KR20210051395A - Method for managing terminal - Google Patents

Abstract

According to an embodiment of the present invention, provided is a terminal management method in which a user can receive a service without delay. The terminal management method comprises the steps of: controlling information on at least one UPF instance to be delivered to a terminal accessing a base station; receiving the information on the UPF instance selected by the terminal among the at least one UPF instance in response to the information to be delivered to the terminal; and controlling a session to be formed between the selected UPF instance and the terminal.

Description

Terminal management method {METHOD FOR MANAGING TERMINAL}

The present invention relates to a terminal management method.

In the LTE communication system, as the type of communication service and the transmission request speed are diversified, the LTE frequency expansion and the evolution to the 5G communication system are actively progressing.

This rapidly evolving 5G communication system accommodates as many terminals as possible based on limited radio resources, while eMBB (enhanced mobile broadband)/mMTC (massive machine type communications)/ It supports URLLC (ultra-reliable and low latency communications) scenarios.

In the 5G communication system, a network structure to support end-to-end terminals, base stations (access), cores and servers is defined, and a single node (e.g., S-GW, P-GW, etc.) in existing LTE (4G) A network structure that separates the functions of control signaling and data transmission/reception, which were performed in a complex manner, to separate the control signaling function area (or control area) (Control Plane) and the data transmission/reception function area (or user area) (User Plane). Is defined.

In this case, various nodes are included in the control plane. For example, the Access and Mobility Function (AMF) that controls access to the wireless section of the terminal, the PCF (Policy Control Function) that manages/controls policies such as terminal information and subscription service information for each terminal, and billing, and a session for using data services for each terminal. For example, a session management function (SMF) that manages/controls a device, a network exposure function (NEF) that shares information with an external network, and the like.

In addition, things such as UPF may be included in the user plane.

PCT Patent Publication, 2018-008944 (published on Jan. 11, 2018)

In a standard dealing with 5G communication system, especially next-generation Beyond 5G (hereinafter referred to as'B5G') technology, the concept of an instance (instance) for a network function (NF) has emerged. The NF instance may include, for example, an SMF instance (an instance), an AMF instance, or a UPF instance.

Thus, for example, whether the UE forms a PDU session through which UPF instance is emerging as an important task. That is, a management method for a UPF instance that will form a PDU session with a terminal is required.

In addition, such a terminal management scheme may affect handover of the terminal. Here, if a high-reliability-low-latency (Ultra-Reliable and Low Latency Communication, URLLC) service is being provided to the terminal at the time when handover should be performed, even after handover, the terminal has a URLLC service of the same quality as before the handover was performed. It is preferred that is provided. That is, even if handover is performed, the URLLC service should be provided to the terminal without interruption, and there should be no delay in performance or speed when the URLLC service is provided.

Accordingly, a problem to be solved of the present invention is to propose a management method for a terminal in consideration of an NF instance.

In addition, on the premise of such an NF instance, when a terminal performs a handover in a 5G communication system, a technology that enables the terminal to provide a URLLC service of the same quality as that provided to the terminal before the handover was performed, even after the handover. Is to provide.

However, the problem to be solved of the present invention is not limited to those mentioned above, and another problem to be solved that is not mentioned can be clearly understood by those of ordinary skill in the art to which the present invention belongs from the following description. will be.

A terminal management method according to an embodiment is a terminal management method performed by an access and mobility function (AMF) device, the step of controlling information on at least one UPF instance to be transmitted to a terminal accessing a base station. And, in response to the information being transmitted to the terminal, receiving information on the UPF instance selected by the terminal from among the at least one UPF instance, and forming a session between the selected UPF instance and the terminal It is carried out including the step of controlling to be.

According to an embodiment, the terminal may directly select the UPF instance. Therefore, from the user's point of view of the terminal, the terminal can form a PDU session with the UPF instance more quickly, and thus, a service without delay can be provided.

In addition, since the UE directly selects the UPF instance can be performed even during handover, there is an advantage that the handover can be performed with low latency.

