KR20220010201A - Network apparatus and service continuity guarantee methed in the apparatus - Google Patents

Abstract

The present invention proposes a network apparatus and a service continuity supporting method, which can realize a technology for guaranteeing mobility between heterogeneous networks that can keep a slice service applied to a session the same even when user equipment (UE) moves between heterogeneous networks (for example, EPS network to 5G network).

Description

NETWORK APPARATUS AND SERVICE CONTINUITY GUARANTEE METHED IN THE APPARATUS

The present invention relates to a heterogeneous inter-network mobility technology capable of maintaining the same service applied to a session even when moving between heterogeneous networks.

5G communication system, while accommodating the maximum number of terminals based on limited radio resources, eMBB (enhanced mobile broadband) / mMTC (massive machine type communications) / URLLC (ultra-reliable and It supports scenarios of low latency communications, high reliability and low latency communications, and low latency services).

In particular, in 5G, a network structure to support a terminal, a base station (access), a core, and a server from end to end is defined, and a single node (eg, S-GW, P-GW, etc.) in the existing EPS (LTE) By separating the functions of control signaling and data transmission/reception that were complexly performed, a network structure is defined in which the control signaling function area (Control Plane) and the data transmission/reception function area (User Plane) are divided.

At this time, in 5G, the control node of the Control Plane includes an Access and Mobility Function (AMF) that controls access to the wireless section of the terminal, a Session Management Function (SMF) that manages/controls sessions for using data services for each terminal, and an external network. It can be defined as NEF (Network Exposure Function) in charge of information sharing function of network, NRF (Network Repository Function) function to manage/control information on each node in the network.

And, in 5G, the data node of the user plane can be defined as a UPF (User Plane Function) that transmits and receives data between the terminal and the application server through a session with the terminal based on the control (interlocking) of the SMF.

On the other hand, since it is difficult to commercialize services only with the 5G standard, telecommunication operators are using the method of linking the existing commercialized EPS (LTE) technology and NR (5G) technology. A situation in which the network moves may inevitably occur.

According to the current 5G standard, when a terminal (UE) supporting 5G creates a session in the EPS network, service information to be applied to the session is determined and transmitted to the terminal (UE), and the terminal (UE) is transferred to the 5G network In the case of movement, the transmission method between networks (EPS network -> 5G network) for service information determined when creating a session in the EPS network is not defined.

That is, when the UE moves between heterogeneous networks (eg, EPS network -> 5G network), there is a problem in that mobility between heterogeneous networks that can maintain the same service applied to a session cannot be guaranteed.

The present invention was created in view of the above circumstances, and the purpose of the present invention is to provide a service applied to a session even when a UE moves between heterogeneous networks (eg, EPS network -> 5G network). The purpose of this is to provide a way to ensure the mobility of heterogeneous manganese that can maintain the same.

In order to achieve the above object, a network device according to a first aspect of the present invention provides specific information among information transmitted from the first network to the terminal for synchronization of session information between the terminal registered in the network device and the first network. information management unit to obtain and store; and a request response unit that, when receiving a request for information about the terminal from another network device, transmits the specific information stored for the session while responding to information according to the request.

Specifically, the specific information includes, for each session of the terminal, slice information (Network Slice Selection Assistance Information, NSSAI) servicing the session, information on the location of the previously moved base station of the terminal for the session, and the terminal for the previous procedure It may include response result information and terminal and session characteristic information.

Specifically, the network device is an MME (Mobility Management Entity) supporting the first network, and the other network device is another MME supporting the first network, or an NF that performs a function of an MME in a second network (Network Function).

Specifically, the information request for the terminal may be received from the other network device when the terminal moves from the first network to a second network supported by the other network device.

In order to achieve the above object, there is provided a service continuity support method performed in a network device according to a second aspect of the present invention, from the first network to the terminal for session information synchronization between a terminal registered in the network device and the first network an information management step of acquiring and storing specific information among the transmitted information; and a request response step of responding to information according to the request and the specific information stored for the session when receiving a request for information about the terminal from another network device.

