WO2021221433A1

WO2021221433A1 - Method and apparatus for controlling communication between devices belonging to communication group

Info

Publication number: WO2021221433A1
Application number: PCT/KR2021/005303
Authority: WO
Inventors: 워드닥미칼; 니에시오베즈키마렉; 크미엑아담; 그르제시아크그르제고르슈; 크위아트코스키마친; 위트코스키마친; 베레스키프르제미슬라브
Original assignee: 삼성전자 주식회사
Priority date: 2020-04-28
Filing date: 2021-04-27
Publication date: 2021-11-04
Also published as: KR20210133373A

Abstract

Disclosed are a method and apparatus for controlling communication between devices belonging to a communication group established with another network. A first AMF of a first network may receive, from a first device connected to the first network, a request to join the communication group set by a second device of a second network and identification information about the second device. In addition, the first AMF may obtain, on the basis of the request to join, identification information about a second policy control function (PCF) included in the second network, and may control, by using the identification information about the second PCF, a first PCF included in the first network to operate as a visiting PCF for the first device so that the first device can communicate with the second device of the second network.

Description

Method and apparatus for controlling communication between devices belonging to a communication group

The present invention relates to a method and apparatus for performing communication between a plurality of devices belonging to a communication group beyond D2D communication.

For a plurality of devices, the concept of establishing a group that collaborates remotely exists. To build groups that collaborate remotely, where there is no direct or routed visibility among the members of the group, a server-based approach typically provided using the cloud can be used. However, such a server-based or back-end-based centralized entity has limitations in that it is expensive in terms of deployment as well as cumbersome in terms of maintenance issues.

Accordingly, there is a need to provide a framework capable of performing communication between remote users.

According to the present disclosure, it is possible to form and manage a communication group between devices included in different networks.

According to the present disclosure, a device may participate in a communication group created in another network to communicate with a remote device.

According to the present disclosure, a method and apparatus for controlling communication between devices belonging to a communication group formed with another network by a first AMF of a first network may be provided. A method for controlling communication between devices belonging to a communication group formed with another network by a first AMF includes, from a first device connected to the first network, a request for participation in the communication group set by a second device of a second network, and receiving identification information of the second device; obtaining identification information of a second Policy Control Function (PCF) included in the second network based on the participation request; and using the identification information of the second PCF, the first PCF included in the first network is visiting the first device so that the first device can communicate with the second device of the second network. It may include; controlling to operate as a PCF.

According to the present disclosure, there is an effect of forming and managing a communication group between devices included in different networks.

According to the present disclosure, there is an effect of a device participating in a communication group created in another network and performing communication with a remote device.

However, effects that can be achieved by the method and apparatus for controlling communication between devices belonging to a communication group according to an embodiment are not limited to those mentioned above, and other effects not mentioned above can be seen from the description below. It will be clearly understood by those of ordinary skill in the art to which the disclosure pertains.

1 is a diagram of a Network Exposure Function.

2 is a diagram for describing a general roaming process for describing the present disclosure.

3 is a diagram for explaining the concept of a communication group and reverse roaming according to an embodiment of the present disclosure.

4 is a diagram illustrating entities included in a core network according to an embodiment of the present disclosure.

5 is a flowchart of a method for controlling communication between devices belonging to a communication group formed with another network by a first AMF of a first network, according to an embodiment of the present disclosure.

6 is a flowchart illustrating a method in which a first PCF of a first network controls communication between devices belonging to a communication group formed with another network, according to an embodiment of the present disclosure.

7 is a diagram illustrating a data flow diagram for communication between devices belonging to a communication group formed with a first network and another network, according to an embodiment of the present disclosure.

8 is a data flow diagram illustrating a method of creating a communication group in a second network, according to an embodiment of the present disclosure.

9 is a diagram illustrating a data flow diagram of a method for a first device of a first network to join a created communication group, according to an embodiment of the present disclosure.

10 is a diagram illustrating a data flow diagram for communication between devices belonging to a communication group formed with a first network and another network, according to an embodiment of the present disclosure.

11 is a flowchart of a method for controlling communication between devices belonging to a communication group formed with another network by a second AMF of a second network, according to an embodiment of the present disclosure.

12 is a flowchart of a method for controlling communication between devices belonging to a communication group formed with another network by a second PCF of a second network according to an embodiment of the present disclosure.

13 is a data flow diagram of a method for creating a communication group in a second network, according to an embodiment of the present disclosure.

14 illustrates a data flow diagram of a method of joining a communication group in a first network, according to an embodiment of the present disclosure.

15 is a block diagram illustrating the structure of an AMF according to an embodiment of the present disclosure.

16 is a block diagram illustrating a structure of a PCF according to an embodiment of the present disclosure.

17 is a block diagram illustrating the structure of a terminal according to an embodiment of the present disclosure.

According to an embodiment of the present disclosure, the first AMF requests identification information of the second PCF from the first NRF included in the first network, and the second AMF included in the second network through the first NRF Identification information of the second PCF may be obtained from the NRF.

According to an embodiment of the present disclosure, based on the participation request and the identification information of the second device, the method further includes: confirming identification information of a communication group in which the first device participates; The identification information may include at least one of information about the second network, identification information of the first device, identification information of the second device, or SUB ID information of the communication group.

According to an embodiment of the present disclosure, using the identification information of the second PCF, the first PCF included in the first network so that the first device can communicate with the second device of the second network Controlling to operate as a visiting PCF for the first device; In, the first AMF transmits identification information of the second PCF to the first PCF, and the first PCF visits the first device When operating as a PCF, the first PCF may establish a roaming session with a second PCF of the second network to receive a policy for the communication group from the second PCF.

According to an embodiment of the present disclosure, the first device is physically connected to a Radio Access Network (RAN) of the first network, and a data network (DN, Data Network) of the second network that has created the communication group can be virtually connected to

According to an embodiment of the present disclosure, the method may further include creating the communication group between the first device connected to the first network and a third device connected to a third network.

According to an embodiment of the present disclosure, generating the communication group between a first device connected to the first network and a third device connected to the third network; from a first device connected to the first network, receiving a communication group creation request for creating a communication group with the third device connected to the third network and identification information of the third device; and controlling, based on the communication group creation request, a first PCF included in the first network to create the communication group to operate as a Home PCF for the third device. may include.

According to an embodiment of the present disclosure, in the first AMF, a transceiver; a memory for storing at least one or more instructions; and at least one processor for controlling communication between devices belonging to the communication group by executing the at least one or more instructions. At least one processor controls the transceiver to receive, from a first device connected to the first network, a request for participation in the communication group set by a second device of a second network and identification information of the second device, , based on the participation request, obtains identification information of a second Policy Control Function (PCF) included in the second network, and uses the identification information of the second PCF to enable the first device to connect to the second network In order to communicate with the second device of , the first PCF included in the first network may be controlled to operate as a visiting PCF for the first device.

According to the present disclosure, a method and apparatus in which a first PCF of a first network controls communication between devices belonging to a communication group formed with another network may be disclosed. A method for controlling communication between devices belonging to a communication group formed with another network by a first PCF of a first network, such that a first device connected to the first network can participate in a communication group created in a second network, Receiving identification information of a second Policy Control Function (PCF) included in the second network from the first AMF included in the first network; and using the identification information of the second PCF, the first PCF is activated to operate as a visiting PCF for the first device so that the first device can communicate with the second device of the second network. step; may include.

According to an embodiment of the present disclosure, when the first PCF is activated to operate as a visiting PCF for the first device, the first PCF establishes a roaming session with a second PCF of the second network, A policy for the communication group may be received from the second PCF.

According to an embodiment of the present disclosure, a tunnel between the first PCF and the second PCF for communication between devices belonging to the communication group may be created.

According to an embodiment of the present disclosure, in order to create the communication group between a first device connected to the first network and a third device connected to a third network, the first PCF is configured as a Home PCF for the third device. It may further include; the step of being activated to operate.

According to an embodiment of the present disclosure, when the first PCF is activated to operate as a Home PCF for the third device, the first network manages the communication group and performs network setting for the communication group and the first PCF may determine a policy for the communication group.

According to an embodiment of the present disclosure, the first PCF may transmit the identification information of the first PCF to the first NRF according to the request of the third network.

According to an embodiment of the present disclosure, the first PCF may transmit the identification information of the first PCF to the first NRF through the first AMF according to the request of the third network.

According to an embodiment of the present disclosure, the first PCF includes a transceiver; a memory for storing at least one or more instructions; and at least one processor for controlling communication between devices belonging to the communication group by executing the at least one or more instructions. At least one or more processors, from the first AMF included in the first network, include the second network included in the second network, so that the first device connected to the first network can participate in the communication group created in the second network. control the transceiver to receive identification information of a Policy Control Function (PCF), and use the identification information of the second PCF so that the first device can communicate with the second device of the second network, the The first PCF may be activated to act as a Visiting PCF for the first device.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

In describing the embodiments, descriptions of technical contents that are well known in the technical field to which the present disclosure pertains and are not directly related to the present disclosure will be omitted. This is to more clearly convey the gist of the present disclosure without obscuring the gist of the present disclosure by omitting unnecessary description.

For the same reason, some components are exaggerated, omitted, or schematically illustrated in the accompanying drawings. In addition, the size of each component does not fully reflect the actual size. In each figure, the same or corresponding elements are assigned the same reference numerals.

Advantages and features of the present disclosure, and a method of achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below, but may be implemented in a variety of different forms, only the present embodiments allow the present disclosure to be complete, and those of ordinary skill in the art to which the present disclosure pertains. It is provided to fully understand the scope of the present disclosure, and the present disclosure is only defined by the scope of the claims. Like reference numerals refer to like elements throughout.

At this time, it will be understood that each block of the flowchart diagrams and combinations of the flowchart diagrams may be performed by computer program instructions. These computer program instructions may be embodied in a processor of a general purpose computer, special purpose computer, or other programmable data processing equipment, such that the instructions performed by the processor of the computer or other programmable data processing equipment are not described in the flowchart block(s). It creates a means to perform functions. These computer program instructions may also be stored in a computer-usable or computer-readable memory that may direct a computer or other programmable data processing equipment to implement a function in a particular manner, and thus the computer-usable or computer-readable memory. It is also possible that the instructions stored in the flow chart block(s) produce an article of manufacture containing instruction means for performing the function described in the flowchart block(s). The computer program instructions may also be mounted on a computer or other programmable data processing equipment, such that a series of operational steps are performed on the computer or other programmable data processing equipment to create a computer-executed process to create a computer or other programmable data processing equipment. It is also possible that instructions for performing the processing equipment provide steps for performing the functions described in the flowchart block(s).