1 conceptually shows the architecture of a 5G communication system according to an embodiment.
2 is a flowchart illustrating a process of a terminal selecting a UPF instance according to an embodiment.
3 is a conceptual diagram schematically showing the concept of handover of a terminal, which is one example to which a terminal management procedure according to an embodiment can be applied.
FIG. 4 is a conceptual diagram illustrating FIG. 3 in more detail.
FIG. 5 exemplarily shows resource information on resources of a source base station measured by a source base station and used by a terminal accessing the source base station.
FIG. 6 exemplarily shows information accompanying a handover support request transmitted from the source base station to the AMF.
FIG. 7 exemplarily shows resource status information of the target base station obtained by the UPF from the target base station.

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in a variety of different forms, and only these embodiments make the disclosure of the present invention complete, and common knowledge in the technical field to which the present invention pertains. It is provided to completely inform the scope of the invention to those who have, and the invention is only defined by the scope of the claims.

In describing the embodiments of the present invention, if it is determined that a detailed description of a known function or configuration may unnecessarily obscure the subject matter of the present invention, a detailed description thereof will be omitted. In addition, terms to be described later are terms defined in consideration of functions in an embodiment of the present invention, which may vary according to the intention or custom of users or operators. Therefore, the definition should be made based on the contents throughout the present specification.

FIG. 1 conceptually illustrates an architecture 10 of a 5G communication system and a user equipment (UE) 500 using the architecture 10 according to an embodiment.

Let's look at the 5G communication system itself represented by the architecture (10). The 5G communication system is an advanced technology from the 4th generation LTE mobile communication technology. This 5G communication system is an extended technology of new radio access technology (RAT, Radio Access Technology) and LTE (Long Tern Evolution) through an evolution of the existing mobile communication network structure or a clean-state structure. It supports eLTE (extended LTE), non-3GPP access, and the like.

However, since the architecture 10 shown in FIG. 1 is only an example, the idea of the present invention is not construed as being limited to the architecture 10 shown in FIG. 1, and the idea of the present invention is not limited to 5G communication. Nor is it construed as being limited to the system.

The architecture 10 includes various components (ie, network functions (NF)). Hereinafter, these components will be described.

Referring to FIG. 1, the architecture 10 includes at least one NF (network function) set. For example, the architecture 10 may include a set of control plane functions (CPF) or a set of user plane functions (UPF). In addition, as shown in FIG. 1, at least one NF set is connected to each other by an SBI, that is, a service based interface.

Each NF set includes various types of instances, and also includes at least one database (DB) in which information on such NF instances is stored. Here, the'NF instance' refers to the smallest unit of NFs designed to perform the functions of each of the NFs. For example, the CPF set may include at least one CPF instance, and the UPF set may include at least one UPF instance.

2 to 6 illustrate a connection relationship between the aforementioned NF instances by way of example.

First, referring to FIG. 2, NF instances may be directly or directly connected to each other.

FIG. 3 is a conceptual diagram conceptually showing that requests and responses are transmitted between NF instances when NF instances are connected as shown in FIG. 2.

Referring to FIG. 3, an NF instance transmitting a request message may be referred to as an NF consumer, and an NF instance receiving such a request message may be referred to as an NF producer.

4 shows that when NF instances are connected as shown in FIG. 2, when one NF instance requests a subscription from another NF instance, another NF instance that has requested such subscription is sent to the NF instance that requested the subscription. It is a conceptual diagram that conceptually shows notify. Here, it indicates that you want to be notified when a subscription or a specific event occurs.

On the other hand, unlike those shown in FIGS. 2 to 4, NF instances may be connected with a service communication proxy (SCP) therebetween so that they may be connected indirectly, that is, indirectly. In this case, each of the NF instances can be connected to the NF instance to be connected to itself through SCP. In this process, the SCP acts as a proxy. That is, there will be many NF instances in the next generation network, and there will be many NF Consumers / NF Producers. To effectively solve this problem, the NF Consumer can make a request to or receive a response from the NF Producer indirectly, that is, indirectly through a Service Communication Proxy (SCP) in the next-generation network. Through this, the next-generation network can provide messenger roles (Load Balancing, message modification for In/Out, etc.) for multiple NF instances through SCP. This is illustrated in FIGS. 5 and 6.

Referring to Fig. 5, NF instances are connected via an SCP. In a situation where any one NF instance wants to be connected to the other NF instance, information about the other NF instance, such as an address, can be provided by the SCP.

