Method and device for processing core network failure in redundant network core communication network

Abstract

An embodiment relates to a method for processing a failure in a second core manager (CM) in a redundant network core communication network. The method involves: a second CM of a second core receiving a second core state request from a second access and mobility management function (AMF) of a second core; the second CM transmitting, to the second AMF, information indicating that the second core is in a standby state; the second CM checking the state of a first core; the second CM confirming that a failure has occurred in the first core; and the second CM transmitting, to the second AMF, information for notifying that the second core is in an active state, wherein the information notifying that the second core is in an active state is related to the switching of a virtual radio access network (vRAN) from the first core to the second core.

Description

Method and device for handling core network failure in a redundant network core communication network

[0001] The following description relates to a wireless communication system, and more specifically, to a method and device for handling core network failure in a redundant network core communication network.

[0002] Wireless communication systems utilize various Radio Access Technologies (RATs), including LTE, LTE-A, and WiFi, and 5G is included. 5G encompasses three key requirements: (1) Enhanced Mobile Broadband (eMBB), (2) Massive Machine Type Communication (mMTC), and (3) Ultra-reliable and Low Latency Communications (URLLC). Some use cases may require optimization across multiple areas, while others may focus on just one Key Performance Indicator (KPI). 5G supports these diverse use cases in a flexible and reliable manner.

[0003] eMBB extends far beyond basic mobile internet access, encompassing rich interactive tasks, cloud computing, and augmented reality media and entertainment applications. Data is a key driver of 5G, and dedicated voice services may not be the first to emerge in the 5G era. In 5G, voice is expected to be handled as an application, simply using the data connection provided by the communication system. The primary drivers of increased traffic volume are the increasing size of content and the growing number of applications requiring high data rates. Streaming services (audio and video), interactive video, and mobile internet connectivity will become more prevalent as more devices connect to the internet. Many of these applications require always-on connectivity to push real-time information and notifications to users. Cloud storage and applications are rapidly growing on mobile communication platforms, applicable to both work and entertainment. Cloud storage is a particular use case driving the growth of uplink data rates. 5G is also used for remote work in the cloud, requiring significantly lower end-to-end latency to maintain a superior user experience when tactile interfaces are used. Entertainment, for example, cloud gaming and video streaming are other key factors driving the demand for mobile broadband. Entertainment is essential on smartphones and tablets, regardless of location, including in highly mobile environments such as trains, cars, and airplanes. Another use case is augmented reality and information retrieval for entertainment, where augmented reality requires extremely low latency and instantaneous data volumes.

[0004] Additionally, one of the most anticipated 5G use cases concerns mMTC, the ability to seamlessly connect embedded sensors across all sectors. The number of potential IoT devices is projected to reach 20.4 billion by 2020. Industrial IoT is one area where 5G will play a key role, enabling smart cities, asset tracking, smart utilities, agriculture, and security infrastructure.

[0005] URLLC encompasses new services that will transform industries through ultra-reliable, low-latency links, such as remote control of critical infrastructure and self-driving vehicles. Reliability and latency are essential for smart grid control, industrial automation, robotics, and drone control and coordination.

[0006] Next, we will look at several use cases in more detail.

[0007] 5G can complement fiber-to-the-home (FTTH) and cable-based broadband (or DOCSIS) by delivering streams rated at hundreds of megabits per second to gigabits per second. These high speeds are required to deliver TV at resolutions beyond 4K (6K, 8K, and beyond), as well as virtual and augmented reality. Virtual reality (VR) and augmented reality (AR) applications include near-immersive sports events. Certain applications may require specialized network configurations. For example, for VR games, game companies may need to integrate their core servers with the network operator's edge network servers to minimize latency.

