Research On TWT Power Saving Mechanism In 802.11ax WLAN

With the rapid development of communication network technology and the popularity of smart terminal devices,people's life and entertainment methods have undergone great changes,and many smart devices have been deeply influenced people's lives.In the context of this smart era,the advantages of wireless local area network(WLAN),such as high throughput,low cost,and easy deployment,have ushered in unprecedented vigorous development.In order to meet the characteristics of high mobility,smart devices that people use basically rely on battery power.However,the endurance is limited.With the continuous expansion of WLAN network density,the communication between wireless devices has become more frequent,and the power consumption of wireless devices has also increased significantly.Device manufacturers must not only develop high-capacity batteries,but also further optimize the power-saving mechanism of devices.The sixth-generation Wi Fi standard IEEE 802.11 ax,which is currently in use,and the seventh-generation Wi Fi standard IEEE 802.11 be that is being drafted,are both formulated for the dense user situation containing a large amount of data of different communication service types.In the Media Access Control(MAC)layer of the IEEE 802.11 ax protocol,a scheduling method for centralized control of users by wireless access points(AP)is added to divide the entire channel of the system to avoid competition between users for channel resources.However,this scheduling method that is uniformly regulated by the AP will also generate a certain amount of overhead in signaling interaction.Especially in the Target Wake Time(TWT)mechanism adopted by the protocol,if the station wakes up on time but finds that the AP does not schedule it,or the AP schedules it but there is no data to report to the AP at this time,it will lead to unnecessary communication power consumption of the site.Therefore,based on the IEEE 802.11 ax and IEEE 802.11 be standards,this thesis conducts an in-depth study on how to reduce the power consumption caused by scheduling signaling overhead and user data alignment and filling overhead in the scenario of centralized AP scheduling.This thesis first analyzes the existing related technical standards,introduces the TWT power-saving mechanism adopted by IEEE 802.11 ax standard,and focuses on the analysis of the broadcast TWT power-saving mechanism in Trigger-enabled mode.In addition,it also introduces the low-power wake-up radio(WUR)technology in the IEEE 802.11 ba standard.Then,combining WUR with the TWT power-saving mechanism in IEEE 802.11 ax,the packet user wake up(Wake up In Advance,WIA)TWT mechanism is proposed,and the corresponding frame structure and mechanism flow are designed.After simulation verification,it shows that the design proposed in this thesis can effectively avoid unnecessary wake-up and listening caused by AP's non-on-demand uplink and downlink scheduling,and further reduce the power consumption of the equipment in the system.Then,a Multi-link Fragmentation Transmission(MFT)algorithm based on Multi-link cooperative transmission technology in IEEE 802.11 be standard is proposed to optimize the problem of additional power consumption of the device caused by padding due to different data lengths when users transmit uplink data in a dense user scenario.It is verified by simulation that the algorithm can effectively reduce the invalid padding overhead.Then based on the algorithm,this thesis improves the WIA TWT mechanism,and proposes a WIA TWT power-saving mechanism with Buffer Status Reports(BSR)feedback and WIA TWT powersaving mechanism based on Long Short-Term Memory(LSTM)traffic prediction.Finally,the simulation shows that the two improved WIA TWT power-saving mechanisms proposed in this thesis can further reduce the power consumption of the system compared to the WIA TWT mechanism that does not apply to MFT algorithm.