1. Virtual AP Presentation
Month Year
doc.: IEEE yy/xxxxr0
January, 2006
Virtual AP Presentation
Date:
Authors:
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S. Ponnuswamy (Aruba Networks)
John Doe, Some Company

2. Non-transmitted BSSID
January, 2006
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 2n)
The BSSID Index (i) is part of the Multiple BSSID Index IE
S. Ponnuswamy (Aruba Networks)

3. Multiple BSSID-TIM element
January, 2006
Multiple BSSID-TIM element
Element ID
Length
Bitmap Control
Partial Virtual Bitmap
Octets: 1
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 2n bits of the TIM are reserved for broadcast
The rest of the bits are shared by all non-transmitted BSSIDs
S. Ponnuswamy (Aruba Networks)

4. Beacon Frame Format Order Information Notes 22 Multiple BSSID
January, 2006
Beacon Frame Format
Order
Information
Notes 22
Multiple BSSID
The Multiple BSSID element is present only within Beacon frames generated by APs which support multiple BSSIDs. 23
Multiple BSSID-Index
The Multiple BSSID-Index element is present only within Beacon frames generated by APs which support multiple BSSIDs. 24
Multiple BSSID-TIM
The Multiple BSSID-TIM element is present only within Beacon frames generated by APs which support multiple BSSIDs. 25
Vendor Specific
One or more vendor specific information elements may appear in the frame.
S. Ponnuswamy (Aruba Networks)

5. Beacon size Basic multiple BSSID element Multiple BSSID-TIM
January, 2006
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
S. Ponnuswamy (Aruba Networks)

6. Beacon size comparison
January, 2006
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
S. Ponnuswamy (Aruba Networks)

7. Beacon size comparison data
January, 2006
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
256
152
209 3
384
169
283 4
512
186
357 5
640
203
431 6
768
220
505 7
896
237
579 8
1024
254
653 9
1152
271
727 10
1280
288
801 11
1408
305
875 12
1536
322
949 13
1664
339
1023 14
1792
356
1097 15
1920
373
1171 16
2048
390
1245
S. Ponnuswamy (Aruba Networks)

8. January, 2006
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
S. Ponnuswamy (Aruba Networks)

9. January, 2006
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
S. Ponnuswamy (Aruba Networks)

10. Probe Request Format January, 2006 Order Information Notes 5
Multiple SSID
The Multiple SSID element is present when the STA requests information on multiple SSIDs. 6
Vendor Specific
One or more vendor specific information elements may appear in the frame.
S. Ponnuswamy (Aruba Networks)

11. Probe Response Format January, 2006 Order Information Notes 21
Multiple BSSID-PR
The Multiple BSSID-PR element is present only within Probe Response frames generated by APs supporting the Multiple BSSID capability. 22
Vendor Specific
One or more vendor specific information elements may appear in the frame.
S. Ponnuswamy (Aruba Networks)

12. Legacy Interoperability
January, 2006
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
S. Ponnuswamy (Aruba Networks)

13. January, 2006
Motion
Motion: “Instruct the editor to include the substantive text in document r2-Virtual AP Proposal into the TGv draft”
Mover/Seconder:
Result
Yes No
Abstain
S. Ponnuswamy (Aruba Networks)

14. January, 2006
References
S. Ponnuswamy (Aruba Networks)