In FIG. 6, it is conceptually illustrated that requests and responses are transmitted between these NF instances in a state in which NF instances are connected via an SCP.

An embodiment of the present invention will be described based on the concept of these NF instances.

7 is a diagram for a procedure of a terminal management method according to an embodiment, and for example, illustrates a procedure in which the terminal 500 selects a UPF instance. However, since FIG. 2 is only an example, the spirit of the present invention is not limited to that shown in FIG. 2.

Referring to FIG. 7, the terminal 500 requests a service request, that is, a service from the AMF 400 (S10). In this case, such a request may include an ID for any one of at least one UPF instance, that is, a UPF instance ID. In FIG. 2, it is shown that the ID for the UPF instance 1 201 is included in the request of S10.

Then, the AMF 400 processes the service request received from the terminal 500 in S10 (S11). Processing the service request in S11 means that the service request received in S10 is processed to be performed in the UPF instance 1 201. For example, the AMF 400 may transmit the ID of the UPF instance 1 201 to the SMF instance while designating the SMF instance. Then, the SMF instance may prepare the UPF instance 1 201 so that the UPF instance 1 201 can establish a PDU session with the terminal 500.

After that, the AMF 400 delivers the service response to the terminal 500 (S20). At this time, S20 may transmit to the terminal 500 that the UPF instance 1 has been completed.

Then, based on the response at S21, the terminal 500 establishes a PDU session with the UPF instance 1 201 designated by the terminal 500 to perform communication (S21).

Meanwhile, after the terminal 500 forms a session with the UPF instance 1 201 (S21), a triggering situation in the terminal 500 or a situation in which triggering is received from the network may occur (S21). Examples of such triggering may include a situation in which the terminal 500 must handover, but is not limited thereto, and various situations may be included.

In this case, the terminal 500 may directly select the desired NF instance, for example, the UPF instance 2 (202), and then form a session with the UPF instance 2.

At this time, the procedure for the terminal 500 to form a session with the UPF instance 2 202 according to the above-described triggering is shown in S30 to S41, and these S30 to S41 are the same as S10 to S21 shown in FIG. , S10 and S21 will be described.

That is, according to an embodiment, the terminal may directly select a desired NF instance, for example, a UPF instance.

Meanwhile, in order for the terminal 500 to select an NF instance, the terminal 500 itself must know information about the NF instance. Accordingly, in one embodiment, the NEF provides information on the NF instance to the AMF 400 indirectly through the SCP (see FIGS. 5 and 6), or directly (see FIGS. 2 and 3) without passing through the SCP, and the AMF ( 400) provides this information to the terminal 500. The process of the AMF 400 providing information to the terminal 500 is not shown in FIG. 7, but may be performed when triggering according to S22 occurs in FIG. 7 or may be performed periodically according to a predetermined period. have. Here, such information may include at least one of a resource, a load, or a capacity for each of at least one instance.

The terminal 500 may select a desired NF instance by using the information provided from the AMF 400 in this way.

In this case, there may be various criteria for the terminal 500 to select an NF instance from the information provided from the AMF 400, and an example of such a criterion will be described below.

<Example of standard>

- Terminal Mobility Management (MM) status and Session Management (SM) status

- Location related: UE Tracking Area, User Location Information

- Feature Related: UE N/W Slice ID (SST, SD)

- Unique identification related: IMSI, SUPI, GPSI, MSISDN, etc.

- UE Radio Capability (RAT Information, name, etc.)

- UE Mode (MICO, NB-IoT, cIoT)

- UE DRX information

- UE's I/F information (e.g. Ethernet, WiFi, NFC, Bluetooth, USB, Radio (3G, 4G, 5G), etc.)

- State-based trigger for a specific terminal session

- Triggering when entering/exiting a specific area for the terminal,

- Triggering when a subscriber handovers or a specific control event,

- QoS status of the terminal, RAT information of the terminal (frequency, RAT, base station name, etc.), performance of the terminal (Throughput, Latency, Jitter (delay fluctuation, i.e. jitter), subscriber's RAT (radio quality signal). ) Triggering is possible based on information (e.g. Radio Resource Block, RB)

- UPF instance resource (e.g. CPU, Memory, I/O, Storage, etc.)

