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A STUDY OF QOS FOR MULTIMEDIA TRAFFIC WLANS DURING HANDOFF

by RAGHAVAN, MUKUND

Abstract (Summary)
Multimedia streams suffer from poor quality of service (QoS) in the IEEE 802.11 wireless local area networks (WLANs) due to the high handoff latency. Since the handoff in such WLANs is a hard handoff, several packets can be lost during the handoff process which causes gaps in the playout of the multimedia stream. In this research work, three schemes have been proposed and their performance has been evaluated through extensive simulations. A novel mechanism called compressed packet coding (CPC) is proposed, in which, compressed future packets are transmitted along with the current packets. The compressed packets are used to substitute the lost packets which eliminates the gaps in the playout of the multimedia stream and ensures good QoS. This is the basic scheme for quality improvement. A cross-layer adaptive scheme that uses the current received signal strength (RSS) and the change in RSS is developed to minimize the overhead involved and maximize the playout quality. Through extensive simulations it is shown that the proposed quality improvement schemes provide improved QoS at a reduced overhead. Further, to reduce the inter-access-point (AP) communication in the network, a composite mobility prediction scheme (CMPS) is proposed. Simulation results show that the proposed CMPS is very successful in predicting the next AP and it can substantially reduce the inter-AP communication. The prospective future work in the area is also presented.
Bibliographical Information:

Advisor:

School:University of Cincinnati

School Location:USA - Ohio

Source Type:Master's Thesis

Keywords:

ISBN:

Date of Publication:01/01/2005

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