In the Internet of Things (IoT), smart devices such as sensors gather data by sensing the IoT environment and communicating with each other. This data is transmitted to a base station to satisfy certain requests of remote users. Energy conservation is a critical issue for battery-powered IoT nodes. The mobility of the sink can effectively conserve the energy of the sensor nodes. However, improper use of the mobile sink may either erode the energy conservation goal or increase the data delivery delay. Thus, to achieve a green IoT network with minimum delay, this paper addresses the energy conservation issue in these networks by proposing a Cross-zone based Routing mechanism for IoT–based WSN (CRIoT). CRIoT has more control over the routing tree by using a grid-based virtual structure with cells of different sizes that are formed by connecting several smaller cross-shaped pieces. These paths are created so that they not only prevent the occurrence of hot spots and prolong the network lifetime but also lead to minimal delay. The simulation results indicate that the proposed routing protocol provides better network performance in terms of delay, energy utilization, network lifetime, and throughput.
