Hybrid Medium Access Control for Time-switching Simultaneous Wireless Information and Power Transfer

This paper presents hybrid medium access control (MAC) for time-switching simultaneous wireless information and power transfer (TS-SWIPT) that improves channel utilization and the timeliness of data and power delivery. To this end, the proposed hybrid MAC uses a superframe structure including a beacon period (BP), a contention access period (CAP), and a channel time allocation period (CTAP), and adaptively adjusts the CAP and CTAP lengths according to the data and power delivery time requested by sensor devices. Furthermore, it adjusts the priority of data and power delivery according to the residual power level of each sensor device. To evaluate the performance of the proposed hybrid MAC, an experimental simulation was conducted. The results show that the proposed hybrid MAC outperforms the existing MAC in terms of resource utilization, aggregate throughput, and charging delay.