Multi-mode mobile terminal and methods for operating the same

摘要

A multi-mode mobile terminal having a subscriber identity is provided which uses knowledge of communications network supported service levels to navigate to a communication mode allowing the greatest possible service availability when the subscriber identity in at least one of the network modes is invalid. The mobile terminal may not only provide the ability to switch communication service from a current mode to an alternative mode to process emergency calls but may also restrict user operations on a communications network based on the services available without a valid subscriber identity. Operations of the mobile terminal invention may be supported by service level information on various communication service providers contained in memory within the mobile terminal or be obtained by the mobile terminal from the networks. Based on services availability information for each communications network available to the mobile terminal, the mobile terminal selects an appropriate network to utilize for a call initiated while the mobile terminal has no valid subscriber identification. An example of such a call would be an emergency call such as a 911 call.