PPDU Recovery Procedure Month Year doc.: IEEE 802.11-yy/xxxxr0 May 2013 PPDU Recovery Procedure Date: 2013-05-14 Authors: Name Affiliations Address Phone Email Yongho Seok LG Electronics LG R&D Complex Anyang-Shi, Kyungki- Do, Korea +82-31-450-1947 yongho.seok@lge.com Matthew Fischer Broadcom mfischer@broadcom.com Minyoung Park Intel Hillsboro, OR +1 503 712 4705 minyoung.park@intel.com Young Hoon Kwon Huawei Jinsoo Choi Jeongki Kim Hangyu Cho Eric Wong Sunnyvale, CA +1 408 922 6672 ewong@broadcom.com Tom Tetzlaff Emily Qi Simone Merlin Qualcomm San Diego, CA +1 858 845 1243 smerlin@qualcomm.com Amin Jafarian Bin Tian Santosh Abraham Menzo Wentink Hemanth Sampath VK jones Yongho Seok, LG Electronics John Doe, Some Company

Authors: May 2013 Month Year doc.: IEEE 802.11-yy/xxxxr0 Name Affiliations Address Phone Email Hongyuan Zhang Marvell Sudhir Srinivasa George Calcev Huawei Rolling Meadows, IL, USA George.Calcev@huawei.com Osama Aboul Magd Betty Zhao David Yangxun Bin Zhen ChaoChun Wang MediaTek James Wang Jianhan Liu Vish Ponnampalam James Yee Huai-Rong Shao   Samsung Electronics Chiu Ngo Minho Cheong ETRI Jae Seung Lee Hyoungjin Kwon Jaewoo Park Sok-kyu Lee Sun, Bo         ZTE Lv, Kaiying         Yongho Seok, LG Electronics John Doe, Some Company

Authors: May 2013 Name Affiliations Address Phone Email Sayantan Choudhury Nokia Klaus Doppler Chittabrata Ghosh Esa Tuomaala Ken Mori Panasonic Rojan Chitrakar Haiguang Wang I2R Shoukang Zheng Yeow Wai Leong Zander Lei Jaya Shankar Anh Tuan Hoang Joseph Teo Chee Ming Anna Pantelidou Renesas Mobile Juho Pirskanen Timo Koskela Liwen Chu STMicroelectronics George Vlantis Yongho Seok, LG Electronics

May 2013 Introduction After transmitting an MPDU that requires an immediate frame as a response, the STA shall wait for a timeout interval of duration of aSIFSTime + aSlotTime + aPHY-RX-START-Delay, starting at the PHY-TXEND.confirm primitive. If a PHYRXSTART.indication primitive does not occur during the timeout interval, the STA concludes that the transmission of the MPDU has failed. (IEEE 802.11-2012) aPHY-RX-START-Delay : The delay from the start of the preamble to the issuance of the RXSTART.indication primitive by the PHY. Yongho Seok, LG Electronics

Proposal on aPHY-RXSTART-Delay May 2013 Proposal on aPHY-RXSTART-Delay 1MHz preamble aPHY-RX-START-Delay of 1MHz PPDU is set to 600us. (=40usX14+40us) >= 2MHz short/long preamble aPHY-RX-START-Delay of >=2MHz PPDU is set to 280us. (=40usX6+40us) STF LTF1 SIG LTF2 … LTF_NLTF DATA (2 symbols) (2 symbols ) (2 symbols) (1 symbol each) STF LTF1 SIGA D-STF D-LTF1 … D-LTF_NLTF SIGB DATA Field (2 symbols) (2 symbols) (2 symbols) (1 symbol) (1 symbol each) Yongho Seok, LG Electronics

Proposed PPDU Recovery Procedure May 2013 Proposed PPDU Recovery Procedure After transmitting an MPDU that requires an immediate frame as a response, the STA shall wait for a timeout interval of duration of aSIFSTime + aSlotTime + aPHY-RX-START-Delay, starting at the PHY-TXEND.confirm primitive The value for aPHY-RX-START-Delay is dependent on the PHY type, and each such value can be found within the PHY-Characteristics table for each individual PHY within its own clause. In S1G PHY, the aPHY-RX-START-Delay is determined by the preamble _type parameter of TXVECTOR. When the TXVECTOR FORMAT is equal to 1MHz preamble, aPHY-RX-START-Delay is set to 600us. When the TXVECTOR FORMAT is equal to >= 2MHz short/long preamble, aPHY-RX-START-Delay is set to 280us. Yongho Seok, LG Electronics

Proposed PPDU Recovery Procedure May 2013 Proposed PPDU Recovery Procedure When a capability element of STA indicates that 1MHz control response will be used, an 1MHz preamble transmission as the response of >= 2MHz short/long preamble is allowed. A S1G STA that sends a control frame in response to a frame carried in an S1G PPDU shall set the TXVECTOR parameter CH_BANDWIDTH to indicate a channel width that is the same or lower as the channel width indicated by the RXVECTOR parameter CH_BANDWIDTH of the frame eliciting the response. Channel Bandwidth of PPDU during the multiple frame exchange sequences in a TXOP shall be the same or narrower than the Channel Bandwidth of the preceding PPDU. Otherwise, an 1MHz preamble transmission as the response of >= 2MHz short/long preamble is not allowed. AP chooses the ACK timeout depending on the preamble type of the frame eliciting the control response. A S1G STA that sends a control frame in response to a frame carried in an S1G PPDU shall set the TXVECTOR parameter CH_BANDWIDTH to indicate a channel width that is the same as the channel width indicated by the RXVECTOR parameter CH_BANDWIDTH of the frame eliciting the response. Yongho Seok, LG Electronics

Proposed PPDU Recovery Procedure May 2013 Proposed PPDU Recovery Procedure ACK (1MHz PPDU) ACK (2MHz PPDU) ACK (1MHz PPDU) DATA (4MHz PPDU) DATA (4MHz PPDU) ACK (1MHz PPDU) ACK (2MHz PPDU) ACK (1MHz PPDU) <Allowed> <Not Allowed> ACK (1MHz PPDU) DATA (2MHz PPDU) DATA (2MHz PPDU) ACK (2MHz PPDU) ACK (1MHz PPDU) <Allowed> <Not allowed> DATA (1MHz PPDU) ACK (1MHz PPDU) <Allowed> Note) frame exchange sequence examples when an 1MHz preamble transmission as the response of >= 2MHz short/long preamble is not allowed. Yongho Seok, LG Electronics

May 2013 Conclusion 11ah MAC protocol overhead should be reduced because the bandwidth of 11ah PHY is quite narrow. If a STA is allowed an 1MHz preamble transmission as the response of >= 2MH preamble, the timeout value for the PPDU recovery is significantly increased from 492us to 812us . Yongho Seok, LG Electronics

May 2013 Straw Poll 1 Do you support to define aPHY-RX-START-Delay as the following? 1MHz preamble: 600us 2MHz/4MHz/8MHz/16MHz: 280us Yongho Seok, LG Electronics

May 2013 Straw Poll 2 Do you support a PPDU recovery procedures defined in slide 6 and 7? Yongho Seok, LG Electronics