Additionally, each block may represent a module, segment, or portion of code that includes one or more executable instructions for executing specified logical function(s). It should also be noted that in some alternative implementations it is also possible for the functions recited in blocks to occur out of order. For example, two blocks shown one after another may in fact be performed substantially simultaneously, or it is possible that the blocks are sometimes performed in the reverse order according to the corresponding function.

In this case, the term '~ unit' used in this embodiment means software or hardware components such as FPGA or ASIC, and '~ unit' performs certain roles. However, '-part' is not limited to software or hardware. The '~ unit' may be configured to reside on an addressable storage medium or may be configured to refresh one or more processors. Thus, as an example, '~' denotes components such as software components, object-oriented software components, class components, and task components, and processes, functions, properties, and procedures. , subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. The functions provided in the components and '~ units' may be combined into a smaller number of components and '~ units' or further separated into additional components and '~ units'. In addition, components and '~ units' may be implemented to play one or more CPUs in a device or secure multimedia card. Also, in an embodiment, '~ unit' may include one or more processors.

1 is a diagram of a Network Exposure Function.

The present disclosure relates to a method of forming a communication group that can be applied not only to the cloud of 4G or 5G, but also can be applied to the fog of 6G.

The present disclosure is a technology for implementing Remote Collaborative Group Establishment (RCGE) beyond D2D (Device-to-Device) communication. According to an embodiment of the present disclosure, a remote collaboration group may be established to provide an Enhanced Multi-Device Experience (EMDE). By using the remote collaboration group according to the present disclosure, it is possible to provide an improved multi-device experience (MDE) for a vehicle-to-vehicle (V2V) service. According to the present disclosure, it is possible to provide an enhanced multi-device experience (EMDE) than the multi-device experience service currently provided by the 5G system.

In the present disclosure, establishing a remote collaboration group may mean creating a framework for performing communication between remote users. Establishing a remote collaboration group according to an embodiment may mean building a framework for enabling instantiation of communication performed between remote users using a specific application.

For example, in the present specification, a remote collaboration group (hereinafter, a communication group) may be built in a manner that does not require a dedicated server or any type of backend. For the current 5G support scheme, the rationale for the concept of network programmability is becoming increasingly clear. Recent Service Based Architecture (SBA) tools provide a so-called RESTful approach for external communication using Network Exposure Functions (NEFs). Currently, in order to build a communication group with decentralization, a server-based approach, which is usually provided using the cloud, can be used. At this time, sessions may be created to allow proper discovery between the separated devices. As an example of the present disclosure, a communication group having decentralization may mean a communication group formed without direct visibility or routed visibility among members belonging to the group.

Thanks to already well-established solutions such as Session Initiation Protocol (SIP), the aforementioned lack of immediate visibility may not cause problems. However, problems can arise when the demanding business requirement of not having a centralized backend emerges. In practice, these server-based or back-end-based centralized entities are not only expensive in terms of deployment, but also cumbersome in terms of maintenance issues. For this reason, in order to develop a globally distributed application program in a manner similar to the existing voice local scenario, the most efficient and flexible solution needs to include a Public Session Management (PSM) service.

The possibility of exposure of network services may be considered, but exposure of network services has already appeared in the form of Service Capability Exposure Function (SCEF) in LTE. In addition, in the case of 5G, network service exposure can be used in the form of the NEF described above in the form provided by 5G.

According to an embodiment, with reference to FIG. 1 , a Network Exposure Function (NEF) 114 uses a specific API (Application Programming Interface) 120 that operates in a Representational State Transfer (REST)ful manner, the core network ( 5G functions that can be used in the Core Network) can be exposed. Thanks to this possibility, a 3rd party service provider 130 can utilize the network programming tools described above to instantiate a configuration designed to provide remote device discovery assuming a backend free mode. have.

The prior art relied on some form of centralized entity maintained externally. The prior art has the disadvantage that the roll-out of the solution is more cumbersome and expensive, especially in terms of additional maintenance, due to the requirement to ensure access to an external server or to deploy a dedicated backend. In particular, in the prior art, if the PLMN lacks routable IP addresses, there is a limitation that the assigned addresses cannot be used for an end-to-end (E2E) connection. In addition, the conventional technique, such as the session initiation protocol, a session management solution is server-based and there is a limitation that external maintenance is required. In addition, the prior art has a problem in that development and maintenance are required to prepare a dedicated solution. In order to solve the above problem, the present disclosure proposes a communication group using a reverse roaming scheme.

According to FIG. 2 , before the first device 210 moves, the first device 210 may be connected to the Home-PLMN 220 . In this case, the first device 210 may be connected to the first base station 225 of the Home-PLMN 220 . Also, in the specification, H-PLMN may mean Home-PLMN.

When the first device 210 moves, the first device 210 may be connected to the Visiting-PLMN 230 . In this case, in the general roaming process, the first device 210 may be physically disconnected from the first base station 225 . Also, according to the movement of the first device 210 , the first device 210 may be physically connected to the second base station 235 of the Visiting-PLMN 230 . Also, the first device 210 may be virtually or logically connected to the AMF 240 of the Visiting-PLMN 230 . Also, in the specification, V-PLMN may mean Visiting-PLMN.

Although not shown in FIG. 2 , the H-PLMN 220 may include a Home-PCF (H-PCF). Also, the V-PLMN 230 may include a visiting-PCF (V-PCF).

3 is a diagram for explaining a communication group and reverse roaming according to an embodiment of the present disclosure.

In general, an Enhanced Multi-Device Experience scenario capable of transmitting and receiving data between devices belonging to a communication group according to the present disclosure may include various mobile devices. In a non-limiting embodiment of the present disclosure, a mobile device may include a smart phone, tablet or other related hardware. Also, as an example, the mobile device may use current 5G technology and infrastructure.

The present disclosure relates to a method of providing a direct connection between a plurality of devices (eg, user equipment) connected to different networks. In the present disclosure, in order to create a communication group or join a device to the communication group, each PCF included in different networks may operate as Home-PCF (H-PCF) or Visiting-PCF (V-PCF). . In this case, Home-PCF (H-PCF) may mean a PCF included in Home-PLMN (H-PLMN) in general roaming. Also, a visiting-PCF (V-PCF) may mean a PCF included in a visiting-PLMN (V-PLMN) in general roaming.

Disclosed is a method for transmitting and receiving data between devices belonging to a communication group according to an embodiment of the present disclosure. A method of reversing the roaming process in a manner in which Home-PCF (H-PCF) and Visiting-PCF (V-PCF) control communication (hereinafter, Reverse Roaming) may be applied to the present disclosure. . That is, in the present disclosure, the concept of reverse roaming may be applied to a communication group to which devices belong. In the present disclosure, reverse roaming may also be defined as virtual roaming, reverse roaming, or the like.

In the present disclosure, a communication group may mean a group created to transmit and receive data between devices included in different networks. The communication group may refer to a group capable of performing communication between a plurality of devices belonging to the group by grouping several devices connected to different networks beyond D2D (Device to Device) communication. As another example, a communication group may be created for devices included in the same network.

First, there may be an initiator device that is a device that creates a communication group and a participant device that is a device that participates in the created communication group. Also, there may be a network to which the initiator device is connected and a network to which the participant device is connected. In order to distinguish and describe the network to which the initiator device is connected and the network to which the participant device is connected, the network to which the participant device is connected is defined as the first network 320 , and the network to which the initiator device is connected is defined as the second network 330 . to explain However, for convenience of explanation, the first network 320 and the second network 330 are shown separately, and each network may be connected to an initiator device or a participant device. For example, according to whether the first network 320 receives a communication group creation request or a communication group join request from a device connected to the first network 320, the entity included in the first network 320 ( entities) may perform different actions. A more detailed description will be given later in the drawings below.

In FIG. 3 , the second device 305 may refer to an initiator device that creates a communication group. The second network 330 may receive a request to create a communication group from the second device 305 . That is, the second device 305 is a device that transmits a request for creating a communication group to the second network 330 , and the second network 330 may mean a network to which the second device 305 is connected. .

In FIG. 3 , a first device 310 may mean a participant device participating in a communication group. The first network 320 may receive a request for joining the communication group created by the second device 305 from the first device 310 . That is, the first device 310 is a device that transmits a request to join the communication group to the first network 320 , and the first network 320 may mean a network to which the first device 310 is connected. .

The concept of reverse roaming defined in the present disclosure is as follows. Referring to FIG. 3 , the second device 305 is a communication group that remotely collaborates with at least one other device (eg, the first device 310 ) connected to an external network (eg, the first network 320 ). In order to create a , it may request the creation of a communication group from the second network 330 . The second network 330 may be provisioned to create a remotely collaborating communication group for the second device 305 and the first device 310 . In order to join (or join) the communication group created in the second network 330 , the first device 310 may request the first network 320 to join the communication group. As a result, between the first network 320 and the second network 330 , a remotely collaborating communication group may be created (or established).

The first device 310 according to an embodiment of the present disclosure may be logically connected to the data network DN in the second network 330 . On the other hand, the first device 310 may still be physically connected to the (R)AN ((Radio) Access Network) of the first network 320 that is the home network of the first device 310 . Here, the home network may refer to a network to which the first device 310 has been connected from the time of requesting participation in the communication group. In the present disclosure, reverse roaming applied to create a communication group or participate in a communication group does not mean that the physical movement of the first device 310 has occurred. Accordingly, unlike general roaming (refer to FIG. 2 ), the network to which the first device 310 is connected is not changed from the first network 320 as a home network to the second network 330 as a visiting network. Therefore, the first device 310, which has joined the communication group, is still the first AMF, the first PCF, the first SMF or the first included in the first network 320 that is the home network of the first device 310 . You can use entities like UPF. In addition, the first device 310 participating in the communication group may also use the second PCF, the second SMF, the second UPF, and the DN included in the second network 330 .