[0008] Automotive is expected to be a significant new driver for 5G, with numerous use cases for in-vehicle mobile communications. Passenger entertainment, for example, demands simultaneous high-capacity and high-mobility mobile broadband. This is because future users will expect high-quality connectivity regardless of their location or speed. Another automotive application is an augmented reality dashboard, which overlays information on what the driver sees through the windshield, identifying objects in the dark and informing the driver about their distance and movement. In the future, wireless modules will enable communication between vehicles, the exchange of information between vehicles and supporting infrastructure, and between vehicles and other connected devices (e.g., devices accompanying pedestrians). Safety systems can guide drivers on alternative courses of action to ensure safer driving, reducing the risk of accidents. The next step will be remotely controlled or self-driving vehicles, which will require highly reliable and fast communication between different self-driving vehicles and between vehicles and infrastructure. In the future, self-driving cars will perform all driving tasks, leaving drivers to focus solely on traffic anomalies that the vehicles themselves cannot detect. The technological requirements for self-driving cars will require ultra-low latency and ultra-high-speed reliability, increasing traffic safety to levels unattainable by humans.

[0009] Smart cities and smart homes, often referred to as "smart societies," will be embedded with dense wireless sensor networks. A distributed network of intelligent sensors will identify conditions for cost- and energy-efficient maintenance of cities or homes. A similar setup can be implemented for each home. Temperature sensors, window and heating controllers, burglar alarms, and appliances will all be connected wirelessly. Many of these sensors typically have low data rates, low power, and low cost. However, for example, real-time HD video may be required for certain types of devices for surveillance purposes.

[0010] The consumption and distribution of energy, including heat and gas, are becoming increasingly decentralized, requiring automated control of distributed sensor networks. Smart grids interconnect these sensors using digital information and communication technologies to collect and act on information. This information can include the behavior of suppliers and consumers, enabling smart grids to improve efficiency, reliability, economic efficiency, sustainable production, and automated distribution of fuels like electricity. Smart grids can also be viewed as another low-latency sensor network.

[0011] The health sector has numerous applications that can benefit from mobile communications. Telecommunications systems can support telemedicine, which provides clinical care in remote locations. This can help reduce distance barriers and improve access to health services that are otherwise unavailable in remote rural areas. It can also be used to save lives in critical care and emergency situations. Mobile-based wireless sensor networks can provide remote monitoring and sensors for parameters such as heart rate and blood pressure.

[0012] Wireless and mobile communications are becoming increasingly important in industrial applications. Wiring is expensive to install and maintain. Therefore, the potential to replace cables with reconfigurable wireless links presents an attractive opportunity for many industries. However, achieving this requires wireless connections to operate with similar latency, reliability, and capacity to cables, while simplifying their management. Low latency and extremely low error rates are new requirements for 5G connectivity.

[0013] Logistics and freight tracking are important use cases for mobile communications, enabling the tracking of inventory and packages anywhere using location-based information systems. Logistics and freight tracking typically require low data rates but wide coverage and reliable location information.

[0014] Wireless communication systems are multiple access systems that support communication with multiple users by sharing available system resources (e.g., bandwidth, transmission power, etc.). Examples of multiple access systems include code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC-FDMA), and multi-carrier frequency division multiple access (MC-FDMA).

[0015] Sidelink (SL) refers to a communication method that establishes a direct link between user equipment (UE), allowing voice or data to be exchanged directly between terminals without going through a base station (BS). SL is being considered as a solution to address the burden on base stations due to rapidly increasing data traffic.

[0016] V2X (vehicle-to-everything) refers to a communication technology that exchanges information with other vehicles, pedestrians, and infrastructure-based objects through wired / wireless communication. V2X can be divided into four types: V2V (vehicle-to-vehicle), V2I (vehicle-to-infrastructure), V2N (vehicle-to-network), and V2P (vehicle-to-pedestrian). V2X communication can be provided through the PC5 interface and / or Uu interface.

