WLAN Paging for Power Saving Month Year May 2006 May 2006 WLAN Paging for Power Saving Date:2006-05-15 Authors: 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>. Emily Qi et al, Intel Corp. Emily Qi et al

Month Year May 2006 May 2006 Abstract This document outlines a WLAN Paging proposal in support of Power Saving objective in accordance with REQ2010. Emily Qi et al, Intel Corp. Emily Qi et al

Agenda Power Saving Goal Power Consumption Issues Month Year May 2006 May 2006 Agenda Power Saving Goal Power Consumption Issues Power Saving Analysis WLAN Paging Concept WLAN Paging Protocol Emily Qi et al, Intel Corp. Emily Qi et al

May 2006 Power Saving Goal Enables 300+ hours of standby operation for handheld and Ultra Mobile PC (UMPC) to support applications, such as VoIP over WLAN Emily Qi et al, Intel Corp.

Power Consumption Issues May 2006 Power Consumption Issues Overhearing Scanning overhead Power consumption during idle The number of reassociations The total system power Emily Qi et al, Intel Corp.

Introducing WLAN Paging May 2006 Introducing WLAN Paging STA “deeply sleeps” or “shuts down” if there is no outgoing/incoming traffic STA wakes up at a time interval (e.g. 2.1s) to check if there is incoming traffic STA doesn’t need to associate with AP when it is in “deep sleep” mode and roaming across APs. If STA roams out of the coverage area of the last known associated AP when STA wants to be “active”, STA will re-associate with a new AP Emily Qi et al, Intel Corp.

PC Power Consumption w/WiFi Month Year May 2006 May 2006 Power Saving Analysis PC Power Consumption w/WiFi System Scanning Idle Misc (filtering,DTIM, PS-Poll, re-association, etc) Total (mw/hour) Active 10W 700mW 100mW N/A 10800mW With Paging 300mW 10mW 40mW 450mW Emily Qi et al, Intel Corp. Emily Qi et al

WLAN Paging Concept Logical Entities: Paging Mode : Paging Domain Month Year May 2006 May 2006 WLAN Paging Concept Logical Entities: Paging Domain Paging Service Controller Paging Group Paging Mode : Discovery and Registration Initialization Operation STA wakes up for Paging scan at the Paging interval (e.g. 2.1s) APs in the Paging Group advertises Paging Indication Message Termination and STA reassociates with an AP. Emily Qi et al, Intel Corp. Emily Qi et al

Paging Logical Entities May 2006 Paging Logical Entities Paging Domain A set of BSSs within the same ESS, identified by a Paging Domain ID Paging Service Controller Provides Paging Service for a set of BSSs in the Paging Domain. Paging Group A logical group to offer a contiguous coverage region in which STA can be paged The paging groups should be large enough so that most STAs will remain within the same paging group most of the time, and small enough such that the paging overhead is reasonable. Emily Qi et al, Intel Corp.

Discovery and Registration Month Year May 2006 May 2006 Discovery and Registration 1 Paging Info (paging interval, PD_ID, PG_ID, timestamp) Beacon and Probe Paging_Reg_REQ() (Paging_ID, Security Context, and etc) 2 Paging_Reg_RSP() Emily Qi et al, Intel Corp. Emily Qi et al

Paging Mode Initialization May 2006 Paging Mode Initialization (Paging Mode profile) Paging_Init_REQ() (Init Paging and Presence Update) Paging_Init_RSP() 3 (Paging Context: Last sync BSSID, Security Context, Paging Interval, … ) Emily Qi et al, Intel Corp.

Paging Scan & Presence Update Month Year May 2006 May 2006 Paging Scan & Presence Update The STA wakes up and Paging Scans at Paging Interval - Active/Passive: Synchronization – channel, timestamp, PG_ID …. 4 5 If PG_ID is different from the STA’s previous PG_ID, or Presence update timer (keep-alive) is expired, the STA will: - Send Presence Update Sync-up paging timer and paging interval Keep alive exp Presence update() Emily Qi et al, Intel Corp. Emily Qi et al

May 2006 Paging Incoming packets 6 APs in the Paging Group Uni-cast /Broadcast <(Protected) PIMs> STAs sync-up paging timer and paging interval If the STA is paged, the STA might want to terminate the Paging mode and re-associate to a selected AP. Otherwise, the STA will be remain in paging mode. Emily Qi et al, Intel Corp.

WLAN Paging Protocol Paging Capability Discovery May 2006 WLAN Paging Protocol Paging Capability Discovery Paging Registration REQ/RSP Keying protocol Paging Initialization REQ/RSP Paging Un-Initialization REQ/RSP Presence Update REQ/RSP Paging Mechanism Unicast Broadcast Multicast using PG Emily Qi et al, Intel Corp.

Protected Paging Indication May 2006 Protected Paging Indication STA MAC Address Paging Event Type Sequence Number Key ID MIC Octets: 6 1 2 8 STA MAC Address indicates the Mobile station that is paged Paging Event type field indicates the traffic type: VoIP, IM, etc … The Sequence Number field enables replay protection. The Key ID field identifies the Integrity Pairwise Temporal Key (IPTK) between the Paging Controller and STA used to compute the MIC. The MIC field shall contain a message integrity code calculated over all of the preceded fields Any message integrity code, such as AES in CMAC mode, or SHA-1 in HMAC mode, will do. Emily Qi et al, Intel Corp.

Proposed Key Hierarchy Month Year May 2006 May 2006 Proposed Key Hierarchy PSPMK := KDF (KDK, “Paging Service” || STA MAC address || Paging Domain ID || length of the key) IPTK:= KDF(PSPMK, Random_Num_STA || Random_Num_LS || length of the key); Emily Qi et al, Intel Corp. Emily Qi et al

Paging Key Distribution Month Year May 2006 May 2006 Paging Key Distribution Emily Qi et al, Intel Corp. Emily Qi et al

May 2006 Feature Summary Paging Domain and Paging Service Controller for Paging Management Paging Capability Discovery and Paging Service Registration for Paging Service Enabling Paging Scan at Paging Interval (e.g. 2.1s) for power efficiency 802.11v Presence update and Paging Group for bandwidth efficiency Protected Paging Indication for forgery protection Emily Qi et al, Intel Corp.

References 06/349r0 Idle Mode Operation for IEEE 802.11v (Jin et al) May 2006 References 06/349r0 Idle Mode Operation for IEEE 802.11v (Jin et al) 06/363r0 Standby Time Improvement (Meylan et al) 05/1073r1 Advanced Power Introduction (Kneckt et al) 05/1075r0 Broadcast and Multicast Enhancements (Jokela et al) Emily Qi et al, Intel Corp.