Specifically, the specific information may include Network Slice Selection Assistance Information (NSSAI) serving for each session of the terminal, for each session.

Specifically, the network device is an MME (Mobility Management Entity) supporting the first network, and the other network device is another MME supporting the first network, or an NF that performs a function of an MME in a second network (Network Function).

Specifically, the information request for the terminal may be received from the other network device when the terminal moves from the first network to a second network supported by the other network device.

A terminal device according to a third aspect of the present invention for achieving the above object includes: an information storage unit for storing information transmitted for synchronization of session information when a session with a first network is created; and a controller configured to create a session with the second network based on the stored information when moving from the first network to the second network.

Specifically, the control unit, for the session created in the second network, by using the slice information (Network Slice Selection Assistance Information, NSSAI) for each session included in the information, from the first network to the second network The same slice service as in the first network can be used even during session movement.

According to the network device of the present invention and the service continuity support method performed in the device, even when the UE moves between heterogeneous networks (eg, EPS network -> 5G network), the service applied to the session is maintained the same. It derives the effect of guaranteeing heterogeneous manganese mobility.

1 is an exemplary diagram showing the structure of a 5G system.
2 is an exemplary diagram illustrating a situation in which service information (eg, SNSSAI) is not transmitted from an EPS network to a 5G network.
3 is a block diagram showing the configuration of a network device according to an embodiment of the present invention.
4 is a block diagram showing the configuration of a terminal device according to an embodiment of the present invention.
5 is a flowchart illustrating a service continuity support method according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

The present invention relates to a heterogeneous inter-network mobility technology capable of maintaining the same service applied to a session even when moving between heterogeneous networks.

1 is an exemplary diagram showing the structure of a 5G system.

As can be seen from FIG. 1, the 5G communication system accommodates the maximum number of terminals based on limited radio resources, while eMBB (enhanced mobile broadband)/mMTC (massive machine type communications) /URLLC (ultra-reliable and low latency communications) scenarios are supported.

In particular, in 5G, a network structure to support a terminal, a base station (access), a core, and a server from end to end is defined, and a single node (eg, S-GW, P-GW, etc.) in the existing EPS (LTE) By separating the functions of control signaling and data transmission/reception that were complexly performed, a network structure is defined in which the control signaling function area (Control Plane) and the data transmission/reception function area (User Plane) are divided.

At this time, in 5G, the control node of the Control Plane includes an Access and Mobility Function (AMF) that controls access to the wireless section of the terminal, a Session Management Function (SMF) that manages/controls sessions for using data services for each terminal, and an external network. It can be defined as NEF (Network Exposure Function) in charge of information sharing function of network, NRF (Network Repository Function) function to manage/control information on each node in the network.

And, in 5G, the data node of the user plane can be defined as a UPF (User Plane Function) that transmits and receives data between the terminal and the application server through a session with the terminal based on the control (interlocking) of the SMF.

In 5G, both the control node of the control plane and the data node of the user plane can be called a network device or a network node (Network Function, NF).

On the other hand, since it is difficult to commercialize services only with the 5G standard, telecommunication operators are using the method of linking the existing commercialized EPS (LTE) technology and NR (5G) technology. A situation in which the network moves may inevitably occur.

And, as part of the structure that uses the existing commercialized EPS (LTE) technology and the NR (5G) technology linking method, some nodes (eg P-GW of EPS, SMF of 5G) between the EPS network and the 5G network has a structure that shares

According to the current 5G standard, when a UE supporting 5G creates a session in the EPS network, service information to be applied to the session is determined and delivered to the UE.

Referring to FIG. 2, when the UE creates a session in the EPS network, SMF+PGW-C provides service information for application/processing to the session, particularly slice information (Network Slice Selection Assistance Information, NSSAI, or S(Single)NSSAI) is obtained through UDM (1).

And, the service information (in particular, SNSSAI) of the session acquired by SMF+PGW-C is delivered to the terminal (UE) through PCO (ePCO) (SMF+PGW-C->MME->eNB) (2), Accordingly, session information can be synchronized between the core (EPS network) and the terminal (UE) (3).

