A node deployment algorithm for maximizing network lifetime in delay-constrained duty-cycled wireless sensor networks

Although duty-cycling is a promising approach to reduce energy consumption in wireless sensor networks, sufficiently long network lifetime may not be achieved due to the hot spot problem. Moreover, a long duty cycle interval can lead to high end-to-end delay, which is not desired in delay-constrained applications. In order to address the hot spot problem and long end-to-end delay, this article proposes a novel energy-balanced node deployment algorithm for maximizing network lifetime in duty-cycled wireless sensor networks while taking into account a delay requirement. In addition, energy-balanced node deployment considers network connectivity and sensing coverage constraints, which are also important factors when wireless sensor networks are deployed. An optimization problem is first formulated where the objective function and constraints are estimated based on node distribution in the area and the network parameters. Then, a non-deterministic algorithm is proposed to derive the optimal number of nodes in each circular layer that meets given constraints and maximizes network lifetime. Numerical analysis and simulations have been conducted to validate the proposed algorithm. The results show that the proposed algorithm can achieve higher network lifetime than other schemes.