1. AP discovery with FILS beacon
Month Year
doc.: IEEE yy/xxxxr0
Mar 2012
AP discovery with FILS beacon
Date:
Authors:
Name
Affiliations
Address
Phone
Yunbo Li
Huawei Technologies Co., Ltd.
F1, Huawei Industrial Base, Bantian Longgang, Shenzhen , China
Robert Sun
Suite 400, 303 Terry Fox Drive, Kanata, Ontario K2K 3J1
Edward Au
Osama Aboul-Magd
Junghoon Suh
Yunbo Li et al ,Huawei.
John Doe, Some Company

2. Month Year
doc.: IEEE yy/xxxxr0
Mar 2012
Abstract
In this presentation, the necessity of passive scanning during AP discovery is described;
FILS beacon is introduced to accelerate the AP discovery.
Huawei.
John Doe, Some Company

3. Conformance w/ TGai PAR & 5C
April 2009
doc.: IEEE /xxxxr0
Mar 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
Huawei.
Rich Kennedy, Research In Motion

4. Introduction Fast Initial link setup is required in TGai
Mar 2012
Introduction
Fast Initial link setup is required in TGai
High link setup time will be less than 100ms, which is hard to achieve when using current AP discovery techniques.
Two ways to discovery AP:
Passive scanning:
indispensable in some scenario;
usually take long time, and need to accelerate it for FILS
Active scanning:
Much quicker, but take much air time and easy to flood the network;
Some filter or cooperate techniques are proposed for FILS;
We introduce a FILS Beacon to accelerate AP discovery
Huawei

5. Necessity of passive scanning
Mar 2012
Necessity of passive scanning
Radar band is overlapped with WiFi 5G band;
Clause of REVmb D12.0: A STA does not transmit in a channel unless the channel has been tested for the presence of radar transmissions according to regulatory requirements.
Passive scanning is needed in Radar band;
Current passive scanning need to be improved to meet the requirement of FILS;
FILS beacon may be an effective method.
Slide 5
Huawei

6. Problems in passive scanning
Mar 2012
Problems in passive scanning
Current beacon transmitted period (100ms) is too long for FILS;
Increase the transmit frequency of Beacon will occupies much air time, because Beacon frame contains a large payload (usually > 100 Bytes);
Increase the transmit frequency of Beacon will consume more power of mobile STAs.
Slide 6
Huawei

7. Mar 2012
FILS Beacon
Define a very short beacon (FILS beacon) to advertise AP, transmit it much more frequently;
FILS beacon only contains several necessary element for discovery;
FILS beacon will not replace the traditional Beacon frame, it will be sent much more frequently between traditional Beacons;
Note：FILS beacon does not exclude active scanning;
Huawei

8. Information in FILS beacon
Mar 2012
Information in FILS beacon
SSID
Network Identifier (optional)
Time to the next beacon
…(other element that will help for FILS)
Huawei

9. Simulation for FILS Beacon
Mar 2012
Simulation for FILS Beacon
NS-2 platform;
5 APs in the simulation;
5 unassociated STAs and 5 associated STAs for each AP;
Each unassociated STAs need to find the AP with intended SSID;
Regular Beacon with a BI of 100ms;
There are only two elements in FILS Beacon: SSID (18 bytes) andTime to next beacon element (6 bytes);
The simulation results are obtained from 15 independent experiments.
Slide 9
Huawei

10. Simulation for FILS Beacon
Mar 2012
Simulation for FILS Beacon
Figure 1 Without background traffic
Slide 10
Huawei

11. Simulation for FILS Beacon
Mar 2012
Simulation for FILS Beacon
Figure 2 Background traffic
Slide 11
Huawei

12. Simulation for FILS Beacon
Mar 2012
Simulation for FILS Beacon
Figure 3 Background traffic
Slide 12
Huawei

13. Simulation for FILS Beacon
Mar 2012
Simulation for FILS Beacon
Figure 4 Background traffic
Slide 13
Huawei

14. What else after FILS beacon
Mar 2012
What else after FILS beacon
Pure passive scanning:
Wait for the next beacon if the waiting time is short;
switch to other channel to do further scanning if waiting time is long;
Hybrid scanning:
Send Probe Request frame with intended SSID, and AP reply with a broadcast Probe Response frame. (Cooperate info can be included for further improvement);
Slide 14
Huawei

15. Conclusion FILS Beacon can reduce the AP discovery time;
Mar 2012
Conclusion
FILS Beacon can reduce the AP discovery time;
It has a optimal number of FILS Beacon within a regular BI (100ms), it could be around 3;
Propose:
Design a specific MAC frame to accelerate the passive scanning of AP discovery for FILS.
Slide 15
Huawei

16. Mar 2012
Straw poll 1
Do you agree the passive scanning need to improve for FILS?
Slide 16
Huawei.

17. Mar 2012
Straw poll 2
Do you agree to introduce the FILS beacon as presented in 12/0042r4 to accelerate AP discovery?
Y: 20
N: 3
More information: 13
Slide 17
Huawei.