In this case, the SMF+PGW-C may be directly interlocked with the MME including the operation of the SGW-C by itself, or information may be transmitted to the MME through a separate SGW.

Synchronization refers to an operation of matching the cognitive information for the corresponding terminal by exchanging target data as needed between core network nodes. Recognition information about the terminal includes accumulated terminal movement information, information on the contents delivered to the terminal according to the previous call processing procedure, status characteristic information of the terminal and the created Session, IMEI, QoS, Codec for call, etc. may include

However, according to the current 5G standard, when this terminal (UE) moves to the 5G network, the transmission method between networks (EPS network -> 5G network) for service information (especially SNSSAI) determined when creating a session in the EPS network This is undefined.

2, when the UE moves to 5G after creating a session in the EPS network, the UE requests location registration from 5G to AMF. At this time, a service for each session separately It does not convey information (especially SNSSAI).

The AMF detects/recognizes the movement of the terminal (UE) and requests and obtains context information to the node in which the terminal (UE) was registered, that is, the Old MME, and based on the acquired context information, the terminal ( Mobility information for UE) may be transmitted.

Here, the AMF can only obtain the context information requested by the AMF from the MME, and the current standard does not define an operation for transmitting service information (especially SNSSAI) for each session from the MME to the AMF, so the terminal (UE) to the SMF ), since service information (in particular, SNSSAI) cannot be delivered when delivering mobility information for cannot but provide seamlessly.

That is, for now, when the UE moves between heterogeneous networks (eg, EPS network -> 5G network), the service (especially the Slice service) applied to the session can be maintained the same, and mobility between heterogeneous networks is guaranteed. There is a problem that cannot be done.

Accordingly, in the present invention, even when the UE moves between heterogeneous networks (eg, EPS network -> 5G network), a new service that can maintain the same service applied to the session and ensure mobility between heterogeneous networks I would like to suggest a way.

Specifically, a network device for realizing the technical method (hereinafter, service continuity support method) proposed by the present invention is proposed.

First, in brief, the service continuity support method proposed by the present invention provides service information determined at the time of session creation (especially SNSSAI) when the UE moves between heterogeneous networks (eg, EPS network -> 5G network). to realize inter-network (EPS network -> 5G network) for

Accordingly, the service continuity support method proposed in the present invention realizes inter-network (EPS network -> 5G network) transfer of service information (especially SNSSAI) determined during session creation, thereby providing the same as before transfer for sessions moved between networks. It is intended to achieve mobility between heterogeneous networks by seamlessly providing services (especially, Slice service) to which the same service information (in particular, SNSSAI) is applied.

Hereinafter, with reference to FIG. 3, a configuration of a network device for realizing a service continuity support method according to an embodiment of the present invention will be described in detail.

As shown in FIG. 3 , the network device 100 according to the embodiment of the present invention may be configured to include an information management unit 110 and a request response unit 120 .

Such a network device 100 may be a node that manages mobility for a terminal (UE), and may correspond to an MME (Mobility Management Entity) when considering an EPS network, and may correspond to an AMF when considering a 5G network can be

In addition, the situation in which the UE to which the present invention is applied moves between heterogeneous networks may be a situation in which the UE moves from EPS to 5G, and a situation in which the UE moves from 5G to EPS. may be

However, hereinafter, for convenience of description, it is assumed that the UE moves from the EPS to 5G, and accordingly, the network device 100 of the present invention will be described as the MME of the EPS network.

All or at least a part of the configuration of the network device 100 may be implemented in the form of a hardware module or a software module, or may be implemented in a form in which a hardware module and a software module are combined.

Here, the software module may be understood as, for example, instructions executed by a processor that controls operations in the network device 100 , and these instructions may have a form mounted in a memory in the network device 100 . .

After all, the network device 100 (MME) according to an embodiment of the present invention realizes the method proposed in the present invention, that is, the service continuity support method, through the above-described configuration, and hereinafter, the network device 100 for realizing this method Each of my components will be described in more detail.

