1. FILS Frame Content Date: 2012-11-01 Authors: February 2008
doc.: IEEE /2376r0
Date: Nov, 2012
FILS Frame Content
Date:
Authors:
Liwen Chu, ST
Liwen Chu, STMicroelectronics

2. Conformance w/ TGai PAR & 5C
Nov 2012
Conformance w/ TGai PAR & 5C
Conformance Question
Response
Does the proposal degrade the security offered by Robust Security Network Association (RSNA) already defined in ? No
Does the proposal change the MAC SAP interface?
Does the proposal require or introduce a change to the architecture?
Does the proposal introduce a change in the channel access mechanism?
Does the proposal introduce a change in the PHY?
Which of the following link set-up phases is addressed by the proposal?
(1) AP Discovery (2) Network Discovery (3) Link (re-)establishment / exchange of security related messages (4) Higher layer aspects, e.g. IP address assignment
1,2
Liwen Chu, ST

3. Non-HT Duplicate FILS Support
Date: Nov, 2012
Non-HT Duplicate FILS Support
Liwen Chu, ST

4. Non-HT Duplicate FILS in 802.11ai
Date: Nov, 2012
Non-HT Duplicate FILS in ai
802.11ai allows an AP to transmit a duplicate FILS frame. (See below.)
In the FILS frame content definition (11-12/1030), there are no indications of the primary channel nor the operating channel bandwidth.
Problem: A STA that receives a duplicate FILS frame doesn’t know where to receive the beacon.
Preamble
Payload/FILS Advertisement
Primary channel of the transmitter
Preamble
Payload/FILS Advertisement
Preamble
Payload/FILS Advertisement
Preamble
Payload/FILS Advertisement
Slide 4
Liwen Chu, ST 4

5. Solution: Optional Primary Channel Indication in FILS
Date: Nov, 2012
Solution: Optional Primary Channel Indication in FILS
A Primary Channel field is added to FILS to indicate the 20MHz primary channel of the BSS:
Operating Class (1 byte),
Since the primary channel that is used to transmit beacon is always 20MHz channel. This can be removed.
Channel Number (1 byte).
A Primary Channel Present subfield (1 bit) indicates whether the FILS frame includes the Operating Class and Channel Number.
When FILS is not transmitted in a non-HT duplicate PPDU, Primary Channel Present is set to 0.
When transmitting a duplicate FILS frame, an AP can indicate the 20MHz primary channel by the Primary Channel field.
A STA that receives FILS in a secondary channel can switch to the primary channel to receive the Beacon at the TBTT.
Liwen Chu, ST 5

6. Multiple BSSID Support
Date: Nov, 2012
Multiple BSSID Support
Liwen Chu, ST

7. Multiple BSSID An AP device may support multiple BSSIDs (with .11v).
Date: Nov, 2012
Multiple BSSID
An AP device may support multiple BSSIDs (with .11v).
Only one AP (the transmitted AP identified by transmitted BSSID) broadcasts beacons.
Once an STA receives a beacon with Multiple BSSID IE, it can figure out the non-transmitted BSSID and the profile of the non-transmitted AP.
Other APs in the same AP device define the operation of their networks through the non-transmitted profiles and the management information of the transmitted AP.
A STA can associate with a non-transmitted AP.
If a STA receives a FILS and decides that the SSID in FILS is not what the STA wants, the STA may sense another channel right away.
Problem: In FILS a STA can’t figure out the networks identified by the non-transmitted BSSIDs.
The STA may miss a BSS that it might want to associate with.
Liwen Chu, ST 7

8. Solution: Multiple BSSID Indication in FILS
Date: Nov, 2012
Solution: Multiple BSSID Indication in FILS
A Multiple BSSID Present bit can be put in FILS frame, e.g. in FD Capability field.
Once a STA receives FILS with Multiple BSSID Present being set to 1, the STA can select to receive the normal beacon or send a Probe Request.
Or the content of the .11v Multiple BSSID IE can be a optional variable field in the FILS frame.
Propose to use option 1.
Liwen Chu, ST 8