When the first device 310 is a participant device participating in the communication group, the first network 320 may perform a roaming operation as if the first device 310 is a PLMN of a visited country. As an example, entities such as the first PCF and the first SMF of the first network 320 may operate as if the first device 310 is connected to a Visiting (visiting or foreign network) PLMN. That is, although the first device 310 is connected to the first network 320 and the first network 320 is a home network for the first device 310 , the first device 310 is Entities (eg, first PCF, first SMF, etc.) may operate as if one network 320 is a visiting network (V-PLMN).

In addition, when the first device 310 is a participant device participating in the communication group, the second network 330 may perform a roaming operation as if it were a PLMN of a country to which the first device 310 was connected before moving. have. For example, entities such as the second PCF and the second SMF of the second network 330 may perform a roaming operation as if the first device 310 is a Home HLMN when located in the V-PLMN. That is, although the first device 310 is connected to the first network 320 and the first network 320 is a home network for the first device 310 , the Entities of the second network 330 (eg, second PCF, second SMF) may operate as if the second network 330 is a home network.

According to the present disclosure, it is possible to provide an effect of interconnecting devices located at a distance belonging to different networks. That is, an H-PLMN (eg, a second network) and a V-PLMN (eg, a first network) for an enhanced multi-device environment (EMDE) may be provided.

In the present disclosure, although the networks to which the devices of the communication group belong are separated, the H-PCF may be connected by the V-PCF in order to establish a communication group capable of remotely cooperating by logically connecting the devices.

The above-described method makes it possible to create a communication group that remotely collaborates by logically connecting two devices even when there is a large geographical separation between the devices. In the past, it was necessary to establish communication with a remote device in a state where public IP addresses and static IP addresses were not available. In order to solve the above problem, a reverse roaming scheme in which a roaming procedure is reversed may be proposed as in the present disclosure. As in this disclosure, when a device roams to a V-PLMN (Visiting_PLMN), a V-PCF instance for this device may be created based on a PCF ID that identifies the H-PCF. The absence of physical roaming may mean that instantiation of the V-PCF is not directly possible. Therefore, instantiation of the V-PCF may be performed by transmitting the PCF ID. For this, a control communication for the H-PCF may be established using a communication device between the V-NRF and the H-NRF. This allows remote devices to connect to both H-PLMN and V-PLMN via each AMF. Also, as another example, the multi-homing function of the UPF may be used. That is, the same device may be connected to both PLMNs. In addition, according to the present disclosure, it is possible to obtain the effects of cost reduction, security and QoS improvement through a server-less design. Also, according to the present disclosure, a communication group may be created without Public and Static IP Addresses.

As described above in FIG. 3 , the first network 410 may refer to a network to which the first device 411, which is a participant device, is connected. Also, the second network 420 may refer to a network to which the second device 421, which is an initiator device, is connected.

4 is a diagram illustrating the structure of a network for performing reverse roaming according to the present disclosure from the perspective of a first device 411 participating in a communication group. At this time, FIG. 4 shows the difference between the structure of the network for processing the basic roaming process and the structure according to the present disclosure for performing reverse roaming.

The first network 410 according to the present disclosure includes a first device 411 , a first (R)AN 412 , a first Access & Mobility Function (AMF) 413 , and a first SMSF (SMS Function) 414 . ), a first NRF (NF Repository Function) 415, a first PCF (Policy Control Function) 416, a first SMF (Session Management Function) 417, and a first UPF (User Plane Function) 418 may include

The second network 420 according to the present disclosure includes a second device 421 , a second (R)AN 422 , a second AMF 423 , a second SMSF 424 , a second NRF 425 , and a second 2 PCFs 426 , a second SMF 427 , and a second UPF 428 may be included.

According to a first embodiment to be described later in the present disclosure, the second PCF 426 may serve as an H-PCF belonging to the Home PLMN for the first device 411 . Also, the second SMF 427 may serve as an H-SMF belonging to the Home PLMN for the first device 411 . Also, the second UPF 428 may serve as an H-UPF belonging to the Home PLMN for the first device 411 . Also, according to a first embodiment to be described later in the present disclosure, the first PCF 416 may serve as a V-PCF belonging to the visiting PLMN for the first device 411 . Also, the first SMF 417 may serve as a V-SMF belonging to the visiting PLMN for the first device 411 . Also, the first UPF 418 may serve as a V-UPF belonging to the visiting PLMN for the first device 411 .

According to a second embodiment ( FIG. 10 ) described later in the present disclosure, the second PCF 426 may serve as a V-PCF belonging to the visiting PLMN to the first device 411 . Also, the second SMF 427 may serve as a V-SMF belonging to the visiting PLMN for the first device 411 . Also, the second UPF 428 may serve as a V-UPF belonging to the visiting PLMN for the first device 411 . In addition, according to a second embodiment to be described later in the present disclosure, the first PCF 416 may serve as an H-PCF belonging to the Home PLMN for the first device 411 . Also, the first SMF 417 may serve as an H-SMF belonging to the Home PLMN for the first device 411 . Also, the first UPF 418 may serve as an H-UPF belonging to the Home PLMN for the first device 411 .

A more detailed difference between the reverse roaming process in this disclosure and the basic roaming process (or original roaming process) (eg, the process defined in 3GPP TS 23.501 Version 15.8.0 Release 15) will be described. First, in the basic roaming process, a device may be physically connected to an (R)AN located in an external network (VPLMN) and logically connected to an external AMF (V-AMF included in the VPLMN).

However, the first device 411 according to an embodiment of the present disclosure may be physically connected to the first (R)AN 412 of the first network 410 that is the home network of the first device 411 . Accordingly, reverse roaming may occur from the first network 410 that is the home network of the first device 411 to the second network 420 that is an external network of the first device 411 . In this case, the second device 421 may establish a communication group.

In the basic roaming process, the V-PCF belonging to the V-PLMN may forward the communication to the H-PCF belonging to the H-PLMN. In the basic roaming process, the H-PCF may perform responsibilities such as the role of the PCF, decision-making, and the like. That is, the H-PCF may finally establish a policy related to roaming.

The second network 420 according to an embodiment of the present disclosure may manage a communication group, and the second network 420 is responsible for setting up a network for managing the communication group. In order to join the first device 411 to the session and the DN 429 managed by the second network 420 , the first device 411 may perform virtual roaming to the second network 420 .

Since the session related to the DN to which the first device 411 is connected according to an embodiment of the present disclosure is in the second network 420 that is a foreign network, the PCF role (H- PCF and V-PCF) may be understood to be “reversed”.

A final policy related to a communication group according to an embodiment of the present disclosure may be set by entities of the second network 420 . Accordingly, the second PCF 426 included in the second network 420 may operate as a Home-PCF for the first device 411 . That is, even though the second network 420 is an external network of the first device 411 , the second PCF 426 is a policy related to the communication group to which the first device 411 intends to participate and the second PCF 411 to participate in the communication group. A policy related to one device 411 may be determined. Also, the first PCF 416 included in the first network 410 may operate as a Visiting-PCF for the first device 411 . That is, even though the first network 410 is the home network of the first device 411 , the first PCF 416 is a policy related to the communication group to which the first device 411 intends to participate and the first PCF to participate in the communication group. 1 A policy related to the device 411 is not determined. In this case, the first PCF 416 may operate as a transit element. Also, communication may be terminated in the second PCF 426 .

For the first device 411 , entities in the first network 410 may act as if the first device 411 visited to use the established session in the communication group.

The second SMF 427 according to an embodiment of the present disclosure may establish a PDU (Packet Data Unit) session between the device and the DN. In the present disclosure, the DN 429 may mean a data network created for a communication group in the second network 420 .

First, in the basic roaming process, a device located in a Foreign PLMN (V-PLMN) may request a session processed by the V-SMF. The H-SMF located in the Home-PLMN may prepare a tunnel for inter-UPF communication. Also, the V-SMF may open a tunnel from the V-UPF of the V-PLMN to the H-UPF of the H-PLMN. V-SMF and H-SMF may manage UPF in their respective networks.

According to an embodiment of the present disclosure, for the first device 411 , the first SMF 417 serving as a V-SMF is connected to the first network 410 that is the home network of the first device 411 . can be located As described above, an operation performed by each SMF included in each network is different from the basic roaming process. Therefore, embodiments of the present disclosure may be described as reverse roaming.

In the present disclosure, the first SMF 417 serving as a V-SMF for the first device 411 may open a communication tunnel to the first UPF 418 located in the first network 410 . . A communication tunnel is created by a second UPF 428 located in a second network 420 managed by a second SMF (SMF serving as an H-SMF for the first device) 427 . can be Therefore, the operation of the present disclosure can be described as reverse roaming.

Also, in the basic roaming process, PCF identification information (eg, PCF_ID) may be retrieved from the Home PLMN and used as a reference in the Foreign PLMN (Visiting PLMN).

Through an operation in which the first network 410, which is a home network for the first device 411 according to an embodiment of the present disclosure, obtains identification information of the second PCF included in the second network 420, the first The PCF may be “reversed” in role with the second PCF. To this end, in the present disclosure, the first NRF 415 and the second NRF 425 may perform communication. Since the PCF according to an embodiment of the present disclosure performs an operation by reversing the general operation method and the operation method defined in 5G, it may be described as reverse roaming.

As described above, the network may perform different operations according to whether it receives a communication group creation request or a communication group join request from a connected device.

In this disclosure, the first device connected to the first network may be a participant device or an initiator device. When the first device according to an embodiment performs the role of a participant device participating in a communication group, the second device may mean a device (role of an initiator device) that has created a communication group to which the first device intends to participate. have. Also, a network to which the second device generating the communication group is connected may correspond to the second network. When the first device according to another embodiment serves as an initiator device that creates a communication group, the third device selects a device (a role of a participant device) requesting participation in the communication group to be created by the first device. can mean Also, a network to which a third device to participate in a communication group is connected may correspond to the third network.

Entities included in each network may perform different roles depending on whether the device's request is to open or create a communication group or to participate in or participate in the communication group.

The first device according to an embodiment of the present disclosure may be physically connected to a Radio Access Network (RAN) of the first network. Also, the first device may be virtually connected to a data network (DN) of the second network in which the communication group is created. The first device may be a device that mimics being physically roaming, using the second network.

