Communication supporting method and apparatus using non-access stratum protocol in mobile telecommunication system

A method by a terminal in a communication system, the method comprising:

• generating an attach request message including information on a temporary identity (ID) related to an old network node;
• and
• transmitting, to a mobility management entity (MME), the attach request message,
• wherein whether the temporary ID is mapped from another ID or the temporary ID is a native temporary ID is identified based on the information on the temporary ID,
• wherein a type of the old network node is identified based on whether the temporary ID is mapped from the other ID or the temporary ID is the native temporary ID, and
• wherein an identification request message is transmitted from the MME to the old network node for requesting an international mobile subscriber identity (IMSI) of the terminal, and an identification response message including the IMSI of the terminal is transmitted from the old network node to the MME in response to the identification request message.

A mobility management entity (MME) in a communication system, the MME comprising:

• a transceiver configured to transmit and receive a signal;
• and
• at least one processor configured to:
• receive, from a terminal, an attach request message including information on a temporary identity (ID) related to an old network node,
• identify whether the temporary ID is mapped from another ID or the temporary ID is a native temporary ID based on the information on the temporary ID,
• identify a type of the old network node based on a result of the identification,
• transmit, to the old network node, an identification request message to request an international mobile subscriber identity (IMSI) of the terminal, and
• receive, from the old network node, an identification response message including the IMSI of the terminal in response to the identification request message.

A terminal in a communication system, the terminal comprising:

• a transceiver configured to transmit and receive a signal;
• and
• at least one processor configured to:
• generate an attach request message including information on a temporary identity (ID) related to an old network node, and
• transmit, to a mobility management entity (MME), the attach request message,
• wherein whether the temporary ID is mapped from another ID or the temporary ID is a native temporary ID is identified based on the information on the temporary ID,
• wherein a type of the old network node is identified based on whether the temporary ID is mapped from the other ID or the temporary ID is the native temporary ID, and
• wherein an identification request message is transmitted from MME to the old network node for requesting an international mobile subscriber identity (IMSI) of the terminal, and an identification response message including the IMSI of the terminal is transmitted from the old network node to the MME in response to the identification request message.