[0017] Meanwhile, as more and more communication devices demand greater communication capacity, the need for improved mobile broadband communication compared to existing radio access technology (RAT) is emerging. Accordingly, communication systems that consider services or terminals sensitive to reliability and latency are being discussed. Next-generation wireless access technologies that consider improved mobile broadband communication, massive machine type communication (MTC), and ultra-reliable and low latency communication (URLLC) can be called new radio access technology (RAT) or new radio (NR). NR can also support vehicle-to-everything (V2X) communication.

[0018] The present disclosure provides a method and device for handling core network failure in a dual network core communication network as a technical problem.

[0019] One embodiment is a method for handling a failure of a second CM (Core Manager) in a dual network core communication network, the method including: a second CM of a second core receiving a second core status request from a second AMF (Access and Mobility Management Function) of the second core; the second CM transmitting information to the second AMF indicating that the second core is in a standby state; the second CM confirming a status of a first core; the second CM confirming that a failure has occurred in the first core; and the second CM transmitting information to the second AMF indicating that the second core is in an active state, wherein the information indicating that the second core is in an active state is related to a transition from the first core to the second core of a vRAN (virtual Radio Access Network).

[0020] One embodiment is a network function (NF) including a second CM (Core Manager) in a redundant network core communication network, comprising: at least one processor; and at least one computer memory operably connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations, wherein the operations include: receiving a second core status request from a second AMF (Access and Mobility Management Function) of the second core by the second CM; transmitting information to the second AMF indicating that the second core is in a standby state by the second CM; confirming a status of a first core by the second CM; confirming that a failure has occurred in the first core; And the second CM transmits information to the second AMF notifying that the second core is in an active state, wherein the information notifying that the second core is in an active state is an NF related to a transition from the first core to the second core of a vRAN (virtual Radio Access Network).

[0021] One embodiment is a non-volatile computer-readable medium having stored thereon program instructions for performing the following operations, wherein the operations include: receiving a second core status request from a second CM (Core Manager) of a second core from a second AMF (Access and Mobility Management Function) of the second core; transmitting information to the second AMF indicating that the second core is in a standby state; confirming a status of the first core; confirming that a failure has occurred in the first core; and transmitting information to the second AMF indicating that the second core is in an active state, wherein the information indicating that the second core is in an active state is related to a transition from the first core to the second core of a vRAN (virtual Radio Access Network).

[0022] Information indicating that the second core is active triggers transmission of an Amf_configurationUpdate message from the second AMF to the vRAN.

[0023] Upon receiving the Amf_configurationUpdate message, the vRAN switches from the first core to the second core.

[0024] After transmitting the Amf_configurationUpdate message, an NG reset message is transmitted from the second AMF to the vRAN.

[0025] The above NG reset message causes the vRAN to release the terminal.

[0026] After release, the above terminal performs a network registration procedure with the second core.

[0027] The second CM determines that the first core has failed based on at least one of a heartbeat failure, a primary NF IP allocation check, or a VRRP Protocol.

[0028] The above first CM requests RAN release to the second AMF of the second core when N2, N3, and N6 IPs (Internet Protocols) are all initially allocated and the first core is changed from Standby to Active state through failover.

[0029] The above first CM determines that AMF is abnormal if the IPs of N3 and N6 exist and the IP of N2 does not exist, and brings down the entire POD (Point of Delivery).

[0030] The above first CM determines that the UPF (User Plane Function) is abnormal when the IPs of N3 and N6 do not exist and only the IP of N2 exists, and brings down the entire POD.

[0031] If a physical server down occurs in the first core, the second CM detects N2, N3, and N6 IP allocation and performs a failover operation.

[0032] In one embodiment, network transition time can be shortened by implementing each network NF status check (Core Manager) process and its own network transition signal FLOW for fast redundancy failover transition.

[0033] The drawings attached to this specification are intended to provide an understanding of the embodiments and to illustrate various embodiments and, together with the description of the specification, to explain the principles.

[0034] Figure 1 shows the Non-Roaming 5G System Architecture.

