Research On Interference-Reducing Topology Control Algorithms For Wireless Sensor Networks

In wireless sensor networks, nodes share communication channel and have limited energy. As a result, interference and node failures are usually happened, which have serious impact on network performance. Topology control is a technology which coordinates the transmission range of each node in WSN to construct a topology with some global properties (such as connectivity, spanner). Topology control technology provides a new way to solve the problem caused by interference and node failure.This thesis studies how to construct a low-interference, fault-tolerant network topology with topology control techniques, in order to guarantee and enhance the network performance. The main works of this thesis are as follows.The importantance of topology control in wireless sensor network are explained and the reason why two-dimensional topology control technology can not be applied to the three-dimensional network is also given. The existing topology control algorithms are discussed from the topology optimization objective point of view, and the shortcomings of these algorithms are proposed.A three-dimensional graph-based interference model and a distributed three-dimensional topology control algorithm (IRTC) are proposed. IRTC uses local information to the coordinator node communication range in order to avoid node communications interference. Theoretical analysis shows that the topology induced by IRTC is an energy spanner and connected; simulation results show that IRTC algorithm reduces network interference significantly.A distributed two-dimensional topology control algorithm (LIMFS) is proposed, and the algorithm is also extended to be applied in three-dimensional network. Based on the graph-based interference model, The LIMFS algorithm uses the generalized version of Kruskal’s algorithm to construct the network topology. Theoretical analysis shows that the topology induced by LIMFS is fault-tolerance and energy spanner; simulation results show that LIMFS algorithm can reduce network interference effectively.A simple and reliable method of extending MATLAB to support simulation of topology control is proposed.