ABSTRACTThe problems of hot spot and energy consumption of nodes in wireless sensor networks (WSNs) have been tackled by the adoption of hybrid energy efficient distributed (HEED) and unequal clustering algorithm to prolong the network lifetime (UCAPN) protocols. These have involved the implementation of unequally sized clusters that are based on the distance of cluster head (CH) from the base station (BS). The BS partitions the network area into several radially divided zones depending on the distance from centre of the field and CHs are independently selected in each zone. Clustering, on the other hand, controls how data are transmitted and allows for aggregation in the clusters. However, whereas these topologies have been able to improve network life time, the problem of network void still persists. To address this, a radially optimized zone-divided energy-aware WSN protocol using bat algorithm is proposed. This protocol considers not only the distance from the BS, but also the angle at which the WSN develops. It gives a unique and equal opportunity for each sensor network to have ambience area for communicating and sensing necessary for its routing operations. Besides, it divides the sensing area into radial zones and employs the unequal clustering method in these zones to resolve the hot-spot problem. Based on the merits of zone-divided networks, CHs with great residual energy present in the high-energy regions are selected as the relay node in the inter-cluster multi-hop routing stage. Simulation results show that the proposed technique outperforms both HEED and UCAPN protocols. Bat algorithm is capable of predicting most critical nodes and generates a scalable and feasible energy-efficient routing technique for radially optimized zone-divided energy-aware WSN. By exploiting the angle at which the WSN develops, this protocol avails equal opportunity for each sensor network to have enough fields for communicating and sensing necessary for its routing operations. Using bat algorithm not only gives a superior packet delivery ratio, hence reducing voids, but also saves on energy consumption at the nodes. Sensor nodes are grouped into clusters to improve network performance.