1. doc.: IEEE 802.11-05/0874r0 Submission September 2005 C Trecker, et alSlide 1 Test Methodology, Metrics and Test Cases for measuring Fast BSS Transition Performance 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, 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 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.http:// ieee802.org/guides/bylaws/sb-bylaws.pdfstuart.kerry@philips.compatcom@ieee.org Date: 2005-09-15 Authors:

2. doc.: IEEE 802.11-05/0874r0 Submission September 2005 C Trecker, et alSlide 2 Abstract This presentation proposes test metrics, test methodologies and test cases to characterize fast BSS transition (FBT) performance as FBT is currently defined in the TGr draft. This presentation is the companion presentation for document 11-05/537r1, which contains text for inclusion into the TGT draft.

3. doc.: IEEE 802.11-05/0874r0 Submission September 2005 C Trecker, et alSlide 3 Outline Background Test Methodology and Topology Metrics Test Cases Results

4. doc.: IEEE 802.11-05/0874r0 Submission September 2005 C Trecker, et alSlide 4 Background Based on current and proposed amendments to the 802.11 standard, BSS Transition consists of up to six stages: SCANNING 802.11 Authentication AuthenticationMethod QOS Admission Control Key Management 802.11 (Re)Association BSS Transition Time STAAP2AP1 Connected AP1 Connected AP2

5. doc.: IEEE 802.11-05/0874r0 Submission September 2005 C Trecker, et alSlide 5 TGr Fast Roaming FT 802.11 Authentication FT 802.11 (Re)Association STAAP2AP1 Connected AP1 Connected AP2 The purpose of TGr is to refine the BSS transition process to minimize the time interval where a STA has lost connectivity to the DS. TGr proposes modifying the current BSS transition process to two or three stages – only the final stage, (Re)Association, is critical path. The FT Authentication phase can be performed over the air or the DS before the FBT occurs

6. doc.: IEEE 802.11-05/0874r0 Submission September 2005 C Trecker, et alSlide 6 TGr Fast Roaming with Pre-reservation FT 802.11 Authentication FT 802.11 (Re)Association STAAP2AP1 Connected AP1 Connected AP2 TGr allows a STA to pre-reserve Security and QOS resources prior to (Re) Association. The pre-reservation mechanism decouples the allocation of the Security and QOS resources from the FBT critical path. The first two phases can be performed over the air or the DS before the FBT occurs FT 802.11 Authentication Confirm over the DS via AP1

7. doc.: IEEE 802.11-05/0874r0 Submission September 2005 C Trecker, et alSlide 7 Test Methodology Create a test bed in a controlled (conducted and isolated) environment with –two APs –one STA –A authentication server –A policy server –A traffic generator –A DS –Wireless traffic analyzers –Wired traffic analyzers Use variable attenuators to simulate varying signal conditions Send periodic data traffic –Uplink only, downlink only, or bidirectional –If possible, send data to/from the STA immediately before and after the FBT. Capture traffic with wireless monitors Analyze traffic to determine length of Fast BSS transition Repeat measurements until have sufficient data to evaluate performance to desired level of accuracy

8. doc.: IEEE 802.11-05/0874r0 Submission September 2005 C Trecker, et alSlide 8 Test Setup VA-1a VA-1bVA-2b VA-2a Resistive Splitter/ Combiner Variable Attenuator RF Path 2 RF Path 1 DS Monitor Authentication Server Wireless Monitor 1 Wireless Monitor 2 AP 1 Traffic Generator Policy Server AP 2 Distribution System STA DS Monitor must be able to hear all of the packets on the DS

9. doc.: IEEE 802.11-05/0874r0 Submission September 2005 C Trecker, et alSlide 9 Attenuator Sweep Diagram Attenuators sweep at a constant rate to produce a linear (in dB) sweep from one extreme to the other

10. doc.: IEEE 802.11-05/0874r0 Submission September 2005 C Trecker, et alSlide 10 Proposed FBT Metrics Two FBT Metrics are proposed: Fast BSS Transition Time. Measures the actual time that a STA takes to execute the critical path of a Fast BSS Transition. Note that the critical path always includes the FT (Re)Association message exchange and can include the FT Authentication exchange when it occurs immediately before the FT (Re) Association message exchange over-the-air. Fast BSS Data Transition Interval. Measures the data interval between the transmission of the last acknowledged data frame sent within an originating BSS and ends after the transmission of the first acknowledged data frame sent within the destination BSS. This metric is only valid when periodic data is being transmitted from the STA and/or being received at the STA.

11. doc.: IEEE 802.11-05/0874r0 Submission September 2005 C Trecker, et alSlide 11 TGr Base Mechanism Data Fast BSS Transition Time STAAP2AP1 Connected AP1 Connected AP2 ACK DS FT Authentication Request FT Authentication Response FT (Re)Association Request FT (Re)Association Response Data ACK Fast BSS Data Transition Interval (Air) Fast BSS Data Transition Interval (DS)

12. doc.: IEEE 802.11-05/0874r0 Submission September 2005 C Trecker, et alSlide 12 TGr Base Mechanism over-the-DS Data Fast BSS Transition Time STAAP2AP1 Connected AP1 Connected AP2 ACK DS FT Authentication Request FT Authentication Response FT (Re)Association Request FT (Re)Association Response Data ACK Fast BSS Data Transition Interval (Air) Fast BSS Data Transition Interval (DS) over the DS via AP1

13. doc.: IEEE 802.11-05/0874r0 Submission September 2005 C Trecker, et alSlide 13 TGr using Pre-reservation over-the-air Data Fast BSS Transition Time STAAP2AP1 Connected AP1 Connected AP2 ACK DS FT Authentication Request FT Authentication Response FT (Re)Association Request FT (Re)Association Response Data ACK Fast BSS Data Transition Interval (Air) Fast BSS Data Transition Interval (DS) FT Authentication Confirm FT Authentication ACK

14. doc.: IEEE 802.11-05/0874r0 Submission September 2005 C Trecker, et alSlide 14 TGr using Pre-reservation over-the-DS Data Fast BSS Transition Time STAAP2AP1 Connected AP1 Connected AP2 ACK DS FT Action Request FT Action Response FT (Re)Association Request FT (Re)Association Response Data ACK Fast BSS Data Transition Interval (Air) Fast BSS Data Transition Interval (DS) FT Action Confirm FT Action ACK over the DS via AP1

15. doc.: IEEE 802.11-05/0874r0 Submission September 2005 C Trecker, et alSlide 15 Test Cases Configuration RSNQOS and RSN Fast Roaming Case FBT Base Mechanism– over the air) FBT Base Mechanism – over the DS) FBT with Pre Reservation over the air FBT with Pre Reservation Over the DS

16. doc.: IEEE 802.11-05/0874r0 Submission September 2005 C Trecker, et alSlide 16 Motion Move to accept proposal 11-05/537r1 into the TGT draft Moved: Seconded:

17. doc.: IEEE 802.11-05/0874r0 Submission September 2005 C Trecker, et alSlide 17 References 11-04/748r1, “Test Methodology for Measuring BSS Transition Time”, J. Spilman 11-04/989r1, “Metrics for Characterizing BSS Transition Time Performance”, C. Wright, C. Polanec 11-05/537r0, “Test Methodology Proposal for Measuring BSS Transition Time”, C. Wright, et al 11-05/757r0, “Test Methodology for Measuring Fast BSS Transition Time”, C. Trecker 11-04/86r3, “Measurement of 802.11 Roaming Intervals”, D. Engwer