In step S510 , the first AMF may receive, from the first device connected to the first network, a request for participation in a communication group set by the second device of the second network and identification information of the second device.

The identification information of the second device according to an embodiment of the present disclosure may include a phone number of the second device, but is not limited thereto.

The second device according to an embodiment of the present disclosure may mean a device that creates a communication group. Also, in this case, the second device may be a subject for creating a communication group, and may mean a terminal connected to the created communication group for the first time.

The first AMF according to an embodiment of the present disclosure may check identification information of a communication group in which the first device participates based on the participation request and identification information of the second device. For example, the identification information of the communication group may include at least one of information about the second network, identification information of the first device, identification information of the second device, or SUB ID information of the communication group. The information on the second network according to an embodiment may include PLMN information, and may include, but is not limited to, mobile country codes (MCC), mobile network codes (MNC), and the like.

In step S520 , the first AMF may acquire identification information of a second policy control function (PCF) included in the second network based on the participation request.

According to an embodiment of the present disclosure, the identification information of the second PCF may mean information previously known to the first network, and may mean information for indicating a communication group created in the second network.

According to an embodiment of the present disclosure, the first AMF may request identification information of the second PCF from the first NRF included in the first network. Also, the first AMF may acquire identification information of the second PCF from the second NRF included in the second network through the first NRF.

In step S530, the first AMF uses the identification information of the second PCF so that the first PCF included in the first network can communicate with the second device of the second network for the first device. It can be controlled to operate as a Visiting PCF. The first PCF according to an embodiment may be controlled to operate as a visiting PCF of the second network.

The first AMF according to an embodiment of the present disclosure may transmit identification information of the second PCF to the first PCF. In the present disclosure, when the first PCF operates as a visiting PCF for the first device, the first PCF may establish a roaming session with the second PCF of the second network. In addition, the first PCF may receive the policy for the communication group from the second PCF.

As described above, each AMF may create a communication group according to which request it receives from a device, and may join the device to the communication group. Accordingly, the first device according to another embodiment may serve as an initiator device for creating a communication group. In this case, the first AMF may create a communication group between the first device connected to the first network and the third device connected to the third network. Also, the first AMF may receive, from the first device connected to the first network, a communication group creation request for creating a communication group with the third device connected to the third network, and identification information of the third device. Based on the communication group creation request, the first AMF may control the first PCF included in the first network to create the communication group to operate as a Home PCF for the third device. A more detailed description will be described later with reference to the operation of the second AMF included in the second network with reference to FIGS. 7 to 9 .

In step S610, the first PCF is a second PCF included in the second network from the first AMF included in the first network so that the first device connected to the first network can participate in the communication group created in the second network. (Policy Control Function) identification information may be received.

In step S620 , using the identification information of the second PCF, the first PCF may be activated to operate as a visiting PCF for the first device so that the first device can communicate with the second device of the second network. The first PCF according to an embodiment may be activated to operate as a visiting PCF of the second network.

The first PCF according to an embodiment of the present disclosure may receive a policy for a communication group from the second PCF by establishing a roaming session with the second PCF of the second network. A tunnel between the first PCF and the second PCF for communication between devices belonging to a communication group according to an embodiment of the present disclosure may be created. According to another embodiment of the present disclosure, each PCF may create a communication group according to which request it receives from the AMF, and may join a device to the communication group. Accordingly, the first device may act as an initiator device that creates a communication group.

According to an embodiment of the present disclosure, to create the communication group between a first device connected to a first network and a third device connected to a third network, a first PCF is activated to operate as a Home PCF for a third device can be For example, when the first PCF is activated to operate as a Home PCF for the third device, the first network may manage the communication group. Also, the first network may perform network setting for a communication group. Also, the first PCF may determine a policy for the communication group. According to an embodiment of the present disclosure, according to a request of a third network, the first PCF may transmit identification information of the first PCF to the first NRF. According to an embodiment of the present disclosure, according to a request of the third network, the first PCF may transmit identification information of the first PCF to the first NRF through the first AMF.

A more detailed description will be described later with reference to the operation of the second PCF included in the second network with reference to FIGS. 7 to 9 .

The second device 710 may create a communication group with the first device 770 . The second device 710 requesting creation of the communication group may request the second network 705, which is its own network, to establish a communication group that remotely cooperates. Also, the second device 710 may invite the first device 770 (a device to join the communication group) connected to another network (eg, the first network 700 ).

The second devices 710 may request the second network 705 to prepare to accept the connection in order to accept the connection with the devices (eg, the first device 770 ) that want to join the communication group. Steps related to a request for a communication group according to an embodiment of the present disclosure may be described later in steps S731, S732, and S733.

According to an embodiment of the present disclosure, the second PCF 713 may operate as a Home PCF (H-PCF) of the participant device. At this time, when the second PCF 713 operates as the H-PCF of the participant device (eg, the first device 770 ), the second PCF 713 is the first network 700 (or the first network 700 ). ) may establish a roaming session based on a connection triggered by the first device 770 connected to the .

For example, in order to perform reverse roaming, the second network 705 may obtain identification information (eg, PCF_ID) of the second PCF 713 included in the second network 705 . According to an embodiment of the present disclosure, when the second PCF 713 operates as an H-PCF for a participant device (eg, the first device 770 ), the identification information of the second PCF 713 is the second It may be stored in the second NRF 714 of the network 705 . According to another embodiment, when the second PCF 713 operates as an H-PCF of a participant device (eg, the first device 770 ), the identification information of the second PCF 713 is the second PCF 713 . ) may be transmitted to the second AMF 711 of the second network 705 . Also, the identification information of the second PCF 713 may be transmitted from the second AMF 711 to the second NRF 714 and stored in the second NRF 714 .

The identification information of the second PCF 713 may mean information for indicating a communication group. In order to activate the first PCF 773 to operate as a Visting-PCF (V-PCF) according to an embodiment, the first PCF 773 and the first AMF 771 are identification information of the second PCF 713 . can be obtained.

The first PCF 773 that has received the identification information of the second PCF 713 may trigger the second PCF 713 that has already been prepared to operate as the H-PCF to operate as the H-PCF.

The first AMF 771 retrieves or obtains information about the identification information of the second PCF 713 in the second NRF 714 of the second network 705 through the first NRF 774 . can

The first device 770 may request to join the first network 700 to join (or join) the communication group of the second network 705 prepared by the second device 710 . As described above, the first AMF 771 retrieves the identification information of the second PCF 713 from the second NRF 714 of the second network 705 through the first NRF 774 or can be obtained (to be described later in steps S753 to S756)

When the first AMF 771 obtains identification information of the second PCF 713 , the first PCF 773 may be activated so that the first PCF 773 operates as a V-PCF. (to be described later in step S757)

When the first PCF 773 operates as the V-PCF, reverse roaming may be performed with respect to the second PCF 713 operating as the H-PCF. The first device 770 joins the communication group through the first network 700 (the home network of the first device). Also, a connection between the first network 700 and the second network 705 may be established. (to be described later in S758) In order to establish the above-described connection, steps before step S758 need to be performed.

Since the first device 770 according to an embodiment of the present disclosure belongs to a communication group and operates as if it is connected to the second network 705, which is actually an external network for the first device 770, "reverse roaming ( reverse roaming). However, the first device 770 is still physically connected to the RAN of the first network 700 , which is a home network. The first device 770 may act like a roaming process to join the communication group, but in reality still remain in the first network 700 .

In step S758, even though the second PCF 713 is included in the second network that is an external network of the first device 770, the first device 770, which is a participant device, operates as an H-PCF of the home network. can The NF of the first network 700 , which is the home network of the first device 770 , operates as a Visiting NF for the first device 770 , and the NF of the second network 705 connected to the first network 700 . They operate like Home NFs of the first device 770 . In order for the communication group according to the present disclosure to operate, the first device 770 may use the second network 705 of the second device 710 to mimic physical roaming.

A first tunnel 791 may be created between the first PCF 773 of the first network 700 and the second PCF 713 of the second network 705 . Also, a second tunnel 792 may be created between the first SMF 775 and the second SMF 715 . Also, a third tunnel 793 may be created between the first UPF 776 and the second UPF 716 .

Each step of the operation of the present disclosure described above will be described later in more detail. Steps S731 to S737 are operations performed in the second network 705 to which the second device 710, which is an initiator terminal for creating a communication group, is connected.

In step S731 , the second device 710 is a network of the second device 710 to form a communication group with the first device 770 connected to another network (eg, the first network 700 ). The network 705 may be requested to create a communication group. For example, the second device 710 may refer to a device having specific identification information. As a non-limiting example, identification information of the second device 710 may include a specific International Mobile Subscriber Identity (IMSI). According to an embodiment of the present disclosure, the second device 710 may mean a first device connected to a communication group being created. The second device 710 according to an embodiment of the present disclosure may transmit a communication group creation request to the second network 705 together with the identification information of the first device 770 received by the second AMF 711 . have. The communication group creation request may refer to a request for creating a communication group, which is a group in which devices connected to different networks transmit and receive data to each other. According to an embodiment of the present disclosure, the second device 710 may transmit a message to request creation of a communication group. For example, the second device 710 may transmit a MOMSISDN-less message, which is a type of SMS, to the second network 705 to request creation of a communication group. The second device 710 of step S731 allows the second network 705 to respond to the communication group join request received from the first device 770 of the first network 700, so that the first device 770 ) may provide unique identification information (eg, IMSI) to the first network 700 .

In this step, the second device 710 may generate identification information of the communication group. The identification information of the communication group may mean identification information representing the communication group so that the second device 710 and the first device 770 can know each other. For example, the communication group identification information (ID) may include a mobile country code (MCC), a mobile network code (MNC), device identification information (eg, IMSI), and a unique SUB_ID. Information included in the communication group identification information (information other than the device identification information (parameters)) may be used to enhance security for a communication group to be created and to distinguish sessions of the communication group.

The first device 770 according to an embodiment needs to notify the first network 700 to which the first device 770 is connected of its intention to participate in the communication group. The first device 770 uses the identification information of the second device 710 , which will be described in more detail in step S751 below.