- UPF instance capability (e.g., features available in PDR, QER, FAR, URR)

- UPF instance Priority (e.g. ID sequential, resource (Throughput, Latency, Jitter))

Based on this criterion, the terminal 500 will be described as an example for selecting any one NF instance, but the following is only exemplary, and the spirit of the present invention is not limited thereto.

The terminal 500 receives information on NF instances from the AMF 400. As described above, such information may be triggered according to S22 or may be periodically transmitted from the AMF 400.

In addition, among these pieces of information, for example, after selecting information on the UE tracking area, which is information related to the location of the terminal, it is possible to select an NF instance that is most closely related to the selected information. To this end, the UE tracking area may include relative values of each NF instance with respect to the location of the terminal 500.

Until now, it has been described that the terminal 500 selects any one NF instance based on information on the NF instances received from the AMF 400. This is summarized as follows.

First, the AMF 400 controls information on at least one UPF instance to be transmitted to the terminal 500 connected to the base station.

In addition, in response to the information being transmitted to the terminal 500, information on the UPF instance selected by the terminal 500 from among the at least one UPF instance is received.

In addition, a session is formed between the selected UPF instance and the terminal.

In the following, on the assumption that the terminal 500 is managed as described above, an embodiment in which such a situation can be utilized will be described. For example, this embodiment may include a situation in which the terminal 500 needs to handover, which will be described below.

FIG. 8 is a conceptual diagram schematically showing the concept of handover from a terminal accessing a source base station to a target base station, which is one example to which a terminal management procedure according to an embodiment can be applied.

8, SMF (100), UPF set (200), source base station (source RAN, S-RAN) (300A), target base station (target RAN, T-RAN) (300B) and target base station (300B) Existing terminals 500B and 500C that are already connected to are shown. The SMF 100, PCF, AMF 400 and UPF set 200 are connected by SBI. Here, it is assumed that the SMF 100 refers to an SMF set, and at least one SMF instance is included in the SMF set.

The terminal 500A shown in FIG. 8 accesses the source base station 300A and is provided with a URLLC service while using the resources of the source base station 300A. While receiving the URLLC service, the terminal 500A may perform handover from the source base station 300A to the target base station 300B. Even after the handover, the terminal 500A needs to be provided with a URLLC service of the same quality as before the handover is performed. That is, even after handover, the corresponding URLLC service should be provided to the terminal 500A without interruption, and there should be no delay in terms of performance or speed when the corresponding URLLC service is provided.

To this end, the amount of resources used by the terminal 500A by accessing the source base station 300A is transferred to the target base station 300B at or before the terminal 500A completes handover to the target base station 300B. It must be prepared.

Accordingly, in an embodiment, when the SMF 100 receives handover information related to the terminal 500A from the AMF 400, the terminal 500A accesses the source base station 300A and provides resource information for the amount of resources used. After acquiring, the UPF 200 so that a resource corresponding to this resource information is secured (arranged) to the target base station 300B at the time when the terminal 500A completes the handover to the target base station 300B or before the completion time. ). If it is difficult to secure enough resources in the target base station 300B due to the existing terminals 500B and C that have already been connected to the target base station 300B, the SMF 100 cooperates with the UPF 200 to obtain the target base station. Take measures to ensure that resources are secured in (300B). As an example of a measure, a plan to recover or reduce some of the resources allocated to the existing terminals 500B and C that are already connected to the target base station 300B or some of the existing terminals 500B and C other than the target base station 300B. A method of requesting a handover to a base station may be included. As an additional measure, for example, a request to limit access to a new terminal to the target base station 300B may be included.

That is, according to an embodiment, when a terminal receiving a URLLC service by accessing a source base station handovers to a target base station, the resource at the source base station used to provide the URLLC service is the time when handover of the terminal is completed or when It may be provided in the target base station before. Accordingly, even immediately after handover, the URLLC service may be seamlessly provided to the terminal, and a delay may not occur in terms of performance or speed when the URLLC service is provided. That is, the high-reliability-low-delay service of the same quality as the high-reliability-low-delay service provided to the terminal before the handover is performed may be provided to the terminal even after the handover.

Hereinafter, with reference to FIG. 9, a detailed description will be given of a procedure of a method for performing the above-described handover.

