Research On The Key Problems Of Wireless Sensor Network Based On Resource Limited

The key technology based on resource limited is still the bottleneck for WSN to be mature. Designing WSN application algorithm with lower energy cost under microwave wireless communication is an effective way to solve the bottleneck above. Such energy-efficient strategies based on resource limited involve many aspects such as density control, energy consumption distribution estimation and node deployment, wireless comnicaiton security, crosslayer design of wireless communication protocol and so on. This thesis conducts detailed research on certain key technologies of WSN based on resource limited through modeling the microwave wireless communication network, the theoretical analysis method and the network simulation technology.Communication protocol, network management and application-based technology of WSN's architecture are first discussed in detail by taking microwave wireless communication as a core and some essential technical questions to be solved before WSN be further developed are analyzed. The summary of the essential technology of WSN provides the detailed technical method and the basic theory research support for the study on the key technology problems based on resource limited such as density control, network lifetime, security problem and cross layer design based on microwave communication.Density control of WSN with microwave wireless communication is studied. The thesis educes a consistency strategy to solve these two fundamental problems by the analysis of geometric relation between the coverage and the connectivity. In order to compare the capability of distributed density control algorithm, it proposes the integer linear programming ILP universal expression form of density control problem. In view of different coverage degree, different from the state transformation principle based on sufficient condition of coverage, the thesis proposes an algorithm based on Monte Carlo algorithm to test whether the nodes are redundant or not and establishes the coverage collision detection and stochastic back-off mechanism. Compares with the CCP algorithm, this plan may not only coveres the region by less active nodes, but also dynamically regulates coverage degree of node's coverage effectiveness sub-scope. Meantime, the proposed coverage collision detection and stochastic back-off mechanism can maintain the stability of network.The network lifetime upper bound and the estimation of node energy consumption distribution based on limited energy are studied to give an instruction for deploying nodes. The thesis elaborates two solution models on the network lifetime upper bound of the collection and the cooperation microwaves wireless communication network. Through modelling energy consumption of node and symmetrical network deployment, as well as the energy consumption analysis, the thesis proposes node energy consumption EC estimation curve. It draws a conclusion that the sink should be located on the information center of gravity for maximizing network lifetime. Compares with the other lifetime upperbound solving model of cooperation network, the proposed EC curve can grasp the energy consumption distribution in the sensor network monitor territory. It can also provide an absolutely standard for appraising the energy availability of route protocol.The microwave wireless communications security questions of WSN based on resource limited are studied. The thesis analyzes the limitation of the ordinary security algorithm applied to WSN as well as the attack form encountered by WSN on the condition that the energy, the wireless communication band width, computation ability and so on have been limited. The feasibility of applying Elliptic Curves Cryptography ECC algorithm to WSN is discussed. The thesis presents an authentication mechanism based on one-way accumulator and Bloom Filter, does a detailed analysis of its security and consolidated program. Compares with Pre-Share Key and Random Key Predistribution, it can know that this mechanism can not only establish a safe connection between any two valid nodes, but also supports nodes joining in or withdrawing from WSN dynamically. It can also prevent attacker from destroying WSN by seizing a little nodes.Energy-efficient cross-layer design of the microwave wireless communication protocol applied to WSN based on limited communication resource is studied. The thesis expounds the necessity of cross layer design from three aspects such as the characteristic of microwave wireless communications channel, wireless access method and the network architecture of WSN. Through analyzes the features of Zigbee protocol stack and the application limitation of two kind of wireless communication mechanisms thoroughly, the thesis proposes a cross layer plan to make node wireless access with TDMA and non-beacon communication mode alternately. For the time slot assignment problem caused by change of network topology, the thesis proposes a strategy called"blind waiting". Compares with AODV+S-MAC, this plan can obtain higher packet receiving rate, lower packet transmission delay and lower average system energy consumption.