1MHz mode PHY based power savings May 2012 doc.: IEEE 802.11-12/0614r0 May 2012 1MHz mode PHY based power savings Date: 2012-05-11 Authors: Sudheer Grandhi, InterDigital Communications Sudheer Grandhi, InterDigital Communications

May 2012 doc.: IEEE 802.11-12/0614r0 May 2012 Abstract This document discusses possibility of power saving at PHY layer for 1MHz mode. Sudheer Grandhi, InterDigital Communications Sudheer Grandhi, InterDigital Communications

PHY Power Saving Issue in 1 MHz Mode May 2012 PHY Power Saving Issue in 1 MHz Mode In the SIGA field of >=2 MHz mode, a STA may use PAID field to achieve PHY layer power savings at the STA: Partial Association Identifier (PAID) field: 9 bits This allows a STA to determine that it is not the intended recipient of the packet when PAID does not match a STA may choose to not decode the remainder of the PPDU for power saving PAID is not present in the 1 MHz preamble SIG field [2] a STA cannot determine whether it is the unintended recipient or not i.e., a STA must always decode the entire PPDU Therefore, the current 1MHz design does not offer the same PHY layer power savings as 2MHz and above Sudheer Grandhi, InterDigital Communications

Proposal: Direction Indication Bit May 2012 Proposal: Direction Indication Bit One of the reserved bits in the SIG field of a 1 MHz mode may be defined to indicate whether the current packet is received from, or destined to the AP A non-AP STA will check the direction indication bit (DIB) in the received SIG If the DIB indicates that the packet is destined to the AP, then in this case the STA can sleep for the remaining duration of the packet Sudheer Grandhi, InterDigital Communications

May 2012 Summary The current 1MHz mode design does not allow PHY layer power saving as 2MHz and above modes Proposal: Use1 bit of reserved SIG bits of 1MHz mode to allow PHY layer power savings Sudheer Grandhi, InterDigital Communications

Questions / Comments ? Thank You! May 2012 doc.: IEEE 802.11-12/0614r0 May 2012 Questions / Comments ? Thank You! Sudheer Grandhi, InterDigital Communications Sudheer Grandhi, InterDigital Communications

May 2012 Straw Poll 1 Do you think that Direction indication bit of 1MHz format should be further studied to allow power savings at the receiver/STA? Yes No Abstain Sudheer Grandhi, InterDigital Communications

May 2012 doc.: IEEE 802.11-12/0614r0 May 2012 References [1] IEEE Std 802.11™-2012: Wireless LAN MAC and PHY Specifications [2] IEEE 802.11-11/1482r4, “Preamble Format for 1 MHz,” Qualcomm and et. al. [3] IEEE 802.11-12/0119r0, “Early ACK Indication,” Marvell and et. al. Sudheer Grandhi, InterDigital Communications Sudheer Grandhi, InterDigital Communications