Method and device for terminal attaching and creating home-routed PDU session in roaming environment supporting network slice

A first network repository function (NRF) entity in a serving public land mobile network (PLMN), the first NRF entity comprising:

• a transceiver for transmitting and receiving signals;
• and
• a controller coupled with the transceiver and configured to:
• receive, from a requesting network function (NF) entity in the serving PLMN via the transceiver, a first NF discovery request message comprising an identifier of a home PLMN, network slice assistance information, network slice instance information, and a data network name,
• transmit, to a second NRF entity in the home PLMN via the transceiver, a second NF discovery request message comprising the network slice assistance information, the network slice instance information, and the data network name, based on the identifier of the home PLMN,
• as a response to the second NF discovery request message, receive, from the second NRF entity via the transceiver, a first NF discovery response message comprising an address of a target NF in the home PLMN, and
• transmit, to the requesting NF entity via the transceiver, a second NF discovery response message comprising the address of the target NF.