Synchronization of Quiet Periods for Incumbent User Detection April 2009 doc.: IEEE 802.19-09/xxxxr0 March 2010 Synchronization of Quiet Periods for Incumbent User Detection Date: 2010-March Authors: Zhou Lan NICT Rich Kennedy, Research In Motion

April 2009 doc.: IEEE 802.19-09/xxxxr0 March 2010 Abstract This document reviews the 802.11-2007 DFS procedure and proposes an amendment of Quiet Period Synchronization mechanism for 802.11af to guarantee the detection of the incumbent users under the FCC rules Zhou Lan NICT Rich Kennedy, Research In Motion

FCC Regulations Refer to FCC 08-260 page 103 April 2009 doc.: IEEE 802.19-09/xxxxr0 March 2010 FCC Regulations Refer to FCC 08-260 page 103 “TV channel availability check time. A TVBD is required to check for TV signals for a minimum time interval of 30 seconds. If a TV signal is detected on a channel indicated as available for use by the database system, the device will provide a notice of that detection to the operator of the device and a means for the operator to optionally remove the channel from the device’s list of available channels” “In-service monitoring. A TVBD must perform in-service monitoring of an operating channel a minimum of once every 60 seconds. There is no minimum channel availability check time for in-service monitoring” Zhou Lan NICT Rich Kennedy, Research In Motion

Dynamic Frequency Selection (DFS) April 2009 doc.: IEEE 802.19-09/xxxxr0 March 2010 Dynamic Frequency Selection (DFS) Associating STAs with an AP in a BSS based on the STA’s supported channels Quieting the current channel so it can be tested for the presence of radar with less interference from other STAs Testing channels for radar before using a channel and while operating in a channel Discontinuing operations after detecting radar in the current channel to avoid further interfering with the radar Detecting radar in the current and other channels based on regulatory requirement Requesting and reporting measurements in the current and other channels Selecting and advertising a new channel to assist the migration of a BSS after radar is detected Zhou Lan NICT Rich Kennedy, Research In Motion

Necessity to Synchronize Quiet Period April 2009 doc.: IEEE 802.19-09/xxxxr0 March 2010 Necessity to Synchronize Quiet Period 802.11 2007 DFS has defined the procedure to quiet the current channel so the channel can be tested for the presence of the incumbent services However according to the procedure (11.9.1 IEEE Std 802.11-2007), the affected STAs are confined inside the same BSS or IBSS During the period when STAs in a certain BSS are quieted, STAs in an adjacent BSS may still be allowed to transmit As a direct consequence, in the quiet period which is supposed to be used to detect incumbent users, there might be signals from adjacent BSSs, which interfere the detection of incumbent users It is important to have a synchronization mechanism to guarantee the clearance of the quiet period for incumbent user detection Zhou Lan NICT Rich Kennedy, Research In Motion

Illustration of the Problem April 2009 doc.: IEEE 802.19-09/xxxxr0 Illustration of the Problem March 2010 Synchronized Quiet Period B B B BSS1 Quiet Quiet Quiet B B B BSS2 Quiet Quiet Quiet B B B BSS3 Quiet Quiet Quiet TV broadcaster B Beacon Quiet Quiet period BSS3 BSS1 BSS2 DS Zhou Lan NICT Rich Kennedy, Research In Motion

April 2009 doc.: IEEE 802.19-09/xxxxr0 March 2010 Assumptions This is no need to mandate Timing Synchronization Function (TSF) for the STAs involved There is a means to allow APs exchange information using wireless or wired transmission The Quieting Channel for Testing function defined in 802.11 2007 will be used for each BSS to adjust the individual quiet period to align with the requested quiet period Zhou Lan NICT Rich Kennedy, Research In Motion

