AP discovery with FILS beacon Month Year doc.: IEEE 802.11-yy/xxxxr0 Jan 2012 AP discovery with FILS beacon Date: 2012-1-8 Authors: Name Affiliations Address Phone email Yunbo Li Huawei Technologies Co., Ltd. F1, Huawei Industrial Base, Bantian Longgang, Shenzhen 518129, China +86 15013596057 liyunbo@huawei.com Robert Sun Suite 400, 303 Terry Fox Drive, Kanata, Ontario K2K 3J1 +1 613 2871948 Rob.sun@huawei.com Edward Au +1 773 782 6875 Edward.au@huawei.com Osama Aboul-Magd +1 613 2871405 Osama.AboulMagd@huawei.com Junghoon Suh +1 613 2871315 Junghoon.suh@huawei.com Yunbo Li et al ,Huawei. John Doe, Some Company
Month Year doc.: IEEE 802.11-yy/xxxxr0 Jan 2012 Abstract In this presentation, current AP discovery mechanisms are summarized; FILS beacon is introduced to speedup the AP discovery. Huawei. John Doe, Some Company
Conformance w/ TGai PAR & 5C April 2009 doc.: IEEE 802.19-09/xxxxr0 Jan 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 802.11? No 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? 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
Introduction Fast Initial link setup is required in TGai Jan 2012 Introduction 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 Huawei
Problems in active scanning Jan 2012 Problems in active scanning Both figures are Cited from KDDI 1413r1 Frames Occupied time 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. Huawei
Problems in passive scanning Jan 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
Jan 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. Huawei
Elements in FILS beacon Jan 2012 Elements in FILS beacon SSID Network Identifier (optional) Huawei
Transmit pattern of FILS Beacon (1/2) Jan 2012 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] Huawei
Transmit pattern of FILS Beacon (2/2) Jan 2012 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. Slide 10 Huawei
Jan 2012 Straw poll 1 Do you agree to introduce the FILS beacon in slide 7 to speedup AP discovery? Huawei.
Straw poll 2 Do you agree the elements of FILS in slide 8? Jan 2012 Huawei.
Jan 2012 Straw poll 3 Which FILS beacon transmit pattern in slide 9 and 10 do you prefer? Option 1 Option 2 Option 3 Slide 13 Huawei.