9 illustrates a procedure of a terminal management method according to an embodiment. This terminal management method is performed by the AMF 400 and the SMF 100. In addition, since what is illustrated in FIG. 9 is only exemplary, the spirit of the present invention is not limited to that illustrated in FIG. 9.

9, SMF (100), UPF set (200), AMF (400), source base station (source RAN, S-RAN) (300A), target base station (target RAN, T-RAN) (300B) and Terminal 500A is shown. Here, it will be described on the premise that at least one UPF instance is included in the UPF set 200.

The AMF 400 knows information on a terminal that has requested or can receive a URLLC service from among a plurality of terminals connected to the source base station 300A, and provides this information to the source base station 300A. The source base station 300A provides a URLLC service to a terminal 500A capable of receiving the URLLC service among terminals connected to the source base station 300A, based on this information provided from the AMF 400.

At this time, packets related to the URLLC service are transmitted and received between the UPF 200 and the source base station 300A, and these packets are user plane packets. Therefore, these packets are transmitted and received through the UPF 200. Accordingly, the UPF 200 may obtain resource information on the resource of the source base station 300A used for transmission and reception of such packets (step A).

FIG. 10 exemplarily shows resource information about the source base station 300A obtained by the UPF 200. Referring to FIG. 10, a time at which resource information is measured by the source base station 300A and resource information measured at the time are shown. Here, in FIG. 10, only throughput and latency are shown as measurement targets, but in addition, bandwidth may also be measured and provided to the UPF 200 from the source base station 300A.

Referring back to FIG. 9, the source base station 300A monitors the connection with the terminal 500A and determines whether a handover is required for the terminal 500A. If it is determined that handover is necessary, the source base station 300A makes a handover support request to the AMF 400 (step B). This step B may correspond to triggering (S22) shown in FIG. 7.

In addition, this step B may be performed in any one of a case where the terminal 500A prepares for handover, performs a handover (execution), and when the handover is completed (completion). In addition, various information may be transmitted from the source base station 300A to the AMF 400 together with the handover support request, which is illustrated in FIG. 11.

11, the ID (or slice ID) of the terminal 500A in need of handover, the session ID of the terminal 500A, the IP address of the terminal 500A, the ID of the target base station 300B, handover support request At least one of the time (generated) made by the source base station 300A (handover request time), the estimated time required for handover, the ID of the UPF instance, and the type of resources to be secured in the target base station 300B are included. It may be transmitted to the AMF 400, but is not limited thereto.

Here, as described above, the ID of the UPF instance may be previously selected based on information previously transmitted from the AMF 400 by the terminal 500A.

In addition, although only throughput is shown as the type of the resource to be secured in FIG. 11, in addition, latency or bandwidth may be included in the kind of the resource to be secured.

Referring back to FIG. 9, the AMF 400 transmits handover information related to the terminal 500A to the SMF 100 through the SBI (step C).

The above-described handover information may include at least one of the above-described information transmitted from the source base station 300A to the AMF 400 in step B, and may include information on whether the handover request has urgency. If the handover request has urgency, the SMF 100 may process the handover request urgently or preferentially over other handover requests, and also in the target base station 300B prior to other handover requests. First, measures can be taken to ensure that resources are secured.

Next, the SMF 100 obtains the resource information of the source base station 300A used by the terminal 500A while receiving the URLLC service and the ID for the UPF instance selected by the terminal 500A from the UPF 200. The resource information acquired by the SMF 100 from the UPF 200 may be the same as described in FIG. 10.

In addition, the SMF (100) to the UPF (200),'make sure that the resource corresponding to the resource information of the source base station (300A) used by the terminal (500A) is secured in the target base station (300B), and in this case, the UPF instance ID A request is made to the target base station 300B to ensure that the corresponding UPF instance is used for such securing, and the UPF 200 takes measures to be performed in accordance with this request. There are two ways to perform this process.

The first method is that when the SMF 100 judges the overall matters related to securing resources and determines the appropriate measures, the UPF 200 only needs to receive and execute these measures from the SMF 100. That is, in this case, the SMF 100 makes a judgment, and the UPF 200 does not make any judgment and only serves as a performer.

On the other hand, the second method is that the SMF 100 simply requests an instruction to secure resources from the UPF 200, and the UPF 200 determines and executes a predetermined decision according to these instructions. to be. That is, in this case, the SMF 100 does not make any judgment, but only gives a command, and the UPF 200 performs both the judgment and the role of the performer.

