An efficient medium access control protocol for RF energy harvesting based IoT devices

Energy efficiency is one of the major challenges in IEEE 802.15.4 based Internet of Things (IoT). In the Medium Access Control (MAC) layer of the IEEE 802.15.4 standard, Guaranteed Time Slot (GTS) are allocated to the IoT devices for data transmission. However, GTS allocation does not consider residual energy of IoT devices resulting in reduced life cycle of these devices. In this paper, we propose an efficient MAC protocol for RF harvesting based IoT devices. The proposed protocol uses residual energy based duty cycle adaptation to prioritize transmission of high energy devices, allowing low energy devices to harvest energy in the mean time. Simulation results show that the life cycle and transmitted data of IoT devices is improved up to 94% and 79% respectively by using the proposed protocol, as compared to the IEEE 802.15.4 standard.