Energy and Load Aware Fog Node Placement for Smart Farming

Smart farming has enabled farmers to reduce cost, improve agricultural yield, and make better decisions using Internet of Things (IoT) technology. IoT nodes such as soil sensors and pH probes provide farmers with a real-time update on the farm. Traditionally, the farm data sensed by IoT nodes are processed by a cloud data center. However, it results in a higher delay in sending results to the farmer. Fog computing is a recent paradigm that reduces the delay by deploying fog nodes on the farm to process the farm data. However, the fog nodes need to be placed in proper locations as it will impact the energy consumption of IoT nodes in transmitting data to the fog node. Moreover, the placement must ensure a fair distribution of load among the fog nodes to ensure effective resource utilization. Therefore, it is critical to determine the optimal location of fog nodes to minimize the energy consumption of IoT nodes and balance load among the fog nodes. We ensure load balancing by minimizing the maximum load. In this paper, we model the fog node placement as an optimization problem and present an Integer Programming Formulation (ILP) formulation of the same. We also propose a placement algorithm designed based onk-means clustering. Our simulation results show that the proposed algorithm performs close to the optimal placement in terms of energy consumption and load distribution.