The information management unit 110 is configured to synchronize session information between a terminal (UE) registered with the network device 100 (MME) and a first network (hereinafter, collectively referred to as an EPS network supported by the MME) in the first network, that is, the EPS network. It performs a function of acquiring and storing specific information among information transmitted to the corresponding terminal (UE).

Here, the information transmitted from the EPS network to the corresponding terminal (UE) means service information transmitted to apply/process the corresponding session when the terminal (UE) creates a session in the EPS network.

That is, when described with reference to FIG. 2 , the information transmitted from the EPS network to the corresponding terminal (UE) is service information for applying/processing to the session created by the SMF+PGW-C for the terminal (UE), particularly the slice After acquiring information (Network Slice Selection Assistance Information, NSSAI or S (Single) NSSAI) through UDM, it is transmitted to the UE (UE) through PCO (ePCO) (SMF+PGW-C->MME->eNB- >UE) information, whereby session information can be synchronized between the core (EPS network) and the terminal (UE).

In this case, the SMF+PGW-C may be directly interlocked with the MME including the operation of the SGW-C by itself, or information may be transmitted to the MME through a separate SGW.

At this time, the information management unit 110, as described above, specific information among the service information for the session delivered to the SMF+PGW-C->MME->eNB->UE, that is, for each session of the UE, a service for the session slice information (SNSSAI) can be acquired and stored.

Specifically, the information management unit 110 checks service information through PCO (ePCO) transmitted from SMF+PGW-C to the UE when a session of the UE (UE) is created in the EPS network, and the corresponding information in the service information. If there is an SNSSAI applied to the session, the SNSSAI can be acquired and mapped/stored in the corresponding session.

Accordingly, according to the present invention, in the MME of the EPS network, the SNSSAI may be mapped/stored and managed for each UE registered in the MME itself and for each session generated in the EPS.

The request response unit 120 performs a function of transmitting the specific information stored for the session while responding to information according to the request when receiving an information request for the terminal (UE) from another network device.

Here, the other network device refers to a first network supported by the network device 100 (MME) of the present invention, that is, another MME supporting an EPS network, or an NF (Network Function) that performs a function of an MME in a second network, for example, a 5G network. ), that is, AMF.

That is, the information request for the terminal (UE) is generated from the AMF by the movement of the terminal (UE) between heterogeneous networks (EPS->5G) if the other network device that generated the request is an AMF supporting the 5G network. /may be an incoming request.

On the other hand, if the other network device that generated the request is another MME supporting the EPS network, the information request for the UE is generated from the other MME by the movement of the UE in the same network (EPS) / It will be an incoming request.

In detail, if the request response unit 120 receives a request for information on a terminal (UE) from the AMF by the movement of the terminal (UE) between heterogeneous networks (EPS->5G), more specifically, when a request for context information is received, The session context information of the UE according to this request is responded to by AMF. Furthermore, if there is an SNSSAI mapped/stored in the corresponding session, this SNSSAI can also be delivered to the AMF.

For this reason, according to the present invention, the AMF detecting/recognizing the movement of the UE is Context information from the Old MME (the network device 100 of the present invention) in which the UE was registered before moving between networks. You can also receive SNSSAI for each session while requesting/obtaining .

In this case, the AMF receives the service information for each session (in particular, SNSSAI) along with the context information requested by the AMF from the MME (the network device 100 of the present invention), and transfers the mobility information for the terminal (UE) to the SMF. Since service information (in particular, SNSSAI) can also be delivered, it is possible to seamlessly provide the Slice service to which the same SNSSAI as in EPS is applied in 5G for a session moving from EPS to 5G.

In addition, the AMF receiving the response from the MME (the network device 100 of the present invention) additionally receives the accumulated location movement information of the additional terminal or information about the response to the terminal and the corresponding terminal for detailed judgment and processing. However, it is possible to re-request the characteristic information for the SESSION, and the MME (the network device 100 of the present invention) that has received the request responds back to the AMF, and the AMF proceeds with detailed call processing using the information according to the purpose. Additional NF Selection or terminal control can be performed.

