1. In-device Multi-radio Coexistence and UL MU operation
Month Year
doc.: IEEE yy/xxxxr0
May 2016
In-device Multi-radio Coexistence and UL MU operation
Date:
Authors:
Name
Affiliation
Address
Phone
Robert Stacey
Intel
2200 Mission College Blvd., Santa Clara, CA 95054, USA    
Chittabrata Ghosh
Eldad Perahia
Shahrnaz Azizi
Po-Kai Huang
Qinghua Li
Laurent Cariou
Xiaogang Chen
Rongzhen Yang
Yaron Alpert
Avi Mansour
Robert Stacey, Intel
John Doe, Some Company

2. Authors (continued) May 2016 Albert Van Zelst Alfred Asterjadhi
Name
Affiliation
Address
Phone
Albert Van Zelst
Qualcomm
Straatweg 66-S Breukelen, 3621 BR Netherlands
Alfred Asterjadhi
5775 Morehouse Dr. San Diego, CA, USA
Bin Tian
Carlos Aldana
1700 Technology Drive San Jose, CA 95110, USA
George Cherian
Gwendolyn Barriac
Hemanth Sampath
Menzo Wentink
Richard Van Nee
Rolf De Vegt
Sameer Vermani
Simone Merlin
Tevfik Yucek  
VK Jones
Youhan Kim
Robert Stacey, Intel

3. 19, Yangjae-daero 11gil, Seocho-gu, Seoul 137-130, Korea
May 2016
Authors (continued)
Name
Affiliation
Address
Phone
Ron Porat
Broadcom
Matthew Fischer
Sriram Venkateswaran
Tu Nguyen
Vinko Erceg
Kiseon Ryu
LG Electronics
19, Yangjae-daero 11gil, Seocho-gu, Seoul , Korea  
Jinyoung Chun
Jinsoo Choi
Jeongki Kim
Suhwook Kim
Hyeyoung Choi
Dongguk Lim
Eunsung Park
Jinmin Kim
HanGyu Cho
Robert Stacey, Intel

4. Authors (continued) May 2016 Phillip Barber Peter Loc Le Liu Jun Luo
Name
Affiliation
Address
Phone
Phillip Barber
Huawei
The Lone Star State, TX
Peter Loc
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
Zhou Lan
F1-17, Huawei Base, Bantian, SHenzhen
Junghoon Suh
Jiayin Zhang
Robert Stacey, Intel

5. Authors (continued) May 2016 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
Saga Tamhane
Mao Yu
Edward Au
Hui-Ling Lou
Thomas Derham
Orange
Brian Hart
Cisco
170 W Tasman Dr, San Jose, CA 95134
Pooya Monajemi
Robert Stacey, Intel

6. Authors (continued) May 2016 Fei Tong Hyunjeong Kang Samsung
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
Yusuke Asai
Koichi Ishihara
Akira Kishida
Akira Yamada
NTT DOCOMO
3-6, Hikarinooka, Yokosuka-shi, Kanagawa, , Japan
Fujio Watanabe
3240 Hillview Ave, Palo Alto, CA 94304
Haralabos Papadopoulos
Robert Stacey, Intel

7. Authors (continued) May 2016 James Yee Mediatek
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
Russell Huang
Bo Sun
ZTE
#9 Wuxingduan, Xifeng Rd., Xi’an, China
Kaiying Lv
Yonggang Fang
Ke Yao
Weimin Xing
Robert Stacey, Intel

8. Authors (continued) May 2016 Joonsuk Kim Apple Cupertino, CA
Name
Affiliation
Address
Phone
Joonsuk Kim
Apple
Cupertino, CA    
Aon Mujtaba
Guoqing Li
Eric Wong
Chris Hartman
Robert Stacey, Intel

9. May 2016
Overview
In this contribution, we discuss in-device multi-radio coexistence and the challenges related to UL MU
We propose a simple mechanism to assist in-device coexistence
Robert Stacey, Intel

10. Overview
May 2016
11ax multi-user capabilities add new challenges for managing the effects of in device coexistence interferers
Uplink Challenges
Shared antenna designs could require dynamic disable/enable of MIMO capability
Trigger frames from AP can overlap interference windows on STA device; periodic reduction of normal Rx sensitivity
Tx power for HE trigger-based PPDUs could be limited due to dynamic coex constraints
Downlink Challenges
DL MU coex challenges are similar to legacy SU, however the triggered ACK can further increase the chances of ACK failures
For OFDMA MU BA transmissions, the AP may desire to use higher MCS to minimize the ACK durations
A higher ACK MCS makes the ACKs more sensitive to STA side periodic Tx power constraints compared to current legacy SU scenarios
Robert Stacey, Intel

11. Shared Antenna Issues May 2016
For products with shared antennas the radio does not always have priority for all antennas and dynamically may need to reduce the number of spatial streams supported
For receive, the STA can inform the AP of a change using the Receive Operating Mode A-Control field, the VHT Operating Mode Notification frame, or drop to SISO operation using SM power save
For transmit, pre-HE STAs did not have an issue as they are in full control of the transmit parameters
But an HE STA will need to follow the AP’s NSS selection in the Trigger frame
Currently no dynamic signaling exists to restrict the AP’s selection
Robert Stacey, Intel

12. STA side Coex and MU UL Operation
May 2016
STA side Coex and MU UL Operation
With UL MU operation, STA side control over the following is lost:
TXOP start timing and duration
Tx power
MCS and NSS
Without control over these aspects, the STA loses much of its ability to mitigate interference
With SU operation, the STA can avoid interference
By not transmitting during periods that another radio is receiving
By reducing the transmit power (and lowering the MCS) if another radio is receiving
Robert Stacey, Intel

13. Proposed mitigation techniques
May 2016
Proposed mitigation techniques
The simplest mitigation technique is to disable UL MU while the device has coex issues
The device would then fall back to SU operation with the full range of existing remedies available
Another approach is to signal a change in transmit operating mode
For example, signal a change in the number of transmit antennas and/or Tx power
This would constrain what Tx parameters appear in a Trigger frame
It may also help the AP select an MCS for the STA
Robert Stacey, Intel

14. Proposed mitigation techniques
May 2016
Proposed mitigation techniques
Both approaches are useful
If interference to another radio is no severe, then transmit parameters can be modified
If interference is sever or the other radio is very active then temporarily disabling MU operation and dropping to SU operation may be better
Robert Stacey, Intel

15. Straw poll #1 Do you support adding the following to the SFD: Y/N/A
May 2016
Straw poll #1
Do you support adding the following to the SFD:
The Receive Operating Mode A-Control field shall include an UL MU Disable field that allows an HE STA to suspend and resume being scheduled by a Trigger frame or UL MU resource scheduling A-Control field
Y/N/A
Robert Stacey, Intel

16. Straw poll #2 Do you support adding the following to the SFD?
Month Year
doc.: IEEE yy/xxxxr0
May 2016
Straw poll #2
Do you support adding the following to the SFD?
The Receive Operating Mode A-Control field shall include the following transmit operating parameters: max Tx NSS and max Tx power
Editorial note: we may want to change the name since it would now include transmit operating parameters
Y/N/A
Robert Stacey, Intel
John Doe, Some Company