Looking at the first method among these, the SMF 100 requests the UPF 200 for resource status information of the target base station 300B (step D). Then, the UPF 200 acquires resource status information of the target base station 300B by monitoring an interface with the target base station 300B (step E). 12 exemplarily shows resource status information of the target base station 300B obtained by the UPF 200 by monitoring an interface with the target base station 300B. Referring to FIG. 12, information on the ID of the terminal connected to the target base station 300B, the throughput and latency of each terminal, and whether a URLLC service is provided to each terminal may be included in the resource status information.

Referring back to FIG. 9, the UPF 200 provides the resource status information of the target base station 300B obtained in step E to the SMF 100 through SBI (step G). Then, the SMF 100 compares the resource information of the source base station 300A used by the terminal 500A with the resource status information of the target base station 300B.

As a result of the comparison, sufficient resources may be secured in the target base station 300B. In this case, the SMF 100 requests the UPF 200 to maintain such a state (a state in which resources are sufficiently secured) through the SBI (step H).

Then, the UPF 200 performs operations related to, for example, PDR, FAR, and QER so that the target base station 300B maintains such a state. As a result of performing the operation, the target base station 300B may be restricted from accessing a new terminal from thereafter, or may have a speed limitation even if access is allowed.

However, as a result of the comparison, sufficient resources may not be secured in the target base station 300B. In this case, the SMF 100 determines a measure to be transmitted to the UPF 200 in order to secure resources, for example, measures related to control of PDR, FAR, QER, and the like. Examples of measures are a plan to recover or reduce some of the resources allocated to the existing terminals 500B and C already connected to the target base station 300B, or a base station other than the target base station 300B. This may include a request for handover. Here, the existing terminal whose part of the resource is recovered or the target of handover to another base station may be a terminal (non-URLLC terminal, 500C) that does not receive URLLC service, and at this time, the existing terminal (500B,C) provides URLLC service. Whether or not the terminal is provided with can be determined through the information shown in FIG. 11, that is, the information provided by the SMF 100 through step G from the UPF 200.

The determined action is transmitted from the SMF 100 to the UPF 200, and the UPF 200 performs a predetermined operation based on the received action so that a resource can be secured in the target base station 300B.

Next, looking at the second method, the SMF 100 requests the UPF 200 to secure the resources of the target base station 300B through the SBI (step D). While requesting, the SMF 100 transmits the resource information of the source base station 300A used while the terminal 500A was provided with the URLLC service to the UPF 200 together. Then, the UPF 200 acquires resource status information of the target base station 300B by monitoring an interface with the target base station 300B (step E), and the obtained resource status information is as shown in FIG. .

Referring back to FIG. 9, the UPF 200 compares the resource information of the source base station 300A used by the terminal 500A with the resource status information of the target base station 300B.

As a result of the comparison, sufficient resources may be secured in the target base station 300B. In this case, the UPF 200 performs operations related to, for example, PDR, FAR, and QER so that the target base station 300B maintains such a state (a state in which resources are sufficiently secured). Accordingly, the target base station 300B may block access of a new terminal from then on and may have a speed limit.

However, as a result of the comparison, sufficient resources may not be secured in the target base station 300B. In this case, the UPF 200 determines a predetermined action for securing resources (eg, actions related to control of PDR, FAR, QER, etc.) and then performs a predetermined action based on the action so that the resource can be secured. The example of action at this time is the same as the first plan.

Looking at the above two methods, the resource information of the source base station 300A used by the terminal 500A while receiving the URLLC service is compared with the resource status information of the target base station 300B. At this time, the resource information of the source base station 300A to be compared may be resource information measured during a predetermined period in time prior to the handover request time (SMF 100 was provided from the AMF 400 in step C). , Any one of a maximum value, a minimum value, or an average value of the resource information measured during such a predetermined period may be a reference of a resource to be secured in the target base station 300B.

Here, whether the resource information is measured during a predetermined period temporally prior to the handover request time may be known based on the'measurement time' for each resource information shown in FIG. 10.

In addition, in step C, information about the estimated time required for handover may be transmitted to the SMF 100. The UPF 200 may control the target base station 300B so that a process of securing a predetermined resource in the target base station 300B can be performed within the expected time required for such a handover.

