Patent ID: 8254916

Claim:
A method for blocking roaming-steering mechanisms, wherein the method carries out a registration of a foreign cellular mobile telephone device ( 3 ) with a national visited mobile network ( 2 ) if a roaming agreement exists between a foreign and the national mobile network operator for mutual billing of mobile radio services, wherein an anti-roaming-steering server ( 5 ) that is installed in the nationally visited mobile network ( 2 ) detects manipulated error messages ( 14 a through 14 d ) and, by means of a suitable influence on signaling processes, performs a targeted manipulation of the registration process ( 8 a through 8 d ) of foreign cellular subscribers, wherein an Update Location message is routed via an anti-roaming steering server ( 5 ) in the national visited mobile network ( 2 ), a roaming steering server ( 7 ) of the foreign mobile network ( 1 ) intercepts the Update Location message from the national visited mobile network ( 2 ) and rejects a Location Update attempt with the error message ( 14 a - 14 d ), the anti-roaming steering server ( 5 ) detects at least one of the error messages, and in a database of the anti-roaming steering server ( 5 ) of the national visited mobile network operator a determination is made as to whether and with which method an anti-roaming steering is to be performed, and if an anti-roaming steering is to be performed, the error message from the roaming steering sever ( 7 ) of the operator of the foreign mobile network ( 1 ) is intercepted in the anti-roaming steering server ( 5 ) of the national visited mobile network operator and not forwarded to the cellular mobile telephone device ( 3 ), the anti-roaming steering server ( 5 ) of the national visited mobile network operator sends to the cellular mobile telephone device ( 3 ) of the foreign customer a simulated successful acknowledgement of the Location Update attempt that results in a faked “Location Update Accept”, wherein no subscriber data is transmitted from a home location register HLR ( 6 ) of the foreign mobile network ( 1 ) to a visitors location register VLR ( 4 ) of the national visited mobile network ( 2 ), with the result that the cellular subscriber is unable to use any telecommunication services, with the exception of emergency calls, and a registration with the national visited mobile network ( 2 ) is prevented in order to prevent a higher signaling load.