As described above, in the service continuity support method proposed by the present invention, when a terminal (UE) moves between heterogeneous networks (eg, EPS network -> 5G network), service information (in particular, SNSSAI) determined at the time of session creation is Transmission between Korean networks (EPS network -> 5G network) is being realized.

Accordingly, the service continuity support method proposed in the present invention provides a service (especially the Slice service) to which the same service information (especially SNSSAI) as before movement is applied for a session moved between heterogeneous networks without interruption, providing service continuity /Heterogeneous manganese mobility can be guaranteed.

On the other hand, the request response unit 120, when the information request for the UE (UE) is received from another MME due to the movement of the UE within the same network (EPS), session information of the UE according to this request is responded to to other MMEs, and furthermore, if there is an SNSSAI mapped/stored in the corresponding session, this SNSSAI can also be delivered to other MMEs.

For this reason, according to the present invention, the other MME that has sensed/recognized the movement of the UE is connected to the Old MME (the network device 100 of the present invention) and the UE in which the UE is registered. When exchanging session information for each session, SNSSAI for each session can also be delivered.

As such, the service continuity support method proposed by the present invention can realize exchange/sharing between MMEs for service information (especially SNSSAI) determined during session creation when the UE moves within the same network.

Hereinafter, the configuration of a terminal device for realizing the service continuity support method according to an embodiment of the present invention will be described in detail with reference to FIG. 4 .

As shown in FIG. 4 , the terminal device 200 according to an embodiment of the present invention may be configured to include an information storage unit 210 and a control unit 220 .

In addition, the situation in which the UE to which the present invention is applied moves between heterogeneous networks may be a situation in which the UE moves from EPS to 5G, and a situation in which the UE moves from 5G to EPS. may be

However, hereinafter, for convenience of description, a situation in which the UE moves from EPS to 5G will be described.

All or at least a part of the configuration of the terminal device 200 may be implemented in the form of a hardware module or a software module, or may be implemented in a form in which a hardware module and a software module are combined.

Here, the software module may be understood as, for example, instructions executed by a processor that controls operations in the terminal device 200 , and these instructions may have a form mounted in a memory in the terminal device 200 . .

After all, the terminal device 200 according to an embodiment of the present invention realizes the method proposed by the present invention, that is, the service continuity support method through the above-described configuration, and hereafter, each The configuration will be described in more detail.

The information storage unit 210 performs a function of storing information transmitted for synchronization of session information when a session is created with the first network, for example, the EPS network.

Here, when the terminal device 200 creates a session in the EPS network, the information transmitted for session information synchronization means service information transmitted to apply/process the corresponding session.

That is, referring to FIG. 2 , when creating a session with the terminal device 200 and the EPS network, SMF+PGW-C provides service information for application/processing to the session created for the terminal device 200 , particularly After acquiring the SNSSAI through UDM, it is transmitted to the terminal device 200 through PCO (ePCO) (SMF+PGW-C->MME->eNB->UE).

The information storage unit 210 receives/stores service information (SNSSAI) transmitted from SMF+PGW-C when creating a session with the terminal device 200 and the EPS network as described above, thereby providing a core (EPS network) and a terminal Session information may be synchronized between the devices 200 .

When moving from a first network, that is, an EPS network, to a second network, for example, a 5G network, the controller 220 creates a session with the second network based on the stored information (hereinafter, service information (SNSSAI)) do.

At this time, the controller 220 uses the slice information (SNSSAI) for each session included in the previously stored service information for the session created in the second network, that is, the 5G network, when moving the session from the EPS network to the 5G network. The same Slice service as in the EPS network can also be used.

That is, according to the service continuity support method of the present invention described with reference to FIG. 3 , when the terminal device 200 moves between heterogeneous networks (eg, EPS->5G), service information determined at the time of session creation (especially SNSSAI) ) by realizing inter-network (EPS->5G) transfer, the same SNSSAI as before movement is transmitted to AMF->SMF for a session in which the terminal device 200 moves between heterogeneous networks (EPS->5G) Since an applicable environment is created, the terminal device 200 can use the Slice service equally and seamlessly even if the SNSSAI stored in the EPS is immediately used for a session that is transferred between heterogeneous networks (EPS->5G). .

