doc.: IEEE /1058r0September 2015 SubmissionSlide 1 CCA consideration for UL MU transmission Date: Kiseon Ryu et al. (LG) NameAffiliationAddressPhone Kiseon Ryu LG Electronics 19, Yangjae-daero 11gil, Seocho-gu, Seoul , Korea Jinyoung Chun Jinsoo Choi Jeongki Kim Giwon Park Dongguk Lim Suhwook Kim Eunsung Park Hyeyoung Choi Hyunhee Park HanGyu Cho Authors:

Intel Corporation. All rights reserved. 2 Intel Labs Wireless Communication Lab, Intel Labs 2 Intel Confidential Submission doc.: IEEE /1058r0 September 2015 Slide 2 Robert Stacey Intel 2111 NE 25th Ave, Hillsboro OR 97124, USA Eldad Perahia Shahrnaz Azizi Po-Kai Huang Qinghua Li Xiaogang Chen Chitto Ghosh Laurent cariou Rongzhen Yang NameAffiliation AddressPhone Ron Porat Broadcom Sriram Venkateswaran Matthew Fischer Leo Montreuil Andrew Blanksby Vinko Erceg Authors (continued)

Intel Corporation. All rights reserved. 3 Intel Labs Wireless Communication Lab, Intel Labs 3 Intel Confidential Submission doc.: IEEE /1058r0 September 2015 Slide 3 Authors (continued) NameAffiliationAddressPhone Hongyuan Zhang Marvell 5488 Marvell Lane, Santa Clara, CA, Yakun Sun Lei Wang Liwen Chu Jinjing Jiang Yan Zhang Rui Cao Jie Huang Sudhir Srinivasa Saga Tamhane Mao Yu Edward Au Hui-Ling Lou

Intel Corporation. All rights reserved. 4 Intel Labs Wireless Communication Lab, Intel Labs 4 Intel Confidential Submission doc.: IEEE /1058r0 September 2015 Slide 4 Authors (continued) NameAffiliationAddressPhone Albert Van Zelst Qualcomm Straatweg 66-S Breukelen, 3621 BR Netherlands Alfred Asterjadhi 5775 Morehouse Dr. San Diego, CA, USA Bin Tian 5775 Morehouse Dr. San Diego, CA, USA Carlos Aldana 1700 Technology Drive San Jose, CA 95110, USA George Cherian 5775 Morehouse Dr. San Diego, CA, USA Gwendolyn Barriac 5775 Morehouse Dr. San Diego, CA, USA Hemanth Sampath 5775 Morehouse Dr. San Diego, CA, USA Menzo Wentink Straatweg 66-S Breukelen, 3621 BR Netherlands Richard Van Nee Straatweg 66-S Breukelen, 3621 BR Netherlands Rolf De Vegt 1700 Technology Drive San Jose, CA 95110, USA Sameer Vermani 5775 Morehouse Dr. San Diego, CA, USA Simone Merlin 5775 Morehouse Dr. San Diego, CA, USA Tevfik Yucek 1700 Technology Drive San Jose, CA 95110, USA VK Jones 1700 Technology Drive San Jose, CA 95110, USA Youhan Kim 1700 Technology Drive San Jose, CA 95110, USA

Intel Corporation. All rights reserved. 5 Intel Labs Wireless Communication Lab, Intel Labs 5 Intel Confidential Submission doc.: IEEE /1058r0 September 2015 Slide 5 Authors (continued) NameAffiliationAddressPhone James Yee Mediatek No. 1 Dusing 1 st Road, Hsinchu, Taiwan Alan Jauh Chingwa Hu m Frank Hsu Thomas Pare Mediatek USA 2860 Junction Ave, San Jose, CA 95134, USA ChaoChun Wang om James Wang Jianhan Liu Tianyu Wu Russell Huang m Joonsuk Kim Apple Aon Mujtaba Guoqing Li Eric Wong Chris Hartman

