Abstract

Study of Distributed Fair Scheduling in Wireless Local Area Networks. (August 2000) Seema Gupta, M.Sc., Indian Institute of Technology Chair of Advisory Committee: Dr. Nitin H. Vaidya A Fair Scheduling policy is required to support dierentiated QoS requirements of contending ows in a wireless channel. This thesis presents a study of the Distributed Fair Scheduling (DFS) algorithm proposed for wireless Local Area Networks. The thesis evaluates DFS protocol and studies the unfairness in IEEE 802.11 standard. The wireless channel capacity varies with time and location due to the presence of location-dependent wireless errors. Therefore, the error-free scheduling specication is not sucient for fair allocation of channel capacity amongst contending ows in an error-prone wireless channel. This thesis borrows the idea of dynamic weight adjustment from prior work and applies it in the Distributed Fair Scheduling algorithm to provide long-term fairness in the presence of wireless errors. iv To my mother, father, brother and sisters v ACKNOWLEDGMENTS I would like to express my sincere thanks to my advisor Dr. Vaidya for his guidance, comments and encouragement. Without his advice, enthusiasm and help, my graduate school experience would not have been so fullling. I would like to thank Dr. Victor Bahl of Microsoft Research for his guidance and comments during the course of work. I thank Dr. Bettati and Dr. Reddy for being part of my advisory committee. I would like to thank Ms. Bhaskaran for her help during the course of work. I would like to thank NSF and Sun Microsystems for supporting me nancially to carry out my research. I would like to thank my parents for their constant encouragement and support. vi TABLE OF CONTENTS CHAPTER Page I

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