Patent ID: 9681303
Date: 2017-06-13
CPC Classifications: H04W

Claim:
1. A method for fraud detection in mobile communication networks, in case of roaming connections, wherein an existing misuse detection system (MEGS) is used for a preliminary analysis of potential roaming frauds and, in a case of a suspicious subscriber identity module, identified by the MEGS, a roaming connection provided for the suspicious subscriber identity module is checked by at least one additional criterion for possible misuse, the method comprising: placing at least one test call to the suspicious subscriber identity module to check a busy rate of the suspicious subscriber identity module to determine if the suspicious subscriber identity module is busy for a specified duration as the criterion, wherein, prior to carrying out the test call, determining a current location of the suspicious subscriber identity module by querying a current Visitor Location Register (VLR) location of the suspicious subscriber identity module, prior to carrying out the test call, determining a current Supplementary Services (SS) status of the suspicious subscriber identity module, comprising Call Waiting, Call Forwarding Unconditional, and Call Forwarding BUSY, at a Home Location Register (HLR), in the case of the current SS status being an active Call Forwarding Unconditional or active Call Forwarding BUSY or active Call Waiting in combination with Integrated Services Digital Network User Part 1 (ISUP1), temporarily deactivating the SS service in the HLR, carrying out the test call after the temporary deactivation, and after completion of the test call, restoring an original SS status, repeating the step of placing the test call a number of times, analyzing whether the busy rate of the suspicious subscriber identity module exceeds a threshold value, and if the busy rate of the suspicious subscriber identity module exceeds the threshold value in the step of analyzing, sending a signal to initiate barring of the suspicious subscriber identity module in the HLR.