[0035] Figure 2 shows the overall 5G NR architecture.

[0036] Figure 3 illustrates a dual server network configuration.

[0037] Figure 4 illustrates the detailed redundancy failover flow when an existing server down failure occurs.

[0038] Figures 5 to 7 are drawings for explaining embodiments.

[0039] In various embodiments of the present disclosure, “ / ” and “,” should be interpreted as indicating “and / or.” For example, “A / B” can mean “A and / or B.” Furthermore, “A, B” can mean “A and / or B.” Furthermore, “A / B / C” can mean “at least one of A, B, and / or C.” Furthermore, “A, B, C” can mean “at least one of A, B, and / or C.”

[0040] In various embodiments of the present disclosure, "or" should be interpreted as meaning "and / or." For example, "A or B" can include "only A," "only B," and / or "both A and B." In other words, "or" should be interpreted as meaning "additionally or alternatively."

[0041] The following technologies can be used in various wireless communication systems, such as CDMA (code division multiple access), FDMA (frequency division multiple access), TDMA (time division multiple access), OFDMA (orthogonal frequency division multiple access), and SC-FDMA (single carrier frequency division multiple access). CDMA can be implemented with wireless technologies such as UTRA (universal terrestrial radio access) or CDMA2000. TDMA can be implemented with wireless technologies such as GSM (global system for mobile communications) / GPRS (general packet radio service) / EDGE (enhanced data rates for GSM evolution). OFDMA can be implemented with wireless technologies such as IEEE (Institute of Electrical and Electronics Engineers) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, and E-UTRA (evolved UTRA). IEEE 802.16m is an evolution of IEEE 802.16e, providing backward compatibility with systems based on IEEE 802.16e. UTRA is part of UMTS (universal mobile telecommunications system). 3GPP (3rd generation partnership project) LTE (long term evolution) is a part of E-UMTS (evolved UMTS) that uses E-UTRA (evolved-UMTS terrestrial radio access), employing OFDMA in the downlink and SC-FDMA in the uplink.LTE-A (advanced) is an evolution of 3GPP LTE.

[0042] 5G NR, the successor to LTE-A, is a new clean-slate mobile communications system featuring high performance, low latency, and high availability. 5G NR can utilize all available spectrum resources, from low-frequency bands below 1 GHz, mid-frequency bands between 1 GHz and 10 GHz, and high-frequency (millimeter wave) bands above 24 GHz.

[0043] For clarity of explanation, the description will focus on LTE-A or 5G NR, but the technical ideas according to one embodiment of the present disclosure are not limited thereto.

[0044] Figure 1 illustrates the Non-Roaming 5G System Architecture disclosed in 3GPP TS 23.501. As illustrated, the 5G Core Network includes various Network Functions (NFs), such as the Access and Mobility Management Function (AMF), the User Plane Function (UPF), and the Session Management Function (SMF). Network functions can be implemented as network elements on dedicated hardware, software instances running on dedicated hardware, or virtualized functions instantiated on a suitable platform. For example, they can run on cloud infrastructure.

[0045] Table 1 below discloses the NFs of the 5G Core Network and their functions.

