KR102353226B1 - Method of Service Recovery Upon Occurrence of a Failure on a Session Management Device - Google Patents

Abstract

Provided is a method for performing service recovery when a failure of a session management device occurs. The method comprises the steps of: detecting, by a core access and mobility management device, a failure in the session management device; transmitting, by the core access and mobility management device, a paging message from to a terminal receiving a service through a protocol data unit (PDU) session generated by interworking with the session management device; transmitting, by the terminal, a service request message to the core access and mobility management device; and transmitting, by the core access and mobility management device, a network reconnection request message to the terminal.

Description

Method of Service Recovery Upon Occurrence of a Failure on a Session Management Device

The present invention relates to mobile communication technology.

In recent years, 5G (5th Generation) communication technology, which is a 5G technology standard for a cellular communication network, has become a hot topic in the communication industry. With 2019 as the first year, many telecommunication companies in many countries are deploying and commercializing 5G communication systems. The 5G communication system provides communication services by dividing the service area into small geographic areas called 'cells' like its predecessor, the 4G communication system. to the Internet and telephone networks. The advantage of the 5G network is that it provides a high download speed of up to 10 gigabits per second (gigabits per second) because the bandwidth is wider than that of the 4G network. Based on this increased download speed, 5G networks are designed to connect anyone and anything, people, machines, things and devices together. 5G communication networks are also expected to create many applications in the Internet of Things (IoT) and Machine to Machine (M2M) areas.

SUMMARY OF THE INVENTION An object of the present invention is to provide a technique for enabling rapid service recovery in the event of a failure of a session management device.

The problems to be solved by the present invention are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

In one aspect, there is provided a method of performing service recovery when a failure of a session management device occurs. The method includes the steps of detecting a failure in a session management device in a core access and mobility management device, and providing a service through a PDU (Protocol Data Unit) session generated by interworking with the session management device in the core access and mobility management device transmitting a paging message to the receiving terminal, the terminal transmitting a service request message to the core access and mobility management device, and the network from the core access and mobility management device to the terminal It may include transmitting a reconnection request message.

In an embodiment, the session management device is a Session Management Function (SMF) defined in 3GPP.

In an embodiment, the core access and mobility management device is an AMF (Core Access and Mobility Management Function) defined in 3GPP.

In an embodiment, the step of detecting that there is a failure in the session management device in the core access and mobility management device includes: a TCP connection (transmission) between the core access and mobility management device and the session management device in the core access and mobility management device and detecting that the Control Protocol Connection) is disconnected.

In an embodiment, the step of detecting that there is a failure in the session management device by the core access and mobility management device includes: transmitting, by the core access and mobility management device, an http ping message to the session management device; and detecting that there is a failure in the session management device when the core access and mobility management device does not receive a response to the http ping message from the session management device.

In one embodiment, the network reconnection request message is a De-registration Request message defined in 3GPP.

In an embodiment, the network reconnection request message includes a Re-registration Required parameter defined as a re-registration type in 3GPP.

In an embodiment, the method further includes performing, by the terminal, re-registration in response to receiving the network reconnection request message from the core access and mobility management device.

In one embodiment, the step of transmitting a paging message from the core access and mobility management device to a terminal receiving a service through a PDU (Protocol Data Unit) session generated by interworking with the session management device comprises: the core and delivering a paging message from the access and mobility management device to a terminal in an idle state, which is receiving a service through a PDU session generated by interworking with the session management device.

In another aspect, there is provided a method of performing service recovery in a core access and mobility management device when a failure of the session management device occurs. The method includes the steps of detecting that there is a failure in the session management apparatus, transmitting a paging message to a terminal in an idle state receiving a service through a PDU session generated by interworking with the session management apparatus, and a service request from the terminal The method may include transmitting a network reconnection request message to the terminal in response to receiving the message.

In one embodiment, the session management device is an SMF defined in 3GPP.

In one embodiment, the core access and mobility management device is an AMF defined in 3GPP.

In an embodiment, detecting that there is a failure in the session management device includes detecting that a TCP connection between the core access and mobility management device and the session management device is disconnected.

In one embodiment, the step of detecting that there is a failure in the session management device includes: transmitting an http ping message to the session management device; and when a response to the http ping message is not received from the session management device, the and detecting that there is a failure in the session management device.

In one embodiment, the network reconnection request message is a De-registration Request message defined in 3GPP.

In an embodiment, the network reconnection request message includes a Re-registration Required parameter defined as a reconnection type in 3GPP.

According to the embodiments of the present invention, there is a technical effect of enabling rapid service recovery in the event of a failure of the session management device.

1 is a diagram illustrating an embodiment of a simplified structure of a 5G core network (5th Generation Core Network).
2 is a diagram illustrating an embodiment of a flowchart for explaining a method of performing service recovery when a failure of the session management apparatus occurs.

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 in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, and these embodiments merely allow the disclosure of the present invention to be complete and those of ordinary skill in the art to which the present invention pertains. It is provided to fully inform the person of the scope of the invention, and the present invention is only defined by the scope of the claims.

