Method and device for operating terminal in wireless communication system

An apparatus comprising:

• transceiver;
• and
• processor connected to the transceiver, wherein the processor is configured to:
• control the transceiver to transmit, to an access management function (AMF), a registration request message related to access switching from an old access with a first type to a new access with a first type;
• and
• perform an access network (AN) release procedure for the old access with the first type after a user plane (UP) connection is completed in the new access with the first type,
• wherein the registration request message comprises a list of PDU sessions to be activated, and
• wherein deactivation of at least one second PDU session is performed based on the list of PDU sessions to be activated.

An apparatus comprising:

• a transceiver;
• and
• a processor connected to the transceiver, wherein the processor is configured to:
• control the transceiver to receive a registration request message related to access switching from an old access with a first type to a new access with a first type, and
• perform an access network (AN) release procedure for the old access with the first type after a user plane (UP) connection is completed in the new access with the first type,
• wherein the processor is configured to request a session management function (SMF) to deactivate at least one protocol data unit (PDU) session based on a list of PDU sessions to be activated received from a terminal.