[0046] NFfunctionAMF (Access and Mobility Management Function) RAN CP interface (N2) termination NAS (N1) termination, NAS encryption and integrity protection. Registration management. Connection management. Accessibility management. Mobility management. Lawful interception (for AMF events and interfaces to LI systems). Provides SM message transfer between UE and SMF. Transparent proxy for SM message routing. Access authentication and access authorization. Provides SMS message transfer between UE and SMSF. SEAF (Security Anchor Function). Interacts with AUSF and UE, receives intermediate key generated as a result of UE authentication process. In case of USIM based authentication, AMF retrieves security material from AUSF. Functions for non-3GPP access network. User Plane Function (UPF) Anchor point for Intra- / Inter-RAT mobility (if applicable). External PDU session point of interconnection to data network. Packet routing and forwarding. Packet inspection. User plane part of policy rule enforcement (e.g. gating, redirection, traffic shaping). Lawful blocking (UP collection). Traffic usage reporting. QoS processing for user plane (e.g. UL / DL rate enforcement, reflected QoS marking in DL). Uplink traffic validation (QoS flow mapping in SDF). Transport level packet marking in uplink and downlink. Downlink packet buffering and downlink data notification triggering. Sends and forwards one or more "end markers" to the source NG-RAN node. Session Management Function (SMF) Session Management Functions UE IP address allocation and management; Selection and control of UP functions; Traffic shaping in UPF. Configure and enforce routing policies to route traffic to appropriate destinations and control some of the QoS for downlink data notifications.PCF (Policy Control Function) Policy Control Function Supports a unified policy framework for managing network behavior. Provides and enforces policy rules to control plane functions. Accesses subscription information related to policy decisions in the Unified Data Repository (UDR). Unified Data Management (UDM) Unified Data Management Generates 3GPP AKA authentication credentials. Processes user identification. Grants access rights based on subscription data (e.g., roaming restrictions). Manages UE's Serving NF registration. Supports service / session continuity. For example, maintains SMF / DNN allocation for ongoing sessions. Supports MT-SMS forwarding. Lawful Interception Function Subscription Management. SMS Management. AUSF (Authentication Server Function) Supports the Authentication Server Function (AUSF) specified by SA WG3. AF (Application Function) Application influence on traffic routing. Access to network exposure functions. Interacts with the policy framework for policy control.

[0047] Additionally, there are various reference points such as N2, N3, and N4, which signify interfaces between different functions or nodes in the network architecture.

[0048]

[0049] Figure 2 illustrates the overall 5G NR architecture. The gNB node provides NR User Plane and Control Plane protocol terminations to the user equipment (UE) and is connected to the 5GC (5G core network) via the NG interface. The ng-eNB node provides Control Plane protocol terminations to the UE and is connected to the 5GC via the NG interface. As illustrated, the UE is connected to an air base station (gNB, or ng-eNB) via the air interface.

[0050]

[0051] The basic dual server network configuration of Drawing 3(a) is a structure that applies the same core network (Core NW) duplication to Ran(gNB)#1 and two servers (#1, #2). The Core SW layer operates a network switch algorithm based on the 3GPP's NG-FLEX specification, and the main NG-FLEX-related specifications can be referred to 23.501 6.3.5, 23.501 5.19.3, 23.501 5.19.5, 23.501 5.21.2, 38.410, and 38.413.

[0052] RAN and Core are connected via NG-AP protocol and perform control plane communication through NG-SETUP process. After the terminal boots and connects to RAN, RAN simultaneously establishes NG-SETUP-based control plane connection with Core#1 and Core#2. At this time, the terminal is connected to Core#1 immediately after booting, and an actual session is established with Core#1 via RAN. On the other hand, Core#2 is only established before the session connection via NG-AP protocol, so no actual traffic session is allocated.

[0053] Figure 4(b) shows the network procedure flow when a failure occurs in an existing redundant environment. If a failure occurs where the Core#1 server goes down, the connection between the RAN and Core#1 is lost. At this time, the SCTP protocol periodically checks the peer status through a heartbeat signal, so it takes some time to recognize the down state. The moment the heartbeat check determines that Core#1 is down, the RAN considers Core#2 as the active core, and the terminal performs the registration procedure with Core#2. In the active-standby architecture, this re-registration and connection transfer can take approximately 10 seconds or more.