The terms used herein are used only to describe specific embodiments and are not intended to limit the present invention. For example, a component expressed in a singular should be understood as a concept including a plurality of components unless the context clearly means only the singular. In addition, in the specification of the present invention, terms such as 'include' or 'have' are only intended to designate that the features, numbers, steps, operations, components, parts, or combinations thereof described in the specification exist, and such The use of the term does not exclude the presence or addition of one or more other features or numbers, steps, operations, components, parts, or combinations thereof. In addition, in the embodiments described in this specification, a 'module' or 'unit' may mean a functional part that performs at least one function or operation.

In addition, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related art, and unless explicitly defined in the specification of the present invention, it should be interpreted in an ideal or excessively formal meaning. doesn't happen

Hereinafter, embodiments of the present invention will be described in more detail with reference to the accompanying drawings. However, in the following description, if there is a risk of unnecessarily obscuring the gist of the present invention, detailed descriptions of well-known functions or configurations will be omitted.

1 is a diagram showing an embodiment of a simplified structure of a 5G core network (5th Generation Core Network). It should be noted that the 5G core network shown in FIG. 1 does not include all the components of the currently commercially available 5G core network, and thus may include more components than the illustrated components.

As shown in FIG. 1 , the 5G core network may include AMF (Core Access and Mobility Management Function, 110), SMF (Session Management Function, 120), and UPF (User Plane Function, 152, 154). The AMF 110 and the SMF 120 perform functions belonging to a control plane, and the UPFs 152 and 154 perform functions belonging to a user plane. In the 5G network, the function of the Serving/Packet Data Network Gateway (SPGW), which is a call processing, signaling processing, and data packet processing equipment in the 4G core network, is a function belonging to the control plane, the SMF 120 and It is divided into UPFs 152 and 154 that perform a data packet processing function, which is a function belonging to the user plane. The AMF 110 provides, for example, a function for access and mobility management in units of a terminal (UE, 130), which may be a 5G SA (Standalone) terminal, and one terminal may be basically connected to one AMF 110. have. AMF 110 is also signaling between core network nodes for mobility between 3GPP access networks, termination for a Radio Access Network (RAN) CP interface, terminal 130 and SMF 120 between. It performs functions such as delivery and provision of session management messages. The SMF 120 provides a session management (SM) function and an IP address allocation and management function of the terminal 130 . When the terminal has a plurality of sessions, each session may be managed by a different SMF. The UPFs 152 and 154 transmit the downlink protocol data unit (PDU) received from the data network (DN) to the terminal 130 via the RAN, and received from the terminal 130 via the RAN. The uplink PDU is delivered to the data network. In one embodiment, one of the UPFs 152 and 154 is a UPF allocated to a PDU session for a voice service, and the other is a UPF allocated to a PDU session for a data service such as the Internet. UPFs 152 and 154 also perform functions such as anchor point, packet routing and forwarding for intra/inter RAT (Radio Access Technology) mobility. Those of ordinary skill in the art will recognize that the functions performed by the AMF 110 , the SMF 120 , and the UPFs 152 and 154 are not limited to the functions described above. The functions performed by the AMF 110 , the SMF 120 , and the UPFs 152 and 154 are described in detail in the 5G SA standard specification (3GPP Rel. 15).

2 is a diagram illustrating an embodiment of a flowchart for explaining a method of performing service recovery when a failure of the session management apparatus occurs.

In the method for performing service recovery according to the disclosed technology, as shown in FIG. 2 , the terminal 130 is connected to the network, a PDU session for a voice service or a data service is generated, and the terminal 130 receives the service through the corresponding session. It is performed as a follow-up procedure in a state in which uplink/downlink traffic is disconnected due to a failure of the session management device 120 during the operation. When a failure occurs in the session management device 120, service recovery cannot be automatically performed, and accordingly, it becomes impossible for the customer to use a voice service or a data service. In addition, even if a failure recovery is performed for the session management device 120 in which the failure occurs, the session information managed by the session management device is erased, so that the terminal 130 uses the session management device 120 from which the failure has been restored. It is impossible to receive service again through

