A new optimal relay nodes selection method for wireless sensor networks

In wireless sensor network, sensor nodes are prone to failure due to different reasons such as environmental impact, radio interference and battery depletion, thus it is extremely vital to integrate an effective fault tolerance method within the network. Furthermore, selection of an optimal path for transmitting sensed data to the base station is significant. This paper presents a new method called optimal relay node selection, which selects two optimal relay nodes based on residual energy, failure probability, distance to relay node and total distance to base station for every collector node. Analytic hierarchy process method was used to determine the weights of relay nodes and Promethee method was used for outranking them. Furthermore, when a primary relay node fails, this method selects the secondary for providing fault tolerance against path failure. The results show that the proposed method outperforms existing algorithms in terms of First Relay Node Dead, Half Relay Node Alive, energy efficiency and throughput.