Research On Topology Evolution Of Wireless Sensor Networks Based On Complex Network

Wireless sensor networks(WSN) is a multi-hop wireless ad-hoc network which consists of a large number of tiny sensor nodes. Scholars concern the topology generation mechanism and self-organizing evolutionary algorithm a lot, cause which is the key means to the communication and overlay, topology control, routing and positioning of WSN. It has become a hot topic in the field that using the complex network theory to analysis the topology dynamic characteristics of WSN at this stage.In this thesis, we paraphrase the measurement of feature parameters and some basic types of model in the complex network theory. Meanwhile, we explain how does the topology of WSN show its complex characteristics, and then introduce the related application of complex network theory into the topology evolution investigation of WSN. Based on the concepts and principles of the complex network theory, we explore the topology generation mechanism and self-organization evolution model, and build a network topology model with optimize performance. Innovation and the main results of the work are as follows: 1. Construct a weighted scale-free WSN topology evolution model based on the energy level of the node. Energy means a lot to the topology of WSN, while the scale-free network model is extremely tolerant of the nodes random failures. So, it’s of highly practical significance to build an energy equilibrium effects WSN topology based on scale-free network model.A node energy level model bas been built based on BBV model innovative, showing which is affected by the energy carrying and distance. We obtain the Energy Level BBV(EL-BBV) model with the side weights producing with both ends of the node. By theoretical analysis, we know the EL-BBV model is a scale-free network doing well in fault-tolerant. The MATLAB simulation also shows that when we compare EL-BBV model to the existing BA, BBV and EAEM model in fault tolerance, it does well in randomly deleting 16 nodes. The number of surviving nodes in the network remain at more than 1/3.When the topology runs after 1000 terms, the node energy level is more concentrated in EL-BBV model with less difference. Compared to the other three models in terms of energy consumption, EL-BBV shows better and effectively extend the life cycle of network. 2. Construct a local-world two-way evolution WSN topology model based on the energy level of the node. In practical, the nodes of WSN only exchange the information with their neighborhood due to the limitation.Based on the existing research, in this thesis, we focus attention on the evolution of WSN topology in local world, the node energy level as well as node and link variables increases in two-way dynamic. When considering the node random added and subtracted, edge random subtracted in the connection policy of the scale-free network topological evolution, we construct a local-world two-way evolution WSN topology model based on the energy level of the node. Make a deep analysis in the distribution of the model through mean-field theory, meanwhile make sure it also having a similar characteristic with the scale-free network using MATLAB simulation. On step, analysis the topological structure peculiarity of the model in the situation of different local world scale and probability to subtract. Finally, simulation and analysis the energy consumption indicators in different local world scale, showing the local world scale range which affecting energy efficiency of the network significantly. The construction and simulation of the WSN topology model provide a useful exploration to our real world WSN which topology evolution proceed following the local world.