Determining a least-cost routing and MAC strategy for a rural communications Ad hoc Network

[摘要] 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 municipalityor law enforcement. Various factors may make the application of fixed infrastructuretelecommunications networks to rural situations like these unfeasible. Fixed infrastructuremay 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 telecommunicationsproblem. Instead of using the client-server architecture approach, ad hoc networksuse a peer-to-peer network architecture that allows the network to change in a more dynamicfashion. Hosts of such a network can join or leave the network dynamically and will share inthe forwarding responsibility. Routing is done dynamically.Transceiver range is still an issue. To counteract this problem satellites can be used to extendthe communications range of a network. Communication with a satellite can be added byusing gateway hosts that are equipped to establish satellite up- or downlinks. Even if onesuch gateway host is deactivated, ad hoc network hosts should be able to find alternativegateways (if such alternative gateways exist).For this thesis, various MAC and Network protocols will be evaluated. One protocol setwill be selected and adapted to a low-bandwidth situation. Cross layer design will be used inan attempt to decrease overhead of this strategy. A simulation model was devised to predictsystem performance. These simulations was followed by interpretation of results which rendereda 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 ofad hoc network protocols. Novel approaches to protocol behaviour analysis have also beendevised.

[发布机构] Stellenbosch University