The Research Of Key Technologies Based On Energy Efficiency In WSN

In recent years, with the development of sensor technology, communications technology and microelectronics technology, there is an emergence of a new network - WSN (wireless sensor networks), which synthesizes sensor techniques, embedded computations, distributed information processing and wireless communication. WSN can cooperate to complete the real-time monitoring, sensing, and gathering information of the objective, carry on processing to the gathering information and transmits the information to the user. Generally, WSN is composed of massive sensor nodes deployed in the monitoring regions.These sensor nodes are limited in battery power capacities and deployed in the nobody-defending environment, so they cannot be continually charged, simultaneously they need to frequently communicate with the base station, therefore the effective energy usage is the key problem which WSN needs to solve.Today, as a new hotspot in the field of information, because WSN involves many interdisciplinary fields, there are many key technologies to be found and research, which include localization technology and routing technology. This paper will focus on these two key technologies.In view of localization techno logy,this paper firstly briefly introduces the basic localization method, then focuses on the investigation of DV-Hop locationalgorithm,and proposes an improved node localization algorithm--DV-HopBLA,together with the discussion of algorithm principle and realization issues. Then, by network simulator (NS-2) tool, this paper compares DV-HopBLA with DV-Hop. The simulatione results show that the performance of DV-HopBLA is significantly improved compared with the DV-Hop. DV-HopBLA can improve location accuracy without extra increasing energy consumption and hardware cost of sensor node.In view of routing technology, this paper firstly briefly introduces WSN routing protocol features and design goals, then analyzes and compares several typical routing protocol.By analyzing these typical characteristics of routing protocol, this paper select directed diffusion for the object of study. This paper analyses the process of directed diffusion. In view of energy consumption, this paper theoreticaly analysis and compares flooding, omniscient multicast and directed diffusion.Theoretical analysis shows that directed diffusion has the superiority. Therefore, directed diffusion can prolong the network lifetime. Then, by NS-2 tool, this paper simulates three algorithms. By analyzing simulation data, it is confirmed that direction detection is indeed an ideal WSN routing protocol.But, in the process of interest propagation and data delivery, directed diffusion causes the massive unnecessary redundant nodes to participate in the information repeater, which will greatly increase the energy consumption of nodes. Against onthe basis of this defect, this paper presents an improved design--DDBD-OH.DDBD-OH introduces the concept of optimal hop. Theoretical analysis shows that it is advantageous in saving average energy of nodes to properly control the number of nodes transmitting information. This paper takes average energy consumption of nodes and time at which the first disabled node happens as the parameters of performance,and,by NS-2, compares DDBD-OH with directed diffusion in many kinds of situation.The results show DDBD-OH achieves average energy saving and prolongs the lifetime of nodes.