Discovering neighbour nodes based on signal strength using Waspmote nodes

Neighbour discovery is essential to achieve high reliability and connectivity between network nodes. It provides each node with a list of information about its neighbours and hence the best route to the base station. The Received Signal Strength Indicator (RSSI) is commonly used to evaluate the link quality between pairs of nodes and to estimate the neighbour location. However, very few experimental tests on the effect of the RSSI on neighbour discovery have been reported in the literature. Thus, the main goals of this paper are investigating how to improve the link quality between the network nodes based on the RSSI value and calculating the required time for each node to discover their neighbours experimentally changes with the number of nodes using Waspmote testbed equipped with XBee-Pro S1 802.15.4 radio module. The results indicate that neighbour discovery is reliable for RSSI above -80 dBm, while, the time required to discover neighbours increases with more neighbours, for example, discovering 1 to 5 nodes reliably requires 3 s, whereas 4 s is required to discover 6 to 10 nodes.