Detecting rogue radio frequency based tags based on locationing

1. A system for detecting rogue radio frequency based devices, comprising:

a plurality of radio frequency based tags configured to be disposed at different fixed locations within an area and operable to periodically broadcast information in a beacon, the information including each tag's unique identity information, respectively;

a map of the area, the map for specifying identified radio frequency based tags and their respective locations within the area;

a mobile device operable to read at least one beacon in proximity to at least one of the radio frequency based tags and send at least one location update message, respectively; and

a server operable to detect rogue radio frequency based devices within the area based on an incorrect location update message and the map.

2. The system of claim 1 , further comprising at least one a plurality if access points operable to relay the at least one location update message in an IEEE 802.11 protocol to the server, wherein each access point is operable to serve a subset coverage area of the map.

3. The system of claim 1 , wherein the server is further operable to compare location update messages from various devices heuristically, wherein if few clients are reporting incorrect location update messages and more of the other clients are reported correct location update messages, then the server interprets this as the presence of a rogue device.

4. The system of claim 2 , wherein the server is further operable to validate a location update message from a device within a coverage area against location update messages from other devices that are also present in same coverage area, wherein if the information of some devices is not consistent compared to majority of clients in the same coverage area, then the server interprets this as the presence of a rogue device in that coverage area.

5. The system of claim 4 , wherein the server validates the comparison for a given time window.

6. The system of claim 2 , wherein the server is further operable to receive subsequent location update messages from the mobile device and associate these subsequent location update messages to detect the rogue radio frequency based device, wherein if a further N number of incorrect location update message are detected within a predetermined time window, then the server interprets this as the presence of a rogue device, and wherein location update messages reported from a boundary of a coverage area are weighted lower than location update messages reported from within the coverage area.

7. The system of claim 6 , wherein the server is operable to check that the reported tags in the location update messages create a correct sequential navigation path of neighboring tags in their correct locations in accordance with the map.

8. The system of claim 2 , wherein the at least one access point is operable to measure a received signal strength indicator of the location update message from the mobile device, and wherein the server is further operable to validate whether the received signal strength for a reported tag is appropriate for that AP and the map location of the tag.

9. The system of claim 1 , wherein when at least one sequential location update message includes the identities of at least two tags that should be distal from each other but the at least one sequential location update message shows them next to each other, the server is operable to determine the existence of a rogue device.

10. The system of claim 1 , wherein when at least one sequential location update message includes the identities of at least two tags, the server is operable to determine whether these tag identities that have not been historically included together, indicating the existence of a rogue tag.

11. The system of claim 1 , wherein the server receiving an unknown tag identity in the location update message indicates the existence of a rogue tag.

12. The system of claim 1 , wherein the server receiving a known tag identity, but determining that the tag is in an improper location, indicates the existence of a rogue tag.

13. The system of claim 1 , wherein the server is further operable to locate a rogue device using an access point coverage area and a legitimate location of a mobile device proximal in time to detecting the rogue device.

14. The system of claim 1 , wherein the information includes a battery status, and wherein the server is further operable to determine if a battery level of an identified tag keeps changing between different battery levels, indicating a rogue tag along with a legitimate tag having the same identity.

15. The system of claim 1 , wherein the information includes a sequence number, and wherein the server is further operable to determine if a sequence number of an identified tag becomes out of sequence, indicating a rogue tag.

16. A method for detecting rogue radio frequency based devices, comprising:

defining a map of an area, the map specifying identified radio frequency based tags and their respective locations within the area;

the radio frequency based tags periodically broadcasting information in respective beacons, the information including each tags unique identity information, respectively;

reading at least one beacon by a mobile device in proximity to at least one of the radio frequency based tags, respectively;

receiving at least one location update message from the mobile device, the message including identity information in the beacon; and

detecting rogue radio frequency based devices within the area based on an incorrect location update message and the map.

17. The method of claim 16 , further comprising the step of relaying the message to an area server, and wherein the detecting step is performed by the server.