doc.: IEEE /1137 Submission Triggered OFDMA Random Access Observations Date: Slide 1 Authors: NameAffiliationAddressPhone Russell Huang Mediatek USA 2860 Junction Ave, San Jose, CA 95134, USA ChaoChun Wang m Tianyu Wu Jianhan Liu James Wang Thomas Pare James Yee Mediatek No. 1 Dusing 1 st Road, Hsinchu, Taiwan Alan Jauh Chingwa Hu Frank Hsu Guoqing LI Apple 1 Infinite Loop Cupertino, CA USA Joonsuk Kim Eric Wong Chris Hartman September 2015 Russell Huang, MediaTek

doc.: IEEE /1137 Submission September 2015 Slide 2 NameAffiliationAddressPhone Kazuyuki Sakoda Sony Electronics m Yusuke Tanaka Eisuke Sakai Yuichi Morioka Masahito Mori Robert Stacey Intel 2111 NE 25th Ave, Hillsboro OR 97124, USA Po-Kai Huang Qinghua Li Xiaogang Chen Chitto Ghosh Rongzhen Yang Laurent cariou Authors (continued) Russell Huang, MediaTek

doc.: IEEE /1137 Submission September 2015 Slide 3 NameAffiliationAddressPhone Yakun Sun Marvell 5488 Marvell Lane, Santa Clara, CA, Hongyuan Zhang Lei Wang Liwen Chu Jinjing Jiang Yan Zhang Rui Cao Sudhir Srinivasa Saga Tamhane Mao Yu Edward Au Hui-Ling Lou Ron Porat Broadcom Matthew Fischer Sriram Venkateswaran Leo Montreuil Andrew Blanksby Vinko Erceg Authors (continued) Russell Huang, MediaTek

doc.: IEEE /1137 Submission September 2015 Slide 4 NameAffiliationAddressPhone Peter Loc Huawei 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 Authors (continued) Russell Huang, MediaTek

doc.: IEEE /1137 Submission September 2015 Slide 5 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 Authors (continued) Russell Huang, MediaTek

doc.: IEEE /1137 Submission September 2015 Slide 6 Authors (continued) NameAffiliationAddressPhone Thomas DerhamOrange Brian Hart Cisco Systems 170 W Tasman Dr, San Jose, CA Pooya Monajemi Russell Huang, MediaTek

doc.: IEEE /1137 Submission 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 Akira Kishida Akira Yamada NTT DOCOMO 3-6, Hikarinooka, Yokosuka- shi, Kanagawa, , Japan Fujio Watanabe 3240 Hillview Ave, Palo Alto, CA com Haralabos Papadopoulos tions.com Russell Huang, MediaTek

doc.: IEEE /1137 Submission September 2015 Slide 8 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 HanGyu Cho Bo Sun ZTE #9 Wuxing duan, Xifeng Rd, Xi’an, China Kaiying Lv Yonggang Fang Ke Yao Weimin Xing Authors (continued) Russell Huang, MediaTek

doc.: IEEE /1137 Submission Overview of the Triggered OFDMA Random Access STAs start UL MU operation after AP sends the trigger frames For random access cases, STAs randomly access an RU by using a certain randomization algorithm. Efficiency is one of the metrics to justify the OFDMA random access mechanisms. –Efficiency = number of resource units with successful transmission/all resource units Slide 9 September 2015 Russell Huang, MediaTek

doc.: IEEE /1137 Submission Review - CSMA vs. Slotted ALOHA Slide 10 Random access can be CSMA or slotted ALOHA CSMA/CA has better efficiency than slotted ALOHA. –Reason: CSMA uses a much smaller slot (different than slotted ALOHA’s slot) to do the carrier sensing before transmission. Using CSMA for MU OFDMA on UL complicates the receiver design. –STAs transmitting at different time in separate sub-channels is a hard problem for the design of the AP’s receiver. Slotted ALOHA in OFDMA random access. –Packets are transmitted in RUs randomly selected by STAs –With traffic following Poisson arrival, the throughput is Ge -G. (P(k=1) = λ k e - λ /k!). The optimal value is.368 September 2015 Russell Huang, MediaTek

doc.: IEEE /1137 Submission To Achieve The Best Efficiency Slide 11 Efficiency depends on the traffic load. Usually randomization is used to tune the traffic load. –36.8% of efficiency is acceptable as long as the system can achieve it consistently. Randomization approaches to tuning the traffic –Backoff mechanism (backoff counter picked in the range of 0 and CW) [1] –Transmission probability control –Etc. Overall traffic and collisions status information in OFDMA random access is difficult for individual STAs to obtain, but easy for AP. With traffic estimation, AP can determine the optimal value of the traffic tuning parameter so that optimal efficiency can be achieved. September 2015 Russell Huang, MediaTek

doc.: IEEE /1137 Submission Randomization Parameter Broadcasting Slide 12 AP broadcasts the randomization parameter(s) to the STAs, which can be –Contention window size –Transmission probability –Etc. The AP can broadcast it in –Beacons, less overhead –Trigger frame, more adaptive We propose AP broadcast the parameter(s) in the trigger frame. September 2015 Russell Huang, MediaTek

doc.: IEEE /1137 Submission Do you support to let AP broadcast a TBD parameter in the trigger frame to the STAs so that STAs can initiate the random access process after the trigger frames? –Yes –No –Abs Strawpoll 1 Slide 13 September 2015 Russell Huang, MediaTek

doc.: IEEE /1137 Submission [1] UL OFDMA-based Random Access Procedure, doc.: IEEE /1105r0 Reference Slide 14 September 2015 Russell Huang, MediaTek