OPNET Technologies
7255 Woodmont Avenue
Bethesda, MD 20814
Tel: 240-497-3000
Fax: 240-497-3001
E-mail: university@opnet.com
Web: www.opnet.com

OPNET is a registered
trademark of OPNET Technologies
© 2001 OPNET Technologies

University: University of Florida
Faculty Sponsor: Dr. Yuguang (Michael) Fang
Project Members: Yang Song

Threshold Optimization of Rate Adaptation Algorithms in IEEE 802.11 Wireless LANs

Rate adaptation algorithms play a crucial role in IEEE 802.11 WLANs. While the network performance depends greatly on the rate adaptation algorithms, the detailed implementation is left to vendors. Due to its simplicity and practicality, the generic rate adaptation algorithm based on up/down thresholds is widely adopted in commercial IEEE 802.11 devices. Taking the popular ARF algorithm for example, the data rate is increased when ten consecutive transmissions are successful and a date rate downshift is triggered by two consecutive failed transmissions. Although widely deployed, the optimal selection of the up/down thresholds for the rate adaptation algorithms remains as an open problem. We attempt to propose a threshold optimization algorithm which can dynamically adjust the up/down thresholds and converge to the stochastic optimum solution in arbitrary stationary random channel environment. The performance enhancement by tuning the thresholds optimally will be validated by simulations based on OPNET packages.

Aug. 28 2008