ROUND TRIP DELAY TIME AS A LINEAR FUNCTION OF DISTANCE BETWEEN THE SENSOR NODES IN WIRELESS SENSOR NETWORK

In a dense wireless sensor networks with portable sensor nodes identification of sensor node location, distance of particular sensor node from some reference node and fault detection are the great challenging issues. Round trip delay (RTD) time measurement technique is an easy way to obtain the information regarding above issues in WSN. But round trip delay measurement is affected by various parameters of wireless sensor network. As the sensor nodes are placed randomly in network, sensor node distance has more impact on this time measurement. So it is necessary to study the relationship between the round trip delay time and Sensor node distance. To prove this relationship the other parameters affecting round trip delay time like speed, data transfer rate, number of sensor nodes in RTD path and other request handled by intermediate nodes are either made constant or disabled. A wireless sensor node hardware designed for this purpose consists of microcontroller (ATMEGA 16L) and ZigBee (XBEE S2) wireless communication module. For configuring the ZigBee module of each sensor nodes in round trip delay path X-CTU software is used. After configuring the all sensor nodes the entire network is simulated in real time by using Dock light V1.9 software. The graph plotted between round trip delay time and sensor node distance proves a linear relationship between it.