Gateway, network assignment method of gateway, MME, network assignment method of MME, terminal, and network connection method of terminal in wireless communication system

A network assignment method of a mobility management entity in a wireless communication system including a first communication network and a second communication network, the method comprising:

• transmitting, when a terminal is connected to the first communication network, a create session request message to a gateway;
• and
• receiving a create session response message including second attach information allocated based on first attach information generated for connection to the first communication network, from the gateway, in response to the create session request message,
• wherein the second attach information is generated for establishing a bearer between the gateway and a second base station operating the second communication network.

A network connection method of a terminal in a wireless communication system including a first communication network and a second communication network, the method comprising:

• transmitting, when the terminal is connected to the first communication network, an attach request message for connection to the second communication network to a second base station operating the second communication network;
• and
• receiving an attach accept message including second attach information allocated based on first attach information generated for connection to the first communication network, in response to the attach request message,
• wherein the second attach information is generated for establishing a bearer between the second base station and a gateway.

A gateway for assigning a network in a wireless communication system including a first communication network and a second communication network, the gateway comprising:

• a transceiver configured to communicate with a first mobility management entity associated with a first base station operating the first communication network and a second mobility management entity associated with a second base station operating the second communication network;
• and
• a controller coupled with the transceiver and configured to:
• control, when a terminal is connected to the first communication network, the transceiver to receive a create session request message from the second mobility management entity,
• allocate second attach information for establishing a bearer between the gateway and the second base station based on first attach information generated for connection to the first communication network, and
• control the transceiver to transmit to the second mobility management entity, a create session response message including the second attach information, in response to the create session request message.

A mobility management entity for assigning a network in a wireless communication system including a first communication network and a second communication network, the second mobility management entity comprising:

• a transceiver configured to communicate with a gateway of the wireless communication system;
• and
• a controller coupled with the transceiver and configured to:
• control, when a terminal is connected to the first communication network, the transceiver to transmit a create session request message to the gateway and
• control the transceiver to receive a create session response message including second attach information allocated based on first attach information generated for connection to the first communication network, in response to the create session request message,
• wherein the second attach information is generated for establishing a bearer between the gateway and a second base station operating the second communication network.

A terminal for connecting to a network in a wireless communication system including a first communication network and a second communication network, the terminal comprising:

• a transceiver configured to communicate with a first base station operating the first communication network and a second base station operating the second communication network;
• and
• a controller coupled with the transceiver and configured to:
• control the transceiver to transmit, when the terminal is connected to the first communication network through the first base station, an attach request message for connection to the second communication network to the second base station operating the second communication network, and
• control the transceiver to receive from the second base station an attach accept message including second attach information generated based on first attach information generated for connection to the first communication network in response to the attach request message,
• wherein the second attach information is generated for establishing a bearer between the second base station and a gateway.