The wireless sensor networks deployed in hostile environments suffer from a high rate of node failures. Such failures may convert a fully-connected sensor network into multiple disjoint sub-networks, leading to the network partition problem. The placement of relay nodes is the only way to restore the lost connectivity because these devices, compared to the sensor nodes, have a higher energy backup, with a longer communication range. In this paper, a new solution is proposed to heal the network partition problem in the wireless sensor network. The solution is based on a zero gradient point inside the convex hull polygon. The proposed solution is compared with various naive approaches, along with existing state-of-the-art solutions, that is, the Spider Web-1C heuristic and Steiner-minimum-tree based optimal relay node placement algorithm. The simulation experiment results confirm the effectiveness of our proposed approach. 
Relay node placement to heal partitioned wireless sensor networks