Intel Corporation. All rights reserved. 6 Intel Labs Wireless Communication Lab, Intel Labs 6 Intel Confidential Submission doc.: IEEE /1058r0 September 2015 Slide 6 Authors (continued) NameAffiliationAddressPhone Phillip Barber Huawei The Lone Star State, TX ch.com Peter Loc Le Liu F1-17, Huawei Base, Bantian, Shenzhen Jun Luo 5B-N8, No.2222 Xinjinqiao Road, Pudong, Shanghai Yi Luo F1-17, Huawei Base, Bantian, Shenzhen Yingpei Lin 5B-N8, No.2222 Xinjinqiao Road, Pudong, Shanghai Jiyong Pang 5B-N8, No.2222 Xinjinqiao Road, Pudong, Shanghai Zhigang Rong Telesis Court, Suite 365, San Diego, CA NA Rob Sun 303 Terry Fox, Suite 400 Kanata, Ottawa, Canada David X. Yang F1-17, Huawei Base, Bantian, Shenzhen Yunsong Yang Telesis Court, Suite 365, San Diego, CA NA Zhou Lan F1-17, Huawei Base, Bantian, SHenzhen Junghoon Suh 303 Terry Fox, Suite 400 Kanata, Ottawa, Canada Jiayin Zhang 5B-N8, No.2222 Xinjinqiao Road, Pudong, Shanghai

Intel Corporation. All rights reserved. 7 Intel Labs Wireless Communication Lab, Intel Labs 7 Intel Confidential Submission doc.: IEEE /1058r0 September 2015 Slide 7 Authors (continued) NameAffiliationAddressPhone 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 (972) Mark Rison Innovation Park, Cambridge CB4 0DS (U.K.) Rakesh Taori 1301, E. Lookout Dr, Richardson TX (972) Sanghyun Chang Maetan 3-dong; Yongtong-Gu Suwon; South Korea Yasushi Takatori NTT 1-1 Hikari-no-oka, Yokosuka, Kanagawa Japan Yasuhiko Inoue Yusuke Asai Koichi Ishihara Junichi Iwatani Shoko Shinohara Akira Yamada NTT DOCOMO 3-6, Hikarinooka, Yokosuka- shi, Kanagawa, , Japan Fujio Watanabe 3240 Hillview Ave, Palo Alto, CA com Haralabos Papadopoulos tions.com

Intel Corporation. All rights reserved. 8 Intel Labs Wireless Communication Lab, Intel Labs 8 Intel Confidential Submission doc.: IEEE /1058r0 September 2015 Slide 8 Authors (continued) NameAffiliationAddressPhone Yuichi Morioka Sony Corporation Konan Minato-ku, Tokyo , Japan Masahito Mori Yusuke Tanaka Kazuyuki Sakoda m William Carney 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 Pooya Monajemi Thomas DerhamOrange

Intel Corporation. All rights reserved. 9 Intel Labs Wireless Communication Lab, Intel Labs 9 Intel Confidential Submission doc.: IEEE /1058r0 September 2015 Introduction (1/2) Kiseon Ryu et al. (LG) Slide 9 11ax SFD [1]: –An UL MU PPDUs (MU-MIMO or OFDMA) is sent as an immediate response (IFS TBD) to a Trigger frame (format TBD) sent by the AP. Currently, the operation of STA for responding to a trigger frame is not clearly defined. –Should STA check the CCA before UL MU transmission or not?

Intel Corporation. All rights reserved. 10 Intel Labs Wireless Communication Lab, Intel Labs 10 Intel Confidential Submission doc.: IEEE /1058r0 September 2015 Why is CCA needed for UL MU Transmission? Kiseon Ryu et al. (LG) Slide 10 11ax UL MU, CCA is done at AP for transmitting the Trigger; what about CCA at UL transmitter? –Need to limit interference to ongoing neighboring STA’s transmissions UL MU interference energy with aggregated power from multiple STAs can be higher than SU UL MU response transmission are longer than usual responses (ACK/BAs), up to the TXOP limit Therefore, CCA check needs to be considered for UL MU transmission. But, the question is whether STA always checks CCA before UL MU transmission.

