DHN: A Dynamic Hierarchical Network Protocol for Wireless Sensor Networks in the Presence of Obstacles

The Internet of Things (IoTs) has been steadily penetrating people's daily life in recent years. One of the key elements of IoT systems is the perception function of the IoT devices. Wireless Sensor Networks (WSN) can wirelessly transmit the information generated by their sensor nodes to a base station for further processing and are therefore suitable to be the perception terminal of IoT systems. Most of the research work on WSN are based on the premises that sensor nodes can communicate with base stations directly. But in practical applications, not all nodes can communicate directly with the base station because of obstacles such as walls, hills and so on. Adding relay nodes is a solution to this problem, but it brings inconvenience to users, because users need to distinguish node types and determine the location of relay nodes. Besides, prolonging the lifetime of WSN as much as possible has been a common requirement in research on WSN. In this paper, a new protocol, named Dynamic Hierarchical Network (DHN) protocol, which can overcome the influence of the obstacles while using homogeneous nodes, and effectively prolong the lifetime of the WSN is proposed. Simulation results show that the proposed protocol is more effective than that based on Dijkstra method.