Reliable Data Delivery in Wireless Sensor Networks with Multiple Sinks and Optimal Routing

Wireless sensor networks are equipped with energy constrained and limited communication range sensor nodes to transmit the sensed data. The constraints made prolonged network lifetime is one of the major concerns while dealing with the energy hole problem. In the presence of nodes whose behaviour is unpredictable as a relay node (unreliable nodes/URNodes) will raise the concern about reliable data delivery and makes enhancement of network lifetime difficult. In this paper, the energy hole problem is addressed by looking for an Alternate Path (AP) by availing the residual energy of other sensor nodes who involves in data transmission rarely. In the presence of URNodes with various percentage of unreliability, the AP approach reaches almost same network lifetime when compared with the network without URNodes. Experiments have been done with increased density of the network sensor nodes with varied number of unreliable node (URNodes) with various percentage of unreliability. The main concern of the work is reliable data delivery with extended network lifetime. So we also considered the adjustable communication range to ensure reliable data delivery. With an adjustable communication range, along with the enhanced network lifetime, the total number of dropped messages due to URNodes are also got reduced.