The invention relates to a method for discovering a home agent serving a mobile node upon the mobile node changing its mobility management scheme in a packet-switched network and the implementation of such method in a mobile node or home agent. In order to propose a home agent discover scheme that maintains session continuity in a seamless manner upon a mobile node changing its mobility management scheme, a mobile node comprises information on its location prior to changing the mobility management scheme to one of the first signaling messages transmitted upon changing the mobility management scheme (home agent discovery message). The receiving node uses this information to identify the home agent serving the mobile node or to provide a hint to the home agent where the mobile node is registered in a response message to the mobile node.

Disclosed is a 5G or pre-5G communication system to be provided to support a data transmission rate higher than that of a 4G communication system such as LTE. The present disclosure relates to a session management method through selection of a roaming operator and utilization of data usage rights of a local operator by a user in a 5G system. The user selects the local operator by switching the operator to a manual mode during roaming, accesses a data usage rights purchase agency through a limited service provided by the operator and then purchases the data usage rights of the local operator, and connects to a data network through authentication of a session by using authentication information included in the data usage rights.

Various embodiments of the disclosure provide a device performing communication and a method for operating the same. According to an embodiment, an operation method comprise receiving, by the AMF, a registration request message from a user equipment (UE) through a base station, the registration request message including network slice selection assistance information (NSSAI) requested from the UE, identifying, by the AMF, whether the requested NSSAI can be serviced, transmitting, by the AMF, a message for requesting a target AMF capable of servicing the requested NSSAI to a network slice manager (NSM) through a network slicing selection function (NSSF) when the requested NSSAI cannot be serviced, and receiving, by the AMF, information regarding the target AMF from the NSM through the NSSF and transmitting the information regarding the target AMF and NSSAI allowed by the target AMF to the base station.

Delivering communication services is provided. A request for a mobile number from a mobile number authority is received from a subscriber. In response to receiving the request from the subscriber, the mobile number is assigned to the subscriber and sent to the subscriber. A request to register with the mobile number authority is received from a communication service provider. In response to receiving the request from the communication service provider, the communication service provider is registered with the mobile number authority. The mobile number from the mobile number authority may be used by the subscriber to subscribe at the same time to a plurality of communication services for a mobile device from a plurality of different communication service providers registered with the mobile number authority.

Provided is a method including: receiving a request for one or more first network slices to be accessed by a terminal; receiving terminal subscription information including information about one or more third network slices subscribed as a default; identifying whether one or more second network slices subscribed by the terminal included in the one or more first network slices are an authentication procedure target; when all of the one or more second network slices are the authentication procedure target, adding all of the one or more second network slices to a pending network slice list; performing an authentication procedure based on at least one of the pending network slice list or the one or more third network slices; and determining, based on a result of the authentication procedure, one or more network slices available to the terminal.

A method at an Access and mobility Management Function (AMF) for facilitating a Protocol Data Unit (PDU) session procedure for a User Equipment (UE) in a 5th Generation System (5GS) network, wherein the 5GS network is interworking with an Evolved Packet System (EPS) network, and a Packet Data Network Gateway Control plane Function+Session Management Function (PGW-C+SMF) supporting the interworking is selected for managing the PDU session. The method comprises determining whether the PDU session supports interworking with the EPS network, based on at least one of a capability of the UE and a subscription data of the UE; and sending an indication which indicates whether the PDU session supports interworking with the EPS network to the PGW-C+SMF.

In a user equipment of a wireless communication system, a method for signal transmission and reception may include: sending a request for a Circuit Switched voice network (CS) service to a Gateway Mobile Switching Center (GMSC) to send and receive data to and from a second user equipment; and receiving a call reject response corresponding to the service request from the GMSC, wherein the call reject response is sent by an entity in a core network of the second user equipment. According to an embodiment, it is possible to provide a suitable service to a sender terminal making a CS service request to a receiver terminal having subscribed only to a PS service without increasing network load.

A system is described in which a default MME (9A) receives a NAS message (S501, S505) from a mobile device (3D); sends a rerouting request (S509) to a base station (5) serving the mobile device (3D) and includes information identifying a group of dedicated MMEs (9D) to which the NAS message should be rerouted. If none of the dedicated MMEs (9D) is available, then the default MME (9A) receives a message from the base station (5), the message rerouting the NAS message to the default MME (9A), instead of a dedicated MME (9D). The default MME (9A) either proceeds (S515a) to serving the mobile device (3D) or the default MME (9A) rejects (S515b) the NAS message.

Relay service is enabled between a residential gateway and a remote user. For example, a 5G residential gateway (5G-RG) may include a relay user equipment (UE) to enable relay service for a 5G core (5GC)-capable UE behind the 5G-RG to connect to the 5GC. The relay UE of the 5G-RG may provide a trusted/untrusted non-3GPP access network for L2 or L3 transport connection to the 5GC-capable UE.

The present invention provides a method for obtaining a serving gateway, a mobility management node, a data gateway, and a system. A method for obtaining a serving gateway according to an embodiment of the present invention includes: when a UE is switched from an old-side mobility management node to a new-side mobility management node, sending, by the new-side mobility management node, a domain name resolution request to a domain name system DNS server according to access information of the UE; receiving a hostname of a device returned, according to the domain name resolution request, by the DNS server; obtaining a hostname of a new-side available S-GW; and selecting the new-side available S-GW closest to the device on geographic topology as a new-side S-GW. User service data transmission time delay can be reduced through the method.