doc.: ieee 802.11-15/0880r2 submission scheduled trigger frames july 2015 slide 1 date: 2015-07-04...

doc.: IEEE 802.11-15/0880r2

Submission

Scheduled Trigger framesJuly 2015

Slide 1

Date: 2015-07-04

Authors: Name Affiliation Address Phone email

Alfred Asterjadhi

Qualcomm

5775 Morehouse Dr. San Diego, CA, USA

aasterja@qti.qualcomm.com

Simone Merlin smerlin@qti.qualcomm.com

Bin Tian btian@qti.qualcomm.com

Carlos Aldana 1700 Technology Drive San

Jose, CA 95110, USA caldana@qca.qualcomm.com

George Cherian 5775 Morehouse Dr. San

Diego, CA, USA

gcherian@qti.qualcomm.com

Gwendolyn Barriac gbarriac@qti.qualcomm.com

Hemanth Sampath hsampath@qti.qualcomm.com

Menzo Wentink

Straatweg 66-S Breukelen, 3621 BR Netherlands

mwentink@qti.qualcomm.com

Richard Van Nee rvannee@qti.qualcomm.com

Albert Van Zelst allert@qti.qualcomm.com

Rolf De Vegt 1700 Technology Drive San

Jose, CA 95110, USA rolfv@qca.qualcomm.com

Sameer Vermani 5775 Morehouse Dr. San

Diego, CA, USA svverman@qti.qualcomm.com

Tevfik Yucek 1700 Technology Drive San

Jose, CA 95110, USA

tyucek@qca.qualcomm.com

VK Jones vkjones@qca.qualcomm.com

Youhan Kim youhank@qca.qualcomm.com

1 A. Asterjadhi, H. Choi, et. al.

doc.: IEEE 802.11-15/0880r2

Submission

July 2015

Slide 2

Authors (continued):

Name Affiliation Address Phone email

Kiseon Ryu

LG Electronics

19, Yangjae-daero 11gil, Seocho-gu, Seoul 137-130,

Korea kiseon.ryu@lge.com

Hyeyouong Choi hy0117.choi@lge.com

Jinyoung Chun jiny.chun@lge.com

Jinsoo Choi js.choi@lge.com

Jeongki Kim jeongki.kim@lge.com

Giwon Park giwon.park@lge.com

Dongguk Lim dongguk.lim@lge.com

Suhwook Kim suhwook.kim@lge.com

Eunsung Park esung.park@lge.com

HanGyu Cho hg.cho@lge.com

Jinmin Kim jinmin1230.kim@lge.com

Shahrnaz Azizi

Intel

2200 Mission College Blvd, Santa Clara, CA 95054

shahrnaz.azizi@intel.com

Eldad Perahia eldad.perahia@intel.com

Robert Stacey 2111 NE 25th Ave, Hillsboro

OR 97124, USA +1-503-724-893 robert.stacey@intel.com

Po-Kai Huang po-kai.huang@intel.com

Qinghua Li quinghua.li@intel.com

Xiaogang Chen xiaogang.c.chen@intel.com

Chittabrata Ghosh chittabrata.ghosh@intel.com

Rongzhen Yang rongzhen.yang@intel.com

Laurent cariou laurent.cariou@intel.com

1 A. Asterjadhi, H. Choi, et. al.

doc.: IEEE 802.11-15/0880r2

Submission Slide 3

Authors (continued)Name Affiliation Address Phone email

Ron Porat

Broadcom

rporat@broadcom.com

Matthew Fischer mfischer@broadcom.com

Sriram Venkateswaran

Tu Nguyen

Vinko Erceg

Lei Wang

Marvell

5488 Marvell Lane, Santa Clara, CA, 95054

858-205-7286 Leileiw@marvell.com

Hongyuan Zhang

hongyuan@marvell.com

Yakun Sun yakunsun@marvell.com

Liwen Chu liwenchu@marvell.com

Jinjing Jiang jinjing@marvell.com

Yan Zhang yzhang@marvell.com

Rui Cao ruicao@marvell.com

Sudhir Srinivasa sudhirs@marvell.com

Saga Tamhane sagar@marvell.com

Mao Yu my@marvel..com

Edward Au edwardau@marvell.com

Hui-Ling Lu hlou@marvell.com

1

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A. Asterjadhi, H. Choi, et. al.

doc.: IEEE 802.11-15/0880r2

Submission Slide 4

Authors (continued)

