Hop Count-based Localization Scheme For Wireless Sensor Network

With the development of computer science,sensor technology,wireless communication and micro-electronic technology,WSN(wireless sensor network) has been presented at the end of the 20th century.As a new solution of information gathering and processing,WSN has many advantages over traditional sensor network. It has a wide range of applications in many areas such as military,industrial and agricultural production,transportation,biology,meteorology,health,security and family etc.As a key technology in WSN,node localization technology has become one of the research focuses.Node localization algorithms can be divided into two categories: range-based schemes and range-free schemes.Range-free schemes are more suitable for WSN because of low cost and energy-effective.Hop count-based localization is range-free scheme which can be implemented easily and do not need extra hardware.But existing hop count-based schemes usually give poor location estimation and would be affected by network topology.This paper finds "block effect" existing in the schemes by analyzing two typical hop count-based schemes DHL and DV-Hop and then introduces a feed-back theory which modifies unknown nodes' location result using anchors' estimate error to increase precision and stabilization.Finally,this paper uses OMNeT++ and MATLAB to simulate DHL and DV-Hop, The simulation result shows that the improved method has fine performance in different network topologies,the different connectivity and density of anchors.Also, the improved method implements the effective control of "block effect" existing in hop count-based localization algorithm and overcomes its inherent flaws to some extent.