1. Fragmentation for MU frames – Follow
Date:
Name
Affiliation
Address
Phone
Alfred Asterjadhi
Qualcomm
5775 Morehouse Dr. San Diego, CA, USA
Albert Van Zelst
Straatweg 66-S Breukelen, 3621 BR Netherlands
Alice Chen
Arjun Bharadwaj
Bin Tian
Carlos Aldana
1700 Technology Drive San Jose, CA 95110, USA
George Cherian
Gwendolyn Barriac
Hemanth Sampath
Lin Yang
Menzo Wentink
Naveen Kakani
2100 Lakeside Boulevard Suite 475, Richardson TX 75082, USA
Raja Banerjea
1060 Rincon Circle San Jose CA 95131, USA
Richard Van Nee
A. Asterjadhi (Qualcomm), et. al.,

2. Authors (continued) Rolf De Vegt Qualcomm Sameer Vermani Simone Merlin
Name
Affiliation
Address
Phone
Rolf De Vegt
Qualcomm
1700 Technology Drive San Jose, CA 95110, USA
Sameer Vermani
5775 Morehouse Dr. San Diego, CA, USA
Simone Merlin
Tao Tian
Tevfik Yucek  
VK Jones
Youhan Kim
Robert Stacey
Intel
2111 NE 25th Ave, Hillsboro OR 97124, USA     
Shahrnaz Azizi
Po-Kai Huang
Qinghua Li
Xiaogang Chen
Chitto Ghosh
Laurent Cariou
Yaron Alpert
Assaf Gurevitz
Ilan Sutskover
A. Asterjadhi (Qualcomm), et. al.,

3. Authors (continued) Hongyuan Zhang Marvell
Name
Affiliation
Address
Phone
Hongyuan Zhang
Marvell
5488 Marvell Lane, Santa Clara, CA, 95054
Yakun Sun
Lei Wang
Liwen Chu
Jinjing Jiang
Yan Zhang
Rui Cao
Sudhir Srinivasa
Bo Yu
Saga Tamhane
Mao Yu
Xiayu Zheng
Christian Berger
Niranjan Grandhe
Hui-Ling Lou
A. Asterjadhi (Qualcomm), et. al.,

4. No. 1 Dusing 1st Road, Hsinchu, Taiwan +886-3-567-0766 Alan Jauh
Name
Affiliation
Address
Phone
James Yee
Mediatek
No. 1 Dusing 1st Road, Hsinchu, Taiwan  
Alan Jauh
Chingwa Hu
Frank Hsu
Thomas Pare
USA
2860 Junction Ave, San Jose, CA 95134, USA
ChaoChun Wang
James Wang
Jianhan Liu
Tianyu Wu
Zhou Lan
Russell Huang
Joonsuk Kim
Apple
Aon Mujtaba  
Guoqing Li
Eric Wong
Chris Hartman
A. Asterjadhi (Qualcomm), et. al.,

5. Authors (continued) Peter Loc Huawei Le Liu Jun Luo Yi Luo Yingpei Lin
Name
Affiliation
Address
Phone
Peter Loc
Huawei
Le Liu
F1-17, Huawei Base, Bantian, Shenzhen
Jun Luo
5B-N8, No.2222 Xinjinqiao Road, Pudong, Shanghai
Yi Luo
Yingpei Lin
Jiyong Pang
Zhigang Rong
10180 Telesis Court, Suite 365, San Diego, CA  NA
Rob Sun
303 Terry Fox, Suite 400 Kanata, Ottawa, Canada
David X. Yang
Yunsong Yang
Junghoon Suh
Jiayin Zhang
Edward Au
Teyan Chen
Yunbo Li
A. Asterjadhi (Qualcomm), et. al.,

6. Authors (continued) Jinmin Kim LG Electronics
Name
Affiliation
Address
Phone
Jinmin Kim
LG Electronics
19, Yangjae-daero 11gil, Seocho-gu, Seoul , Korea
Kiseon Ryu
Jinyoung Chun
Jinsoo Choi
Jeongki Kim
Dongguk Lim
Suhwook Kim
Eunsung Park
JayH Park
HanGyu Cho
Thomas Derham
Orange
Bo Sun
ZTE
#9 Wuxingduan, Xifeng Rd., Xi'an, China
Kaiying Lv
Yonggang Fang
Ke Yao
Weimin Xing
Brian Hart
Cisco Systems
170 W Tasman Dr, San Jose, CA 95134
Pooya Monajemi
A. Asterjadhi (Qualcomm), et. al.,

