Thesis (MScIng)--University of Stellenbosch, 2007. / ENGLISH ABSTRACT: Keywords: digital signal processing, OSI layer, network protocols, embedded systems,
satellite technology
This thesis describes the design and implementation of a rural e-mail system for the Sumbandila
satellite. The rural e-mail system was developed during a project sponsored by
the Department of Communications of the South African government. The complete Open
Systems Interconnect (OSI) layer structure of the protocol architecture used on the satellite
hardware and software is described. The equivalent implementation of the OSI layer on the
ground station hardware is given. This includes the adaptation of the soundmodem Open
Source Software modem to work for the e-mail system’s OSI layer. The design of the Application
Layer e-mail system is described and the implementation of this design using the
Python, Korn Shell and C programming environments is also given. The procedures used to
test the system for reliability and the use of a database to create detailed logs of the e-mail
system is shown to have generated a reliable system that is easily maintained. A critical
evaluation of the system is provided in the last chapter. / AFRIKAANSE OPSOMMING: Sleutelwoorde: Syferseinverwerking, OSI-lae, netwerkprotokolle, toegewyde stelsels, satelliettegnologie
Hierdie tesis beskryf die ontwerp en implementering van ’n plattelandse e-posstelsel vir die
Sumbandila satelliet. Die plattelandse e-posstelsel is ontwikkel in opdrag van die Departement
van Kommunikasie van die Suid-Afrikaanse regering. Die volledige Open Systems
Interconnect (OSI) laagstruktuur van die protokol-argitektuur wat in die satelliet se apparatuur
en programmatuur gebruik is, word beskryf. Die ekwivalente implementering
van die OSI-laag op die grondstasie-apparatuur word gegee, insluitende die aanpassing van
soundmodem, ’n oopbronkode sagteware-modem. Hierdie sagteware-modem word gebruik in
die e-posstelsel se fisiese laag. Die ontwerp van die toepassingslaag van die e-posstelsel word
beskryf, asook die implementering van hierdie ontwerp met behulp van Python, die Korninterpreteerder
en C. Die prosedures waarvolgens stelselbetroubaarheid getoets is, en die
gebruik van ’n databasis om noukeurige joernale van e-postransaksies te hou, demonstreer
dat ’n betroubare, onderhoubare stelsel gemplementeer is. In die laaste hoofstuk word die
stelsel krities geevalueer.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/17745 |
| Date | 12 1900 |
| Creators | Cooke, Adrian (Adrian Gerard) |
| Contributors | Van Rooyen, G-J., Stellenbosch University. Faculty of Engineering. Dept. of Electrical and Electronic Engineering. |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | English |
| Type | Thesis |
| Format | x, 73 leaves : ill. |
| Rights | Stellenbosch University |
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