A novel caching mechanism for Internet of Things (IoT) sensing service with energy harvesting

Caching has shown the success in performance improvement for many wireless communications and networking systems. In this paper, we introduce a caching mechanism for the energy harvesting based Internet of Things (IoT) sensing service. In the service, a sensor harvests energy from an environment. The energy is stored in the battery, and the sensor uses it for sensing and transmitting the reading to the user. A sensing cache can be implemented at a wireless gateway of the sensor to avoid activating the sensor too frequently, hence reducing its energy consumption. We develop an analytical model to investigate the benefit of the proposed caching mechanism. We also introduce the threshold adaptation algorithm that allows the sensing cache dynamically to adjust the parameter of caching to maximize the combined hit rate of the sensing service from multiple sensors. The performance evaluation clearly shows the tradeoff between energy consumption and caching.