1. doc.: IEEE 802.11-11/0273r0 February 2011 Stefan Aust, NEC Communication Systems Submission Slide 1 TGah Use Case: AP Power Saving in Smart Grid Authors: Date: February 28, 2011 NameCompanyAddressPhoneemail Stefan Aust NEC Communication Systems, Ltd. 1753 Shimonumabe, Nakahara- ku, Kawasaki, Kanagawa 211- 8666, Japan +81 44 435 1177 aust.st@ncos.nec.co.jp

2. doc.: IEEE 802.11-11/0273r0 February 2011 Stefan Aust, NEC Communication Systems Submission Slide 2 Objective Proposed AP power saving use case in Smart Grid for IEEE 802.11ah TG Submission supports DCN 11/46r2 “AP Power Saving” by adding a use case scenario description AP power saving features are highly attractive for wireless Smart Grid applications to increase customer acceptance and to reduce CO2 emissions (Green Grid)

3. doc.: IEEE 802.11-11/0273r0 February 2011 Stefan Aust, NEC Communication Systems Submission Motivation IEEE 802.11ah MAC should provide energy saving functions so that it can be deployed in Smart Grid as a communication infrastructure that –Reduces energy costs –Reduces unnecessary CO2 emissions that may occur during idle periods Idle times –Night time with less/no meter data –Different meter strategies (gas, water, power) cause different idle times –Periodic monitoring and transmission of meter data, e.g., every 30 min. [3] Idle time is an excellent candidate for power saving –Between meter data transmissions 11ah AP/STAs may change the state from active to sleep to reduce energy consumption and CO2 emissions 11ah STAs may change to sleep mode (not part of this submission, see [4]) 11ah APs may change to sleep mode (part of this submission, see [5]) Slide 3

4. doc.: IEEE 802.11-11/0273r0 February 2011 Stefan Aust, NEC Communication Systems Submission Use Case: AP Power Saving in Smart Grid 11ah STA(*) Meter/sensor 11ah AP(**) IEEE 802.11ah network Request: AP sleep Response Slide 4 (*) = IEEE 802.11ah STA with proposed AP power saving support (**) = IEEE 802.11ah AP with proposed AP power saving support sleep t active t 11ah STAs 11ah AP active sleep active Transmission of meter data Idle period, e.g., night time AP sleep state Sleep duration day night day night day

5. doc.: IEEE 802.11-11/0273r0 February 2011 Stefan Aust, NEC Communication Systems Submission Use Case Scenario Description: AP Power Saving in Smart Grid During communication idle periods in Smart Grid –11ah AP: Request AP wants to change from active to sleep mode –11ah STA: Response STA state support: AP active/AP light sleep/AP deep sleep STAs high priority messages supported during light sleep mode Proposed 11ah AP modes (similar to IEEE 802.11s) [6] –active mode: A link specific power mode in which the AP operates in the Awake state. –light sleep mode: A link specific power mode in which the AP operates in the Awake or the Doze state and where the AP is expected to receive frames from the STA. –deep sleep mode: A link specific power mode in which the AP operates in the Doze state and where the AP is not expected to receive frames from the STA. E.g., utilizing IEEE 802.11v features [7] Slide 5

6. doc.: IEEE 802.11-11/0273r0 February 2011 Stefan Aust, NEC Communication Systems Submission Slide 6 References [1]IEEE P802.11 Wireless LANs, IEEE 802.11ah Call for proposals, IEEE 802.11-10/1373r0, 11.11.2010 [2]IEEE P802.11 Wireless LANs, Proposed IEEE 802.11ah Use Cases, IEEE 802.11-11/0017r5 [3]Smart Meter Service Information (Japanese), October 4, 2010 [4]IEEE P802.11 Wireless LANs, BSS Max Idle Period and Sleep Interval, IEEE 802.11-10/1326r0, 11.8.2010 [5]IEEE P802.11 Wireless LANs, AP Power Saving, IEEE 802.11-11/46r2, 15.1.2011 [6]IEEE 802.11s(TM)/D7.0, 2010 [7]IEEE 802.11v(TM)/D16.0, 2010

7. doc.: IEEE 802.11-11/0273r0 February 2011 Stefan Aust, NEC Communication Systems Submission Acknowledgement This contribution was funded in part by a grant from the Promotion program for Reducing global Environmental loaD through ICT innovation (PREDICT) led by the Ministry of Internal Affairs and Communications, Japan. Slide 7