WSN Self-Address Collision Detection and Solving

The complexity and number of interconnected elements comprising today's networks have stressed the need for autonomic computing techniques. This need is even bigger in wireless sensor networks, because sensor nodes should work continuously without operator intervention, i.e. have self-organiztaion and self-configuration algorithms. The first action that a wireless sensor network should do is to establish the network address of each node without collisions. However, this scenarios are dynamic which means that network partitions and rejoins are common and node addition and failure are not uncommon, which means that the network should be able to reconfigure itself without compromising availability. In this paper we show a solution to detect address collisions in dynamic scenarios wasting a minimum level of energy (i.e. without periodic beacons or any other kind of message), and we describe a collision solving protocol which minimizes the impact on the already established routes, which also minimizes energy loss because there is no need to rerun the routing protocol. In order to develop the present solution we have implemented several preliminary solutions that revealed some lessons about wireless communications on sensor nodes which were useful to the optimization of the final solution.