James Yee

Mediatek

No. 1 Dusing 1st Road, Hsinchu, Taiwan

+886-3-567-0766 james.yee@mediatek.com

Alan Jauh alan.jauh@mediatek.com

Chingwa Hu chinghwa.yu@mediatek.com

Frank Hsu frank.hsu@mediatek.com

` 1 Thomas Pare

Mediatek USA

2860 Junction Ave, San Jose, CA 95134, USA

+1-408-526-1899 thomas.pare@mediatek.com

ChaoChun Wang chaochun.wang@mediatek.com

James Wang james.wang@mediatek.com

Jianhan Liu Jianhan.Liu@mediatek.com

Tianyu Wu tianyu.wu@mediatek.com

Russell Huang russell.huang@mediatek.com

` 1

Name Affiliation Address Phone email

1

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A. Asterjadhi, H. Choi, et. al.

doc.: IEEE 802.11-15/0880r2

Submission Slide 5

Authors (continued)

Name Affiliation Address Phone email

Phillip Barber

Huawei

The Lone Star State, TX pbarber@broadbandmobiletech.com

Peter Loc peterloc@iwirelesstech.com

Le Liu F1-17, Huawei Base, Bantian,

Shenzhen +86-18601656691 liule@huawei.com

Jun Luo 5B-N8, No.2222 Xinjinqiao

Road, Pudong, Shanghai jun.l@huawei.com

Yi Luo F1-17, Huawei Base, Bantian,

Shenzhen +86-18665891036 Roy.luoyi@huawei.com

Yingpei Lin 5B-N8, No.2222 Xinjinqiao

Road, Pudong, Shanghai linyingpei@huawei.com

Jiyong Pang 5B-N8, No.2222 Xinjinqiao

Road, Pudong, Shanghai pangjiyong@huawei.com

Zhigang Rong 10180 Telesis Court, Suite 365, San Diego, CA 92121

NA zhigang.rong@huawei.com

Rob Sun 303 Terry Fox, Suite 400 Kanata, Ottawa, Canada

Rob.Sun@huawei.com

David X. Yang F1-17, Huawei Base, Bantian,

Shenzhen david.yangxun@huawei.com

Yunsong Yang 10180 Telesis Court, Suite 365, San Diego, CA 92121

NA yangyunsong@huawei.com

Zhou Lan F1-17, Huawei Base, Bantian,

SHenzhen +86-18565826350 Lanzhou1@huawei.com

Junghoon Suh 303 Terry Fox, Suite 400 Kanata, Ottawa, Canada

Junghoon.Suh@huawei.com

Jiayin Zhang 5B-N8, No.2222 Xinjinqiao

Road, Pudong, Shanghai +86-18601656691 zhangjiayin@huawei.com

1

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A. Asterjadhi, H. Choi, et. al.

doc.: IEEE 802.11-15/0880r2

Submission Slide 6

Authors (continued)Name Affiliation Address Phone email

Thomas Derham Orange

thomas.derham@orange.com

1 Yasushi Takatori

NTT

1-1 Hikari-no-oka, Yokosuka, Kanagawa 239-0847 Japan

takatori.yasushi@lab.ntt.co.jp

Yasuhiko Inoue inoue.yasuhiko@lab.ntt.co.jp

Yusuke Asai asai.yusuke@lab.ntt.co.jp

Koichi Ishihara ishihara.koichi@lab.ntt.co.jp

Akira Kishida kishida.akira@lab.ntt.co.jp

Akira Yamada

NTT DOCOMO

3-6, Hikarinooka, Yokosuka-shi, Kanagawa, 239-8536,

Japan yamadaakira@nttdocomo.co

m

Fujio Watanabe 3240 Hillview Ave, Palo

Alto, CA 94304 watanabe@docomoinnovatio

ns.com

Haralabos Papadopoulos

hpapadopoulos@docomoinnovations.com

1 Fei Tong

Samsung

Innovation Park, Cambridge CB4 0DS (U.K.)

+44 1223 434633 f.tong@samsung.com

Hyunjeong Kang Maetan 3-dong; Yongtong-Gu

Suwon; South Korea +82-31-279-9028 hyunjeong.kang@samsung.co

m

Kaushik Josiam 1301, E. Lookout Dr, Richardson TX 75070

(972) 761 7437 k.josiam@samsung.com

Mark Rison Innovation Park,

Cambridge CB4 0DS (U.K.) +44 1223 434600 m.rison@samsung.com

Rakesh Taori 1301, E. Lookout Dr, Richardson TX 75070

(972) 761 7470 rakesh.taori@samsung.com

Sanghyun Chang Maetan 3-dong; Yongtong-Gu

Suwon; South Korea +82-10-8864-

1751 s29.chang@samsung.com

1

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doc.: IEEE 802.11-15/0880r2

Submission Slide 7

Authors (continued)

