SUBSCRIBER IDENTITY MODULE (SIM)-BASED FILTERING OF INCOMING/OUTGOING CALLS /TEXT MESSAGES

摘要

The application relates to filtering of incoming and outgoing events such as calls, texts or e-mails. Filtering is performed by a so-called firewall system which is based on a SIM which comprises the SIM application toolkit. The firewall system (5) comprises an incoming call filtering module (20), an outgoing call filtering module (22), an incoming text message filtering module (24), and an outgoing text message filtering module (2S). The firewall system (5) uses the incoming call filtering module (20) to filter incoming calls. A comparison module of the incoming call filtering module (20) compares the identifier number of an incoming call with one or more approved identifier numbers (406). If the identifier number of the incoming call does not match at least one of the one or more approved identifier numbers, a termination module of the incoming call filtering module (20) instructs the SIM (3) to send a command to the telephone (1) which causes it to be disconnected from the telecommunication network (410). In this embodiment of the invention, the command which the termination module instructs the SIM (3) to send to the telephone (1) comprises a REFRESH command provided as part of the SIM application toolkit application (9).The parameters of the REFRESH command are set to cause the telephone 1 to be disconnected from the telecommunication network.