An Energy-Efficient Routing Protocol for 3D Wireless Sensor Networks

Energy optimization is a key problem of the energy-limited wireless sensor network (WSN), which is usually deployed in the three-dimensional space. In order to alleviate this problem, this paper studies the energy-efficient routing protocol for 3D WSN. The less sensor nodes work simultaneously, the more energy is saved. To minimize energy consumption on the premise of satisfying the full coverage of discrete points of interest (DPOI), finding the least and optimal node set for routing is an important problem. Through studying this problem, we propose an algorithm employing the improved genetic algorithm to find the minimum set of sensor nodes which can ensure the full coverage of DPOI. On the basis of the optimal node set, we propose a new adaptive clustering routing optimizing energy consumption, which includes three parts. The first one is selecting the cluster head according to the residual energy of the sensor node and the distance from the base station. The second one is setting the intra-cluster communication mode by considering the angle of node space. The last one is deciding inter-cluster communication mode by combining single-hop and multi-hop. To fully utilize the energy of the network, we design a node wake-up scheme to wake up the sleep node to replace the sensor nodes which runs out of energy. This policy also can make our proposed protocol suitable for the rechargeable WSN. In addition, we also consider the additional energy consumption of retransmission caused by the unreliable wireless channel. Simulation results show that our proposed scheme is obviously superior to other existing schemes in prolonging the WSN lifetime.