Name Affiliation Address Phone email

Bo Sun

ZTE

#9 Wuxingduan, Xifeng Rd Xian, China

sun.bo1@zte.com.cn

Kaiying Lv lv.kaiying@zte.com.cn

Yonggang Fang

Ke Yao

Weimin Xing

Brian Hart Cisco Systems

170 W Tasman Dr, San Jose, CA 95134

brianh@cisco.com

Pooya Monajemi pmonajem@cisco.com

Joonsuk Kim

Apple

joonsuk@apple.com

Aon Mujtaba mujtaba@apple.com

Guoqing Li guoqing_li@apple.com

Eric Wong ericwong@apple.com

Chris Hartman chartman@apple.com

1

July 2015

A. Asterjadhi, H. Choi, et. al.

doc.: IEEE 802.11-15/0880r2

Submission

Introduction

• MU procedures are under discussion in 11ax– The AP enables multiple STAs to transmit UL frames via Trigger frames (TFs)– MU STAs wait for the TF prior to transmitting UL frames

• Upon reception of a TF intended to them they can transmit to the AP

• In this presentation we focus on trigger frame scheduling with TWT signaling [1]– This way we also enable other useful operation modes for power save that fit in the

11ax use cases• I.e., STAs wake up only in the allocated TWT SP and can sleep outside of them

• For simplicity, we focus on the implicit TWT operation which enables:– “Broadcast” TWT: Scheduled by the AP, irrespective of TWT requests, and indicated

in the Beacon for multiple STAs (a generic scheduling mechanism that covers operation in [1])

– “Solicited” TWT: Scheduled by the AP, accounting for the STA’s TWT request

July 2015

Slide 8 A. Asterjadhi, H. Choi, et. al.

doc.: IEEE 802.11-15/0880r2

Submission

Basics of Trigger TWTs

• “Broadcast” trigger TWT:– AP indicates the target trigger times in a TWT response included in the Beacon

• The pattern can be periodic, aperiodic (i.e., single indication for multiple Trigger frames)– The pattern is only valid for the Beacon Interval following the Beacon.

• The AP can indicate the broadcast trigger TWTs during a TWT Setup

• “Solicited” trigger TWT:– A STA requests the AP to schedule TFs (using TWT request)

• TWT pattern is based on STA’s UL traffic pattern and QoS requirements– The pattern can be periodic or aperiodic

– The AP responds confirming or providing alternative TWT schedules• The AP allocates its resources based on multiple STA’s information

– STAs with similar traffic pattern can be allocated in similar TWTs, with similar TWT service periods (SPs), and other similar parameters

July 2015

Slide 9

Beacon

TF

Next TWT Beacon

TF

TF

TF

TWT element: Implicit TWT, Next TWT, TWT Wake Interval

TWT Wake Interval

DL/ULMU

DL/ULMU

DL/ULMU

DL/ULMU

A. Asterjadhi, H. Choi, et. al.

doc.: IEEE 802.11-15/0880r2

Submission

Solicited Trigger TWT

• Trigger TWT setup (negotiated):– Setup of TWT parameters is the same as for basic TWT operation with the following additions:

• The HE non-AP STA may request scheduling of a TF at the start of each TWT• The AP confirms scheduling of a TF at the start of each TWT

• Trigger TWT operation:– AP schedules a TF at the beginning of each TWT SP– Non-AP STAs wake up at the TWT, wait for the TF and get ready for MU DL/UL exchange

• STAs are not supposed to contend during the TWT SP but rather wait for the TFs sent by the AP• During the TWT SP, STAs can exchange PS-Polls, APSD trigger frames, UL/DL BUs, etc. upon reception

of TFs.

• STAs that negotiate TWT need not wake up to read the Beacon frame– DL BU availability is notified during the TWT SP itself.– STAs can renegotiate their TWTs when a traffic pattern changes

July 2015

Slide 10

STA 1 STA 2 Poll 4Poll 2

Trigger

Poll 1

STA 4

TWT Wake Interval

TWT SP

Next TWT(s)TWT Setup(s)

Ack

Trigger

BU 1BU 2BU 4

BA 1

BA 2BA 4

A. Asterjadhi, H. Choi, et. al.

doc.: IEEE 802.11-15/0880r2

Submission

Broadcast Trigger TWT

• TWT setup for broadcast trigger TWT– TWT request/response can be exchanged by a STA and an AP to negotiate the target Beacon

frame monitored by the PS STA.– Example of operation

• A STA sends a TWT Request to request the broadcast trigger TWT operation. • An AP sends a TWT Response including the Target Wake Time set to the target TBTT and TWT Wake

Interval set to the ListenInterval of the STA.• A STA monitors the Beacon frame with the period of TWT Wake Interval (ListenInterval) from the time of

Target Wake Time (target TBTT).• If a STA receives the target trigger times in a TWT response included in the Beacon, the STA may save its

power till the time and the STA wakes up at the target trigger time to receive the Trigger frame.• Otherwise, the STA save its power according to TWT Wake Interval.

