Abstract:
Outside the confines of cities and metropolitan areas, telecommunications may still be required.
Farmers may, for example, want to communicate with each other or with local municipality
or law enforcement. Various factors may make the application of fixed infrastructure
telecommunications networks to rural situations like these unfeasible. Fixed infrastructure
may prove to be ineffective due to geographic, social or monetary reasons.
Ad hoc networking seems like an intriguing solution to these elements of the rural telecommunications
problem. Instead of using the client-server architecture approach, ad hoc networks
use a peer-to-peer network architecture that allows the network to change in a more dynamic
fashion. Hosts of such a network can join or leave the network dynamically and will share in
the forwarding responsibility. Routing is done dynamically.
Transceiver range is still an issue. To counteract this problem satellites can be used to extend
the communications range of a network. Communication with a satellite can be added by
using gateway hosts that are equipped to establish satellite up- or downlinks. Even if one
such gateway host is deactivated, ad hoc network hosts should be able to find alternative
gateways (if such alternative gateways exist).
For this thesis, various MAC and Network protocols will be evaluated. One protocol set
will be selected and adapted to a low-bandwidth situation. Cross layer design will be used in
an attempt to decrease overhead of this strategy. A simulation model was devised to predict
system performance. These simulations was followed by interpretation of results which rendered
a theoretical basis with which network behaviour can be explained and even predicted.
A tool-like framework has, in effect, been developed for the simulation and development of
ad hoc network protocols. Novel approaches to protocol behaviour analysis have also been
devised.
