Current wireless networks still employ techniques originally designed for their xed
wired counterparts. These techniques make assumptions (such as a xed topology,
a static enviroment and non-mobile nodes) that are no longer valid in the wireless
communication environment. Furthermore, the techniques and protocols used in
wireless networks should take the number of users of a network into consideration,
since the channel is a shared and limited resource. This study deals with nding an
optimal solution to resource allocation in wireless mesh networks. These networks
require a solution to fair and optimal resource allocation that is decentralised and
self-con guring, as users in such networks do not submit to a central authority.
The solution presented is comprised of two sections. The rst section nds the
optimal rate allocation, by making use of a heuristic. The heuristic was developed by
means of a non-linear mixed integer mathematical formulation. This heuristic nds a
feasible rate region that conforms to the set of constraints set forth by the wireless
communication channel. The second section nds a fair allocation of rates among all the users in the network. This section is based on a game theory framework, used for
modelling the interaction observed between the users. The fairness model is de ned
in strategic form as a repeated game with an in nite horizon.
The rate adaptation heuristic and fairness model employs a novel and e ective
information distribution technique. The technique makes use of the optimized link
state routing protocol for information distribution, which reduces the overhead
induced by utilising multi-point relays. In addition, a novel technique for enforcing
cooperation between users in a network is presented. This technique is based on the
Folk theorem and ensures cooperation by threat of punishment. The punishment, in
turn, is executed in the form of banishment from the network.
The study describes the performance of the rate adaptation heuristic and fairness
model when subject to xed and randomised topologies. The xed topologies
were designed to control the amount of interference that a user would experience.
Although these xed topologies might not seem to re
ect a real-world scenario, they
provide a reasonable framework for comparison. The randomised network topology
is introduced to more accurately represent a real-world scenario. Furthermore, the
randomised network topologies consist of a signi cant number of users, illustrating
the scalability of the solution. Both data and voice tra c have been applied to the rate adaptation heuristic and fairness model.
It is shown that the heuristic e ectively reduces the packet loss ratio which
drops below 5% after about 15 seconds for all xed topologies. Furthermore, it
is shown that the solution is near-optimal in terms of data rate and that a fair
allocation of data rates among all nodes is achieved. When considering voice tra c,
an increase of 10% in terms of data rate is observed compared to data tra c. The
heuristic is successfully applied to large networks, demonstrating the scalability of the
implementation. / Dissertation (MEng)--University of Pretoria, 2013. / gm2014 / Electrical, Electronic and Computer Engineering / unrestricted
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:up/oai:repository.up.ac.za:2263/40815 |
| Date | January 2013 |
| Creators | Jansen van Vuuren, Pieter Albertus |
| Contributors | Maharaj, Bodhaswar Tikanath Jugpershad, pieterjansenv@gmail.com, Alfa, Attahiru S. |
| Publisher | University of Pretoria |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Dissertation |
| Rights | © 2013 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. |
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