1. doc.: IEEE 802.11-11/0060r1 Submission January 2011 Minyoung Park, Intel Corp.Slide 1 Low Power Capability Support for 802.11ah Date: 2011-01-17 Authors:

2. doc.: IEEE 802.11-11/0060r1 Submission January 2011 Minyoung Park, Intel Corp.Slide 2 Abstract This presentation proposes low power capability support for 802.11ah

3. doc.: IEEE 802.11-11/0060r1 Submission Previous Presentation on 802.11ah Usages and Power Consumption Analysis Doc#: IEEE 802.11-10/1268r0 Usages –Smart metering (electricity, gas, water, …) –Sensors (home, health, building, …) –Collecting information from wireless sensing devices Traffic –Low duty cycle: data may be collected every few minutes, hours, or days –Small packet sizes: 10s or 100s of bytes Wireless sensing devices (Low-Power STAs) –Battery powered and low-cost –Multiple years of battery life Multiple years of battery life can be achieved by –Low sleep state power consumption –Low duty cycle January 2011 Minyoung Park, Intel Corp.Slide 3

4. doc.: IEEE 802.11-11/0060r1 Submission Motivation AP does not know limited capabilities of Low-Power STAs AP does not treat Low-Power STAs differently from the other STAs Example: BSS Max Idle period (802.11v) –AP has only one Max Idle period which allows the STAs to be associated for the Max Idle period without sending any frames to the AP Low-Power STAs need to be treated differently from the other STAs January 2011 Minyoung Park, Intel Corp. Slide 4 AP STAs without low power constraint Need to transmit frames to the AP every 60 secs Low-Power STAs which need to sleep for 10s of minutes also need to wakeup and send frames to the AP every 60 secs; otherwise they are disconnected and need to reassociate when they wakeup. A single Max Idle Period = 60 secs

5. doc.: IEEE 802.11-11/0060r1 Submission Low Power Capability Support Provide low power capability support for Low-Power STAs Low Power Capability element –A mechanism to exchange low power capability information between an AP and Low-Power STAs so that the AP can treat the Low-Power STAs differently from the rest of the other associated STAs –Exchanged in (Re)Association Request/Response frames –Format –Low Power Capability Info field Variable in length Example: Max Idle Period field January 2011 Minyoung Park, Intel Corp.Slide 5

6. doc.: IEEE 802.11-11/0060r1 Submission Example: Max Idle Period January 2011 Minyoung Park, Intel Corp.Slide 6 Max Idle Period field in Low Power Capability Info field Low-Power STA asks the AP to use the Max Idle Period value set in the Low Power Capability element in the (Re)Association Request frame If the AP can support the Max Idle Period value in the (Re)Association Request frame, the AP sets the same or a larger Max Idle Period value in the Low Power Capability Info field in the (Re)Association Response frame AP STAs without low power constraint Need to transmit frames to the AP every 60 seconds Low Power STAs can sleep for 30 minutes without being disconnected from the AP AP applies different Max Idle periods for different classes of STAs - STAs without low power constraint: 60 seconds - Low-Power STAs: 30 minutes

7. doc.: IEEE 802.11-11/0060r1 Submission Summary Wireless sensing devices in the 802.11ah usage model –Expected to be battery powered –Require multiple years of battery life –Low power consumption –Low cost Proposed low power capability support for Low-Power STAs Low Power Capability element –Low-Power STAs provide their limited capability information to the AP –The AP treats the Low-Power STAs differently from the other STAs to support low power consumption January 2011 Minyoung Park, Intel Corp.Slide 7