Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE credits
Mobile Ad-hoc Network (MANET) is a collection of nodes consisting of an infrastructure without any backbone. Due to this feature, a distributed approach has to be considered for implementing resource allocations. This work concentrates on distributed Spatial re-use Time Division Multiple Access (STDMA) scheme, based upon a Cluster Architecture, and how performance can be improved by implementing Power Control (PC). Two distributed Power Control Algorithms are proposed: full information PC and One-hop Information PC. They both aim at improving the performance of the network by adopting the same technique but while the first one is a trade off between a centralized approach and a distributed technique, the second emphasizes the distributed feature, thus reducing the amount of information nodes need to exchange. In order to evaluate the performance of these two algorithms a Centralized Power Control is implemented and results have been compared between them all.
Results are collected for a great variety of networks: the distributed Power Control algorithms can always improve the chosen metric, though the percentage of gain depends upon the topology of the network. Moreover, the shown improvement for the distributed techniques equals the one obtained with the centralized approach. Due to the distributed approach the proposed algorithms need to iterate the process until the final power values are computed, while the controller, of the centralized scheme, can directly calculate these values as long as it has a complete topological knowledge of the network.
Even though the distributed algorithms require some time to achieve the final power values, convergence is ensured in all cases, therefore they are always able to avoid malfunctions and the possibility of a disastrous power control. The proposed PC differ in terms of speed convergence and overhead: Full Information PC ensures a faster convergence, while One-hop Information PC reduces the overhead and most of the times is able to improve the performance faster compared to the previous PC, two suitable features for MANETs.
2005. , 48 p.