Probe Request and Response in TGai October 2011 doc.: IEEE 802.11-11/1414r0 October 2011 Probe Request and Response in TGai Date: 2011-10-27 Authors: Katsuo Yunoki, KDDI R&D Laboratories Katsuo Yunoki, KDDI R&D Laboratories

October 2011 doc.: IEEE 802.11-11/1414r0 October 2011 Abstract This document describes a technical proposal for TGai which addresses the following phase. AP Discovery Katsuo Yunoki, KDDI R&D Laboratories Katsuo Yunoki, KDDI R&D Laboratories

Conformance w/ TGai PAR & 5C October 2011 doc.: IEEE 802.11-11/1414r0 October 2011 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 Katsuo Yunoki, KDDI R&D Laboratories Katsuo Yunoki, KDDI R&D Laboratories

October 2011 doc.: IEEE 802.11-11/1414r0 October 2011 Background Time occupied situation in the real case was presented in Doc. 寄与文書案(1)r. The time occupied rate will become higher and higher because of Smartphone increasing. Thus, we have to consider reducing needless packet exchanges which occur packet collisions and bigger latency in order to obtain the FILS advantages effectively. Katsuo Yunoki, KDDI R&D Laboratories Katsuo Yunoki, KDDI R&D Laboratories

Probe Request / Response October 2011 doc.: IEEE 802.11-11/1414r0 October 2011 Probe Request / Response In order to search the surrounding APs, a STA receives Beacon and transmit Probe Request in Broadcast. APs transmit Probe Response for responding received Probe Requests in unicast. STA AP1 AP2 AP3 AP4 Probe Request (wildcard) Probe Response Katsuo Yunoki, KDDI R&D Laboratories Katsuo Yunoki, KDDI R&D Laboratories

Example of Probe Request October 2011 doc.: IEEE 802.11-11/1414r0 October 2011 Example of Probe Request This STA transmits multiple “Probe Request” about every 15 seconds. 5 Probe Requests were observed around time stamp of 104 seconds. No Time source destination Info 72.980854 48:XX:bc:bc:a3:XX Broadcast Probe Request, SN=2207, FN=0, Flags=........C, SSID=Broadcast 73.001232 Probe Request, SN=2208, FN=0, Flags=........C, SSID=Broadcast 73.024225 Probe Request, SN=2209, FN=0, Flags=........C, SSID=Broadcast 73.044726 Probe Request, SN=2210, FN=0, Flags=........C, SSID=Broadcast 73.068847 Probe Request, SN=2211, FN=0, Flags=........C, SSID=Broadcast 73.087848 Probe Request, SN=2212, FN=0, Flags=........C, SSID=Broadcast 88.829271 Probe Request, SN=2229, FN=0, Flags=........C, SSID=Broadcast 88.872488 Probe Request, SN=2231, FN=0, Flags=........C, SSID=Broadcast 88.892895 Probe Request, SN=2232, FN=0, Flags=........C, SSID=Broadcast 88.915885 Probe Request, SN=2233, FN=0, Flags=........C, SSID=Broadcast 1 104.676169 Probe Request, SN=2251, FN=0, Flags=........C, SSID=Broadcast 2 104.69654 Probe Request, SN=2252, FN=0, Flags=........C, SSID=Broadcast 3 104.720389 Probe Request, SN=2253, FN=0, Flags=........C, SSID=Broadcast 4 104.740292 Probe Request, SN=2254, FN=0, Flags=........C, SSID=Broadcast 5 104.762662 Probe Request, SN=2255, FN=0, Flags=........C, SSID=Broadcast 135.522181 Probe Request, SN=2273, FN=0, Flags=........C, SSID=Broadcast 135.54242 Probe Request, SN=2274, FN=0, Flags=........C, SSID=Broadcast 135.565428 Probe Request, SN=2275, FN=0, Flags=........C, SSID=Broadcast 135.585791 Probe Request, SN=2276, FN=0, Flags=........C, SSID=Broadcast 135.608792 Probe Request, SN=2277, FN=0, Flags=........C, SSID=Broadcast 135.62938 Probe Request, SN=2278, FN=0, Flags=........C, SSID=Broadcast * Source MAC address was modified. Katsuo Yunoki, KDDI R&D Laboratories Katsuo Yunoki, KDDI R&D Laboratories

