Peer Power Save Mode Date: 2008-01-15 Authors: January 2008 Notice: This document has been prepared to assist IEEE 802.11. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. Release: The contributor grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution, and any modifications thereof, in the creation of an IEEE Standards publication; to copyright in the IEEE’s name any IEEE Standards publication even though it may include portions of this contribution; and at the IEEE’s sole discretion to permit others to reproduce in whole or in part the resulting IEEE Standards publication. The contributor also acknowledges and accepts that this contribution may be made public by IEEE 802.11. Patent Policy and Procedures: The contributor is familiar with the IEEE 802 Patent Policy and Procedures <http:// ieee802.org/guides/bylaws/sb-bylaws.pdf>, including the statement "IEEE standards may include the known use of patent(s), including patent applications, provided the IEEE receives assurance from the patent holder or applicant with respect to patents essential for compliance with both mandatory and optional portions of the standard." Early disclosure to the Working Group of patent information that might be relevant to the standard is essential to reduce the possibility for delays in the development process and increase the likelihood that the draft publication will be approved for publication. Please notify the Chair <stuart.kerry@philips.com> as early as possible, in written or electronic form, if patented technology (or technology under patent application) might be incorporated into a draft standard being developed within the IEEE 802.11 Working Group. If you have questions, contact the IEEE Patent Committee Administrator at <patcom@ieee.org>. Alexander Safonov, IITP RAS

PSM in the current 802.11z-D0.01 document (1/2) January 2008 PSM in the current 802.11z-D0.01 document (1/2) TDLS Rx Path Switch Request/Response 1 Encapsulated DATA frame (TDLS Rx Path Switch Request) Path Element (AP Path Switch) AP AP AP Encapsulated DATA frame (TDLS Rx Path Switch Response) Path Element (AP Path Switch) 2 QSTA1 changes to Power Saving Mode 3 QSTA2 QSTA2 QSTA1 QSTA1 QSTA1 Alexander Safonov, IITP RAS

PSM in the current 802.11z-D0.01 document (2/2) January 2008 PSM in the current 802.11z-D0.01 document (2/2) Data is sent on the AP path, but not on the direct one AP 3 TIM element DATA frame 1 PS-poll 4 DATA frame 5 QSTA2 QSTA1 2 QSTA1 awakes Alexander Safonov, IITP RAS

Motivation When a peer is in PSM, the direct link is not used January 2008 Motivation When a peer is in PSM, the direct link is not used The AP path is used, thus two successful transmissions of a long data packet are needed to deliver the packet from peer to peer No QoS differentiation because of legacy AP Is there another way of operation in PSM? Alexander Safonov, IITP RAS

Peer Power Save Mode Peers enter PSM remaining on the direct path January 2008 Peer Power Save Mode Peers enter PSM remaining on the direct path Data is buffered at the originator QSTA, but not at the legacy AP QoS differentiation Peers use the concept of Service Period (SP) to deliver data directly but not over the AP Using full potential of the direct path Peers may use TLDS TIM sent over the AP path to inform the peer about buffered data Alexander Safonov, IITP RAS

Atlanta history (07/2761r4) 07/2769r2: two concepts were proposed January 2008 Atlanta history (07/2761r4) 07/2769r2: two concepts were proposed SP is unscheduled Only one of two peers may enter PSM simultaneously SP is scheduled Both peers may enter PSM at the same time Straw polls: Are you in favor to consider Unscheduled PSM (as per doc. 2760r1)? Yes: 24; No: 0; I don’t know: 1 Are you in favor to consider Scheduled PSM (as per doc. 2760r1)? Yes: 11; No: 6; I don’t know: 6 Alexander Safonov, IITP RAS

January 2008 Power Save Mode in TDLS TDLS STA has two options when it is going to enter PSM Switch to the AP path with its peer Enter Peer PSM (PPSM) informing the peer while remaining at the direct path Alexander Safonov, IITP RAS

January 2008 Peer PSM (1/3) To enter PPSM, a TDLS STA sends to its peer a frame with Power Management field set to 1 When a STA is in PPSM, its peer STA shall stay in active mode and buffer frames for the STA in PPSM The STA in PPSM may wake up at some arbitrary time and initiate an unscheduled SP by sending a trigger frame to the peer The STA in PPSM remains in awake state until it receives a frame, with the EOSP bit set to 1 Alexander Safonov, IITP RAS

January 2008 Peer PSM (2/3) The peer STA in active mode may assemble the partial virtual bitmap containing the buffer status for STAs in the PPSM and send it out in the TIM field of TDLS TIM broadcast frame If STA in TDLS PPSM receives TDLS TIM frame, it must initiate the unscheduled SP The transmission interval of TDLS TIM frame is out of scope Alexander Safonov, IITP RAS

Peer PSM(3/3) Power Management bit controls the state in PPSM January 2008 Peer PSM(3/3) Power Management bit controls the state in PPSM Unscheduled SP is triggered to retrieve buffered data from peer If QSTA2 wishes to inform QSTA1 about buffered data it may send a TDLS TIM frame AP Encapsulated DATA frame (TDLS TIM) QSTA1 changes to Power Saving Mode QSTA1 changes to Power Saving Mode 4 Null DATA frame (Power Management Field is set to 0) 6 2 QSTA2 QSTA1 5 Buffered DATA frame (EOSP is set to 1) QSTA1 wakes up 3 A frame with Power Management bit set to 1 1 Alexander Safonov, IITP RAS

January 2008 Motion Move to include the normative text in document 11-08-0071-00-000z-normative-text-peer-power-save-mode.doc into the TGz current draft Mover: Seconder: Result: Alexander Safonov, IITP RAS