Method and device for supporting UE mobility between networks
The present disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. A method of an AMF entity of the present disclosure comprises the steps of: receiving a registration request message for network registration from a UE moved from a first network that is an SNPN to a second network, wherein the registration request message includes temporary ID information of the UE and network ID (NID) information of the first network to which the temporary ID information is allocated; identifying a first AMF entity belonging to the first network on the basis of the temporary ID information and the NID information; transmitting, to the first AMF entity, a request message for requesting context information of the UE; and receiving a response message including the context information from the first AMF entity.
1 . A method by a first access and mobility management function (AMF) in a first network, the method comprising:
receiving, from a user equipment (UE) through a base station, a registration request message, wherein the registration request message includes a temporary identifier (ID) of the UE and a network ID (NID) of a second network which is a standalone non-public network (SNPN);
determining that the temporary ID is associated with the second network, and determining a second AMF based on the temporary ID and the NID;
transmitting, to the second AMF, a request message for requesting context information of the UE; and
receiving, from the second AME, a response message including the context information.
2 . The method of claim 1 , further comprising:
transmitting, to the second AMF, a registration state update message including a protocol data unit (PDU) session ID to be released when mobility of the UE from the second network to the first network is mobility between SNPNs.
3 . The method of claim 2 , wherein the PDU session ID is obtained from the context information of the UE.
4 . The method of claim 2 , further comprising:
deleting session management (SM) context information associated with the PDU session ID from the context information of the UE.
5 . The method of claim 2 , wherein the second AMF requests a first session management function (SMF) belonging to the second network to release session management (SM) context information associated with the PDU session ID.
6 . The method of claim 1 , wherein the temporary ID is a 5G-globally unique temporary identifier (GUTI).
7 . The method of claim 1 , wherein the second AMF is selected by a base station receiving the registration request message.
8 . The method of claim 1 , further comprising:
transmitting, to the UE, a registration accept message including the UE's temporary ID information newly allocated by the first network.
9 . A first access and mobility management function (AMF) entity in a first network, comprising:
a transceiver; and
at least one processor connected to the transceiver, wherein the at least one processor is configured to:
receive, from a user equipment (UE) through a base station, a registration request message, wherein the registration request message includes a temporary identifier (ID) of the UE and a network ID (NID) of a second network which is a standalone non-public network (SNPN),
determine that the temporary ID is associated with the second network, and determine a second AMF entity based on the temporary ID and the NID,
transmit, to the second AMF entity, a request message for requesting context information of the UE; and
receive, from the second AMF entity, a response message including the context information.
10 . The first AMF entity of claim 9 , wherein the at least one processor is further configured to:
transmit, to the second AMF entity, a registration state update message including a protocol data unit (PDU) session ID to be released when mobility of the UE from the second network to the first network is mobility between SNPNs.
11 . The first AMF entity of claim 10 , wherein the PDU session ID is obtained from the context information of the UE.
12 . The first AMF entity of claim 10 , wherein the at least one processor is further configured to:
delete session management (SM) context information associated with the PDU session ID from the context information of the UE.
13 . The first AMF entity of claim 10 , wherein the second AMF entity requests a first session management function (SMF) entity belonging to the second network to release session management (SM) context information associated with PDU session ID.
14 . The first AMF entity of claim 9 , wherein the temporary ID is a 5G-globally unique temporary identifier (GUTI).
15 . The first AMF entity of claim 9 , wherein the second AMF entity is selected by a base station receiving the registration request message.
16 . The first AMF entity of claim 9 , wherein the at least one processor is further configured to:
transmit, to the UE, a registration accept message including the UE's temporary ID information newly allocated by the first network.