An Optimal Sensor Localization Technology for WSN

An Optimal Sensor Localization Technology for WSN Chen xiaoyan, Zheng shijue Department of Computer Science , Hua Zhong Normal University,430079,China xiaoyan0205@126.com

AbstractA methodology for generating optimal sensor location design for wireless sensor network(WSN) is presented. Location of sensors, cost of measurement and frequency of sampling are important factors that have been incorporated in the sensor network design formulation. The proposed methodology is based on the beacon-less location discovery

scheme between the quality of state estimation and the total measurement cost associated with the sensor network. To accommodate different sampling frequencies and evaluate their effect on state estimation accuracy, a unique method is used. In general, higher accuracies of the state estimates are realizable at expense of higher measurement cost. Incorporation of these conflicting objectives of minimizing measurement cost and maximizing estimation accuracy results in a combinatorial optimization problem. The resulting solutions can be then analyzed by the process designer for determining an appropriate WSN.

1.Introduction Sensor networks have been proposed for various applications.In many of these applications,nodes deed to find their locations. For example,in rescue applications,rescue personnel can perform their tasks only if location of the hazardous event is known. Location is also important for geographic routing protocols,in which the location information is used to select the next forwarding host among the sender󰂶s neighbors. Because of the constraints on sensors, finding location for sensors is a challenging problem.The location discovery problem is

This work is partially supported by 󰂳The research of foreign Chinese distance visualized teaching model󰂴 (The National Society Science Fund of P.R.China) No: 07BYY033

referred to as localization problem in the literature. Wireless sensor network (WSN) throw a large number of low-cost, low-power wireless sensor to the region, sensors form a distributed network rapidly through self-organizing, which has broad application prospects in the military and civilian fields.Comparing to traditional wireless networks, wireless sensor networks have the following features: (1) a sensor node (SN) in a WSN is expected to be battery equipped, and to change or recharge the power supply is usually very difficult. Therefore energy conservation, which is essential for prolonging the lifetime of the SN and correspondingly of the network, is a more crucial issue in WSNs than such other performance metrics utilized for traditional network systems as throughput and latency. (2)Sensor nodes due to be low-cost, small size and low power consumption, hardware, so its software resources are very limited. (3) No center. Wireless sensor networks are generally point to point network.(4)self-organization. Wireless sensor networks emplaced independent on any preconceived infrastructure. (5) Multi-hop routing. The communication distance of network nodes is limited, if hope to communicate with the distant nodes, intermediate nodes can achieve through the Multi-hop routing. (6) Dynamic topology. Wireless sensor networks is a dynamic network, node can move anywhere, network topology changes at any time, so network should have a dynamic network topology organizational functions.Wireless sensor networks have broad applications in many areas; the majority of applications are dependent on sensor nodes to monitor the location information of objective, which shows node localization is very important in wireless sensor network. Currently, the most extensive localization application is the Global Position System (GPS), but it will be restricted by cost, power consumption and expansibility.Therefore, node localization does not apply to low-cost self-organizing sensor networks.[1]

Currently, a variety of algorithms have been

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