An Adaptive Tail Time Scheme for Saving Power of Smart Devices

Abstract

Power management of Wi-Fi interfaces can greatly impact the battery life time of a smart device. Thus, many commercial devices utilize the Power Save Mode - Adaptive (PSM-A) mechanism to save wireless energy by switching wireless radio between high and low power. Tail timer is introduced in PSM-A to put the radio in high power state until the timer expires, allowing near future packets to arrive without much delay. However, this fixed tail timer may result in considerable amount of energy drainage under different types of traffic. This paper proposes power saving mode Adaptive Tail Timer (ATT), a simple yet efficient way to save energy wastage by adaptively resizing the tail timer according to the data packet arrival times. The interface sleep management is only done on Media Access Control (MAC) level, hence this scheme does not require any information from other layers. The simulation results show up to 61% energy savings compared to fixed tail time length of 1500 ms.