[0054] As mentioned above, the Heartbeat signal of the Stream Control Transmission Protocol (SCTP) protocol monitors and maintains the status of a connection. The main purposes of the Heartbeat are to monitor endpoint reachability, measure RTT of idle paths, and check path status in a multi-homed environment. SCTP can monitor endpoint reachability by periodically transmitting HEARTBEAT chunks, and the receiving endpoint can confirm availability by responding with a HEARTBEAT ACK chunk. The structure of a Heartbeat chunk can be composed of a chunk type, flags, length, and optional parameters. This Heartbeat mechanism can play a crucial role in a multi-homed environment, such as monitoring the status of multiple paths, detecting failures, and switching to an alternate path when necessary. The Heartbeat operation can be achieved by the sender transmitting a HEARTBEAT chunk, and the receiver immediately responding with a HEARTBEAT ACK.

[0055] Referring to FIG. 3 and FIG. 1 described above, three major interfaces may exist in the aforementioned 5G core network. First, N2 is the control plane interface between the RAN and the AMF, which can be responsible for important signaling connections between the base station and the core network. This can be a key element that performs the network control function. N3 refers to the user plane interface between the RAN and the UPF, and can serve as an important path for actual user data traffic to travel. This ensures that actual user data can be transmitted stably. N6 can be defined as the interface between the UPF and an external data network. It is responsible for connections to the Internet or various external services, and can ultimately provide a path for users to communicate with external networks.

[0056]

[0057] Figure 4 illustrates the detailed redundancy failover flow in the event of an existing server down failure. As illustrated in Figure 4, when a physical server failure (e.g., power cable down, S401) occurs, the vRAN performs an SCTP HeartBeat check on the AMF of vCore#1. As illustrated, the SCTP HeartBeat check may take approximately 8 to 18 seconds. After the SCTP Detect process is complete, the RAN detects the NG-SETUP connection failure with the existing Core#1 and attempts to connect to Core#2 to perform network registration of the terminal. As a result, the total Core N / W transition time may take more than 10 seconds.

[0058] Accordingly, the following discloses a network failure recovery method, device, etc. for overcoming a failover problem that occurs in one core in a dual network core communication network.

[0059]

[0060] Referring to FIG. 5, a method for handling a failure of a second CM (Core Manager, CM#2) in a dual network core communication network according to an embodiment of the present invention includes: a second CM of a second core receives a request for the status (vCore Status) of the second core from a second AMF (Access and Mobility Management Function, AMF#2) of the second core, and the second CM can transmit information to the second AMF notifying that the second core is in a Standby state. (S505) The second CM can check the status of the first core (CM#1), and the second CM can confirm that a failure has occurred in the first core (S507). The second CM can transmit information to the second AMF notifying that the second core is in an active state.

[0061] The information indicating that the second core is active may be related to a transition from the first core to the second core of a vRAN (virtual Radio Access Network). Specifically, the information indicating that the second core is active may trigger transmission of an Amf_configurationUpdate message from the second AMF to the vRAN (S509). That is, the second AMF may transmit an Amf_configurationUpdate message to the vRAN. The vRAN, which receives the Amf_configurationUpdate message, may transition from the first core to the second core. After transmission of the Amf_configurationUpdate message, an NG reset message may be transmitted from the second AMF to the vRAN (S510). The NG reset message causes the vRAN to release the terminal (S511). After the release, the terminal may perform a network registration procedure (S512) with the second core.

[0062]

[0063] The second CM may determine that a failure has occurred in the first core based on at least one of a heartbeat failure, a primary NF IP allocation confirmation, or a VRRP Protocol.

[0064] The above second CM is a CM according to one embodiment of the present invention, and is illustrated in Fig. 6(a) which illustrates the structure of a monitoring process (Core Manager). The CM may include a Linux-based monitoring process creation / check algorithm. The CM may perform at least one of the following operations: monitoring the status of NF PODs (the smallest deployable computing unit that can be created and managed in Kubernetes) within each Core, monitoring whether IPs are allocated to major NFs, or checking the SCTP protocol (server down).

[0065] Figure 6(b) is a CM monitoring process, Failover: Server Down Case. Looking at the SCTP Down Case (server down) occurrence flow, the CM process of Core#2 can detect the occurrence of a Core#1 server down. One or more of the following can be used to detect a server down: Heartbeat failure, confirmation of primary NF IP allocation, or VRRP Protocol.

