In order to solve power management technology in IEEE 802.11 ah, an improved Target Wake Time (TWT) mechanism is proposed to schedule the awake time of stations in multi-user scenario. TWT mechanism permits the access point (AP) to define a specific or set of times for individual stations (STA) to wake up from doze state to access the medium. It can reduce energy consumption greatly because TWT STAs may enter doze state until their TWT arrives. Contention is also decreased since simultaneous transmission is avoided. Considering that not all STAs are TWT-functioned, AP allocates a non-TWT period of time for non-TWT STAs according to their buffered traffic. Simulation results show that the improved TWT mechanism has greatly reduced energy consumption and transmission delay, which can meet the requirements of IoT applications.

Internet of Things(IoT); low power consumption; multi-user; target wake time (TWT); transmission delay