The method for performing service recovery according to the disclosed technology starts from the step S205 of detecting that there is a failure in the session management device 120 in the core access and mobility management device 110 as shown in FIG. 2 . In this step, the core access and mobility management device 110 detects that a TCP connection (Transmission Control Protocol Connection) between the core access and mobility management device 110 and the session management device 120 is broken, thereby providing the session management device 120 . You can detect that there is a disability. Alternatively, in this step, the core access and mobility management device 110 transmits an http ping message to the session management device 120 , and the core access and mobility management device 110 sends the session management device 120 . If a response to the http ping message is not received from the session management device 120 , it may be detected that there is a failure. In an embodiment, when the core access and mobility management device 110 repeatedly delivers the http ping message to the session management device 120 a predetermined number of times and does not receive a response, it indicates that the session management device 120 has a failure. can detect In an embodiment, the session management apparatus 120 is a Session Management Function (SMF ) defined in the 3rd Generation Partnership Project (3GPP). In one embodiment, the core access and mobility management device 110 is a Core Access and Mobility Management Function (AMF) defined in 3GPP. In step S210, a terminal in an idle state receiving a service through a PDU (Protocol Data Unit) session generated by interworking with the session management device 120 in the core access and mobility management device 110 ( 130) to deliver a paging message. In step S215 , the terminal 130 transmits a service request message to the core access and mobility management apparatus 110 in response to receiving the paging message from the core access and mobility management apparatus 110 . In step S220 , the core access and mobility management apparatus 110 transmits a network reconnection request message to the terminal 130 in response to receiving the service request message from the terminal 130 . In one embodiment, the network reconnection request message is a De-registration Request message defined in 3GPP. The network reconnection request message transmitted from the core access and mobility management device 110 to the terminal 130 may include a Re-registration Required parameter defined as a re-registration type in 3GPP. In step S225, network re-registration is performed by referring to the network reconnection request message received by the terminal 130 and the Re-registration Required parameter included therein. In this step, the terminal 130 releases the existing PDU session and performs a network reconnection procedure to request a PDU session creation to the network. 130) can receive a voice service or a data service through the created session. As such, the core access and mobility management device 110 detects a failure of the session management device 120, and the corresponding session management device interworks to provide a service recovery procedure for terminals in an idle state receiving a service through a generated PDU session. to enable these terminals to quickly restore service.

In the above description, the meaning of the description that a component is connected to or coupled to another component does not only mean that the component is directly connected or coupled to the other component, but also means that one or more other components are interposed therebetween. It should be understood to include the meaning that may be connected or coupled via an element. In addition, terms for describing the relationship between the elements (eg, 'between', 'between', etc.) should also be interpreted with similar meanings.

In the embodiments disclosed herein, the arrangement of the illustrated components may vary depending on the environment or requirements in which the invention is implemented. For example, some components may be omitted or some components may be integrated and implemented as one. Also, the arrangement order and connection of some components may be changed.

In the above, various embodiments of the present invention have been shown and described, but the present invention is not limited to the specific embodiments described above, and the above-described embodiments depart from the gist of the present invention as claimed in the appended claims. Without this, various modifications may be made by those of ordinary skill in the art to which the present invention pertains, and these modified embodiments should not be understood separately from the technical spirit or scope of the present invention. Accordingly, the technical scope of the present invention should be defined only by the appended claims.

110: AMF
120: SMF
130: UE
152, 154: UPF
170: gNB

Claims (16)

A method of performing service recovery in the event of a failure of a session management device, the method comprising:
detecting, in the mobility management device, that the session management device has a failure;
Transmitting a paging message from the mobility management device to a terminal in an idle state receiving a service through a protocol data unit (PDU) session generated by interworking with the session management device;
transmitting, by the terminal, a service request message to the mobility management device; and
transmitting a network reconnection request message from the mobility management device to the terminal;
The network reconnection request message is a De-registration Request message defined in 3GPP, and includes a Re-registration Required parameter defined as a re-registration type in 3GPP,
In response to the terminal receiving the network reconnection request message from the mobility management device, the method further includes the step of performing network re-registration by referring to the network reconnection request message and a Re-registration Required parameter included therein How to perform service recovery.
According to claim 1,
The session management device is a Session Management Function (SMF) defined in 3GPP, the service recovery performing method.
According to claim 1,
The mobility management device is AMF (Core Access and Mobility Management Function) defined in 3GPP, service recovery performing method.
According to claim 1,
The step of detecting, by the mobility management device, that there is a failure in the session management device comprises the step of detecting, in the mobility management device, that a TCP connection (Transmission Control Protocol Connection) between the mobility management device and the session management device is broken. How to perform service recovery.
According to claim 1,
The step of detecting, in the mobility management device, that there is a failure in the session management device,
transmitting, by the mobility management device, an http ping message to the session management device; and
and detecting, by the mobility management apparatus, that there is a failure in the session management apparatus when it does not receive a response to the http ping message from the session management apparatus.
delete delete delete delete A system for performing service recovery in the event of a failure of the session management device, comprising:
terminal;
session management device; and
Detecting that there is a failure in the session management device, and delivering a paging message to the terminal in an idle state receiving a service through a PDU session created by interworking with the session management device, and receiving a service request message from the terminal and a mobility management device for transmitting a network reconnection request message to the terminal in response,
The network reconnection request message is a De-registration Request message defined in 3GPP, and includes a Re-registration Required parameter defined as a re-registration type in 3GPP,
In response to receiving the network reconnection request message from the mobility management device, the terminal refers to the network reconnection request message and a Re-registration Required parameter included therein to perform network re-registration. A system for performing network re-registration .
11. The method of claim 10,
The session management device is an SMF defined in 3GPP, a service recovery performing system.
11. The method of claim 10,
The mobility management device is an AMF defined in 3GPP, service recovery performing system.
11. The method of claim 10,
and the mobility management device detects that a failure exists in the session management device by detecting that a TCP connection between the mobility management device and the session management device is broken.
11. The method of claim 10,
wherein the mobility management device transmits an http ping message to the session management device, and detects that there is a failure in the session management device when it does not receive a response to the http ping message from the session management device. delete delete

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