Peer Power Save Mode Date: 2008-03-17 Authors: March 2008 March 2008 doc.: IEEE 802.11-08/0070r1 March 2008 Peer Power Save Mode Date: 2008-03-17 Authors: Alexander Safonov, IITP RAS Alexander Safonov, IITP RAS

PSM in 802.11z-D0.02 (1/2) TDLS Rx Path Switch Request/Response March 2008 doc.: IEEE 802.11-08/0070r1 March 2008 PSM in 802.11z-D0.02 (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 Alexander Safonov, IITP RAS

PSM in 802.11z-D0.02 (2/2) Legacy PSM March 2008 doc.: IEEE 802.11-08/0070r1 March 2008 PSM in 802.11z-D0.02 (2/2) Legacy PSM In PSM, AP path is used, but not direct path AP 3 TIM element DATA frame 1 PS-poll 4 DATA frame 5 QSTA2 QSTA1 in PSM 2 QSTA1 awakes Alexander Safonov, IITP RAS Alexander Safonov, IITP RAS

Legacy PSM vs. Peer PSM Legacy PSM Proposed Peer PSM March 2008 doc.: IEEE 802.11-08/0070r1 March 2008 Legacy PSM vs. Peer PSM Legacy PSM In PSM, the AP path is still used thus two successful transmissions of a long data packet are needed to deliver the packet from peer to peer Data is buffered at the AP which becomes a bottleneck No QoS differentiation because of the legacy AP Proposed Peer PSM 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 to deliver data directly, but not over the AP Using full potential of the direct path A Service Period may be initiated at arbitrary time or after a beacon by using Peer Traffic Indication frame Alexander Safonov, IITP RAS Alexander Safonov, IITP RAS

Peer PSM (1/2) The case when QSTA2 is in Active mode March 2008 doc.: IEEE 802.11-08/0070r1 March 2008 Peer PSM (1/2) The case when QSTA2 is in Active mode Power Management bit controls the state in Peer PSM Service Period is triggered to retrieve buffered data from peer QSTA2 may inform QSTA1 about buffered data by sending Peer Traffic Indication over the AP AP 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 in Active Mode QSTA1 in Peer PSM 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 Alexander Safonov, IITP RAS

Encapsulated DATA frame (Peer Traffic Indication) March 2008 doc.: IEEE 802.11-08/0070r1 March 2008 Peer PSM (2/2) The case when both QSTA1 and QSTA2 are in Peer PSM Power Management bit controls the state in Peer PSM Service Period is triggered to retrieve buffered data from peer A QSTA may inform the peer QSTA about buffered data by sending Peer Traffic Indication over the AP Encapsulated DATA frame (Peer Traffic Indication) 4 AP A frame with Power Management bit set to 1 1 2 QSTA2 changes to Power Saving Mode QSTA1 changes to Doze state 4 Null DATA frame (Power Management Field is set to 0) 6 QSTA2 QSTA1 in Peer PSM QSTA2 wakes up 3 5 Buffered DATA frame (EOSP is set to 1) Alexander Safonov, IITP RAS Alexander Safonov, IITP RAS

March 2008 doc.: IEEE 802.11-08/0070r1 March 2008 Motion Move to include the normative text in document 11-08-0071-03-000z-normative-text-peer-power-save-mode.doc into the current TGz draft Mover: Seconder: Result: Alexander Safonov, IITP RAS Alexander Safonov, IITP RAS