Usage of the Synchronized Quiet Period April 2009 doc.: IEEE 802.19-09/xxxxr0 March 2010 Usage of the Synchronized Quiet Period The purpose of the Quiet Period Synchronization is to guarantee a clear period that will not be used by any 802.11 STAs in the concerned area to meet the requirement of incumbent user detection specified by FCC A Quiet Period Synchronization request is sent by an AP to the APs that are members of the ESS as requested in the frame Upon receiving the request, an AP shall respond whether it will perform the Quiet Period Synchronization operation The mechanism by which the list of APs in the ESS is determined is outside the scope of this amendment The mechanism and algorithm by which to decide which AP will send the Quiet Period Synchronization is outside the scope of this amendment Zhou Lan NICT Rich Kennedy, Research In Motion

Requesting a Synchronized Quiet Period April 2009 doc.: IEEE 802.19-09/xxxxr0 March 2010 Requesting a Synchronized Quiet Period An AP requesting to start a Quiet Period Synchronization procedure shall send a Quiet Period Synchronization Request frame to the APs that are located in the concerned area The Quiet Period Synchronization Request frame contains a dialog token to distinguish requests from different APs The Quiet Period Synchronization Request frame contains the BSSID of the APs that the request is sent to The Quiet Period Synchronization Request frame contains requested timing information for quiet period synchronization Quiet Period Offset: specify the time offset of the starting time of the quiet period relative to the reception of the preamble of the Quiet Period Synchronization Request frame Quiet Period: specify the interval between two Quiet Periods Quiet Duration: specify the duration of the Quiet period Zhou Lan NICT Rich Kennedy, Research In Motion

Receiving a Request of Synchronized Quiet Period April 2009 doc.: IEEE 802.19-09/xxxxr0 March 2010 Receiving a Request of Synchronized Quiet Period An AP upon reception of a Quiet Period Synchronization Request frame checks the BSSID contained in the request and shall respond if the BSSID matches If the AP will adjust the quiet period according to the request, a positive response shall be sent back to the AP initiated the request If the AP will not adjust the quiet period, a negative response with the reason code shall be sent back the AP initiated the request Zhou Lan NICT Rich Kennedy, Research In Motion

Synchronized Quiet Period Request Frame April 2009 doc.: IEEE 802.19-09/xxxxr0 March 2010 Synchronized Quiet Period Request Frame Quiet Period Synchronization Request frame is a Public Action Frame Category Action Dialog Token Protocol Information Element Quiet Period Synchronization Request Element 1 2 3 variable Octets: Zhou Lan NICT Rich Kennedy, Research In Motion

Synchronized Quiet Period Response Frame April 2009 doc.: IEEE 802.19-09/xxxxr0 March 2010 Synchronized Quiet Period Response Frame Quiet Period Synchronization Response frame is a Public Action Frame Category Action Dialog Token Protocol Information Element Quiet Period Synchronization Response Element 1 2 3 variable Octets: Zhou Lan NICT Rich Kennedy, Research In Motion

Synchronized Quiet Period Request Element April 2009 doc.: IEEE 802.19-09/xxxxr0 March 2010 Synchronized Quiet Period Request Element Quiet Period Synchronization Request element Element ID Length Request Token Quiet Period Offset Quiet Period Quiet Duration Optional Sub-elements 1 2 variable Octets: Zhou Lan NICT Rich Kennedy, Research In Motion

Synchronized Quiet Period Response Element April 2009 doc.: IEEE 802.19-09/xxxxr0 March 2010 Synchronized Quiet Period Response Element Quiet Period Synchronization Response element Element ID Length Request Token BSSID Result Reason code 1 2 6 Octets: Zhou Lan NICT Rich Kennedy, Research In Motion

Optional Sub-element format April 2009 doc.: IEEE 802.19-09/xxxxr0 March 2010 Optional Sub-element format Sub-element ID Name Length field Extensible SSID 0 to 32 1-220 Reserved 221 Vendor Specific 1 to 255 222-225 Zhou Lan NICT Rich Kennedy, Research In Motion

April 2009 doc.: IEEE 802.19-09/xxxxr0 March 2010 Conclusion A Quiet Period Synchronization procedure is proposed to meet the FCC requirement of incumbent user detection The procedure utilizes the original Quieting Channel procedure with only changes on the message exchange for synchronization Two Public Action Frames and two Information Elements are proposed to facilitate the procedure Zhou Lan NICT Rich Kennedy, Research In Motion