September 2012 doc IEEE 802 11 121084 r

September 2012 doc. : IEEE 802. 11 -12/1084 r 4 TIM and Page Segmentation Date: 2012 -09 -18 Authors: Name Chittabrata Ghosh Sayantan Choudhury Klaus Doppler Esa Tuomaala Eric Wong Matthew Fischer Minyoung Park Adrian Stephens Tom Tetzlaff Emily Qi Simone Merlin Santosh Abraham Menzo Wentink Alfred Asterjadhi Amin Jafarian Hemanth Sampath VK jones Submission Affiliations Nokia Broadcom Intel Qualcomm Qualcomm Address 2054 Unversity Ave. , # 600, Berkeley, CA 94704 Phone Email +1 650 200 7566 chittabrata. ghosh@nokia. co m Sunnyvale, CA +1 408 922 6672 Hillsboro, OR +1 503 712 4705 San Diego, CA Slide 1 +1 858 845 1243 ewong@broadcom. com mfischer@broadcom. com minyoung. park@intel. com smerlin@qualcomm. com Chittabrata Ghosh, Nokia

September 2012 doc. : IEEE 802. 11 -12/1084 r 4 Authors: Name Yong Liu Hongyuan Zhang Sudhir Srinivasa George Calcev Affiliations Marvell Huawei Osama Aboul Magd Young Hoon Betty Zhao David Yangxun Huawei Bin Zhen Huawei Chao. Chun Wang James Wang Jianhan Liu Vish Ponnampalam James Yee Huai-Rong Shao Chiu Ngo Minho Cheong Jae Seung Lee Hyoungjin Kwon Heejung Yu Sok-kyu Lee Sun, Bo Lv, Kaiying Submission Address Rolling Meadows, IL, USA Phone Email George. Calcev@huawei. co m Media. Tek Samsung Electronics ETRI ETRI ZTE Slide 2 Chittabrata Ghosh, Nokia

September 2012 doc. : IEEE 802. 11 -12/1084 r 4 Authors: Name Yongho Seok Jinsoo Choi Jeongki Kim Jin Sam Kwak Ken Mori Rojan Chitrakar Haiguang Wang Shoukang Zheng Yeow Wai Leong Zander Lei Jaya Shankar Anh Tuan Hoang Joseph Teo Chee Ming Submission Affiliations LG Electronics Panasonic I 2 R I 2 R Address Slide 3 Phone Email yongho. seok@lge. com Chittabrata Ghosh, Nokia

September 2012 doc. : IEEE 802. 11 -12/1084 r 4 Introduction • Based on the AID hierarchical addressing [1], a Page consists of multiple blocks (e. g. , 32) • A page segment may refer to an ordered range of blocks (e. g. , 8) out of all blocks in one Page • TIM segmentation is accepted in 802. 11 ah specification framework supporting a subset of STAs per TIM segment • Need a mechanism for assignment of page segments among multiple TIM segments • Indication of such assignment to STAs in allocated page segments Submission Slide 4 Chittabrata Ghosh, Nokia

September 2012 doc. : IEEE 802. 11 -12/1084 r 4 Motivation • STAs waking up in DTIM for group addressed frames are assigned in subsequent TIM segments for unicast (DL/UL) traffic • Challenge – Indication of subset of STAs assigned to each TIM segment • Within assigned page segment in a TIM segment, intermediate blocks may not have buffered data at AP – STAs with no UL data in such blocks need to still wake up at assigned TIM segment • We propose to introduce a Segment Count IE in DTIM beacon frame to indicate length of page segment assigned to TIM segments • We propose a mechanism for early indication of buffered data per block Submission Slide 5 Chittabrata Ghosh, Nokia

September 2012 doc. : IEEE 802. 11 -12/1084 r 4 Page Segmentation • • We propose to have a fixed length page segment per TIM segment within one DTIM beacon interval Length of page segment may vary over multiple DTIM beacon intervals Length of page segment = (Number of blocks in one page / number of TIM segments in DTIM beacon interval) Each ordered page segment is assigned sequentially to TIM segments, first page segment being assigned to DTIM segment Ordered Blocks in Page 1 Page Segment 1 TIM Segment 1 (DTIM) Submission Page Segment 2 TIM Segment 2 Slide 6 Page Segment N TIM Segment N Chittabrata Ghosh, Nokia

September 2012 doc. : IEEE 802. 11 -12/1084 r 4 Page Bitmap for Power Save • Block level indication of buffered traffic in DTIM beacon frame • STAs with its corresponding block bit set to 0 go back to sleep after decoding DTIM beacon frame and may not wake up at assigned TIM segment • Page Bitmap field for buffered traffic indication of blocks in assigned page segments for all TIM segments in DTIM beacon interval • This field may be indicated in Segment Count IE • The first block in Page Bitmap corresponds to Page offset in segment count IE • The terminal block in Page Bitmap corresponds to end block in last assigned page segment • Size of Page Bitmap varies between 0 – 4 octets (assuming a maximum of 32 blocks in one Page) Submission Slide 7 Chittabrata Ghosh, Nokia