Intel Corporation. All rights reserved. 11 Intel Labs Wireless Communication Lab, Intel Labs 11 Intel Confidential Submission doc.: IEEE /1058r0 September 2015 Various UL MU transmission modes 11ax supports various UL MU transmission modes –A Standalone Trigger frame in a TXOP –DL/UL cascading TXOP structure –Multiple Trigger frames in a TXOP Kiseon Ryu et al. (LG) Slide 11 UL MU PPDUTrigger TXOP AP Gains the channel access DL ULDL ACK /BA UL MU PPDUTrigger + DL MU Data TXOP AP Gains the channel access DLULDL ACK /BA UL MU PPDUTrigger TXOP AP Gains the channel access DL ULDL ACK /BA UL MU PPDUTrigger DL ULDL ACK /BA

Intel Corporation. All rights reserved. 12 Intel Labs Wireless Communication Lab, Intel Labs 12 Intel Confidential Submission doc.: IEEE /1058r0 September 2015 How to check CCA for UL MU transmission Option 1: check the CCA before the Trigger frame –Signal detection and energy detection are allowed –Standalone Trigger frame in a TXOP can be applied Option 2: check the energy during the xIFS between the Trigger frame and the UL MU PPDU –Only energy detection is allowed –DL/UL cascading TXOP structure and Multiple Trigger frames in a TXOP can be applied Kiseon Ryu et al. (LG) Slide 12 UL MU PPDUTrigger CCACCA CCACCA UL MU PPDU Trigger CCACCA CCACCA

Intel Corporation. All rights reserved. 13 Intel Labs Wireless Communication Lab, Intel Labs 13 Intel Confidential Submission doc.: IEEE /1058r0 September 2015 When to check CCA for UL MU transmission Option 1: Always check CCA – When a STA receives a Trigger frame, it will respond with PPDU using the idle channel by checking CCA. Option 2: Check CCA under TBD condition – When a STA receives a Trigger frame, it will respond with considering CCA in the channel under TBD condition – For TBD condition, we should consider the various UL MU scenarios such as the following trigger response frame types and the UL MU PPDU length ACK/BA: CCA may not be needed Data frame, simultaneous CTS: CCA may be needed Short MAC control frame (e.g., Buffer status report, BF feedback, PS-Poll) : CCA may or may not be needed UL MU PPDU protected by RTS/CTS: CCA may not be needed Option 2 is preferred to support various UL MU scenarios. Kiseon Ryu et al. (LG) Slide 13

Intel Corporation. All rights reserved. 14 Intel Labs Wireless Communication Lab, Intel Labs 14 Intel Confidential Submission doc.: IEEE /1058r0 September 2015 Conclusion To avoid severe interference to OBSS on-going transmission, UL MU STA should consider CCA before sending UL MU PPDU. –When to check CCA is TBD –How to check CCA is TBD Kiseon Ryu et al. (LG) Slide 14

Intel Corporation. All rights reserved. 15 Intel Labs Wireless Communication Lab, Intel Labs 15 Intel Confidential Submission doc.: IEEE /1058r0 September 2015 Reference [1] IEEE /0132r7 “Specification Framework for TGax” Kiseon Ryu et al. (LG) Slide 15

Intel Corporation. All rights reserved. 16 Intel Labs Wireless Communication Lab, Intel Labs 16 Intel Confidential Submission doc.: IEEE /1058r0 September 2015 Straw poll Do you agree to add to the SFD? 4 Multi-user (MU) features 4.1 General STA shall consider CCA to respond to a Trigger frame under a non-null TBD set of conditions. Yes: No: Abstain: Kiseon Ryu et al. (LG) Slide 16