| 摘要 |
<p>A telecommunications system, such as a mobile telecommunications system, comprises a plurality of networks such as all owned or controlled in common. Smart cards are used for enabling terminals within the system to communicate. If the networks are GSM or UMTS networks, the smart cards can be SIM cards. A SIM card management centre (10) is provided which carries out the process normally carried out by a network operator for registering one of the SIM cards with its network (as its 'home' network), using information supplied by the SIM card supplier. In addition, however, the SIM card management centre (10) can re-register each smart card with a different one of the networks (as its new home network). One of these networks is a common network embracing or including all or some of the other networks, such as embracing the areas which they cover. Secret information relating to all the networks (including the common network) is pre-stored, in respective records, on each SIM card at the outset. The record specific to a particular one of the networks merely has to be activated when the SIM card is to be registered or re-registered with that network. The need for transmission of new secret information to the SIM card when re-registering it with a different one of the networks, which would potentially compromise security, is avoided. In this way, therefore, SIM cards for all or some of the users can be migrated onto the common network which could thus take the place of the individual networks and could thus cover a larger geographical area.</p> |
