmasi

Farzad R. Salmasi received the B.S. degree in electrical engineering from the Sharif University of Technology, Tehran, Iran, in 1994, the M.Sc. degree in electrical engineering from the Amirkabir University of Technology, Tehran, in 1997, and the Ph.D. degree in electrical engineering from Texas A&M University, College Station, in 2002. From 2002 to 2004, he was with the Electro Standards Laboratories, Cranston, RI, as a Research Scientist. Since September 2004, he has been with the School of Electrical and Computer Engineering, Faculty of Engineering, University of Tehran. His main research areas include fault tolerant control, networked control systems, and mechatronics. Dr Salmasi is an IEEE senior member.

Xinzhi Liu

Xinzhi Liu received the B.Sc. degree in mathematics from Shandong Normal University, Jinan, China, in 1982, and the M.Sc. and Ph.D. degrees in applied mathematics from the University of Texas at Arlington, Arlington, TX, USA, in 1987 and 1988, respectively. He was a Post-Doctoral Fellow with the University of Alberta, Edmonton, AB, Canada, from 1988 to 1990. He joined the Department of Applied Mathematics, University of Waterloo, Waterloo, ON, Canada, as an Assistant Professor in 1990, where he became an Associate Professor and a Full Professor in 1994 and 1997, respectively. He has authored or co-authored over 300 research articles, two research monographs, and 20 edited books. His current research interests include systems analysis, stability theory, hybrid dynamical systems, impulsive control, complex dynamical networks, and communication security.