Infrastructure-less collaborative indoor positioning for time critical operations

Localisation defines the process of determining the topographical location of sensor nodes in wireless sensor network. Current localisation method is space oriented which adopts GPS (Global Positioning System) signal to yield the location information of the nodes. The GPS signals are suited for outdoor environments, however they fail to work indoors, which makes the need to opt for terrestrial localisation of utmost importance. The localisation architecture deals in designing localisation service through WSN where sensor nodes are mobile in a cluster environment. The wireless sensor applications, significantly need reliable and robust information of the physical location of the nodes in the network. The paper shows localisation using the Time Difference of Arrival (TDOA) for distance estimation and trilateration technique for the position calculation. The Mean Square Error analysis (MSE) of the actual position in contrast to the calculated position further assists the sensor nodes to achieve reliable location information.