Abstract: A mobile terminal, which is registered to either a first mobile communication network or a second communication network, determines whether it is possible to register to the first mobile communication network on the basis of control information received from the second mobile communication network. Then, the mobile terminal attempts to register to the first mobile communication network a predetermined number of times in a case that it is determined that it is possible to register to the first mobile communication network.

Abstract: A mobile terminal, which is registered to either a first mobile communication network or a second communication network, determines whether it is possible to register to the first mobile communication network on the basis of control information received fi-om the second mobile communication network. Then, the mobile terminal attempts to register to the first mobile communication network a predetermined number of times in a case that it is determined that it is possible to register to the first mobile communication network.

Abstract: A mobile terminal, which is registered to either a first mobile communication network or a second communication network, determines whether it is possible to register to the first mobile communication network on the basis of control information received from the second mobile communication network. Then, the mobile terminal attempts to register to the first mobile communication network a predetermined number of times in a case that it is determined that it is possible to register to the first mobile communication network.

Abstract: IP server W and gateway server GWS transmit data in HTML format in response to a request from mobile unit MS. At this stage, in the HTML data, the personal identification information request data string is added to a URL of the page corresponding to a service, which requires user authentication. As the HTML data is received by mobile unit MS, the user carries out an inputting operation to designate the URL while the image corresponding to the HTML is displayed on the liquid crystal display unit. Then, mobile unit MS reads out personal identification information from ROM, and transmits to mobile packet communication network MPN. IP server W carries out user authentication on the basis of personal identification information transmitted from mobile unit MS in this manner.

Abstract: A mobile terminal, which is registered to either a first mobile communication network or a second communication network, determines whether it is possible to register to the first mobile communication network on the basis of control information received from the second mobile communication network. Then, the mobile terminal attempts to register to the first mobile communication network a predetermined number of times in a case that it is determined that it is possible to register to the first mobile communication network.

Abstract: IP server W and gateway server GWS transmit data in HTML format in response to a request from mobile unit MS. At this stage, in the HTML data, the personal identification information request data string is added to a URL of the page corresponding to a service, which requires user authentication. As the HTML data is received by mobile unit MS, the user carries out an inputting operation to designate the URL while the image corresponding to the HTML is displayed on the liquid crystal display unit. Then, mobile unit MS reads out personal identification information from ROM, and transmits to mobile packet communication network MPN. IP server W carries out user authentication on the basis of personal identification information transmitted from mobile unit MS in this manner.

Abstract: A subscriber information storing module is fixedly and internally housed within a mobile station, which is provided with an interface which permits an IC card storing subscriber information to be loaded. When a power supply is turned on, if a module is not loaded into the interface, subscriber information in the internally housed module is used to perform an activation processing for the mobile station. When an IC card is loaded into the interface, an examination is made to see if the subscriber number of the IC card and the subscriber number of the mobile station coincide, and if they coincide, the internally housed module is disabled, and subscriber information of the IC card is used.