Granted Patent B2

US 9,426,619 · App. 15/049,228 · Granted Aug 23, 2016

Abstract

Claims (31)

1. A method comprising:

receiving messages from plural positioning devices;

decoding from a message received from a first positioning device information identifying a mobile device and a signal strength measure relating to a strength of a signal received from the mobile device at the first positioning device;

using the signal strength measure to calculate a threshold signal strength; and

distributing the threshold signal strength to the plural positioning devices.

2. A method as claimed in claim 1 , wherein using the signal strength measure to calculate a threshold signal strength comprises:

comparing the signal strength measure to a maximum signal strength measure corresponding to the mobile device and relating to a time within a predetermined time window;

disregarding the signal strength measure if the maximum signal strength measure is not exceeded; and

providing the signal strength measure as the threshold signal strength if the threshold is exceeded.

3. A method as claimed in claim 1 , wherein using the signal strength measure to calculate a threshold signal strength comprises:

updating a record in a list with the signal strength measure if the threshold is exceeded; and

adding a new record to the list with the signal strength measure if the threshold is not exceeded.

4. A method as claimed in claim 1 , comprising maintaining a list of disallowed mobile devices, and distributing the list to the plural positioning devices.

5. A method as claimed in claim 1 , wherein the measure of strength of the received wireless signal is signal power.

6. Apparatus comprising:

at least one processor; and

at least one memory including computer program code;

the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to perform:

receiving messages from plural positioning devices;

decoding from a message received from a first positioning device information identifying a mobile device and a signal strength measure relating to a strength of a signal received from the mobile device at the first positioning device;

using the signal strength measure to calculate a threshold signal strength; and

distributing the threshold signal strength to the plural positioning devices.

7. Apparatus as claimed in claim 6 , wherein using the signal strength measure to calculate a threshold signal strength comprises:

comparing the signal strength measure to a maximum signal strength measure corresponding to the mobile device and relating to a time within a predetermined time window;

disregarding the signal strength measure if the maximum signal strength measure is not exceeded; and

providing the signal strength measure as the threshold signal strength if the threshold is exceeded.

8. Apparatus as claimed in claim 6 , wherein using the signal strength measure to calculate a threshold signal strength comprises:

updating a record in a list with the signal strength measure if the threshold is exceeded; and

adding a new record to the list with the signal strength measure if the threshold is not exceeded.

9. Apparatus as claimed in claim 6 , wherein the at least one memory and the computer program are further configured to, with the at least one processor, cause the apparatus to perform maintaining a list of disallowed mobile devices, and distributing the list to the plural positioning devices.

10. A non-transitory machine readable medium comprising computer code stored thereon that when executed by a processor causes an apparatus to perform the method of claim 1 .

Assignments (12)