Thesis (MEng)--University of Stellenbosch, 2001. / ENGLISH ABSTRACT: SRMA currently used on the SUNSAT field station is an effective MAC layer protocol but lacks
several features. Sufficient support for flexible communication, acknowledgement of individual
data packets, simultaneous communication of multiple instances from a higher layer over a
single underlying layer, and a robust FTP procedure to transfer large amounts of data are some of
the features that the SUNSA T field station should cater for.
ORBCOMM, GSM and WAP implementations are discussed. Some features from these
implementations that are useful in the LEO communication environment are designed into an
additional layer of software. This additional layer, called middleware, is proposed and uses
SRMA services to deliver store-and-forward services. It supports high volumes of short
transactions and session suspend and resume facilities between the SUNSA T satellite and field
station.
Keywords: SUNSAT, Communication, Field station, WAP, GSM, ORBCOMM / AFRIKAANSE OPSOMMING: Die SRMA pakketkommunikasie-protokol op SUNSA T se prototipe grondterminaal is
voldoende om die oordrag van boodskappe oor die kommunikasieverbinding te reguleer. Dit is
onvoldoende om fasiliteite soos kommunikasie van 'n aantal instansies in 'n hoër kommunikasie
laag oor 'n enkele laer laag en om 'n robuuste data oordrag protokol vir groot hoeveelhede data
van 'n grondterminaal te ondersteun.
ORBCOMM, GSM en WAP stelsel toepassings word bespreek. Resultate wat spruit uit die drie
toepassings word gebruik om kommunikasie in 'n lae wentelbaan kommunikasie omgewing te
bevorder. 'n Bykomende sagteware laag, bekend as middle-ware, word aanbeveel om
voorafgenoemde funksionaliteit mee te implimenteer. Die middle-ware gebruik die beskikbare
dienste van die SRMA pakketkommunikasie-protokol om toegang te verkry na die
kommunikasie kanaal. Sodoende kan hoë volumes kort transaksies, en sessie-stop en hervat
fasiliteite 'n werklikheid gemaak word.
Sleutelwoord: SUNS AT, Kommunikasie, grondterminaal, WAP, GSM, ORBCOMM
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/52338 |
| Date | 12 1900 |
| Creators | Cardoza, Andrew Robert |
| Contributors | Mostert, S., 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 | 177 p. : ill. |
| Rights | Stellenbosch University |
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