Mobile terminal, forwarding intermediate node and mobile communications system

A forwarding intermediate node for relaying between one or plurality of different operator networks and a mobile communications network to which a mobile terminal is connected, comprising:

• an IP address information-to-network identification code storing means for receiving IP address information and a network identification code from an operator network and stores the IP address information in association with the network identification code;
• a message request signal receiving means for receiving a message request signal from a mobile terminal;
• and,
• a message transmitting means for, when a network identification code is added to the message request signal received by the message request signal receiving means, selecting the IP address information corresponding to the network identification code based on the IP address information-to-network identification code storing means and transmitting a message added with the network identification code to the mobile terminal.

A forwarding intermediate node for relaying between one or plurality of different operator networks and a mobile communications network to which a mobile terminal is connected, comprising:

• a network identification code storing means for, when establishing communications with an operator network, receiving a network identification code from the operator network and storing the code in association with the operator network;
• a message request signal receiving means for receiving a message request signal from a mobile terminal;
• an IP address information request signal transmitting means for, when a network identification code is added to the message request signal received by the message request signal receivingmeans, transmitting an IP address information request signal to an operator network corresponding to the network identification code;
• an IP address information receiving means for receiving IP address information from the network operator;
• and,
• a message transmitting means for transmitting a message including the IP address information received by the IP address information receiving means and the network identification code, to the mobile terminal.

A mobile communications system comprising:

• one or plurality of different operator networks;
• a mobile communications network;
• a forwarding intermediate node for relaying between operator networks and the mobile communications network;
• and
• a mobile terminal connected to the mobile communications network,
• the forwarding intermediate node comprising:
• an IP address information-to-network identification code storing means for receiving IP address information and a network identification code from the operator network and storing the IP address information in association with the network identification code;
• a message request signal receiving means for receiving a message request signal from the mobile terminal;
• and,
• a message transmitting means for, when a network ID code is added to the message request signal received by the message request signal receiving means, selecting IP address information corresponding to the network ID code based on the IP address information-to-network ID code storing means and transmitting a message added with the network ID code to the mobile terminal,
• the mobile terminal comprising:
• a message request signal transmitting means for transmitting the message request signal added with the network identification code, to the forwarding intermediate node;
• a message receiving means for receiving the message added with the network identification code, from the forwarding intermediate node;
• an IP address acquisition means for acquiring an IP address from the message received by the message receiving means;
• a network identification code acquisition means for acquiring the network identification code from the message received by the message receiving means;
• and,
• an operator-to-IP address storing means for storing the operator network corresponding to the network identification code acquired by the network identification code acquisition means, in association with the IP address,
• wherein the mobile terminal reads out the IP address corresponding to the operator network as a communication destination, from the operator-to-IP address storing means and uses the IP address as the IP address of the mobile terminal to perform communications with the operator network.