Localization
is an important aspect in the field of wireless sensor networks (WSNs) that has developed significant research
interest among academia and research community. Wireless sensor
network is formed by a large number of tiny, low energy, limited processing
capability and low-cost sensors that
communicate with each other in ad-hoc fashion.
The task of determining physical coordinates of sensor nodes in WSNs is known as localization or positioning and is a key
factor in today’s communication systems to estimate the place of origin of
events. As the requirement of the positioning accuracy for different
applications varies, different localization methods are used in different applications and there are several challenges in some special
scenarios such as forest fire detection.
The localization algorithms for WSNs depend on various measurement techniques. Measurement
techniques in WSNs localization can be broadly classified into three categories. Angle of Arrival (AOA)
measurements, distance related measurements &Radio Signal Strength (RSS) profiling techniques
Based on the measurement of inter-sensor distance, localization
algorithms in WSNs can be broadly
classified into two categories: centralized and distributed. In centralized
localization technique, all the inter-sensor measured distances are sent to the central
location where the positions of each and every sensor node are calculated. On the other hand, in distributed localization technique, the individual
sensor nodes calculate their own position by utilizing the distance
measurement from other anchor nodes.