Patent ID: 9538405
Date: 2017-01-03
CPC Classifications: G01S,H04W

Claim:
1. A displacement detection server for detecting potential displacement of a wireless transceiver connected to a machine-to-machine device, the displacement detection server comprising: a receiver hardware apparatus for receiving an updated radio environment message, the updated radio environment message comprising information identifying updated radio characteristics of at least two radio cells, the updated characteristics being measured by the wireless transceiver; a processor configured to determine whether the updated radio characteristics of said at least two radio cells differ more than a certain predetermined amount from previous radio characteristics of a previous radio environment message from the wireless transceiver; and a transmitter hardware apparatus, wherein the displacement detection server is arranged to use the transmitter to send a displacement indication message to a device management server as a result of the processor determining that the updated radio characteristics differ more than the certain predetermined amount from the previous radio characteristics, the displacement indication message indicating potential displacement of the wireless transceiver, the displacement detection server is located remotely from the wireless transceiver, the information identifying updated radio characteristics of the at least two radio cells comprises a first set of received signal strength values, said first set of received signal strength values comprising a first received signal strength value based on a measured strength of a signal from a first cell and a second received signal strength value based on a measured strength of a signal from a second cell, the previous radio characteristics of said previous radio environment message comprises a second set of received signal strength values, said second set of received signal strength values comprising a third received signal strength value based on a measured strength of a signal from the first cell and a fourth received signal strength value based on a measured strength of a signal from the second cell, and the processor is configured to determine whether the updated radio characteristics of said at least two radio cells differ more than the certain predetermined amount from the previous radio characteristics of the previous radio environment message by determining whether the first set of received signal strength values differs more than the certain predetermined amount from the second set of received signal strength values.