Step S731 and step S751 both have a common feature of using identification information (eg, IMSI) of another terminal belonging to a communication group. However, in step S731 , the second device 710 may prepare the second network 705 to connect with the first network 700 . Meanwhile, in step S751 , the first network 700 may activate a process for joining the first device 770 to the communication group.

In step S732 , the second AMF 711 may transmit a communication group creation request to the second SMSF 712 . In addition, the second SMSF 712 may identify the communication group creation request of the second device 710 and trigger the second AMF 711 to make reverse roaming to the first device 770 for the communication group. have. As another example, the second device 710 may transmit the communication group creation request to the second SMSF 712 . According to an embodiment of the present disclosure, when the communication group creation request is generated using a message method (eg, MOMSISDN-less message method), the second SMSF 712 decodes the message to communicate the communication requested by the second device 710 You can check the creation request information for the group. In addition, the second SMSF 712 may transmit a communication group creation request of the second device 710 to the second AMF 711 . The second AMF 711 may check and process the communication group creation request of the second device 710 . Also, the second AMF 711 may trigger to create or establish a communication group (reverse roaming to the first device 770 for group communication).

In step S732 and step S752 to be described later, the second SMSF 712 and the first SMSF 772 may decode a signal (eg, a message) received from the device. In step S732 , the second SMSF 712 may decode the request message to establish a communication group in the second network 705 . In step S752 , the first SMSF 772 may decode a message requesting to join the communication group being created or created by the second device 710 in the second network 705 . For example, the second AMF 711 may transmit a message to the second SMSF 712 to identify or decode the request. The second SMSF 712 may then trigger the second AMF 711 to create and establish a communication group. As an example, the trigger sets the data network (DN) setting in the second network 705 and other functions of the second network 705 for the communication group, or the first network 700 for the first device 770 . preparing the second network 705 for a reverse roaming connection of

In step S733 , the second AMF 711 may request the second PCF 713 to create a communication group in order to establish a communication group. The second PCF 713 according to an embodiment may operate as a Home PCF for the first device 770 . Also, the second PCF 713 may accept the roaming session from the first device 770 . In the present disclosure, the second PCF 713 may operate according to a general function of the PCF included in the second network 705 with respect to the second device 710 . In addition, the second PCF 713 may operate as the PCF of the Home PLMN for the first device 770 . That is, the second PCF 713 may operate like the PCF of the Home PLMN for the first device 770 in addition to the general PCF function. When the second PCF 713 according to an embodiment of the present disclosure receives a request for establishing a communication group from the second AMF 711 , the second PCF 713 is the first device 770 . It can operate as an H-PCF for In this case, the second PCF 713 operating as the H-PCF may accept the reverse roaming connection of the first PCF 773 serving as the V-PCF. Alternatively, when the second PCF 713 is activated to operate as the H-PCF, the second PCF 713 may accept the reverse roaming session from the first device 770 .

In step S734 , the second PCF 713 may store identification information of the second PCF 713 of the second network 705 in the second NRF 714 .

In steps S735, S736, and S737, the second network 705 may configure the SMF, UPF and DN for the communication group. In step S735 , the second PCF 713 may determine a policy for mobility and session management so that the second AMF 711 and the second SMF 715 operate correctly. As an example, an N7 link of a standard document may be established between the second PCF 713 and the second SMF 715 . Also, in step S736 , the second SMF 715 may manage a session in the second network 705 and allocate an IP address. The second SMF 715 may communicate and control the second UPF 716 for data transmission. Also, the second SMF 715 may operate like the H-SMF, and in this case, the H-SMF may perform the session and IP address assignment of the first device 770 . In this case, as an example, an N4 link of a standard document may be established between the second SMF 715 and the second UPF 716 . In step S737, a data network (DN) for communication between devices belonging to a future communication group may be generated.

In steps S738 and S739 , the second network 705 may configure the second SMF 715 and the second UPF 716 for a reverse roaming connection from the first device 770 .

Steps S751 to S760 are operations performed in the first network 700 to which the first device 770, which is a participant terminal to participate in the communication group, is connected. In step S751 , the first device 770 is a first network that is a network of the first device 770 in order to belong to a communication group created by an initiator terminal (eg, the second device 710 ) connected to another network. It may request to join the communication group at 700 . For example, the first device 770 may mean a device having specific identification information. As a non-limiting example, the identification information of the first device 770 may include a specific International Mobile Subscriber Identity (IMSI). According to an embodiment of the present disclosure, the first device 770 transmits a communication group participation request to the first network 700 together with the identification information of the second device 710 received by the first AMF 771 . can In this case, the communication group subscription request may mean a request for a device to participate in a communication group, which is a group in which devices connected to different networks transmit and receive data to each other. According to an embodiment of the present disclosure, as a method for the first device 770 to request to participate in a communication group, there is a method for transmitting a message. For example, the first device 770 may transmit a MOMSISDN-less message, which is a type of SMS, to the first network 700 to request participation in the communication group.

The first device 770 of the corresponding step S751, so that the first network 700 can be connected to the communication group created by the second device 710 of the external network (eg, the second network 705), the second Unique identification information (eg, IMSI) of the device 710 may be provided to the second network 705 . The first device 770 may request to belong to a communication group having specific communication group identification information. For example, the identification information (ID) of the communication group may include a mobile country code (MCC), a mobile network code (MNC), identification information of a device (eg, IMSI), and a unique SUB_ID.

In step S752 , the first AMF 771 may transmit a communication group participation request to the first SMSF 772 . In addition, the first SMSF 772 may identify the communication group join request of the first device 770 and trigger the first AMF 771 to participate in reverse roaming to the first device 770 for the communication group. have. As an example, the first device 770 may transmit the communication group participation request to the first SMSF 772 . According to an embodiment of the present disclosure, when the communication group participation request is generated in a message method (eg, MOMSISDN-less message method), the first SMSF 772 decodes the message and the communication requested by the first device 770 You can check the creation request information for the group. In addition, the first SMSF 772 may transmit a communication group participation request of the first device 770 to the first AMF 771 .

The first AMF 771 may check and process the communication group participation request of the first device 770 . Also, the first AMF 771 may trigger to create or establish a communication group (reverse roaming to the first device 770 for group communication).

In steps S753 to S756 , the first AMF 771 may obtain identification information of the second PCF 713 included in the second network 705 from the second network 705 . In step S753 , the first AMF 771 may request identification information of the second PCF 713 from the first NRF 774 . Also, in step S754 , the first NRF 774 may request identification information of the second PCF 713 from the second NRF 714 . In step S755 , the first NRF 774 may obtain identification information of the second PCF 713 from the second NRF 714 . Also, in step S756 , the first AMF 771 may obtain identification information of the second PCF 713 from the first NRF 774 .

In step S757, the first AMF 771 uses the identification information of the second PCF 713 to reverse roaming to the first PCF 773 of the first network 700 (in this case, operating as a V-PCF). you can request According to an embodiment of the present disclosure, the first AMF 771 is a second PCF (in this case, operated as an H-PCF) 713 created in the second network 705 in which a communication group is established. ), the first PCF 773 may be activated as a V-PCF by providing identification information (eg, PCF_ID). Using the above-described method, reverse roaming may be performed in step S758 , and reverse roaming may be performed using the first tunnel 791 , the second tunnel 792 , and the third tunnel 793 .

In step S758 , the first PCF (operating as V-PCF) 773 uses the identification information of the second PCF (operating as H-PCF at this time) 713 , and the second PCF of the second network 705 . In this case, reverse roaming may be performed at 713 (operation as H-PCF). As described above, the identification information of the second PCF 713 may mean an ID of a PCF instance in the second network 705 . In addition, as described above, the second PCF 713 performs a basic PCF function for the second device 710 that has established the communication group, and Home-PCF for the first device 770 participating in the communication group. It can also function as

According to an embodiment of the present disclosure, the first tunnel 791 means a tunnel between the first PCF (operating as a visiting-PCF) 773 and the second PCF (in this case, operating as a Home-PCF) 713 . can do.

In operation S758 , the first device 770 may perform a role of a participant in the communication group through the first network 700 that is an actual home network of the first device 770 . In addition, in the corresponding step, a connection between two different networks (eg, the first network 700 and the second network 705 ) may be established. In order to establish such a network-to-network connection, the previous step of step S758 is necessary. As described above in FIG. 3 , the reason that the operation of the present disclosure can be described as “reverse roaming” is that, as in step S758, the first device 770 is connected to the second network 705, which is an external network in fact. , because the first device 770 is still physically connected to the (R) AN of the first network 700 , which is a home network. That is, in step S758 , the second PCF 713 operates with the first device 770 as a PCF (H-PCF) included in the home network in normal roaming.

Based on the identification information (eg, PCF_ID) of the second PCF 713 collected from the second network 705 by the first network 700 , the first PCF 773 activated as V-PCF is H - A connection (eg, a first tunnel) to the PCF activated second PCF 713 may be opened. In step S759, the first PCF 773 may communicate with the first SMF 775 operating as a Visting-SMF (hereinafter, V-SMF). The first PCF 773 may determine a policy for mobility and session management so that the first AMF 771 and the first SMF (operating as a V-SMF) 775 operate correctly. In the present disclosure, the second tunnel 792 may refer to a tunnel between the second SMF (operating as Home-SMF) 715 and the first SMF (operating as V-SMF) 775 . In step S760 , the first SMF (operating as a V-SMF) 775 may manage a session and allocate an IP address. Also, the first SMF (operating as a V-SMF) 775 may communicate with and control the first UPF 776 . In the present disclosure, the third tunnel 793 may refer to a tunnel between the first UPF 776 and the second UPF 716 .

After successful reverse roaming setup, the second device 710 and the first device 770 may be connected to the data tunnel of the communication group. A communication group can be created immediately and directly by joining the same data network (DN).

Steps S731 to S737 and steps S751 to S760 described above in FIG. 7 describe operations performed in each network according to the flow. Accordingly, steps S751 to S760 are not necessarily performed after steps S731 to S737. That is, after some steps of the second network 705 are performed, the steps of the first network 700 may be performed.

As described above, reverse roaming may be established through virtual relocation of the first device 770 , as involved in physical roaming. Through the obtained identification information of the PCF, the instantiation of the Home-PCF of the second PCF 713 may be called. At this time, through the operation of requesting identification information of the PCF between the first NRF 774 and the second NRF 714 and receiving the identification information of the PCF, the identification information of the PCF is transmitted through the second network 705, may be transmitted to the first network 700 . Thus, backward control communication with the first PCF 773 can be effectively established. By doing so, communication groups can be joined to the same data network (DN), and communication groups can be created immediately and directly.

