Protection Assurance Method Month Year doc.: IEEE 802.11-06/1660r1 Nov 2006 Protection Assurance Method Date: 2006-11-10 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>. kaberi banerjee, Stuart Kerry , NXP Semiconductors kaberi banerjee, Stuart Kerry

Month Year doc.: IEEE 802.11-06/1660r1 Nov 2006 Abstract This presentation is associated with CID 4522. It attempts to address some deficiencies that exist in the proposed Greenfield protection mechanism that is covered by section 9.13.3.2. kaberi banerjee, Stuart Kerry , NXP Semiconductors kaberi banerjee, Stuart Kerry

Nov 2006 Related CID CID 4522 : Comment : Green field protection. Transmission of GF PPDUs is not allowed when there is at least one non-HT or non-GF STA associated with the BSS; Proposed Change :Change the statement to " All GF capable devices shall not transmit GF PPDUs when there is at least one non-HT or non-GF STA associated with this BSS.“ Status : COEX Deferred then passed to MAC: until TGn has determined whether or not to make Greenfield a mandatory part of the .11n spec. kaberi banerjee, Stuart Kerry , NXP Semiconductors

Problem Definition Nov 2006 -- After the Association of the non-HT device and before the next Beacon interval, The GF/HT devices are unaware of the presence of the non-HT device in the BSS; kaberi banerjee, Stuart Kerry , NXP Semiconductors

Nov 2006 Solution Method -- AP’s announcement of non-HT STA presence via a management Action Frame/Probe response frame ; -- *** Note RIFS protection may not be needed on the basis of some recent resolution; changes will be made to reflect the fact; the important point to notice is that there is a need to signal dynamically the change in state of protection status of the BSS. kaberi banerjee, Stuart Kerry , NXP Semiconductors

Protection State Definition Nov 2006 Protection State Definition -- These bits together define the Protection state kaberi banerjee, Stuart Kerry , NXP Semiconductors

BSA Protection Mechanisms Nov 2006 BSA Protection Mechanisms Two Mechanisms are available Protection Within the BSS – indication of the applicability of a protection mechanism within the BSS; Currently done via Beacon frames and the HT/ERP Information Element; Protection of OBSS cases – indication may be done in a dynamic manner; Changed state in the OBSS is recorded in an OBSS Information Element; OBSS Information Element captures the Protection status bit and action bits as shown. kaberi banerjee, Stuart Kerry , NXP Semiconductors

Frames used to announce Protection State change Nov 2006 Frames used to announce Protection State change Candidate Solutions : one of the following -- Broadcast Management Action Frame – Protection Announcement Frame - Compact; - can accommodate variable lengths; -- Probe Response Frame - recognizable by all devices - already a part of the implementations -- Measurement Pilot Frames : - periodic - timestamp required kaberi banerjee, Stuart Kerry , NXP Semiconductors

Protection Announcement Management Action Frame Nov 2006 Protection Announcement Management Action Frame kaberi banerjee, Stuart Kerry , NXP Semiconductors

References Draft –P802.11n/D1.06 Nov 2006 kaberi banerjee, Stuart Kerry , NXP Semiconductors