7. Authors (continued) Fei Tong Samsung Hyunjeong Kang Kaushik Josiam
Name
Affiliation
Address
Phone
Fei Tong
Samsung
Innovation Park, Cambridge CB4 0DS (U.K.)
Hyunjeong Kang
Maetan 3-dong; Yongtong-Gu Suwon; South Korea
Kaushik Josiam
1301, E. Lookout Dr, Richardson TX 75070
(972)
Mark Rison
Rakesh Taori
(972)
Sanghyun Chang
Yasushi Takatori
NTT
1-1 Hikari-no-oka, Yokosuka, Kanagawa Japan
Yasuhiko Inoue
Shoko Shinohara
Yusuke Asai
Koichi Ishihara
Junichi Iwatani
Akira Yamada
NTT DOCOMO
3-6, Hikarinooka, Yokosuka-shi, Kanagawa, , Japan
Fujio Watanabe
3240 Hillview Ave, Palo Alto, CA 94304
Haralabos Papadopoulos
A. Asterjadhi (Qualcomm), et. al.,

8. Authors (continued) Name Affiliation Ron Porat Broadcom
Address
Phone
Ron Porat
Broadcom
Sriram Venkateswaran
Matthew Fischer
Leo Montreuil
Andrew Blanksby
Vinko Erceg
Masahito Mori
Sony Corp.
Yusuke Tanaka
Yuichi Morioka
Kazuyuki Sakoda
William Carney
A. Asterjadhi (Qualcomm), et. al.,

9. Introduction
MU TXOP 1
MU TXOP 2 … AP
Trigger
Trigger BA
MPDU
F-MPDU
F-MPDU …
MPDU
F-MPDU
STA1
STA2
STA3
Allowing fragmentation within A-MPDUs was discussed in [1]
Passed motion in the last F2F:
“The spec shall support fragmentation negotiation in A-MPDUs for HE STAs.”
Fragments within A-MPDUs are beneficial for 11ax:
As an efficient way of using the allocated resources in MU operation
Aggregate fragments in an A-MPDU instead of padding as much as possible
As a means of closing the uplink for limited range devices
Transmit a fragment in an UL resource that is insufficient for a full MSDU
Dealing with fragments brings additional complexity to the system
Need for generating fragments on the fly, (e.g., within IFS after trigger), processing/memory requirements etc.
A. Asterjadhi (Qualcomm), et. al.,

10. Proposal We propose the fragmentation levels* that can be negotiated
Level 0 - No Support for fragments - (Level 0)
Level 1 - Support for fragments as a “VHT” single MPDU only
Level 2 - Support for single fragment of an MSDU per A-MPDU
Level 3 - Support for multiple fragments of an MSDU per A-MPDU
By enabling the STAs to negotiate different levels of fragmentation
It is possible to achieve a good trade-off between benefits and complexity
Enabling an implementation-friendly design
* Note: STAs operate using up to the agreed level of fragmentation
A. Asterjadhi (Qualcomm), et. al.,

11. Fragmentation Levels (1)
No support for fragmentation
Originator does not generate fragments
Recipient does not support reception of fragments
Pros: No added complexity because fragmentation is not supported
Cons: Padding is always needed for filling any unused RUs
Fragmentation – Level 1
Originator may aggregate one fragment of an MSDU in a “VHT” Single MPDU format
Recipient responds with an Ack to the eliciting “VHT” Single MPDU
Pros: Basic fragmentation that allows to send a fragment when the RU is not enough to send a full MSDU
Cons: Does not solve the inefficiency issue when the RU allows for multiple MSDUs plus a fragment
A. Asterjadhi (Qualcomm), et. al.,

12. Fragmentation Levels (Cont)
Originator may aggregate up to one fragment per MSDU in an A-MPDU
Recipient responds with Ack (if VHT Single MPDU) or BlockAck if A-MPDU
Pros: Can reuse HT-immediate BA signaling and solves the inefficiency issue for RU that needs padding
Cons: Cannot aggregate more than 1 fragment of an MSDU, however, it should not be a recurring issue
Fragmentation – Level 3
Originator may aggregate more than one fragment per MSDU in an A-MPDU
Pros: Allows the originator to transmit more than one fragment per MSDU in an A-MPDU
Cons: Requires extra capabilities from STAs (score maintenance, win size, etc.)
A. Asterjadhi (Qualcomm), et. al.,

13. Summary We follow up on fragmentation for MU and propose:
Different levels of fragmentation that can be negotiated to have a good trade-off between benefits and complexity
A. Asterjadhi (Qualcomm), et. al.,

14. Straw Poll 1 Do you support to add to the 11ax SFD:
The 11ax fragmentation negotiation shall allow the following fragmentation types (levels) to be indicated:
Level 0: No support for fragments
Level 1: Support for a fragment in a “VHT” single MPDU only
Level 2: Support for up to one fragment per MSDU in an A-MPDU
Level 3: Support for multiple fragments of an MSDU per A-MPDU
A. Asterjadhi (Qualcomm), et. al.,

15. References
[1] C. Ghosh (Intel) et.al., r0 Fragmentation with MU operation
A. Asterjadhi (Qualcomm), et. al.,