As described above, according to an embodiment, when a terminal receiving a URLLC service by accessing a source base station performs handover to a target base station, resources in the source base station used to provide the URLLC service are It may be provided in the target base station before the time point or the time point of completion. Accordingly, even immediately after handover, the URLLC service may be provided to the terminal without interruption, and a delay may not occur in terms of performance or speed when the URLLC service is provided. That is, a high-reliability-low-delay service having the same quality as the high-reliability-low-delay service provided to the terminal before the handover is performed may be provided even after the handover.

On the other hand, the invention related to the terminal management method described above is included in the method in the form of a computer readable recording medium storing a computer program programmed to perform each step included in the method or stored in a computer readable recording medium. It may be implemented in the form of a computer program programmed to perform each of the steps.

The above description is merely illustrative of the technical idea of the present invention, and those of ordinary skill in the art to which the present invention pertains will be able to make various modifications and variations without departing from the essential quality of the present invention. Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but to explain the technical idea, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

According to an embodiment, a high-reliability-low-delay service having the same quality as a high-reliability-low-delay service provided to the terminal before the handover is performed may be provided even after the handover.

400: AMF
500: terminal

Claims (12)

A terminal management method performed by an access and mobility function (AMF) device, comprising:
Controlling information on at least one UPF instance to be transmitted to a terminal accessing the base station; and
In response to the information being transmitted to the terminal, receiving information on a UPF instance selected by the terminal from among the at least one UPF instance; and
Including the step of controlling to form a session (session) between the selected UPF instance and the terminal
Terminal management method. The method of claim 1,
Controlling the information on the at least one UPF instance to be transmitted,
Performed when there is triggering for the terminal or triggering from the network
Terminal management method. The method of claim 1,
Information on the at least one UPF instance,
It is delivered from a predetermined NF instance through a service communication proxy (SCP) or from the predetermined NF instance without passing through the service communication proxy.
Terminal management method. The method of claim 1,
In the information on the at least one UPF instance transmitted to the terminal,
At least one of a resource, a load, or a capacity for each of the at least one instance is included.
Terminal management method. The method of claim 1,
Further comprising the step of obtaining information on the at least one UPF instance from a predetermined control plane function (CPF)
Terminal management method. The method of claim 1,
The base station is a source base station,
In the information received in the receiving step,
Handover information on a terminal to be handed over from the source base station to a predetermined target base station is additionally included,
The above method,
Controlling the terminal to handover from the source base station to the target base station through a session formed between the terminal and the selected UPF instance.
Terminal management method. The method of claim 6,
The above method,
Obtaining resource information on the resource of the source base station required for the terminal,
Even if the resource corresponding to the obtained resource information is secured in the target base station, further comprising the step of requesting the selected UPF instance
Terminal management method. The method of claim 7,
The resource information obtained in the obtaining step,
Including at least one of throughput, latency, and bandwidth measured between the source base station and the terminal
Terminal management method. The method of claim 7,
The received handover information,
Includes time information on the time at which the handover is requested,
The resource information obtained in the obtaining step,
Further including resource information on the resources used by the source base station for a period prior to the time at which the handover is requested
Terminal management method. The method of claim 7,
The terminal management method
After receiving the handover information, further comprising the step of receiving resource status information on the resource provided in the target base station from the selected UPF instance,
The controlling step,
Comparing the acquired resource information with the resource status information received for the target base station,
Based on the comparison result, deriving a measure to ensure that a resource corresponding to the acquired resource information is secured in the target base station, and
Including the step of requesting the UPF instance to perform the derived action
Terminal management method. The method of claim 10,
The resource status information for the target base station received from the UPF instance,
Including at least one of throughput, latency, bandwidth between the target base station and a terminal accessing the target base station, and information on whether a high-reliability-low-delay service is provided to a terminal accessing the target base station.
Terminal management method. The method of claim 10,
The step of requesting the UPF instance,
A request to reduce the resources of the target base station allocated to some of the terminals accessing the target base station, a request to handover the part of the terminal to a base station other than the target base station, and the terminal does not additionally access the target base station. Including requesting at least one of the requests for restricting to be prevented from the UPF instance
Terminal management method.

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