Thesis (Ph. D.)--Mechanical Engineering, Georgia Institute of Technology, 2008. / Wayne J. Book, Committee Member ; Young-Hui Chang, Committee Member ; T. Richard Nichols, Committee Member ; Lena H. Ting, Committee Co-Chair ; Stephen P. DeWeerth, Committee Co-Chair.

J.M. Schumacher. / Bibliography: p. 44-45. / "January, 1982"

Alan J. Laub. / Bibliography: leaf 32. / Cover title. Research supported by NASA Grant NGL-22-009-124, DOE Grant ET-78-(01-3395).

J.M. Schumacher. / "June, 1982" / Bibliography: p. 21-22.

Peter M. Thompson, Gunter Stein, Michael Athans. / "October, 1982." / Bibliography: leaf 17. / NASA Grant NGL-22-009-124

Peter M. Thompson, Gunter Stein, Michael Athans. / "April, 1983" (Revision of LIDS-P-1257) / Bibliography: leaf 14. / "NGL-22-009-124"

N.A. Lehtomaki, D. Castanon, B. Levy, G. Stein, N.R. Sandell, Jr., M. Athans. / "June 1983" / Bibliography: p. [23-24] / "NGL-22-009-124"

Gunter Stein. / "August 30, 1985." "October 1985" / Bibliography: leaf 15. / "This work was supported in part by Honeywell Internal IR&D, and by the NASA Ames and Langley Research Centers under Grant NAG-2-297."

The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Title from PDF of title page (University of Missouri--Columbia, viewed on November 18, 2009). Thesis advisor: Dr. Roger Fales. Includes bibliographical references.

With the increasing use of multimedia applications on the wireless network, the functionalities of the IEEE 802.11 WLAN was extended to allow traffic differentiation so that priority traffic gets quicker service time depending on their Quality of Service (QoS) requirements. The extended functionalities contained in the IEEE Medium Access Control (MAC) and Physical Layer (PHY) Specifications, i.e. the IEEE 802.11e specifications, are recommended values for channel access parameters along traffic lines and the channel access parameters are: the Minimum Contention Window CWmin, Maximum Contention Window CWmax, Arbitration inter-frame space number, (AIFSN) and the Transmission Opportunity (TXOP). These default Enhanced Distributed Channel Access (EDCA) contention values used by each traffic type in accessing the wireless medium are only recommended values which could be adjusted or changed based on the condition of number of associated nodes on the network. In particular, we focus on the Contention Window (CW) parameter and it has been shown that when the number of nodes on the network is small, a smaller value of CWmin should be used for channel access in order to avoid underutilization of channel time and when the number of associated nodes is large, a larger value of CWmin should be used in order to avoid large collisions and retransmissions on the network. Fortunately, allowance was made for these default values to be adjusted or changed but the challenge has been in designing an algorithm that constantly and automatically tunes the CWmin value so that the Access Point (AP) gives out the right CWmin value to be used on the WLAN and this value should be derived based on the level of activity experienced on the network or predefined QoS constraints while considering the dynamic nature of the WLAN. In this thesis, we propose the use of feedback based control and we design a controller for wireless medium access. The controller will give an output which will be the EDCA CWmin value to be used by contending stations/nodes in accessing the medium and this value will be based on current WLAN conditions. We propose the use of feedback control due to its established mathematical concepts particularly for single-input-single-output systems and multi-variable systems which are scenarios that apply to the WLAN.