doc.: ieee 802.11-15/0880r2 submission scheduled trigger frames july 2015 slide 1 date: 2015-07-04...
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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
Simone Merlin [email protected]
Bin Tian [email protected]
Carlos Aldana 1700 Technology Drive San
Jose, CA 95110, USA [email protected]
George Cherian 5775 Morehouse Dr. San
Diego, CA, USA
Gwendolyn Barriac [email protected]
Hemanth Sampath [email protected]
Menzo Wentink
Straatweg 66-S Breukelen, 3621 BR Netherlands
Richard Van Nee [email protected]
Albert Van Zelst [email protected]
Rolf De Vegt 1700 Technology Drive San
Jose, CA 95110, USA [email protected]
Sameer Vermani 5775 Morehouse Dr. San
Diego, CA, USA [email protected]
Tevfik Yucek 1700 Technology Drive San
Jose, CA 95110, USA
VK Jones [email protected]
Youhan Kim [email protected]
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 [email protected]
Hyeyouong Choi [email protected]
Jinyoung Chun [email protected]
Jinsoo Choi [email protected]
Jeongki Kim [email protected]
Giwon Park [email protected]
Dongguk Lim [email protected]
Suhwook Kim [email protected]
Eunsung Park [email protected]
HanGyu Cho [email protected]
Jinmin Kim [email protected]
Shahrnaz Azizi
Intel
2200 Mission College Blvd, Santa Clara, CA 95054
Eldad Perahia [email protected]
Robert Stacey 2111 NE 25th Ave, Hillsboro
OR 97124, USA +1-503-724-893 [email protected]
Po-Kai Huang [email protected]
Qinghua Li [email protected]
Xiaogang Chen [email protected]
Chittabrata Ghosh [email protected]
Rongzhen Yang [email protected]
Laurent cariou [email protected]
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
Matthew Fischer [email protected]
Sriram Venkateswaran
Tu Nguyen
Vinko Erceg
Lei Wang
Marvell
5488 Marvell Lane, Santa Clara, CA, 95054
858-205-7286 [email protected]
Hongyuan Zhang
Yakun Sun [email protected]
Liwen Chu [email protected]
Jinjing Jiang [email protected]
Yan Zhang [email protected]
Rui Cao [email protected]
Sudhir Srinivasa [email protected]
Saga Tamhane [email protected]
Mao Yu [email protected]
Edward Au [email protected]
Hui-Ling Lu [email protected]
1
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A. Asterjadhi, H. Choi, et. al.
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Submission Slide 4
Authors (continued)
James Yee
Mediatek
No. 1 Dusing 1st Road, Hsinchu, Taiwan
+886-3-567-0766 [email protected]
Alan Jauh [email protected]
Chingwa Hu [email protected]
Frank Hsu [email protected]
` 1 Thomas Pare
Mediatek USA
2860 Junction Ave, San Jose, CA 95134, USA
+1-408-526-1899 [email protected]
ChaoChun Wang [email protected]
James Wang [email protected]
Jianhan Liu [email protected]
Tianyu Wu [email protected]
Russell Huang [email protected]
` 1
Name Affiliation Address Phone email
1
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A. Asterjadhi, H. Choi, et. al.
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Submission Slide 5
Authors (continued)
Name Affiliation Address Phone email
Phillip Barber
Huawei
The Lone Star State, TX [email protected]
Peter Loc [email protected]
Le Liu F1-17, Huawei Base, Bantian,
Shenzhen +86-18601656691 [email protected]
Jun Luo 5B-N8, No.2222 Xinjinqiao
Road, Pudong, Shanghai [email protected]
Yi Luo F1-17, Huawei Base, Bantian,
Shenzhen +86-18665891036 [email protected]
Yingpei Lin 5B-N8, No.2222 Xinjinqiao
Road, Pudong, Shanghai [email protected]
Jiyong Pang 5B-N8, No.2222 Xinjinqiao
Road, Pudong, Shanghai [email protected]
Zhigang Rong 10180 Telesis Court, Suite 365, San Diego, CA 92121
Rob Sun 303 Terry Fox, Suite 400 Kanata, Ottawa, Canada
David X. Yang F1-17, Huawei Base, Bantian,
Shenzhen [email protected]
Yunsong Yang 10180 Telesis Court, Suite 365, San Diego, CA 92121
Zhou Lan F1-17, Huawei Base, Bantian,
SHenzhen +86-18565826350 [email protected]
Junghoon Suh 303 Terry Fox, Suite 400 Kanata, Ottawa, Canada
Jiayin Zhang 5B-N8, No.2222 Xinjinqiao
Road, Pudong, Shanghai +86-18601656691 [email protected]
1
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A. Asterjadhi, H. Choi, et. al.
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Submission Slide 6
Authors (continued)Name Affiliation Address Phone email
Thomas Derham Orange
1 Yasushi Takatori
NTT
1-1 Hikari-no-oka, Yokosuka, Kanagawa 239-0847 Japan
Yasuhiko Inoue [email protected]
Yusuke Asai [email protected]
Koichi Ishihara [email protected]
Akira Kishida [email protected]
Akira Yamada
NTT DOCOMO
3-6, Hikarinooka, Yokosuka-shi, Kanagawa, 239-8536,
Japan [email protected]
m
Fujio Watanabe 3240 Hillview Ave, Palo
Alto, CA 94304 watanabe@docomoinnovatio
ns.com
Haralabos Papadopoulos
1 Fei Tong
Samsung
Innovation Park, Cambridge CB4 0DS (U.K.)
+44 1223 434633 [email protected]
Hyunjeong Kang Maetan 3-dong; Yongtong-Gu
Suwon; South Korea +82-31-279-9028 [email protected]
m
Kaushik Josiam 1301, E. Lookout Dr, Richardson TX 75070
(972) 761 7437 [email protected]
Mark Rison Innovation Park,
Cambridge CB4 0DS (U.K.) +44 1223 434600 [email protected]
Rakesh Taori 1301, E. Lookout Dr, Richardson TX 75070
(972) 761 7470 [email protected]
Sanghyun Chang Maetan 3-dong; Yongtong-Gu
Suwon; South Korea +82-10-8864-
1751 [email protected]
1
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Submission Slide 7
Authors (continued)
Name Affiliation Address Phone email
Bo Sun
ZTE
#9 Wuxingduan, Xifeng Rd Xian, China
Kaiying Lv [email protected]
Yonggang Fang
Ke Yao
Weimin Xing
Brian Hart Cisco Systems
170 W Tasman Dr, San Jose, CA 95134
Pooya Monajemi [email protected]
Joonsuk Kim
Apple
Aon Mujtaba [email protected]
Guoqing Li [email protected]
Eric Wong [email protected]
Chris Hartman [email protected]
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