DMODL — Distributed Multi-hop On-Demand Localization using virtual anchor nodes in Wireless Sensor Networks

Localization system is not only for location identification, but also provides the base for routing, density control, tracking and a number of other communication network aspects. One of the main methods to improve localization accuracy is to increase the number of anchor nodes. However number of anchor nodes is always limited due to constraints such as hardware cost, energy consumption and so on. In this paper, we propose a novel Distributed Multi-hop On-Demand Localization(DMODL)algorithm, in which sensor nodes will localize as and when demand comes with the help of minimum GPS embedded nodes called actual anchor node(AAN). The localized nodes become virtual anchor node(VAN) and assist remaining sensor nodes to localize along with AAN. As a result, the DMODL achieves high localization ratio and energy efficiency by minimizing the hardware cost and communication overhead. Simulation results demonstrate that, the DMODL algorithm provides significant improvements in the number of VAN, localization ratio, energy efficiency.

1. INTRODUCTION

Wireless, Sensors and Networks are three different technologies that jointly form Wireless Sensor Networks(WSN). WSN consists of tiny sensor nodes forming an ad hoc distributed data sensing and propagation network which collects the information on the surrounding environment. It is widely used in both the military and civilian applications such as target tracking, surveillance, and security management [1] [2]. Each sensor node consists of four basic units; sensing unit, processing unit, radio unit, and power unit. With their capabilities for monitoring and control, the network can provide a fine global picture of the target area through the integration of the data collected from many sensors each providing a coarse local view [3].