Transcript 12/0042r0: AP Discovery with FILS Beacon (Yunbo Li, Huawei)
Jan 2012 doc.: IEEE 802.11-12/0042r0
AP discovery with FILS beacon
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Date: 2012-1-8 Authors: email Name
Yunbo Li Robert Sun Edward Au Osama Aboul-Magd Junghoon Suh
Affiliations Address
Huawei Technologies Co., Ltd.
Huawei Technologies Co., Ltd.
Huawei Technologies Co., Ltd.
Huawei Technologies Co., Ltd.
Huawei Technologies Co., Ltd.
F1, Huawei Industrial Base, Bantian Longgang, Shenzhen 518129, China Suite 400, 303 Terry Fox Drive, Kanata, Ontario K2K 3J1 Suite 400, 303 Terry Fox Drive, Kanata, Ontario K2K 3J1 Suite 400, 303 Terry Fox Drive, Kanata, Ontario K2K 3J1 Suite 400, 303 Terry Fox Drive, Kanata, Ontario K2K 3J1
Phone
+86 15013596057 +1 613 2871948 +1 773 782 6875 +1 613 2871405 +1 613 2871315 [email protected]
Osama.AboulMagd@hua wei.com
m Submission Slide 1 Yunbo Li et al ,Huawei.
Jan 2012 doc.: IEEE 802.11-12/0042r0
Abstract
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In this presentation, current AP discovery mechanisms are summarized; FILS beacon is introduced to speedup the AP discovery.
Submission Slide 2 Huawei.
Jan 2012 doc.: IEEE 802.11-12/0042r0
Conformance w/ TGai PAR & 5C
Conformance Question
Does the proposal degrade the security offered by Robust Security Network Association (RSNA) already defined in 802.11?
Does the proposal change the MAC SAP interface?
Does the proposal require or introduce a change to the 802.1 architecture?
Does the proposal introduce a change in the channel access mechanism?
Response
No No No No Does the proposal introduce a change in the PHY?
No 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 Submission Slide 3 Huawei.
Jan 2012
Introduction
doc.: IEEE 802.11-12/0042r0 Fast Initial link setup is required in TGai
– High link setup time will be less than 100ms
Two ways to discovery AP:
– Passive scanning: passively receive Beacon – Active scanning: actively probe request/ probe response exchange
Current discovery mechanisms don’t meet the requirement
– Passive scanning is too slow, beacon period usually 100ms – Active scanning take much air time and easy to flood the network
We introduce a FILS Beacon to speedup AP discovery
Submission Slide 4 Huawei
Jan 2012 doc.: IEEE 802.11-12/0042r0
Problems in active scanning
Frames Occupied time
Both figures are Cited from KDDI 1413r1
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One probe request will cause many probe response; Probe request/ response exchange will flood the network when there are many STAs; Mobile devices are battery consumption critical, while active scanning consume more power.
Submission Slide 5 Huawei
Jan 2012 doc.: IEEE 802.11-12/0042r0
Problems in passive scanning
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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.
Submission Slide 6 Huawei
Jan 2012 doc.: IEEE 802.11-12/0042r0
FILS Beacon
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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.
Submission Slide 7 Huawei
Jan 2012 doc.: IEEE 802.11-12/0042r0
Elements in FILS beacon
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SSID Network Identifier (optional)
Submission Slide 8 Huawei
Jan 2012 doc.: IEEE 802.11-12/0042r0
Transmit pattern of FILS Beacon (1/2)
Option 1:
• Predefine a set of transmit modes, and randomly choose one transmit mode; – E.g. evenly set 6 time points within a Beacon period, following is 9 predefined patterns, 1 means transmit while 0 means doesn’t. – Example of predefined patterns: [1 0 1 0 0 0] [1 0 0 1 0 0] [1 0 0 0 1 0] [0 1 0 1 0 0] [0 1 0 0 1 0] [0 1 0 0 0 1] [0 0 1 0 1 0] [0 0 1 0 0 1] [0 0 0 1 0 1] Submission Slide 9 Huawei
Jan 2012 doc.: IEEE 802.11-12/0042r0
Transmit pattern of FILS Beacon (2/2)
Option 2:
• Set a time length T, AP will send out a FILS beacon if it doesn’t receive any of Beacon, Probe Response or FILS beacon for T.
Option 3:
• Periodically transmitted at a frequency higher than beacon. If transmit time is overlapped with beacon, only beacon will be transmitted.
Submission Slide 10 Huawei
Jan 2012
Straw poll 1
doc.: IEEE 802.11-12/0042r0
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Do you agree to introduce the FILS beacon in slide 7 to speedup AP discovery?
Submission Slide 11 Huawei.
Jan 2012
Straw poll 2
doc.: IEEE 802.11-12/0042r0
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Do you agree the elements of FILS in slide 8?
Submission Slide 12 Huawei.
Jan 2012
Straw poll 3
doc.: IEEE 802.11-12/0042r0
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Which FILS beacon transmit pattern in slide 9 and 10 do you prefer?
– Option 1 – Option 2 – Option 3 Submission Slide 13 Huawei.