As described above, according to the service continuity support method according to the embodiments of the present invention, even when the UE moves between heterogeneous networks (eg, EPS network -> 5G network), the service applied to the session is the same It derives the effect of ensuring heterogeneous manganese mobility that can be maintained in

Hereinafter, a service continuity support scheme (method) proposed by the present invention will be described in detail with reference to FIG. 5 .

For convenience of description, in the following description, the network device 100 (MME) will be referred to as a subject performing the service continuity support scheme (method) proposed in the present invention.

In addition, hereinafter, for convenience of description, a situation in which the UE moves from EPS to 5G will be described.

First, when generating a session (PDU Session) for a UE (UE) in the EPS network (S10), SMF+PGW-C provides service information for application/processing to the session created for the UE (UE), especially SNSSAI, UDM After being acquired through the UE, it is transferred to the UE through PCO (ePCO) (SMF+PGW-C->MME->eNB->UE), whereby session information is transmitted between the core (EPS network) and the UE (UE). may be synchronized (S20).

Here, according to the service continuity support method (method) proposed in the present invention, SNSSAI information is included for synchronization of terminal session information in step S20, and QoS for the corresponding session, delay information, additionally interlocked network node information, and It is also possible to transmit billing information, etc. together.

At this time, according to the service continuity support scheme (method) proposed in the present invention, the network device 100 (MME) provides service information for a session delivered to SMF+PGW-C->MME->eNB->UE as described above. Among them, specific information, that is, slice information (SNSSAI) serving a session for each session of the UE may be obtained and stored (S30).

Specifically, the network device 100 (MME) checks service information through a PCO (ePCO) transmitted from SMF+PGW-C to the UE (UE) when a session of the UE (UE) is created in the EPS network, and service information If there is an SNSSAI that is applied to the session within, you can acquire this SNSSAI and map/store it to the session.

Accordingly, according to the present invention, in the MME of the EPS network, the SNSSAI may be mapped/stored and managed for each UE registered in the MME itself and for each session generated in the EPS.

In addition, according to the service continuity support method (method) proposed in the present invention, the network device 100 (MME) may manage several pieces of transmitted information together with SNSSAI, and characteristic information (cumulative) of the session created with the terminal. Location data, IMEI, QoS, Codec for calls, etc.) can be managed.

On the other hand, when the UE moves to the 5G network after creating a session in the EPS network, the UE requests location registration from 5G to AMF (S40).

Accordingly, the AMF detects/recognizes the movement of the UE, and requests the context information to the node in which the UE is registered, that is, the Old MME.

According to the service continuity support scheme (method) proposed in the present invention, the network device 100, MME, more specifically, when a request for context information is received from the AMF for the information request for the UE (S50), as described above (S50), this time The session context information of the UE according to the request is responded to by AMF. Furthermore, if there is an SNSSAI mapped/stored in the corresponding session, this SNSSAI may also be delivered to the AMF (S60).

For this reason, according to the present invention, the AMF detecting/recognizing the movement of the UE is Context information from the Old MME (the network device 100 of the present invention) in which the UE was registered before moving between networks. You can also receive SNSSAI for each session while requesting/obtaining .

In this case, the AMF receives the service information for each session (in particular, SNSSAI) along with the context information requested by the AMF from the MME (the network device 100 of the present invention), and transfers the mobility information for the terminal (UE) to the SMF. Since service information (in particular, SNSSAI) can also be delivered, it is possible to seamlessly provide the Slice service to which the same SNSSAI as in EPS is applied even in 5G for a session moving from EPS to 5G (S70).

In addition, according to the service continuity support method (method) proposed in the present invention, the network device 100 (MME) can selectively transmit all information managed in step S30 in step S60, and in this case, AMF in step S70 transmits the information to the SMF or determines the service optimized by itself (e.g., NF selection in consideration of physical information (e.g., UPF that is closer and UPF with low latency) in the 5G network for the terminal and established session information), etc. ) can also be provided through the call processing procedure.