At this time, one or more different first networks 700 may be connected to the second network 705 . DNs (data networks) and sessions in one network can be transferred to another network. As an example, AI implemented in the network may determine to establish or terminate a connection with another device. For example, AI implemented in a network can establish or terminate a connection between an IoT device, such as a vehicle, and a smart city infrastructure. As an example, AI implemented in the device may determine to establish or terminate a connection with another device. As an example, a network other than the first network 700 and the second network 705 may be used according to an application type (eg, V2V emergency application). For example, inter-PLMN QoS (inter-PLMN QoS) may be affected according to application requirements. As an example, the AI may determine the network (PLMN) location of the data network (DN) for the best quality of service. For example, instead of reverse roaming, a third-party application function (AF) connected to a core network through NEF may perform communication between devices.

8 is a data flow diagram illustrating a method of creating a communication group in a second network, according to an embodiment of the present disclosure. As the details are described above with reference to FIG. 7 , repeated contents will be omitted.

In step S801 , the second device 710 may request the second AMF 711 to generate identification information and a communication group of the first device 770 . This may correspond to step S731 described above.

In the present disclosure, steps S802 to S805 are necessary steps when the second device 710 requests to create a communication group in a message in a format that can be decoded by the SMSF. Accordingly, when the second device 710 requests the creation of a communication group in a format other than a message, it may not necessarily be performed. In step S802 , the second AMF 711 may transmit a communication group creation request to the second SMSF 712 . In step S803, the second SMSF 712 may decode the message. In step S804, the second SMSF 712 may confirm the communication group creation request. In step S805 , the second SMSF 712 may transmit an instruction from the message to the second AMF 711 . This may correspond to step S732 described above.

In step S806 , the second AMF 711 may create a communication group for the first device 770 . Also, the second AMF 711 may manage a communication group. In step S807 , the second AMF 711 may control the second PCF 713 to operate as a Home-PCF. This may correspond to step S733 described above.

In step S808 , the second PCF 713 may transmit identification information of the second PCF 713 to the second NRF 714 . This may correspond to step S734 described above. In step S809 , the second NRF 714 may store identification information of the second PCF 713 . In step S810, the second PCF 713 may determine a policy for the communication group. In this case, the second PCF 713 may operate as a Home-PCF for the first device 770 . In step S811 , the second PCF 713 may transmit the determined policy to the second SMF 715 . In step S812 , the second PCF 713 may manage a session for the communication group. In step S813 , the second SMF 715 may allocate an IP address to the second UPF 716 . In step S814, the second UPF 716 may generate a DN for the communication group.

9 is a diagram illustrating a data flow diagram of a method for a first device of a first network to join a created communication group, according to an embodiment of the present disclosure. As the details are described above with reference to FIG. 7 , repeated contents will be omitted.

In step S901 , the first device 770 may transmit the identification information of the second device 710 and the communication group participation request to the first AMF 771 .

At this time, in the present disclosure, steps S902 to S905 are necessary steps when the first device 770 requests to create a communication group in a message in a format that can be decoded by the SMSF. Accordingly, when the first device 710 requests creation of a communication group in a format other than a message, it may not necessarily be performed. In step S902 , the first AMF 771 may decode and transmit the message to the first SMSF 772 . In step S903, the first SMSF 772 may decode the message. In step S904, the first SMSF 772 may confirm the communication group participation request. In step S905 , the first SMSF 772 may transmit an instruction from the message to the first AMF 771 . This may correspond to step S752 described above.

In step S906 , the first AMF 771 may request identification information of the second PCF 713 from the first NRF 774 . This may correspond to step S753 described above. In step S907 , the first NRF 774 may request identification information of the second PCF 713 from the second NRF 714 . This may correspond to step S754 described above. In step S908 , the second NRF 714 may transmit identification information of the second PCF 713 to the first NRF 774 . This may correspond to step S755 described above. In step S909 , the first NRF 774 may transmit identification information of the second PCF 713 to the second AMF 711 . In step S910 , the first AMF 771 may obtain identification information of the second PCF 713 . This may correspond to step S756 described above. In step S911 , the first AMF 771 may request reverse roaming based on the identification information of the second PCF 713 . This may correspond to the above-described step S757. In operation S912 , the first PCF 773 may perform reverse roaming with respect to the second PCF 713 through the first tunnel 791 . This may correspond to the above-described step S758. In step S913, the second PCF 713 may determine a policy for the communication group. Also, the first PCF 773 may agree with the second network on policies for the first device.

Unlike the above-described embodiment, in the embodiment of FIG. 10 , the second PCF included in the second network connected to the second device requesting creation of the communication group may operate as a V-PCF for the first device. Also, the first PCF included in the first network connected to the first device requesting participation in the communication group may operate as an H-PCF for the first device.

Steps S1031 to S1044 are operations performed in the second network 1005 to which the second device 1010, which is an initiator terminal for creating a communication group, is connected. In addition, since some contents overlap with the description of FIG. 7 described above, overlapping contents will be omitted.

In step S1031 , the second device 1010 establishes a communication group with the first device 1070 , which is a participant terminal connected to the first network 1000 , and a second network 1005 , which is a network of the second device 1010 . ) to create a communication group. Since it overlaps with the above-described step S731, a detailed description thereof will be omitted.

In step S1032 , the second AMF 1011 may transmit a communication group creation request to the second SMSF 1012 . In addition, the second SMSF 1012 may read the communication group creation request of the second device 1010 and trigger the second AMF 1011 to make reverse roaming to the first device 1070 for the communication group. . Since it overlaps with the above-described step S732, a detailed description thereof will be omitted.

In step S1033 , the second AMF 1011 may request identification information (eg, PCF_ID) of the first PCF 1073 operating as the H-PCF of the first network from the second NRF 1014 . Also, in step S1034 , the second NRF 1014 may transmit the request of the second AMF 1011 to the first NRF 1074 in the second network 1000 .

In step S1035 , the second NRF 1014 may receive PCF identification information of the first PCF (which may operate as an H-PCF) 1073 from the first NRF 1074 . In step S1036 , the second AMF 1011 may receive PCF identification information of the first PCF 1073 from the first NRF 1074 through the second NRF 1014 .

In step S1037, the second AMF 1011 sets reverse roaming to the first PCF 1073 in the second PCF 1013 using the identification information of the first PCF (operating as H-PCF) 1073. you can request In step S1038 , the second PCF (operating as V-PCF) 1013 reverse roaming using the identification information of the first PCF (operating as H-PCF) 1073 in the first network 1000 . ) can be set. In step S1039 , the second PCF 1013 may notify the second AMF 1011 that the first device 1070 is logically attached in a control plane. That is, it may be recognized that both the first device 1070 and the second device 1010 are logically connected to the second network 1005 . However, the physical session of the first device 1070 must still be maintained over the first network 1000 .

In step S1040 , the second PCF 1013 may determine a policy for mobility and session management so that the second AMF 1011 and the second SMF 1015 operate correctly. In step S1041 , the second SMF 1015 may manage a session in the second network 1005 and allocate an IP address. In addition, the second SMF 1015 may communicate with and control the second UPF 1016 for data transmission. In step S1042, a data network (DN) for future device-to-device communication may be created.

Steps S1051 to S1057 are operations performed in the first network 1000 to which the first device 1070, which is a participant terminal to participate in the communication group, is connected.

In step S1051 , the first device 1070 is a first network that is a network of the first device 1070 to belong to a communication group created by an initiator terminal (eg, the second device 1010 ) connected to another network. You can request to join the communication group at 1000 . The detailed description of step S1051 corresponds to step S751 described above with reference to FIG. 7 , and thus a detailed description thereof will be omitted.

In step S1052 , the first AMF 1071 may transmit a communication group participation request to the first SMSF 1072 . Also, the first SMSF 1072 may read the communication group join request of the first device 1070 and trigger the first AMF 1071 to participate in reverse roaming for the first device 1070 for the communication group. . Detailed description of step S1052 corresponds to step S752 described above with reference to FIG. 7 , and thus a detailed description thereof will be omitted.

In step S1053 , the first AMF 1071 may request that the first PCF (operating as an H-PCF) 1073 store identification information of the first PCF in the first NRF 1074 . Accordingly, it is possible to enable the second AMF 1011 to obtain the identification information of the first PCF 1073 . In step S1054 , the first PCF (operating as an H-PCF) 1073 may store identification information of the first PCF in the first NRF 1074 .

The first tunnel 1091 is a reverse tunnel between the second PCF (operating as V-PCF) 1013 and the first PCF (operating as H-PCF) 1073 . In step S1055, the control communication from the second PCF (operating as V-PCF) 1013 to the first PCF (operating as H-PCF) 1073 operates as if physical roaming (reverse roaming) occurred. can In addition, the first device 1070 is the second AMF ( 1011) may be attached virtually. In step S1056 , the first PCF (operating as an H-PCF) 1073 may communicate with the first SMF 1075 . The first PCF (operating as an H-PCF) 1073 is for mobility and session management so that the first AMF 1071 and the first SMF 1075 can properly perform an operation. policy can be determined. The second tunnel 1092 may refer to a tunnel between the first SMF 1075 and the second SMF 1015 . In step S1057, the first SMF 1075 may manage the session and allocate an IP address. The first SMF 1075 may communicate and control the first UPF 1076 for data transmission. The third tunnel 1093 may refer to a tunnel between the first UPF 1076 and the second UPF 1016 . If the reverse roaming setup is successful, the first device 1070 and the second device 1010 may be connected to a data tunnel of a communication group.

Step S1055 (shown by dash line) in FIG. 10 does not indicate a physical interaction unlike other solid lines. The line of S1055 may mean a virtual connection established through interaction between the first AMF, the first PCF (operating as an H-PCF), and the first NRF.

11 is a flowchart for explaining the embodiment described with reference to FIG. 10, and content overlapping with FIG. 10 will be omitted. According to an embodiment of the present disclosure, the first device may be physically connected to a Radio Access Network (RAN) of the first network. Also, the first device may be virtually connected to a data network (DN) of the second network in which the communication group is created. The first device may be a device that mimics being physically roaming, using the second network.

