Rilod: Reduction of information loss in a WSN system in the presence of dumb nodes

A sensor node behaves as “dumb,” when it continues to sense its vicinity, but fail to communicate with its neighbors due to the shrinkage in the communication range attributed to adverse environmental conditions such as rainfall, fog, and high temperature. However, the node behaves normally with the resumption of favorable environmental conditions. The nodes get isolated from the network only temporarily because of the temporal nature of adverse environmental conditions. Therefore, the dumb behavior of sensor nodes is temporary in nature. During the period of isolation, a sensor node continues its sensing, but it cannot send the sensed information to the sink, which increases the possibility of information loss in the network. Connectivity reestablishment of an isolated node with the network by activating the intermediate sleep nodes or adjusting the communication range gives the opportunity to send data to the sink. However, all the isolated nodes cannot reestablish connectivity due to the unavailability of intermediate nodes in the reduced or adjusted communication range. In this context, we propose a scheme, named RILoD, for a self-adaptive wireless sensor network, in which we use mobile mules to collect data from these isolated nodes and deliver them to the parent node, which can, in turn, forward the data to the sink. Using this technique, every isolated node can send their sensed information to the sink. Simulation results show that the proposed scheme reduces information loss by up to 32%. Furthermore, the proposed scheme has improved success probability of data delivery over the existing state of the art.