According to the service continuity support method (method) proposed in the present invention, the network device 100 (MME), unless the service continuity support function to realize the present invention is turned off (S80 No), the above-described step S30 and thereafter can be performed repeatedly.

As described above, the service continuity support method (method) proposed in the present invention maintains the same service applied to the session even when the UE moves between heterogeneous networks (eg, EPS network -> 5G network). It derives the effect of guaranteeing heterogeneous manganese mobility.

The service continuity support method (method) according to an embodiment of the present invention may be implemented in the form of program instructions that can be executed through various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, etc. alone or in combination. The program instructions recorded on the medium may be specially designed and configured for the present invention, or may be known and available to those skilled in the art of computer software. Examples of the computer-readable recording medium include magnetic media such as hard disks, floppy disks and magnetic tapes, optical media such as CD-ROMs and DVDs, and magnetic such as floppy disks. - includes magneto-optical media, and hardware devices specially configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions include not only machine language codes such as those generated by a compiler, but also high-level language codes that can be executed by a computer using an interpreter or the like. The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

Although the present invention has been described in detail with reference to preferred embodiments so far, the present invention is not limited to the above-described embodiments, and without departing from the gist of the present invention as claimed in the following claims, the technical field to which the present invention pertains It will be said that the technical idea of the present invention extends to a range where various modifications or corrections are possible by anyone having ordinary knowledge in the present invention.

According to the network device and the service continuity support method performed in the network device according to the present invention, when the UE moves between heterogeneous networks (eg, EPS network -> 5G network), service information determined at the time of session creation (especially , SNSSAI) in terms of realizing inter-network transmission (EPS network -> 5G network), as it goes beyond the limits of existing technologies, the possibility of marketing or sales of the applied device rather than just the use of the related technology is sufficient. In addition, it is an invention that has industrial applicability because it can be clearly implemented in reality.

100: network device
110: information management unit 120: request response unit

Claims (10)

A network device comprising:
an information management unit for acquiring and storing specific information among information transmitted from the first network to the terminal for synchronization of session information between the terminal registered in the network device and the first network; and
and a request response unit that, when receiving a request for information on the terminal from another network device, transmits the specific information stored for the session while responding to the information according to the request. The method of claim 1,
The specific information is
Network device, characterized in that for each session of the terminal, including slice information (Network Slice Selection Assistance Information, NSSAI) serving the session. The method of claim 1,
The network device is an MME (Mobility Management Entity) supporting the first network,
The other network device is
Another MME supporting the first network, or a network device characterized in that it is an NF (Network Function) that performs a function of an MME in the second network. The method of claim 1,
The information request to the terminal,
When the terminal moves from the first network to a second network supported by the other network device, the network device is received from the other network device. In the service continuity support method performed in a network device,
an information management step of acquiring and storing specific information among information transmitted from the first network to the terminal for synchronization of session information between the terminal registered in the network device and the first network; and
and a request response step of responding to information according to the request and the specific information stored for the session when receiving a request for information about the terminal from another network device. 6. The method of claim 5,
The specific information is
For each session of the terminal, the service continuity support method, characterized in that it includes slice information (Network Slice Selection Assistance Information, NSSAI) servicing the session. 6. The method of claim 5,
The network device is an MME (Mobility Management Entity) supporting the first network,
The other network device is
The service continuity support method, characterized in that it is another MME supporting the first network, or an NF (Network Function) that performs a function of the MME in the second network. 6. The method of claim 5,
The information request to the terminal,
The service continuity support method, characterized in that the terminal is received from the other network device when the terminal moves from the first network to a second network supported by the other network device. an information storage unit for storing information transmitted to synchronize session information when a session with the first network is created; and
and a controller configured to create a session with the second network based on the stored information when moving from the first network to the second network. 10. The method of claim 9,
The control unit is
Using Network Slice Selection Assistance Information (NSSAI) for each session included in the information for the session created in the second network, even when a session is moved from the first network to the second network, the first A terminal device, characterized in that it uses the same slice service as in the network.

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