September 2012 doc. : IEEE 802. 11 -12/1084 r 4 Frame Format for Segment Count IE • The segment count IE (4 -8 octets) shall consist of the following fields: • Element ID (1 octet): Identification of the segment count IE • Length (1 octet): Length of this IE • Page Index (2 bits): Indication of page currently assigned in beacon • Page Segment Count (5 bits) field indicating number of TIM segments; for instance, - A value of 4 indicates 4 TIM segments in DTIM beacon interval - A value of 8 indicates 8 TIM segments in DTIM beacon • Page Offset (5 bits) field indicating the first block in assigned page segments • Reserved (4 bits): Reserved bits for future use • Page Bitmap (0 - 4 octets) field for blocks of all page segments in DTIM element Element ID Submission Length Page Index Page Segment Count Slide 8 Page Offset Reserved Page Bitmap Chittabrata Ghosh, Nokia

September 2012 doc. : IEEE 802. 11 -12/1084 r 4 Segment Count IE in Beacon • • • Segment count IE is only transmitted in DTIM beacon frames and not in TIM segments This element indicates assignment of STAs in TIM segments – Indicates wake-up interval for STAs within page segments STAs within the assigned page segment wake up at corresponding TIM segment sequentially based on the page segment count field in the IE Length of page segment = (Number of blocks in Page Bitmap /page segment count) Page offset and Page segment count fields in the segment count IE indicate initial block offset and range of TIM element in each TIM segment – Block offset / start = page offset + ((length of page segment) * (TIM segment number -1)) + 1 – Block Range = page offset + length of page segment * TIM segment number STAs with their block bit set to 0 in Page Bitmap field may not wake up at assigned TIM segment Submission Slide 9 Chittabrata Ghosh, Nokia

September 2012 doc. : IEEE 802. 11 -12/1084 r 4 TIM IE • In IEEE Spec Framework: – When the complete traffic indication bitmap is divided into multiple segments, each segment shall indicate the range of the AIDs (bitmap) it is covering • Proposal: include the TIM Segment Number field in TIM IE Bitmap control (1 octet) Element ID Length DTIM Count DTIM Period 1 octet TIM Segment R Number (n) 5 bit 1 bit Page Index Partial Virtual Bitmap (TIM Segment bitmap) 2 bit – TIM Segment Number field (5 bits): indicates the index of the TIM Segment – The TIM bitmap information covered in the TIM IE is calculated as follows: • TIM segment start = page offset + ((length of page segment) * (TIM segment number -1)) + 1 • TIM segment end = page offset + length of page segment * TIM segment number Submission Slide 10 Chittabrata Ghosh, Nokia

September 2012 doc. : IEEE 802. 11 -12/1084 r 4 TIM Segmentation Illustration • Segment Count IE indicates assignment of page segments in following TIM segments Page (2048 STAs) in 1 DTIM Interval Beacon Page Segment 1 (512 STAs) Page Segment 2 (512 STAs) Page Segment 3 (512 STAs) Page Segment 1 Submission Page Segment Count = 4 Length of Page Segment Page Offset Segment Count IE for STAs in all Page Segments Page Segment 4 (512 STAs) Short Beacon TIM Segment Number = 2 Short Beacon TIM Segment Number = 3 Page Segment 2 Slide 11 Short Beacon TIM Segment Number = 4 Page Segment 3 Page Segment 4 Chittabrata Ghosh, Nokia

September 2012 doc. : IEEE 802. 11 -12/1084 r 4 Summary • We proposed to introduce a segment count IE in DTIM beacon frame in order to indicate length of page segments assigned to TIM segments • We proposed to have a Page Bitmap field in segment count IE for early indication of buffered data for blocks in assigned page segments • We proposed to add the TIM Segment Number field in TIM IE Submission Slide 12 Chittabrata Ghosh, Nokia

September 2012 doc. : IEEE 802. 11 -12/1084 r 4 Reference [1] TGah Efficient TIM Encoding, doc. IEEE 802. 1112/388 r 0 Submission Slide 13 Chittabrata Ghosh, Nokia

September 2012 doc. : IEEE 802. 11 -12/1084 r 4 Pre-Motion 1 • Do you agree to have a fixed length page segment per TIM segment as described in Slide 6? Submission Slide 14 Chittabrata Ghosh, Nokia

September 2012 doc. : IEEE 802. 11 -12/1084 r 4 Pre-Motion 2 • Do you agree to introduce a Page Bitmap for early indication of block-level buffered data? Submission Slide 15 Chittabrata Ghosh, Nokia

September 2012 doc. : IEEE 802. 11 -12/1084 r 4 Pre-Motion 3 • Do you agree to have a Segment Count IE as in Slide 9 for indication of assignment of STAs in TIM segments? Submission Slide 16 Chittabrata Ghosh, Nokia

September 2012 doc. : IEEE 802. 11 -12/1084 r 4 Pre-Motion 4 • Do you agree to have the frame format for the Segment Count IE as shown in Slide 8? Submission Slide 17 Chittabrata Ghosh, Nokia

September 2012 doc. : IEEE 802. 11 -12/1084 r 4 Pre-Motion 5 • Do you agree to include the TIM Segment Number field in the TIM IE as shown in Slide 10? Submission Slide 18 Chittabrata Ghosh, Nokia