An energy-optimization topology control for three-dimensional wireless sensor networks

Energy optimization routing protocol is considered an essential problem in wireless sensor networks (WSNs) as it can affect the network lifetime. Most of the existing routing algorithms are designed for two-dimensional networks, which cannot be transferred to three-dimensional WSNs. Due to a lack of knowledge about the third dimension, 2D routing algorithms perform badly in a real-life 3D environment such as a hill, an urban area, an underground area, an underwater area, and so forth. These networks also suffer from problems such as routing stretch, energy efficiency, and load balancing. Therefore, in this paper, a mixed integer linear programming is formulated as an optimal WSN topology control problem to address the energy optimization routing problem in 3D terrain. The proposed method is a self-organized network that uses clustering and sleep/wake-up schemes to maximize the network lifetime and minimize energy consumption. Simulations revealed that our algorithm is robust to various terrains and significantly increases the network lifetime when compared to a well-known protocol, i.e., the multi-hop low energy adaptive clustering hierarchy (LEACH), with an improved average of 44.94 %. The results also suggested that the energy balancing strategy provided better solutions than the minimizing total energy scheme due to the optimal load balancing scheme of the cluster head selection at each decision round. Furthermore, our global optimal solutions can serve as a benchmark for all heuristic algorithms. Though the number of variables in our optimization problem grows nonlinearly with the number of sensor nodes, the computation time is rather practical as the problem is linear.