Emergency call handling

A user terminal for use with a communications system, the user terminal comprising:

• a non-volatile memory;
• a subscriber identity authentication unit configured in use to communicate with a removable subscriber identity module and with said communications system in order to authenticate a subscriber identity stored in said subscriber identity module;
• a recording unit for recording in said non-volatile memory, details of unauthenticated emergency calls made from the terminal in the absence of a subscriber identity module;
• and
• a data handling unit configured, following re-installation of a subscriber identity module into the user terminal and at or following authentication of a subscriber to said system, to retrieve any emergency call details from said non-volatile memory, and to provide these to said system,
• wherein each of the unauthenticated emergency calls is an emergency call in which a subscriber is not fully authenticated or registered.

A method of handling unauthenticated emergency calls in a communication system that requires authentication of subscriber identities for non-emergency calls, the method comprising:

• upon authentication of a subscriber identity stored on a subscriber identity module installed in a user terminal, storing the subscriber identity in a non-volatile memory of the user terminal outside of said subscriber identity module;
• and
• following removal of the subscriber identity module from the user terminal, initiating an unauthenticated emergency call from the terminal, providing a user terminal identity in place of the subscriber identity in a call setup request during the initiation, retrieving the used and authenticated subscriber identity from said non-volatile memory and providing this to the communications system during the initiation,
• wherein the unauthenticated emergency call is an emergency call in which a subscriber is not fully authenticated or registered,
• wherein said user terminal identity is an International Mobile Equipment Identifier (IMEI) identity.

A method of handling unauthenticated emergency calls in a communication system that requires authentication of subscriber identities for non-emergency calls, the method comprising:

• following removal of a subscriber identity module from a user terminal, storing within a non-volatile memory of the terminal, details of unauthenticated emergency calls made from the terminal in the absence of the subscriber identity module;
• and
• following re-installation of a subscriber identity module into the user terminal and at or following authentication of a subscriber to said system, retrieving any emergency call details from said non-volatile memory, and providing these to said system,
• wherein each of the unauthenticated emergency calls is an emergency call in which a subscriber is not fully authenticated or registered.