[0066] The Core#2 monitoring process can send signal messages to AMF. Signals can include status information signals, Amf_configurationUpdate, and NG-Reset message trigger signals.

[0067] Core#2 AMF can process event transmissions to the RAN via signals. The RAN can also receive these events and perform rapid network re-registration procedures for the terminal.

[0068] This method can reduce the network re-registration time from 10 seconds to 7 seconds.

[0069] In Figure 6, kubectl is a command line interface for controlling a Kubernetes cluster. As shown, kubectl can be used by the CM to check and manage the status of each POD. In a failover situation, the CM monitors the status of the Active / Standby PODs through kubectl and can restart or change the status of the PODs as needed.

[0070]

[0071] Figure 7 illustrates the contents related to the duplication check algorithm of CM according to one embodiment.

[0072] Referring to Fig. 7, the Down Case logic algorithm transmits a RAN Release request event to the AMF because it is a case where the N2, N3, and N6 IPs (Internet Protocol) are all allocated for the first time in the corresponding Core and the first Core becomes Active from Standby through Failover (S701). Applying this to the above-described embodiment, the first CM can request a RAN release to the second AMF of the second Core when the N2, N3, and N6 IPs (Internet Protocol) are all allocated for the first time and the first Core becomes Active from Standby through failover.

[0073] Regarding S702, when AMF Pod is down, the failover algorithm determines that the NF (AMF) is abnormal if the IP of N2 does not exist and performs failover by bringing down the entire Active Core POD. If this is applied to the above-described embodiment, the first CM can determine that the AMF is abnormal and bring down the entire POD (Point of Delivery) if the IPs of N3 and N6 exist and the IP of N2 does not exist.

[0074] Regarding S703, the UPF Pod down Failover algorithm performs failover by determining the NF (UPF) as abnormal and bringing down the entire Active Core POD if the IPs of N3 and N6 do not exist. If this is applied to the above-described embodiment, the first CM can determine the UPF (User Plane Function) as abnormal and bring down the entire POD if the IPs of N3 and N6 do not exist and only the IP of N2 exists.

[0075] With respect to S704, the physical Server Down Failover algorithm detects the N2, N3, and N6 IP allocations of the Core Manager of the Standby Core and performs a Failover operation. Applying this to the above-described embodiment, if a physical server down occurs in the first core, the second CM can detect the N2, N3, and N6 IP allocations and perform a Failover operation from the Standby to the Active of the second core.

[0076]

[0077] In connection with the above description, in a redundant network core communication network, a Network Function (NF) including a second CM (Core Manager) includes at least one processor and at least one computer memory operably connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations, wherein the operations include: a second CM (Core Manager) of a second core receiving a second core status request from a second AMF (Access and Mobility Management Function) of the second core; the second CM transmitting information to the second AMF indicating that the second core is in a standby state; the second CM confirming a status of a first core; the second CM confirming that a failure has occurred in the first core; and the second CM transmitting information to the second AMF indicating that the second core is in an active state, wherein the information indicating that the second core is in an active state may be related to a transition from the first core to the second core of a vRAN (virtual Radio Access Network).

[0078] Also, in a nonvolatile computer-readable medium storing program instructions for performing the following operations, the operations include: receiving a second core status request from a second CM (Core Manager) of a second core from a second AMF (Access and Mobility Management Function) of the second core; transmitting information to the second AMF indicating that the second core is in a standby state; confirming a status of the first core by the second CM; confirming that a failure has occurred in the first core; and transmitting information to the second AMF indicating that the second core is in an active state by the second CM, wherein the information indicating that the second core is in an active state may be related to a transition from the first core to the second core of a vRAN (virtual Radio Access Network).