Example of Probe Response October 2011 doc.: IEEE 802.11-11/1414r0 Example of Probe Response October 2011 3 SSID were responded for probe requests. 26 probe responses were observed for 5 probe requests in Slide 7. No Time stamp source destination Into 1 104.678041 Matsushi_c5:XX:c0 48:XX:bc:bc:XX:2b Probe Response, SN=1983, FN=0, Flags=..m.....C, BI=100, SSID=AAA 2 104.679289 Matsushi_c5:XX:c1 Probe Response, SN=1984, FN=0, Flags=..m.....C, BI=100, SSID=BBB 3 104.680289 Probe Response, SN=1984, FN=0, Flags=..m.R...C, BI=100, SSID=BBB 4 104.681294 5 104.682414 Matsushi_c5:XX:c6 Probe Response, SN=1985, FN=0, Flags=........C, BI=100, SSID=CCC 6 104.683417 Probe Response, SN=1985, FN=0, Flags=....R...C, BI=100, SSID=CCC 7 104.722046 Probe Response, SN=1989, FN=0, Flags=..m.....C, BI=100, SSID=AAA 8 104.723294 Probe Response, SN=1990, FN=0, Flags=..m.....C, BI=100, SSID=BBB 9 104.724538 Probe Response, SN=1991, FN=0, Flags=........C, BI=100, SSID=CCC 10 104.741788 Probe Response, SN=1992, FN=0, Flags=..m.....C, BI=100, SSID=AAA 11 104.742788 Probe Response, SN=1992, FN=0, Flags=..m.R...C, BI=100, SSID=AAA 12 104.743665 13 104.744913 Probe Response, SN=1993, FN=0, Flags=..m.....C, BI=100, SSID=BBB 14 104.746167 Probe Response, SN=1994, FN=0, Flags=........C, BI=100, SSID=CCC 15 104.764165 Probe Response, SN=1995, FN=0, Flags=..m.....C, BI=100, SSID=AAA 16 104.76516 Probe Response, SN=1995, FN=0, Flags=..m.R...C, BI=100, SSID=AAA 17 104.766049 18 104.767043 19 104.768286 Probe Response, SN=1996, FN=0, Flags=..m.....C, BI=100, SSID=BBB 20 104.769288 Probe Response, SN=1996, FN=0, Flags=..m.R...C, BI=100, SSID=BBB 21 104.770289 22 104.77129 23 104.784916 Probe Response, SN=1998, FN=0, Flags=..m.....C, BI=100, SSID=AAA 24 104.785787 Probe Response, SN=1998, FN=0, Flags=..m.R...C, BI=100, SSID=AAA 25 104.786788 26 104.787662 Katsuo Yunoki, KDDI R&D Laboratories Katsuo Yunoki, KDDI R&D Laboratories

October 2011 doc.: IEEE 802.11-11/1414r0 October 2011 Considerations “Probe Request / Response” cause packet flooding even if the STA doesn’t have any connecting capabilities to surrounding APs. Transmitting “Probe Request” every 15 seconds doesn’t help the fast AP discovery. Avoiding needless packets may bring clearer WLAN air circumstances. Katsuo Yunoki, KDDI R&D Laboratories Katsuo Yunoki, KDDI R&D Laboratories

Proposal I’d like to propose that: October 2011 doc.: IEEE 802.11-11/1414r0 October 2011 Proposal I’d like to propose that: STA complied with TGai shall not use the wildcard SSID in SSID element of “Probe Request”. AP complied with TGai shall not transmit “Probe Response” for “Probe Request” with the wildcard SSID. I’d like to invite comments from experts. Katsuo Yunoki, KDDI R&D Laboratories Katsuo Yunoki, KDDI R&D Laboratories

References doc.: IEEE 11-11/1413r0 October 2011 Katsuo Yunoki, KDDI R&D Laboratories Katsuo Yunoki, KDDI R&D Laboratories