1. doc.: IEEE 802.11-05/1219r2 Submission January, 2006 S. Ponnuswamy (Aruba Networks)Slide 1 Virtual AP Presentation 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: 2006-01-16Authors:

2. doc.: IEEE 802.11-05/1219r2 Submission January, 2006 S. Ponnuswamy (Aruba Networks)Slide 2 Non-transmitted BSSID AP_BSSID is the legacy BSSID from beacon’s MAC header Virtual AP BSSID(i) = (AP_BSSID n LSBs set to zero) | ((n LSBs of AP_BSSID) + i) mod 2 n ) The BSSID Index (i) is part of the Multiple BSSID Index IE

3. doc.: IEEE 802.11-05/1219r2 Submission January, 2006 S. Ponnuswamy (Aruba Networks)Slide 3 Multiple BSSID-TIM element The format is the similar to the legacy TIM element –DTIM Count/DTIM Period are carried separately in Multi-BSSID element Legacy stations interpret the legacy TIM element Stations associated with one of the non-transmitted BSSIDs interpret the Multiple BSSID-TIM element The first 2 n bits of the TIM are reserved for broadcast The rest of the bits are shared by all non-transmitted BSSIDs Element IDLengthBitmap Control Partial Virtual Bitmap Octets:1111 - 251

4. doc.: IEEE 802.11-05/1219r2 Submission January, 2006 S. Ponnuswamy (Aruba Networks)Slide 4 Beacon Frame Format OrderInformationNotes 22Multiple BSSID The Multiple BSSID element is present only within Beacon frames generated by APs which support multiple BSSIDs. 23Multiple BSSID- Index The Multiple BSSID-Index element is present only within Beacon frames generated by APs which support multiple BSSIDs. 24Multiple BSSID- TIM The Multiple BSSID-TIM element is present only within Beacon frames generated by APs which support multiple BSSIDs. 25Vendor Specific One or more vendor specific information elements may appear in the frame.

5. doc.: IEEE 802.11-05/1219r2 Submission January, 2006 S. Ponnuswamy (Aruba Networks)Slide 5 Beacon size Basic multiple BSSID element –SSID and multiple BSSID Index elements included Multiple BSSID-TIM An AP may opt to transmit one or more detailed BSSID profiles

6. doc.: IEEE 802.11-05/1219r2 Submission January, 2006 S. Ponnuswamy (Aruba Networks)Slide 6 Beacon size comparison Average beacon length of 128 bytes The worst case includes all optional elements Medium access and PHY (preamble/PLCP) overhead is not counted

7. doc.: IEEE 802.11-05/1219r2 Submission January, 2006 S. Ponnuswamy (Aruba Networks)Slide 7 Beacon size comparison data # VAPs Legacy beacon size (multiple beacons) Minimum beacon size with proposed solution Maximum beacon size with proposed solution 1 128 2 256152 209 3 384169 283 4 512186 357 5 640203 431 6 768220 505 7 896237 579 8 1024254 653 9 1152271 727 10 1280288 801 11 1408305 875 12 1536322 949 13 1664339 1023 14 1792356 1097 15 1920373 1171 16 2048390 1245

8. doc.: IEEE 802.11-05/1219r2 Submission January, 2006 S. Ponnuswamy (Aruba Networks)Slide 8 Probe Responses Use similar format as beacons, with the exception of the BSSID-Index element –DTIM information is nor present in probe response The number of BSSIDs returned could be different from the ones advertised The BSSID in the MAC header may be different from the one in the beacons

9. doc.: IEEE 802.11-05/1219r2 Submission January, 2006 S. Ponnuswamy (Aruba Networks)Slide 9 Probe Requests Ability to request responses from multiple BSSIDs using Multiple SSID element –An STA can send a broadcast request with multiple SSIDs that may span multiple physical APs More than one Multiple SSID element may be included in a probe request

10. doc.: IEEE 802.11-05/1219r2 Submission January, 2006 S. Ponnuswamy (Aruba Networks)Slide 10 Probe Request Format OrderInformationNotes 5Multiple SSIDThe Multiple SSID element is present when the STA requests information on multiple SSIDs. 6Vendor SpecificOne or more vendor specific information elements may appear in the frame.

11. doc.: IEEE 802.11-05/1219r2 Submission January, 2006 S. Ponnuswamy (Aruba Networks)Slide 11 Probe Response Format OrderInformationNotes 21Multiple BSSID-PRThe Multiple BSSID-PR element is present only within Probe Response frames generated by APs supporting the Multiple BSSID capability. 22Vendor SpecificOne or more vendor specific information elements may appear in the frame.

12. doc.: IEEE 802.11-05/1219r2 Submission January, 2006 S. Ponnuswamy (Aruba Networks)Slide 12 Legacy Interoperability The beacon appears like a legacy beacon to legacy STAs –The new IE should be ignored by legacy STAs Multiple BSSID aware STAs can use all the IEs defined in the document All frames from the AP, except the beacon, should use the appropriate BSSID in the MAC header

13. doc.: IEEE 802.11-05/1219r2 Submission January, 2006 S. Ponnuswamy (Aruba Networks)Slide 13 Motion Motion: “Instruct the editor to include the substantive text in document 11-05-1120r2-Virtual AP Proposal into the TGv draft” Mover/Seconder: Result –Yes –No –Abstain

14. doc.: IEEE 802.11-05/1219r2 Submission January, 2006 S. Ponnuswamy (Aruba Networks)Slide 14 References