Method and system for wireless local area network proximity recognition
A method and system for proximity detection, recognition and classification of a wireless local area network (WLAN) enabled device without a WLAN infrastructure. The proximity recognition system monitors WLAN communications at one or more known locations. The proximity of a WLAN device (transmitter) is sensed by examining signal strength received therefrom as the device engages in a sequence of protocol data unit exchanges seeking WLAN association.
1. A method for detecting in a venue, the proximity of a mobile device that is enabled, according to a communications protocol, to request access to a wireless local area network (WLAN) infrastructure element, comprising the steps of:
(a) monitoring wireless communications in the venue in accordance with the communications protocol;
(b) detecting first message from the mobile device that was sent as part of the communications protocol to request access to the WLAN infrastructure element, and reading from said first message, the identity of the requested WLAN infrastructure element;
(c) artificially provoking second message to be sent from the mobile device by sending a provocatively-formatted message to the mobile device without the use of WLAN infrastructure elements, the provocatively-formatted message being a message that is formatted with an identity of its source, to be said read identity of the requested WLAN infrastructure element of said first message, said second message counting as more than normal for the communications protocol as being provoked by said provocatively-formatted message that uses as its out-of-protocol source address, said read identity of the requested WLAN infrastructure element.
2. The method of claim 1 , wherein said first message is a probe request.
3. The method of claim 2 , wherein said provocatively-formatted message is the probe response message.
4. The method of claim 2 , wherein said provocatively-formatted message is the disassociate-ion message.
5. The method of claim 2 , wherein said provocatively-formatted message is the beacon message.
6. The method of claim 2 , wherein said identity of the requested WLAN infrastructure element is its service set identifier (SSID).
7. The method of claim 1 , further comprising the step of:
(d) detecting said second message from the mobile device and using said second message to generate additional information that is useful in detecting proximity of the mobile device.
8. A proximity detection device for detecting in a venue, the proximity of a mobile device that is enabled, according to a communications protocol, to request access to a WLAN infrastructure element organized under that protocol, that
(a) monitors wireless communications in the venue in accordance with the communications protocol;
(b) detects first message from the mobile device that was sent as part of the communications protocol to request access to the wireless local area network, and reads from said first message, the identity of the requested WLAN infrastructure element;
(c) artificially provokes second message from the mobile device by sending a provocatively-formatted message to the mobile device without the use of WLAN infrastructure elements, the provocatively-formatted message being a message that is formatted with an identity of its source, to be said read identity of the requested WLAN infrastructure element of said first message, said second message counting as more than normal for the communications protocol as being provoked by said provocatively-formatted message that uses as its out-of-protocol source address, said read identity of the requested WLAN infrastructure element.
9. The device of claim 8 , wherein said first message is a probe request.
10. The device of claim 9 , wherein said provocatively-formatted message is the probe response message.
11. The device of claim 9 , wherein said provocatively-formatted message is the disassociate-ion message.
12. The device of claim 9 , wherein said provocatively-formatted message is the beacon message.
13. The device of claim 9 , wherein said identity of the requested WLAN infrastructure element is its service set identifier (SSID).
14. The device of claim 8 , wherein said PRD detects said second message from the mobile device and uses said second message to generate additional information that is useful in detecting proximity of the mobile device.