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EP-4021032-B1 - METHOD AND APPARATUS FOR SELECTING CORE NETWORK IN MOBILE COMMUNICATION SYSTEM

EP4021032B1EP 4021032 B1EP4021032 B1EP 4021032B1EP-4021032-B1

Inventors

  • JEONG, SANGSOO
  • PARK, JONGHAN
  • CHOI, YONG-SEOK

Dates

Publication Date
20260506
Application Date
20161108

Claims (4)

  1. A method of operating a terminal device (10) for selecting a core network in a mobile communication system, the method comprising: when a location registration of the terminal device (10) is successful with respect to a previously selected dedicated core network, acquiring, from a node of the previously selected dedicated core network, a service information to which a user subscribed, wherein the service information is used when selecting a new dedicated core network, storing the service information, determining whether the stored service information is valid, and transmitting the service information to a base station apparatus (20), when the stored service information is determined to be valid, wherein the service information includes service type information applicable to the terminal device (10) and a valid timer indicating a time during which the service type information is valid.
  2. The method of claim 1, further comprising: when the location registration is needed again due to a movement or change on state of the terminal device (10), determining a validity of the stored service information.
  3. The method of claim 2, wherein cases where the location registration is needed again include: where the terminal device (10) deviates from a registered tracking area, TA, where the terminal device (10) is out of an area or coverage of an operator, where the radio access technology, RAT, in use needs to be changed, and when receiving a detach command from the network.
  4. The method of claim 2, Wherein the determining the validity includes at least one of: (i) determining whether the previously selected dedicated core network has the same PLMN identification information as that of the new dedicated core network to attach, (ii) determining whether the terminal device (10) does the location registration in a new area rather than the existing area where the previous registration occurred, and (iii) determining whether there is service information for which the valid timer has not expired among the pieces of service information stored in the terminal (10).

Description

[Technical Field] The present disclosure in some embodiments relates to a method and an apparatus for selecting a core network individually configured according to the type of service subscribed to by a user in a mobile communication system. [Background] The statements in this section merely provide background information related to the present disclosure and do not necessarily constitute prior art. A mobile communication carrier can separate and operate a core network for each service for the sake of easiness of system operation and QoS (quality of service) protection. For example, a mobile communication system may be composed of two core networks. One is a dedicated core network which is dedicated to a specific service (for example, Internet of Things or IoT), and the other is a common core network used commonly for all other services. Operating a core network separately in this manner enables to efficiently support different requirements for each device and user. However, when a user terminal (User Equipment: UE) connects or attaches to the network, an appropriate core network needs to be selected based on the subscription information of the user terminal. FIG. 1 is a flowchart of a conventional core network selection process. Specifically, FIG. 1 shows, as a technology introduced by the 3GPP Release 13 standard, selecting a service-specific core network by using the service information (usage type) included in the subscription information when the user terminal attaches to the network for the first time. When a terminal 10 attaches to the network (Step S110), a base station (eNodeB) 20 cannot select a service-specific core network due to lack of information on the terminal. The base station 20 first selects a basic core network determined according to the setting, and transmits an attach request message (S112). A core network node 'MME 1' 30a that has received this message sends a location update request message to a home subscriber server (HSS) 40 (S114), and receives, from the HSS 40, a user's subscribed service information (UE usage type) (S116). When the attached core network does not support the subscribed service, the 'MME 1' 30a selects another core network 'MME 2' 30b that supports the subscribed service (S118). Then, in order to re-direct the terminal to the other selected core network, the 'MME 1' 30a sends a NAS request message to the base station 20 (S120). The subsequent process is the same as the conventional location registration (attach/tracking area update (TAU)) process. The conventional method of selecting a core network needs a base station to first attempt to attach a terminal to a preset default core network, and then re-direct the terminal device to another core network, resulting in two attempted attachments. This increases the time for attachment and overhead disadvantageously. In addition, the conventional method provides the user with only a default type of service when the relevant network is not able to support the user's subscribed service, which prohibits efficient use of resources and impedes the improvement of user's QoS. Part of the deficiencies lies in the fact that a mobility management entity (MME) determines to select the core network and that only one service type is permitted for a single user. 3GPP DRAFT S2-153067 provides a method for selection of DCN (dedicated core network). 3GPP DRAFT TR 23.711 (v0.1.2) provides dedicated core network mechanism. 3GPP DRAFT S2-153816 provides DCN selection assistance parameter description. [Disclosure] [Technical Problem] The present disclosure in some embodiments seeks to provide a method and apparatus for selecting an appropriate core network according to the type of user subscribed service without re-routing in selecting the core network in the mobile communication system. [Summary] The present invention is set out by the appended claims. According to the present invention, a method of operating a terminal device for selecting a core network in a mobile communication system as defined by independent claim 1, includes when a location registration of the terminal device is successful with respect to a previously selected dedicated core network, acquiring, from a node of the previously selected dedicated core network, a service information to which a user subscribed, wherein the service information is used when selecting a new dedicated core network, storing the service information, determining whether the stored service information is valid, and transmitting the service information to a base station apparatus, when the stored service information is determined to be valid. The service information includes service type information applicable to the terminal device and a valid timer indicating a time during which the service type information is valid. [Advantageous Effects] As described above, according to some embodiments of the present disclosure, a method and apparatus are provided for selecting an appropriate core network ac