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Quality of Service Support in IEEE 802.11 Wireless LAN

Pattara-atikom, Wasan (2005) Quality of Service Support in IEEE 802.11 Wireless LAN. Doctoral Dissertation, University of Pittsburgh. (Unpublished)

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Wireless Local Area Networks (WLANs) are gaining popularity at an unprecedented rate, at home, at work, and in public hot spot locations. As these networks become ubiquitous and an integral part of the infrastructure, they will be increasingly used for multi-media applications. The heart of the current 802.11 WLANs mechanism is the Distributed Coordination Function (DCF) which does not have any Quality of Service (QoS) support. The emergence of multimedia applications, such as the local services in WLANs hotspots and distributions of entertainment in residential WLANs, has prompted research in QoS support for WLANs. The absence of QoS support results in applications with drastically different requirements receiving the same (yet potentially unsatisfactory) service. Without absolute throughput support, the performance of applications with stringent throughput requirements will not be met. Without relative throughput support, heterogeneous types of applications will be treated unfairly and their performance will be poor. Without delay constraint support, time-sensitive applications will not even be possible. The objective of this dissertation is, therefore, to develop a comprehensive and integrated solution to provide effective and efficient QoS support in WLANs in a distributed, fair, scalable, and robust manner.In this dissertation, we present a novel distributed QoS mechanism called Distributed Relative/Absolute Fair Throughput with Delay Support (DRAFT+D). DRAFT+D is de- signed specifically to provide integrated QoS support in IEEE 802.11 WLANs. Unlike any other distributed QoS mechanism, DRAFT+D supports two QoS metrics (throughput and delay) with two QoS models (absolute and relative) under two fairness constraints (utilitarian and temporal fairness) in the same mechanism at the same time a fully distributed manner. DRAFT+D is also equipped with safeguards against excessive traffic injection DRAFT+D operates as a fair-queuing mechanism that controls packet transmissions (a) by using a distributed deficit round robin mechanism and (b) by modifying the way Backoff Interval (BI) are calculated for packets of different traffic classes. Fair relative throughput support is achieved by calculating BI based on the throughput requirements. Absolute throughput and delay support are achieved by allocating sufficient shares of bandwidth to these types of traffic.


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Item Type: University of Pittsburgh ETD
Status: Unpublished
CreatorsEmailPitt UsernameORCID
ETD Committee:
TitleMemberEmail AddressPitt UsernameORCID
Committee ChairBanerjee,
Committee CoChairKrishnamurthy, Prashantprashant@mail.sis.pitt.eduPRASHK
Committee MemberTipper, Davidtipper@tele.pitt.eduDTIPPER
Committee MemberWeiss, Martin B Hmbw@pitt.eduMBW
Committee MemberVaidya,
Date: 17 June 2005
Date Type: Completion
Defense Date: 31 March 2005
Approval Date: 17 June 2005
Submission Date: 6 April 2005
Access Restriction: No restriction; Release the ETD for access worldwide immediately.
Institution: University of Pittsburgh
Schools and Programs: School of Information Sciences > Information Science
Degree: PhD - Doctor of Philosophy
Thesis Type: Doctoral Dissertation
Refereed: Yes
Uncontrolled Keywords: Quality of Service and Wireless Networks
Other ID:, etd-04062005-171735
Date Deposited: 10 Nov 2011 19:34
Last Modified: 15 Nov 2016 13:38


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