doc.: IEEE /1067r0 Submission September 2015 Jeongki Kim, LG ElectronicsSlide 1 MU TXOP Truncation Date: Authors: NameAffiliationAddressPhone Jeongki Kim LG Electronics 19, Yangjae-daero 11gil, Seocho-gu, Seoul , Korea Kiseon Ryu Jinsoo Choi Jinyoung Chun Suhwook Kim Hyeyoung Choi Dongguk Lim Eunsung Park Jinmin Kim HanGyu Cho

doc.: IEEE /1067r0 Submission 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) Jeongki Kim, LG ElectronicsSlide 2 September 2015

doc.: IEEE /1067r0 Submission 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 Jeongki Kim, LG ElectronicsSlide 3 September 2015

doc.: IEEE /1067r0 Submission 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 Jeongki Kim, LG ElectronicsSlide 4 September 2015

doc.: IEEE /1067r0 Submission 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 Jeongki Kim, LG ElectronicsSlide 5 September 2015

doc.: IEEE /1067r0 Submission 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 Jeongki Kim, LG ElectronicsSlide 6 September 2015

doc.: IEEE /1067r0 Submission 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 Jeongki Kim, LG ElectronicsSlide 7 September 2015

doc.: IEEE /1067r0 Submission 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 Jeongki Kim, LG ElectronicsSlide 8 September 2015

doc.: IEEE /1067r0 Submission Background (1/2) TXOP truncation in legacy system [1] –When a STA gains access to the channel using EDCA and empties its transmission queue, it may transmit a CF-End frame provided that the remaining duration is long enough to transmit this frame. –By transmitting the CF-End frame, the STA is explicitly indicating the completion of its TXOP. Jeongki Kim, LG ElectronicsSlide 9 September 2015

doc.: IEEE /1067r0 Submission Background (2/2) Example 1) DL MU procedure –If AP does not have any DL MU data in queue, the AP can send CF-End to truncate the remaining TXOP Example 2) UL MU procedure –2-1) Like DL MU, if all the MU STAs doesn’t have any data, an AP can send CF-End –2-2) If AP does not receive data from all MU STAs in response to TF, the AP can send CF-End to truncate the remaining TXOP Jeongki Kim, LG ElectronicsSlide 10 September 2015 AP2 MU STAs DL MU frames TXOP Duration Nominal end of TXOP C-E MU BA DL MU frames MU BA DL MU frames MU BA AP2 MU STAs TF: Trigger frame, C-E: CF-End, TF UL MU frames C-E TXOP Duration Nominal end of TXOP

doc.: IEEE /1067r0 Submission Motivation A CF-End frame sent by an OBSS STA can truncate the NAV set by MyBSS’s frame –When a NAV is reset(0), if a channel is idle, a STA can send a frame It will affect the on-going transmission of MyBSS’s frame It will happen more often in 11ax because 11ax considers UL MU procedure and assumes the dense environment (i.e., a lot of OBSSs) We provide a simple rule to avoid resetting the NAV set by myBSS frame due to an OBSS CF- End frame Jeongki Kim, LG ElectronicsSlide 11 September 2015 AP2 (BSS2) MU STAs STA3 TF: Trigger frame, C-E: CF-End AP1 (BSS1) STAs TF UL MU frames MU BA 2) NAV resetting by CF-End 1) NAV set by TF C-E Frames Collision

doc.: IEEE /1067r0 Submission Proposal (1/2) In legacy system, a STA saves the TXOP holder address and uses the saved TXOP holder address for responding with the CTS after receiving RTS –“A STA shall save the TXOP holder address for the BSS in which it is associated, which is the MAC address from the Address 2 field of the frame that initiated a frame exchange sequence except when this is a CTS frame, in which case the TXOP holder address is the Address 1 field.” –“If a STA receives an RTS frame with the RA address matching the MAC address of the STA and the MAC address in the TA field in the RTS frame matches the saved TXOP holder address, then the STA shall send the CTS frame after SIFS, without regard for, and without resetting, its NAV.” We can reuse it for TXOP truncation Jeongki Kim, LG ElectronicsSlide 12 September 2015

doc.: IEEE /1067r0 Submission Proposal (2/2) Proposed method: When a STA receives a CF-End from an OBSS STA, if the last NAV update was caused by a Intra- BSS frame, the STA should not reset its NAV Jeongki Kim, LG ElectronicsSlide 13 September ) TA (AP1) of CF-End doesn’t match TXOP holder address(AP2), Not reset NAV 1) NAV updated by TF Save TXOP holder address(AP2) AP2 (BSS2) MU STAs STA3 TF: Trigger frame, C-E: CF-End AP1 (BSS1) STAs TF UL MU frames MU BA C-E

doc.: IEEE /1067r0 Submission Conclusion We propose a simple rule of truncating the MU TXOP set by TF of myBSS –A STA that receives a CF-End does not reset its NAV unless the NAV was set by a frame originating from the STA sending a CF- End frame It can protect the TXOP set by a my-BSS frame from OBSS TXOP truncation Jeongki Kim, LG ElectronicsSlide 14 September 2015

doc.: IEEE /1067r0 Submission Reference [1] IEEE REVmc_D4.0 Jeongki Kim, LG ElectronicsSlide 15 September 2015

doc.: IEEE /1067r0 Submission Straw Poll Do you agree to add the following text in SFD? –When a STA receives a CF-End from an OBSS STA, if the last NAV update was caused by a Intra-BSS frame, the STA should not reset its NAV Jeongki Kim, LG ElectronicsSlide 16 September 2015