Review of Multi-user Wakeup Schemes Month Year doc.: IEEE 802.11-yy/xxxxr0 May 2017 Review of Multi-user Wakeup Schemes Date: 2017-05-03 Authors: Name Affiliation Address Phone Email Yong CHENG Huawei Device Tian An Cloud Park, Bantian, Longgang, Shenzhen, 518129, P.R. China.   yong.chengyong@huawei.com Ping FANG ping.fang@huawei.com Yunsong YANG yangyunsong@huawei.com Yong CHENG, et. al., Huawei Device John Doe, Some Company

May 2017 Abstract TGba has passed the Motion that “802.11ba spec shall define a mechanism to wake up multiple WUR mode STAs (e.g., multi-user wake-up frame)”, but a multi-user wakeup mechanism has not been defined yet. This contribution presents six multi-user wakeup schemes, and pros and cons of each scheme, so to help TGba to choose one or more multi-user wakeup schemes. Yong CHENG, et. al., Huawei Device

May 2017 Background TGba January F2F meeting passed the following motion [1, 2] regarding multi-user wakeup, but a specific multi-user wakeup scheme has not been defined yet. [1] 11-17-0526-00-00ba-meeting-minutes-march-2017.docx [2] 11-17-0054-03-00ba-wur-mac-issus Yong CHENG, et. al., Huawei Device

Multi-user Wakeup Schemes May 2017 Multi-user Wakeup Schemes In the following slides, six multi-user wakeup schemes are discussed, along with their pros and cons: Opt1: Send a WUP carrying multiple unicast WUR IDs Opt2: Send TIM in a WUP Opt3: Group STAs and send group TIM in the first WUP, and send (multiple) short TIM in the second WUP Opt4: Group STAs and send a group-addressed WUP, and send full TIM in a Wi-Fi frame Opt5: Send multiple unicast WUPs using OFDMA Opt6: Group STAs and send group-cast/multi-cast WUPs using OFDMA Yong CHENG, et. al., Huawei Device

Opt1: WUP with Multiple Unicast WUR IDs May 2017 Opt1: WUP with Multiple Unicast WUR IDs AP sends a WUP carrying multiple unicast WUR IDs to simultaneously wake up multiple STAs, similar as shown in [1]. Pros: It can specify the target STAs that need to be woken up. It will not wake up the unintended STAs. Cons: WUP may become too long to transmit, e.g., with a TX rate of 125 kbps [2]. WUP (WUR ID 1, WUR ID 2, WUR ID 3) AP STA1 STA2 STA3 STA4 Main radio on DL Data (STA 1, 2, 3) PS-Polls from STA 1~3 [1] 11-17-0028-00-00ba-on-waking-up-of-multiple-wur-stations [2] 11-17-0366-01-00ba-wur-modulation-and-coding Yong CHENG, et. al., Huawei Device

Opt2: Send TIM Info with WUP May 2017 Opt2: Send TIM Info with WUP AP sends TIM in WUP to simultaneously wake up multiple STAs [1]. Pros: It can specify the target STAs that need to be woken up. It will not wake up the unintended STAs. Cons: TIM info may take too much time to send, e.g., with a TX rate of 125 kbps [2]. Longest TIM: 2048 bits; shortest TIM: 48 bits [802.11-2016] WUP (TIM : STA1, STA2, STA3) AP STA1 STA2 STA3 STA4 Main radio on MU PPDU (STA 1, 2, 3) PS-Polls from STA 1~3 [1] 11-17-0054-03-00ba-wur-mac-issus [2] 11-17-0366-01-00ba-wur-modulation-and-coding Yong CHENG, et. al., Huawei Device

