Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: In recent years the demand for bandwidth has dramatically increased because of
new applications for data and multimedia, and wireless technology has prevailed as
a prominent technology for data connectivity, especially for home, office and last
mile services.
As wireless communications are dependant upon spectrum availability, which is
communal, this scarce commodity in communication has to be used as efficiently
as possible. Some aspects of this requirement are addressed in this project.
We chose the IEEE 802.11b standard for this particular investigation because of
its widespread use, the vast amount of applicable literature, the variety of software
simulation tools and the ease with which equipment can be obtained.
The IEEE 802.11 standard specified the Point Coordination Function as the de-
terministic protocol. Recently research into this aspect has stagnated, and it was the
purpose of this project to investigate how existing infrastructure networks could be
improved by optimising some modes of the 802.11 protocol. The investigation also
hoped to determine when to change between Distributed Coordination Function
(DCF) and Point Coordination Function (PCF), and to provide an adaptive protocol
to do so.
This thesis presents mathematical models for the operation of DCF and PCF modes,
which is compared with results from a network simulator (ns2), for theoretical veri-
fication. A protocol is also proposed to dynamically switch between DCF and PCF,
to harness the advantages they present. / AFRIKAANSE OPSOMMING: Die afgelope paar jaar het die aanvraag na bandwydte dramaties verhoog as gevolg
van nuwe toepassings vir data en multimedia, en draadlose tegnologie het voorgekom
as ’n dominante tegnologie vir data konnektiwiteit, veral vir die huis, kantoor en
laaste myl dienste.
Omdat draadlose kommunikasie afhanklik is van spektrum beskikbaarheid, wat
gemeenskaplik is, moet hierdie skaars kommoditeit in kommunikasie so effektief
moontlik gebruik word. Sekere aspekte van die vereiste sal in die tesis ondersoek
word.
Dit is besluit om die IEEE 802.11b standard vir die spesifieke ondersoek te gebruik
as gevolg van die wye toepassing, die groot hoeveelheid beskikbare literatuur, die
verskeidenheid simulasie sagteware en die gemak waarmee die toerusting bekom
kan word.
Die IEEE 802.11 standaard spesifiseer the Punt Koordinasie Funksie (PCF) as die
deterministiese protokol vir die betrokke standaard. Onlangs het navorsing oor
hierdie aspek gestagneer, en dit is die doel van die projek om te ondersoek hoe
bestaande infrastruktuur netwerke moontlik verbeter kan word deur optimering van
sekere modusse van die 802.11 protokol. Die ondersoek hoop ook om te bepaal
wanneer die oorgang van die Distrubusie Koordinasie Funksie (DCF) en Punt Ko-
ordinasie Funksie sal plaasvind, en om ’n dienooreenstemmende protokol te on-
twikkel.
Die tesis verskaf wiskundige modelle vir die werking van die DCF en PCF modusse,
wat vergelyk word met resultate uit ’n netwerk simulator (ns2), vir teoretiese ver-
ifikasie. ’n Protokol word ook voorgestel om dinamies te wissel tussen DCF and
PCF, om die voordele wat die protokolle verskaf te gebruik.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/4118 |
| Date | 03 1900 |
| Creators | Greyling, Neville |
| Contributors | Wolhuter, R., University of Stellenbosch. Faculty of Engineering. Dept. of Electrical and Electronic Engineering. |
| Publisher | Stellenbosch : University of Stellenbosch |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | Unknown |
| Type | Thesis |
| Format | 193 p. : ill. |
| Rights | University of Stellenbosch |
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