In operation S1110 , the second AMF may receive, from the second device connected to the second network, a communication group creation request for creating a communication group with the first device of the first network and identification information of the first device.

According to an embodiment of the present disclosure, the identification information of the second device may include a phone number of the second device, but is not limited thereto. According to an embodiment of the present disclosure, the second AMF may generate identification information of a communication group to be created by the second device based on the generation request and identification information of the first device. In this case, the identification information of the communication group may include at least one of information about the second network, identification information of the first device, identification information of the second device, or SUB ID information of the communication group. The information on the second network may include PLMN information, and may include, for example, mobile country codes (MCC), mobile network codes (MNC), and the like.

In step S1120 , the second AMF may acquire identification information of a first policy control function (PCF) included in the first network based on the generation request.

According to an embodiment of the present disclosure, the second AMF may request identification information of the first PCF from the second NRF included in the second network. Also, the second AMF may obtain identification information of the first PCF from the first NRF included in the first network through the second NRF.

In step S1130, the second AMF uses the identification information of the first PCF, so that the first device can communicate with the second device of the second network, the second PCF included in the second network is connected to the first device. It can be controlled to operate as a Visiting PCF. For example, the second PCF may be controlled to operate as a visiting PCF of the first network.

According to an embodiment of the present disclosure, the second AMF may transmit identification information of the first PCF to the second PCF. In the present disclosure, when the second PCF operates as a visiting PCF for the first device, the second PCF may establish a roaming session with the first PCF of the first network. In addition, the second PCF may receive a policy for the communication group from the first PCF.

12 is a flowchart of a method for controlling communication between devices belonging to a communication group formed with another network by a second PCF of a second network according to an embodiment of the present disclosure. 12 is a flowchart for explaining the embodiment described with reference to FIG. 10 , and content overlapping with FIG. 10 will be omitted.

In step S1210, the second PCF includes a first policy control function (PCF) included in the first network from the second AMF included in the second network to create a communication group with the first device connected to the first network. ) of the identification information can be received. In step S1220 , using the identification information of the first PCF, the second PCF may be activated to operate as a visiting PCF for the first device so that the first device can communicate with the second device of the second network.

The second PCF according to an embodiment may be activated to operate as a visiting PCF of the first network. According to an embodiment of the present disclosure, the second PCF may establish a roaming session with the first PCF of the first network to receive a policy for a communication group from the first PCF. According to an embodiment of the present disclosure, a tunnel between the first PCF and the second PCF for communication between devices belonging to a communication group may be created.

13 is a data flow diagram of a method for creating a communication group in a second network, according to an embodiment of the present disclosure. As the details are described above with reference to FIGS. 10 to 12 , repeated contents will be omitted.

In operation S1301 , the second device 1010 may request the second AMF 1011 to generate identification information and a communication group of the first device 1070 .

In the present disclosure, steps S1302 to S1305 are necessary steps when the second device 1010 requests creation of a communication group in a message in a format that the SMSF can decode. Accordingly, when the second device 1010 requests creation of a communication group in a format other than a message, it may not necessarily be performed. In step S1302 , the second AMF 1011 may transmit a communication group creation request signal to the second SMSF 1012 . In step S1303, the second SMSF 1012 may decode the message. In step S1304, the second SMSF 1012 may confirm the communication group creation request. In step S1305 , the second SMSF 1012 may transmit an instruction from the message to the second AMF 1011 .

In step S1306 , the second AMF 1011 may create a communication group for the first device 1070 . Also, the second AMF 1011 may manage a communication group. In step S1307 , the second AMF 1011 may control the second PCF 1013 to operate as a Visiting-PCF.

In step S1308 , the second AMF 1011 may request identification information of the first PCF 1073 from the second NRF 1014 . In step S1309 , the second NRF 1014 may request identification information of the first PCF 1073 from the first NRF 1074 . In step S1310 , the second NRF 1014 may receive identification information of the first PCF 1073 from the first NRF 1074 . In step S1311 , the second AMF 1011 may obtain identification information of the first PCF 1013 from the second NRF 1014 .

In step S1312 , the second AMF 1011 may instruct the second PCF 1013 to establish reverse roaming. In operation S1313 , the second PCF 1013 may establish reverse roaming from the second PCF 1013 to the first PCF 1073 . In operation S1313 , the second PCF 1013 may notify the second AMF 1011 of a logical attachment of the first device 1070 .

14 illustrates a data flow diagram of a method of joining a communication group in a first network, according to an embodiment of the present disclosure. As the details are described above with reference to FIGS. 10 to 12 , repeated contents will be omitted.

In step S1401 , the first device 1070 may transmit the identification information of the second device 1010 and the communication group participation request to the first AMF 1071 .

In the present disclosure, steps S1402 to S1405 are necessary steps when the first device 1070 requests to create a communication group in a message in a format that can be decoded by the SMSF. Accordingly, when the first device 1070 requests creation of a communication group in a format other than a message, it may not necessarily be performed. In step S1402 , the first AMF 1071 may decode and transmit the message to the first SMSF 1072 . In step S1403, the first SMSF 1072 may decode the message. In step S1404, the first SMSF 1072 may confirm the communication group participation request. In step S1405 , the first SMSF 1072 may transmit an instruction from the message to the first AMF 1071 .

In step S1406, the first AMF 1071 may request the first PCF 1073 to store the identification information of the first PCF in the first NRF. The first PCF 1073 may transmit identification information of the first PCF to the first NRF in response to the request. Also, in step S1408, the first PCF 1073 may determine a policy for the communication group.

The AMF of FIG. 15 may correspond to the first AMF and the second AMF of the present disclosure. Referring to FIG. 15 , the AMF may include a transceiver 1510 , a memory 1520 , and a processor 1530 . According to the above-described AMF communication method, the AMF transceiver 1510 , the processor 1530 , and the memory 1520 may operate. However, the components of the AMF are not limited to the above-described examples. For example, the AMF may include more or fewer components than the aforementioned components. In addition, the transceiver 1510 , the processor 1530 , and the memory 1520 may be implemented in the form of a single chip. Also, the processor 1530 may include one or more processors.

The transmitter/receiver 1510 collectively refers to an AMF receiver and an AMF transmitter, and may transmit/receive a signal to/from a terminal or a network entity. A signal transmitted and received with a terminal, a base station, or another network entity may include control information and data. To this end, the transceiver 1510 may include an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and down-converts a received signal. However, this is only an example of the transceiver 1510 , and components of the transceiver 1510 are not limited to the RF transmitter and the RF receiver.

Also, the transceiver 1510 may receive a signal through a wireless channel and output it to the processor 1530 , and transmit the signal output from the processor 1530 through a wireless channel.

The memory 1520 may store programs and data necessary for the operation of the AMF. Also, the memory 1520 may store control information or data included in a signal obtained from the AMF. The memory 1520 may be configured as a storage medium or a combination of storage media, such as ROM, RAM, hard disk, CD-ROM, and DVD. Also, the memory 1520 may not exist separately and may be included in the processor 1530 .

The processor 1530 may control a series of processes so that the AMF operates according to the above-described embodiment of the present disclosure. For example, the processor 1530 may receive a control signal and a data signal through the transceiver 1510 and process the received control signal and data signal. In addition, the processor 1530 may include the processed control signal and data signal. A signal may be transmitted through the transceiver 1510 .

According to an embodiment of the present disclosure, the processor 1530 is configured to receive, from a first device connected to a first network, a request for participation in a communication group set by a second device of a second network and identification information of the second device. control the transceiver to control the transceiver, acquire identification information of a second Policy Control Function (PCF) included in the second network based on the participation request, and use the identification information of the second PCF to enable the first device to connect to the second network In order to communicate with the second device of , the first PCF included in the first network may be controlled to operate as a visiting PCF for the first device.

According to an embodiment of the present disclosure, the processor 1530 requests identification information of the second PCF from the first NRF included in the first network, and receives the second PCF from the second NRF included in the second network through the first NRF. 2 PCF identification information can be obtained.

According to an embodiment of the present disclosure, the processor 1530 may check identification information of a communication group in which the first device participates based on the participation request and identification information of the second device. In this case, the identification information of the communication group may include at least one of information about the second network, identification information of the first device, identification information of the second device, or SUB ID information of the communication group.

According to an embodiment of the present disclosure, the processor 1530 may control the transceiver to transmit identification information of the second PCF to the first PCF. At this time, when the first PCF operates as a visiting PCF for the first device, the first PCF establishes a roaming session with the second PCF of the second network, and receives the policy for the communication group from the second PCF. have.

According to an embodiment of the present disclosure, the processor 1530 may create a communication group between the first device connected to the first network and the third device connected to the third network.

According to an embodiment of the present disclosure, the processor 1530 receives, from a first device connected to a first network, a communication group creation request for creating a communication group with a third device connected to a third network, and identification information of the third device may control the transceiver to receive , and, based on the communication group creation request, control the first PCF included in the first network to create the communication group to operate as a Home PCF for the third device.

The PCF of FIG. 16 may correspond to the first PCF and the second PCF of the present disclosure. Referring to FIG. 16 , the PCF may include a transceiver 1610 , a memory 1620 , and a processor 1630 . According to the PCF communication method described above, the transceiver 1610 , the processor 1630 , and the memory 1620 of the PCF may operate. However, the components of the PCF are not limited to the above-described examples. For example, the PCF may include more or fewer components than the aforementioned components. In addition, the transceiver 1610 , the processor 1630 , and the memory 1620 may be implemented in the form of a single chip. Also, the processor 1630 may include one or more processors.

The transceiver 1610 collectively refers to a receiver of the PCF and a transmitter of the PCF, and may transmit/receive a signal to and from a terminal, a base station, or another network entity. A signal transmitted and received with a terminal or a network entity may include control information and data. To this end, the transceiver 1610 may include an RF transmitter for up-converting and amplifying the frequency of a transmitted signal, and an RF receiver for low-noise amplifying a received signal and down-converting the frequency. However, this is only an embodiment of the transceiver 1610 , and components of the transceiver 1610 are not limited to the RF transmitter and the RF receiver.

