Device, a system, a method and computer program for identifying interfering devices in position measurements

A method of identifying if an interference device is active in a positioning system determining positions of a plurality of mobile terminals, the method comprising:

• receiving individual position data from individual ones of the plurality of mobile terminals which individual position data indicates an individual location where the individual ones of the mobile terminals are located based on positioning signals received by the mobile terminals;
• identifying if at least some of the individual position data may have been affected by one or more interfering signals transmitted by at least one interfering device and interfering with the positioning signals, by:
• identifying if a number of the mobile terminals in a first area is higher than a maximum threshold number, and, if so, determining that individual position data of the number of mobile terminals may have been affected by the one or more interfering signals of the at least one interfering device;
• identifying if a number of the mobile terminals in a second area is lower than a minimum threshold number;
• and, if so, determining that individual position data of the number of mobile terminals may have been affected by the one or more interfering signals of the at least one interfering device;
• and
• receiving further individual position data which further individual position data indicates further areas in which individual ones of the mobile terminals are located based on another positioning technique than a positioning technique used to determine the individual position data as received from the individual ones of the mobile terminals;
• the individual locations indicated by the individual position data are areas in which respective individual ones of the mobile terminals are located, and determining if, for one or more individual ones of the mobile terminals, the areas overlap with the further areas at least to a minimum extent, and, if not, determining that individual position data of the one or more individual ones of the mobile terminals may have been affected by the one or more interfering signals from the at least one interfering device.

A system comprising:

• an interference detection device comprising:
• a processing unit and memory storing instructions of a computer program configured when executed by the processing unit, to cause the processing unit to:
• receive individual position data from individual ones of a plurality of mobile terminals which individual position data indicates an individual location where the individual ones of the mobile terminals are located based on positioning signals received by the mobile terminals;
• identify if at least some of the individual position data may have been affected by one or more interfering signals transmitted by at least one interfering device and interfering with the positioning signals, by:
• identifying if a number of the mobile terminals in a first area is higher than a maximum threshold number, and, if so, determining that individual position data of the number of mobile terminals may have been affected by the one or more interfering signals of the at least one interfering device;
• identifying if a number of the mobile terminals in a second area is lower than a minimum threshold number;
• and, if so, determining that individual position data of the number of mobile terminals may have been affected by the one or more interfering signals of the at least one interfering device;
• and
• receiving further individual position data which further individual position data indicates further areas in which individual ones of the mobile terminals are located based on another positioning technique than a positioning technique used to determine the individual position data as received from the individual ones of the mobile terminals;
• the individual locations indicated by the individual position data are areas in which respective individual ones of the mobile terminals are located, and determining if, for one or more individual ones of the mobile terminals, the areas overlap with the further areas at least to a minimum extent, and, if not, determining that individual position data of the one or more individual ones of the mobile terminals may have been affected by the one or more interfering signals from the at least one interfering device;
• and
• one or more mobile terminals configured to receive positioning signals, calculate their individual position based on these received positioning signals and transmit individual position data indicating the individual position to the interference detection device.