Opt3: Group TIM and Short TIM May 2017 Opt3: Group TIM and Short TIM STAs are partitioned into multiple groups: G1, G2, …, Gn. AP sends group TIM in WUP in the first step, followed by one or multiple WUPs carrying the short TIM per group in the second step. Group TIM: TIM information with respect to groups Short TIM: TIM information with respect to the STAs in one group Pros: TIM information is hierarchically arranged and much shorter. It can be used to wake up all STAs in one or more groups. Cons: AP needs to send two WUPs. For a target STA, the STA needs to receive the first and the second WUPs correctly. 1 G1 G2 G3 G4 Gn Group TIM in WUP in the first step … Short TIM of Group 2 Short TIM of Group 4 STA 2 STA 7 STA 13 (Multiple) WUPs carrying short TIM in the second step [1] 11-17-0354-00-00ba-initial-thoughts-on-mac-procedures Yong CHENG, et. al., Huawei Device

Opt4: Group-Addressed WUP and Wi-Fi TIM Frame May 2017 Opt4: Group-Addressed WUP and Wi-Fi TIM Frame STAs are partitioned into multiple groups: G1, G2, …, Gn. AP sends a group-addressed WUP, followed by a Wi-Fi TIM frame. Broadcast WUP to wake up all STAs), or Group-cast WUP (WUP with group IDs, or WUP with group TIMs) to wakeup up multiple STAs Wi-Fi TIM frame: Wi-Fi Beacon, or Public Action Frame carrying TIM info Pros: WUP is simple and short. AP sends one group-addressed WUP. Cons: Unintended STAs may be woken up by the group-addressed WUP. Broadcast (or Group-cast) WUP AP STA1 STA2 STA3 STA4 Wi-Fi TIM frame (TIM: STA1, STA2, STA4) Main radio on Main radio enters sleep Yong CHENG, et. al., Huawei Device

Opt5: Send Multiple Unicast WUPs via OFDMA May 2017 Opt5: Send Multiple Unicast WUPs via OFDMA AP assigns different WUR channels to different STAs, e.g., a 4 MHz WUR channel within a 20 MHz Wi-Fi channel. AP employs OFDMA to multiplex multiple unicast WUPs, each unicast WUP is intended for a target WUR/STA, e.g., multiplexing 6 WUPs in a 40 MHz Wi-Fi channel [1]. Pros: Multiple unicast WUPs are sent out simultaneously, and it will not wake up unintended STAs. Cons: AP needs to manage the allocation of different WUR channels to different STAs, and it is not suitable to multiplex a large number of unicast WUPs in a limited BW. L-STF WUP for STA7 L-LTF L-SIG WUP for STA4 WUP for STA8 WUP for STA2 WUP for STA6 WUP for STA5 4 MHz WUR channel 2 MHz guard band 40 MHz channel [1] 11-17-0385-00-00ba-concurrent-transmission-of-data-and-a-wake-up-signal-in-802-11ax-follow-up [2] 11-17-0028-00-00ba-on-waking-up-of-multiple-wur-stations Yong CHENG, et. al., Huawei Device

Opt6: Send Group-cast WUPs with OFDMA May 2017 Opt6: Send Group-cast WUPs with OFDMA STAs may be partitioned into multiple groups: G1, G2, …, Gn. AP assigns different WUR channels to different groups/STAs. AP employs OFDMA to multiplex multiple group-cast/multi-cast WUPs, e.g., multiplexing 6 group-cast/multi-cast WUPs in a 40 MHz Wi-Fi channel [1]. A multi-cast WUP may carry a group ID (group-cast) or multiple unicast WUR IDs (multi-cast). Pros: Multiple group-cast WUPs are sent out simultaneously to wake up multiple STAs. Cons: AP needs to manage the allocation of different WUR channels for different groups/STAs and the grouping of STAs. L-STF Group-cast WUP for Group7 L-LTF L-SIG Group-cast WUP for Group4 Group-cast WUP for Group8 Group-cast WUP for Group2 Group-cast WUP for Group6 Group-cast WUP for Group5 4 MHz WUR channel 2 MHz guard band 40 MHz channel Yong CHENG, et. al., Huawei Device