Greenfield protection mechanism September 2006 doc.: IEEE 802.11-06/1458r0 September 2006 Greenfield protection mechanism Date: 2006-9-19 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>. Douglas, B., et al. Joonsuk Kim, Broadcom Corp.

September 2006 doc.: IEEE 802.11-06/1458r0 September 2006 Abstract The current Greenfield protection mechanism given in clause 9.13.3.2 does not adequately address the issue of collisions between Greenfield and non-Greenfield devices. To ensure proper interoperability with 11a/b/g devices, we propose changes to the current text to minimize the probability of collision between GF devices and non-GF devices. This presentation addresses the following letter ballot comments: CID 118, 4017, 4035, 4511, 4522, 10292, 12030, 12048, 12127, 12049 Douglas, B., et al. Joonsuk Kim, Broadcom Corp.

Current Greenfield protection is not adequate September 2006 Current Greenfield protection is not adequate There are over 500 million legacy 802.11a/b/g devices that cannot receive Greenfield transmissions, and never will. These devices will collide with GF mode transmissions in the 2.4 and 5 GHz bands. These collisions will degrade the QOS of voice and video traffic carried over legacy 802.11a/b/g devices and voice and video traffic carried over 802.11n GF and mixed-mode devices. We must introduce strong mechanisms to minimize the probability of collisions between GF and non-GF devices. Although a protection is said to be required in the current text (below), no protection method is specified. The protection used is left up to the implementers. Douglas, B., et al.

Current Greenfield Protection Text September 2006 Current Greenfield Protection Text Douglas, B., et al.

Proposed changes to text (1) September 2006 Proposed changes to text (1) 9.13.3.2 Greenfield protection If there are one or more non-HT STA or one or more non-Greenfield STA associated to an HT AP, that HT AP shall set the Non-GF Devices Present bit in the Additional HT IE frame to 1. If an HT AP is not capable of receiving Greenfield transmissions, that HT AP shall set the Non-GF Devices Present bit in the Additional HT IE frame to 1. The HT AP must advertise the presence of devices not capable of receiving Greenfield transmissions in its probe responses and in its beacon transmissions.  Every 802.11n AP or STA that detects the Non-GF Devices Present bit set in a received beacon,  shall not use Greenfield mode for transmission. Douglas, B., et al.

Proposed changes to text (2) September 2006 Proposed changes to text (2) 7.3.2.47 HT Information element Table n21 – HT Information Element Non-Greenfield Devices Present Indicates if any STAs that are not capable of receiving Greenfield transmissions have associated, or indicates that the AP itself is not capable of receiving Greenfield transmissions. Present in Beacon and Probe response frames transmitted by an AP. See 9.13.3.2. Set to 0 if the AP and all STAs that are associated to the AP are capable of receiving Greenfield transmissions. Set to 1 if the AP or one or more associated STAs are not capable of receiving Greenfield transmissions. Douglas, B., et al.

Proposed changes to resolutions September 2006 Proposed changes to resolutions CIDs 118, 4017, 4035, 4511, 12127: R C CIDs 12030, 12048, 10292, 12049: R A CID 4522: C Douglas, B., et al.

Straw Poll Would You support the proposed changes to the text? September 2006 Straw Poll Would You support the proposed changes to the text? Douglas, B., et al.

September 2006 Feedback What modifications would you suggest to improve what is being proposed by this submission? Douglas, B., et al.