Releasing mobile terminal such as mobile telephone to work with any SIM by comparing outgoing call time with threshold value to determine validity

摘要

The method involves detecting the talk time (9) of outgoing calls made by the mobile terminal using a call time meter (10), and comparing it with a threshold value (12). The mobile terminal can be released for use with any subscriber identification module if the threshold value is exceeded. The comparison may be made when the terminal is switched on. At manufacture, the terminal may be restricted to the use of certain SIMs. An Independent claim is included for a mobile radio terminal.