WLAN Power-Saving Using Service Period Interruption

With the proliferation of Internet of Things (IoT), the utilization of existing and widely deployed wireless local area networks (WLANs) has attracted significant attention. Power-saving is one of the key subjects for WLANs to apply IoT applications especially in which IoT devices are driven by batteries. Target Wake Time (TWT) is a new function to improve power-saving for WLAN stations (STAs) by extending their sleep period much longer and the battery life of IoT devices can be extended. The service period (SP) is one of the crucial parameters of TWT as it is the period in which STAs are active and using their power. From the power-saving aspect, shorter SP realizes lower power-usage, while SP requires a certain period for necessary IoT data communication. However, it is difficult to define an appropriate SP, especially for IoT applications. As a result, SP includes a waiting time for STAs in which STAs experience unnecessary energy consumption.In this paper, a novel SP duration control scheme based on SP interruption (SPI) is proposed for further improvement of TWT power-saving efficiency. SPI is a scheme for STAs using TWT to manage their active period more effectively. Performance of this new scheme in a few IoT scenarios is evaluated with a computer simulation. The simulation result showed that SPI provided better power-saving performance, such as a 56.7% reduction in energy consumption per STA from the regular TWT under an IoT service for video signal upload.