9. Date: Nov, 2012
FD Capability Field
Liwen Chu, ST

10. FD Capability Field in 11-12/1030
Date: Nov, 2012
FD Capability Field in 11-12/1030
Liwen Chu, ST 10

11. FD Capability Discussion
Date: Nov, 2012
FD Capability Discussion
The FD Capability field is for network selection and not for BSS operation.
Most bits in Capability field are for BSS operation. They should not be in FD Capability, e.g. subfields in Capability field except Privacy subfield.
dot11PHYType includes many old types which should not be in FD Capability.
2 bits should be used to identify the network type: 11b, 11a/11g, 11n, 11ac.
Or, 2 bits should be used to identify the BSS capability: 20MHz, 40MHz, 80MHz, 160MHz/80MHz+80MHz.
Or, their combination.
Supported Minimum Rate field provides no help to BSS selection.
What is helpful is the network’s maximum rate that is identified by
the maximum data rate, or
the combination of channel bandwidth, number of spatial stream, modulation, and coding rate). The most valuable items are channel bandwidth and number of spatial streams.
Liwen Chu, ST 11

12. Updated FD Capability Option 1: Option 2: Date: Nov, 2012
Operation Channel Width
PHY Type
Nss (Number of Spatial Streams)
Multiple BSSID Support
Privacy
IPv4 Support
IPv6 Support
Reserved
000: 20MHz
001: 40MHz
010: 80MHz
011: 160MHz
100: Reserved
101: Reserved
110: Reserved
111: Reserved
000: 11b
001: 11a/11g
010: 11n
011: 11ac
100: Reserved
101: Reserved
110: Reserved
111: Reserved
000: 1
001: 2
010: 3
011: 4
100: 8
101: Reserved
110: Reserved
111: Reserved
Option 2: B0 B2 B3 B5 B6 B7 B8 B9
B10
B15
Operation Channel Width
Nss (Number of Spatial Streams)
Multiple BSSID Support
Privacy
IPv4 Support
IPv6 Support
Reserved
000: 20MHz
001: 40MHz
010: 80MHz
011: 160MHz
100: Reserved
101: Reserved
110: Reserved
111: Reserved
000: 1
001: 2
010: 3
011: 4
100: 8
101: Reserved
110: Reserved
111: Reserved
Liwen Chu, ST 12

13. Updated FD Capability (Cont’d)
Date: Nov, 2012
Updated FD Capability (Cont’d)
Option 3: B0 B2 B3 B5 B6 B7 B8 B9
B10
B15
PHY Type
Nss (Number of Spatial Stream)
Multiple BSSID Support
Privacy
IPv4 Support
IPv6 Support
Reserved
000: 11b
001: 11a/11g
010: 11n
011: 11ac
100: Reserved
101: Reserved
110: Reserved
111: Reserved
000: 1
001: 2
010: 3
011: 4
100: 8
101: Reserved
110: Reserved
111: Reserved
Option 2 is preferable since it is simple and conveys enough information (i.e. Bandwidth, and Nss) to describe the BSS PHY data rate.
Liwen Chu, ST 13

14. Date: Nov, 2012
Straw Poll 1
Do you support to add 1-bit Primary Channel Present and optional 8-bit Primary Channel field in FILS frame?
Yes No
Abstain
Liwen Chu, ST 14

15. Date: Nov, 2012
Straw Poll 2
Do you support to add 1-bit Multiple BSSID Present in FILS frame?
Yes No
Abstain
Liwen Chu, ST 15

16. Straw Poll 3 Do you support option 2 of FILS Capability in slide 12?
Date: Nov, 2012
Straw Poll 3
Do you support option 2 of FILS Capability in slide 12?
Yes No
Abstain
Liwen Chu, ST 16