In addition, the transceiver 1610 may receive a signal through a wireless channel, output it to the processor 1630 , and transmit a signal output from the processor 1630 through a wireless channel.

The memory 1620 may store programs and data necessary for the operation of the PCF. Also, the memory 1620 may store control information or data included in a signal obtained from the PCF. The memory 1620 may be configured as a storage medium or a combination of storage media, such as ROM, RAM, hard disk, CD-ROM, and DVD. Also, the memory 1620 may not exist separately and may be included in the processor 1630 .

The processor 1630 may control a series of processes so that the PCF operates according to the above-described embodiment of the present disclosure. For example, the processor 1630 may receive a control signal and a data signal through the transceiver 1610 and process the received control signal and data signal. In addition, the processor 1630 may include the processed control signal and data signal. A signal may be transmitted through the transceiver 1610 .

According to an embodiment of the present disclosure, the processor 1630 is configured to allow the first device connected to the first network to participate in the communication group created in the second network, from the first AMF included in the first network, to the second network. Controls the transceiver to receive the identification information of the second PCF (Policy Control Function) included in the second PCF, and uses the identification information of the second PCF so that the first device can communicate with the second device of the second network, 1 PCF may be activated to act as a Visiting PCF for the first device.

According to an embodiment of the present disclosure, the processor 1630 establishes a roaming session with the second PCF of the second network, and may control the transceiver to receive a policy for a communication group from the second PCF.

According to an embodiment of the present disclosure, the processor 1630 is configured to generate a communication group between the first device connected to the first network and the third device connected to the third network, so that the first PCF is configured as a Home PCF for the third device. It can be activated to work as

According to an embodiment of the present disclosure, when the first PCF is activated to operate as a Home PCF for the third device, the processor 1630 manages the communication group and performs network setting for the communication group. and the first PCF may control to determine a policy for the communication group.

According to an embodiment of the present disclosure, the processor 1630 may control the transceiver to transmit the identification information of the first PCF to the first NRF according to a request of the third network.

According to an embodiment of the present disclosure, the processor 1630 may control the transceiver to transmit the identification information of the first PCF to the first NRF through the first AMF in response to a request from the third network.

The terminal of FIG. 17 may correspond to the first device, the second device, and the third device of the present specification. Referring to FIG. 17 , the terminal may include a transceiver 1710 , a memory 1720 , and a processor 1730 . According to the communication method of the terminal described above, the transceiver 1710 , the processor 1730 , and the memory 1720 of the terminal may operate. However, the components of the terminal are not limited to the above-described example. For example, the terminal may include more or fewer components than the aforementioned components. In addition, the transceiver 1710 , the processor 1730 , and the memory 1720 may be implemented in the form of a single chip. Also, the processor 1730 may include one or more processors.

The transceiver 1710 collectively refers to a receiver of a terminal and a transmitter of the terminal, and may transmit/receive a signal to and from a network entity, a base station, or another terminal. A signal transmitted and received with a network entity, a base station, or another terminal may include control information and data. To this end, the transceiver 1710 may include an RF transmitter that up-converts and amplifies a frequency of a transmitted signal, and an RF receiver that low-noise amplifies and down-converts a received signal. However, this is only an embodiment of the transceiver 1710 , and components of the transceiver 1710 are not limited to the RF transmitter and the RF receiver.

Also, the transceiver 1710 may receive a signal through a wireless channel and output it to the processor 1730 , and transmit a signal output from the processor 1730 through a wireless channel.

The memory 1720 may store programs and data necessary for the operation of the terminal. Also, the memory 1720 may store control information or data included in a signal obtained from the terminal. The memory 1720 may be configured as a storage medium or a combination of storage media such as ROM, RAM, hard disk, CD-ROM, and DVD. Also, the memory 1720 may not exist separately and may be included in the processor 1730 .

The processor 1730 may control a series of processes so that the terminal can operate according to the above-described embodiment of the present disclosure. For example, the processor 3130 may receive a control signal and a data signal through the transceiver 3110 and process the received control signal and data signal. In addition, the processor 3130 may include the processed control signal and data signal. A signal may be transmitted through the transceiver 3110 .

Meanwhile, the above-described embodiment can be written as a program that can be executed on a computer, and can be implemented in a general-purpose digital computer that operates the program using a computer-readable medium. In addition, the structure of data used in the above-described embodiment may be recorded in a computer-readable medium through various means. In addition, the above-described embodiment may be implemented in the form of a computer program product including a recording medium including instructions executable by a computer, such as a program module executed by a computer. For example, methods implemented as software modules or algorithms may be stored in a computer-readable recording medium as computer-readable codes or program instructions.

Computer-readable media may be any recording media that can be accessed by a computer, and may include volatile and nonvolatile media, removable and non-removable media. The computer readable medium may include, but is not limited to, a magnetic storage medium, for example, a ROM, a floppy disk, a hard disk, and the like, and an optically readable medium, for example, a storage medium such as a CD-ROM or DVD. . In addition, computer-readable media may include computer storage media and communication media.

In addition, a plurality of computer-readable recording media may be distributed in network-connected computer systems, and data stored in the distributed recording media, for example, program instructions and codes, may be executed by at least one computer. have.

The device-readable storage medium may be provided in the form of a non-transitory storage medium. Here, 'non-transitory storage medium' is a tangible device and only means that it does not contain a signal (eg, electromagnetic wave). It does not distinguish the case where it is stored as For example, the 'non-transitory storage medium' may include a buffer in which data is temporarily stored.

According to an embodiment, the method according to various embodiments disclosed in this document may be provided as included in a computer program product. Computer program products may be traded between sellers and buyers as commodities.

The computer program product is distributed in the form of a device-readable storage medium (eg compact disc read only memory (CD-ROM)), or through an application store (eg Play Store™) or on two user devices (eg, It can be distributed (eg downloaded or uploaded) directly, online between smartphones (eg: smartphones). In the case of online distribution, at least a portion of the computer program product (eg, a downloadable app) is stored at least in a machine-readable storage medium, such as a memory of a manufacturer's server, a server of an application store, or a relay server. It may be temporarily stored or temporarily created.

On the other hand, the embodiments of the present disclosure disclosed in the present specification and drawings are only presented as specific examples to easily explain the technical content of the present disclosure and help the understanding of the present disclosure, and are not intended to limit the scope of the present disclosure. That is, it is obvious to those of ordinary skill in the art to which the present disclosure pertains that other modifications are possible based on the technical spirit of the present disclosure. In addition, each of the above embodiments may be operated in combination with each other as needed.

Claims

A method for controlling communication between devices belonging to a communication group formed with another network by a first AMF of a first network,

receiving, from a first device connected to the first network, a request for participation in the communication group set by a second device of a second network and identification information of the second device;

obtaining identification information of a second Policy Control Function (PCF) included in the second network based on the participation request; and

Using the identification information of the second PCF, the first PCF included in the first network is a Visiting PCF for the first device so that the first device can communicate with the second device of the second network. Including; controlling to operate as a method.
The method of claim 1,

Based on the participation request, obtaining identification information of the second PCF included in the second network;

requesting identification information of the second PCF from a first NRF (NF Repository Function) included in the first network; and

Obtaining identification information of the second PCF from a second NRF included in the second network through the first NRF;
The method of claim 1,

Based on the participation request and the identification information of the second device, the step of confirming the identification information of the communication group in which the first device participates; further comprising,

The communication group identification information includes at least one of information on the second network, identification information of the first device, identification information of the second device, or SUB ID information of the communication group.
The method of claim 1,

Using the identification information of the second PCF, the first PCF included in the first network is a Visiting PCF for the first device so that the first device can communicate with the second device of the second network. Controlling to operate as;

transmitting identification information of the second PCF to the first PCF; A method comprising
The method of claim 1, wherein the first device is physically connected to a radio access network (RAN) of the first network, and is virtually connected to a data network (DN) of the second network in which the communication group is created. connected way.
The method of claim 1,

creating the communication group between the first device connected to the first network and a third device connected to a third network;
7. The method of claim 6,

creating the communication group between a first device connected to the first network and a third device connected to the third network;

receiving, from a first device connected to the first network, a communication group creation request for creating a communication group with the third device connected to the third network, and identification information of the third device; and

Controlling a first PCF included in the first network to operate as a Home PCF for the third device to create the communication group based on the communication group creation request.
A method in which a first PCF of a first network controls communication between devices belonging to a communication group formed with another network,

A second Policy Control Function (PCF) included in the second network from the first AMF included in the first network so that the first device connected to the first network can participate in the communication group created in the second network receiving identification information of and

activating the first PCF to operate as a visiting PCF for the first device so that the first device can communicate with a second device of the second network by using the identification information of the second PCF; A method comprising
The method of claim 8, wherein the step of activating the first PCF to operate as a visiting PCF for the first device comprises:

establishing, by the first PCF, a roaming session with a second PCF of the second network; and

receiving a policy for the communication group from the second PCF.
9. The method of claim 8,

A tunnel between the first PCF and the second PCF for communication between devices belonging to the communication group is created.
9. The method of claim 8,

activating the first PCF to act as a Home PCF for the third device to create the communication group between a first device connected to the first network and a third device connected to a third network How to.
The method of claim 11 , wherein the step of activating the first PCF to operate as a Home PCF for the third device comprises:

The first PCF includes; determining a policy for the communication group;

The first network manages the communication group and performs network setup for the communication group.
12. The method of claim 11,

In response to the request of the third network, transmitting the identification information of the first PCF to the first NRF; further comprising a method.
12. The method of claim 11,

In response to the request of the third network, transmitting the identification information of the first PCF to the first NRF through the first AMF; The method further comprising a.
In the first AMF of the first network for controlling communication between devices belonging to a communication group formed with another network,

transceiver;

a memory for storing at least one or more instructions; and

At least one processor for controlling communication between devices belonging to the communication group by executing the at least one or more instructions;

The at least one or more processors,

Controls the transceiver to receive, from a first device connected to the first network, a request for participation in the communication group set by a second device of a second network, and identification information of the second device,

Based on the participation request, it obtains identification information of a second PCF (Policy Control Function) included in the second network,

Using the identification information of the second PCF, the first PCF included in the first network is a Visiting PCF for the first device so that the first device can communicate with the second device of the second network. Controlling to operate as, the first AMF.