– Note. It is applicable to PS STAs which should monitor the TIM Beacon frame with certain periodicity.

July 2015

Slide 11

AP

STA1, STA2

Target trans. Time 1

SIFS

Awake State

SIFS

STA1, STA2 STA1, STA2

TWT Req

TIMBeacon

TWT Res

TFDL MU Data

UL MUPS-Poll

▪ ▪ ▪

▪ ▪ ▪

▪ ▪ ▪

▪ ▪ ▪

TIMBeacon

TIMBeacon

Target TBTT Listen Interval

(Target TBTT, Listen Interval)

Doze Doze Doze Doze

A. Asterjadhi, H. Choi, et. al.

doc.: IEEE 802.11-15/0880r2

Submission

Benefits of TWTs

• TWT scheduling improves power saving for the SU case as exemplified in [1]– It also eases contention as the STAs should not access the medium outside the TWT

SPs

• For the MU case, the STA indicates/negotiates with the AP:– The TWT SPs during which it is active and the rest of the times during which it is

inactive• Similar benefits to the SU case: STAs save power, eases channel contention,

– To send TFs at the start of the TWT SPs• Enables MU operation during the TWT SP and protects the medium access for the STA

– Increases throughput as transmissions are protected at the receiver– Increases network efficiency due to MU transmissions and reducing collisions

• The AP uses the TWT scheduling to:– Spread out the wake up and access times of the STAs easing contention – Allocate MU resources more efficiently (as it can be based on received feedback)

• Avoids allocating resources to STAs with no UL data

July 2015

Slide 12 A. Asterjadhi, H. Choi, et. al.

doc.: IEEE 802.11-15/0880r2

Submission

TWT element

• Define a Triggered subfield in the Request Type field of the TWT element:– Set to 1 in a TWT Request to request for a TF at the start of the TWT– Set to 1 in a TWT Response to indicate that a TF will be scheduled at the start of the TWT

• Most of the use cases for 11ax seem to be covered by implicit TWT setup– So suggestion is that for 11ax the Implicit field of the TWT element be set to 1

• Some more evaluations are needed to understand the benefits of explicit TWT– Which requires the use of TACK/STACK/BAT frames

– Hence, here we focus only on the implicit TWT

July 2015

Slide 13

  B0 B1 B3 B4 B5 B6 B7 B9 B10  B14 B15

  TWT Request

TWT Setup Command

ReservedTriggered Implicit Flow Type TWT Flow

IdentifierWake Interval

Exponent TWT Protection

Bits: 1 3 1 1 1 3 5 1

  Element ID Length Control Request

Type

TargetWake Time

TWT Group

Assignment

Nominal Minimum

Wake Duration

TWT Wake Interval Mantissa

TWT Channel

NDP Paging

(optional)

Octets: 1 1 1 2 8 or 0 9 or 3 or 0 1 2 1 0 or 4

A. Asterjadhi, H. Choi, et. al.

doc.: IEEE 802.11-15/0880r2

Submission

Summary of Trigger TWT

• Define implicit TWT operation for 11ax that enables:– Solicited TWT:

• STA and the AP negotiate the TWT parameters– STA sends TWT request and AP responds with a TWT response

– Broadcast TWT: • AP indicates to STAs the TWT parameters

– AP sends TWT response to the STAs without receiving TWT requests

• The proposed Trigger TWT procedure– Inherits the power saving properties of the TWT protocol [1]

July 2015

Slide 14 A. Asterjadhi, H. Choi, et. al.

doc.: IEEE 802.11-15/0880r2

Submission

Straw Poll #1 • Do you support to add the following text in the SFD:

– The spec shall include a mechanism that allows a target transmission time for a Trigger frame to be indicated. The mechanism is based on implicit TWT operation and additionally enables:• Broadcast triggered TWT by including a TWT element in the Beacon• Solicited triggered TWT by using implicit TWT negotiation procedure

• Yes• No• Abstain

Slide 15

July 2015

A. Asterjadhi, H. Choi, et. al.

doc.: IEEE 802.11-15/0880r2

Submission

Straw Poll #2

• Do you support to add the following text in the SFD:– When the broadcast triggered TWT is enabled, STA and AP may exchange

TWT request/response to indicate the target Beacon frame to be monitored by the PS STA.

• Yes• No• Abstain

July 2015

Slide 16 A. Asterjadhi, H. Choi, et. al.

doc.: IEEE 802.11-15/0880r2

Submission

References

[1] M. Fischer (Broadcom) et. al., 11-12-0823-00-00ah-targetwaketime

Slide 17

July 2015