[0079]

[0080] In the above description, IP (Internet Protocol) may be VIP (Virtual IP).

[0081] According to the above-described embodiment of the present invention, the network transition time can be shortened by implementing each network NF status check (Core Manager) process and its own network transition signal FLOW for fast dual failover.

[0082] That is, the invention is that the NF status process immediately transmits a signal Notify to Core#2 when a failure is detected by the Core#1 NF / server status check algorithm, so that the terminal connected to the VRAN quickly re-registers with Core#2.

[0083] The embodiments described above can be applied to a dual or single network structure using a private 5G network (e.g., private 5G) in a factory / hospital, etc.

Claims

1. In a method for handling a failure of a second CM (Core Manager) in a dual network core communication network, The second CM of the second core receives a second core status request from the second AMF (Access and Mobility Management Function) of the second core; The second CM transmits information to the second AMF notifying that the second core is in a standby state; The above second CM checks the status of the first core; The second CM confirms that a failure has occurred in the first core; and The second CM transmits information to the second AMF informing that the second core is active; Includes, A method in which information indicating that the second core is active is related to a transition from the first core to the second core of a vRAN (virtual Radio Access Network).

2. In paragraph 1, A method in which information indicating that the second core is active triggers transmission of an Amf_configurationUpdate message from the second AMF to the vRAN.

3. In paragraph 2, A method in which a vRAN that receives the Amf_configurationUpdate message switches from the first core to the second core.

4. In paragraph 2, A method in which an NG reset message is transmitted from the second AMF to the vRAN after transmitting the Amf_configurationUpdate message.

5. In paragraph 4, A method wherein the above NG reset message causes the vRAN to release the terminal.

6. In paragraph 5, A method in which the above terminal performs a network registration procedure with the second core after release.

7. In paragraph 1, A method wherein the second CM determines that a failure has occurred in the first core based on at least one of a heartbeat failure, a primary NF IP allocation confirmation, or a VRRP Protocol.

8. In paragraph 1, A method in which the first CM requests RAN release to the second AMF of the second core when N2, N3, and N6 IPs (Internet Protocols) are all initially allocated and the first core is changed from Standby to Active state through failover.

9. In paragraph 1, The above first CM is a method for determining that AMF is abnormal and bringing down the entire POD (Point of Delivery) when the IPs of N3 and N6 exist and the IP of N2 does not exist.

10. In paragraph 1, The above first CM is a method for determining that the UPF (User Plane Function) is abnormal and bringing down the entire POD when the IPs of N3 and N6 do not exist and only the IP of N2 exists.

11. In paragraph 1, A method in which, when a physical server down occurs in the first core, the second CM detects N2, N3, and N6 IP allocations and performs a failover operation.

12. In a dual network core communication network, in the NF (Network Function) including the second CM (Core Manager), at least one processor; and At least one computer memory operably connected to said at least one processor and storing instructions that, when executed, cause said at least one processor to perform operations; The above actions are, The second CM (Core Manager) of the second core receives a second core status request from the second AMF (Access and Mobility Management Function) of the second core; The second CM transmits information to the second AMF notifying that the second core is in a standby state; The above second CM checks the status of the first core; The second CM confirms that a failure has occurred in the first core; and The second CM transmits information to the second AMF informing that the second core is active; Includes, Information indicating that the second core is active is related to the transition from the first core to the second core of the vRAN (virtual Radio Access Network), NF 13. In a non-volatile computer-readable medium storing program instructions for performing the following operations, the operations are: The second CM (Core Manager) of the second core receives a second core status request from the second AMF (Access and Mobility Management Function) of the second core; The second CM transmits information to the second AMF notifying that the second core is in a standby state; The above second CM checks the status of the first core; The second CM confirms that a failure has occurred in the first core; and The second CM transmits information to the second AMF informing that the second core is active; Includes, Information indicating that the second core is active is related to a transition from the first core to the second core of a vRAN (virtual Radio Access Network).

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