FORM 2
THE PATENTS ACT, 1970 (39 OF 1970) & THE PATENT RULES, 2003
COMPLETE SPECIFICATION
(See section 10 and rule 13)
“METHOD AND SYSTEM FOR CONCURRENTLY
MANAGING SUBSCRIPTION NOTIFICATIONS ON ONE OR
MORE NETWORK FUNCTIONS (NFS)”
We, Jio Platforms Limited, an Indian National, of Office - 101, Saffron, Nr. Centre Point, Panchwati 5 Rasta, Ambawadi, Ahmedabad - 380006, Gujarat, India.
The following specification particularly describes the invention and the manner in which it is to be performed.

METHOD AND SYSTEM FOR CONCURRENTLY MANAGING SUBSCRIPTION NOTIFICATIONS ON ONE OR MORE NETWORK
FUNCTIONS (NFS)
FIELD OF INVENTION
[0001] Embodiments of the present disclosure relate generally to the field of wireless communication systems. More particularly, embodiment of the present disclosure relates to a method and system for concurrently managing subscription notifications on one or more Network Functions (NFs).
BACKGROUND
[0002] The following description of the related art is intended to provide background information pertaining to the field of the disclosure. This section may include certain aspects of the art that may be related to various features of the present disclosure. However, it should be appreciated that this section is used only to enhance the understanding of the reader with respect to the present disclosure, and not as admissions of the prior art.
[0003] Wireless communication technology has rapidly evolved over the past few decades, with each generation bringing significant improvements and advancements. The first generation of wireless communication technology was based on analog technology and offered only voice services. However, with the advent of the second-generation (2G) technology, digital communication and data services became possible, and text messaging was introduced. 3G technology marked the introduction of high-speed internet access, mobile video calling, and location-based services. The fourth-generation (4G) technology revolutionized wireless communication with faster data speeds, better network coverage, and improved security. Currently, the fifth-generation (5G) technology is being deployed, promising even faster data speeds, low latency, and the ability to connect

multiple devices simultaneously. With each generation, wireless communication technology has become more advanced, sophisticated, and capable of delivering more services to its users.
[0004] In the current scenario to ensure tremendous accessibility, constant and sustained services, and efficient fault tolerant mechanisms, one of the known solutions is to deploy Network Functions (NFs) in a cluster of 3 instances, wherein the instances act as an Active, a Standby and a Spare NFs. These three Network Functions (NFs) may be defined as follows:
• Active: The Active instance is the primary NF that handles live traffic and performs the intended functions. It is responsible for processing requests, executing tasks, and delivering services to clients or end-users.
• Standby: The Standby instance NF is a redundant copy of the Active NF. This instance closely monitors the Active instance and maintains synchronized state information. The Standby instances are ready to take over the Active role instantly in case of a failure or disruption in the Active instance. They ensure seamless failover and continuity of services.
• Spare: The Spare instance NF is an additional backup NF that remains idle but is fully configured and synchronized with the Active and Standby instances NFs. It serves as an additional safety net in case both the Active and Standby instances encounter failures simultaneously. The Spare instance can be quickly activated to restore services in such critical situations.
[0005] Further, any changes made on the Active instance are propagated to the Standby and Spare instances NF to keep them updated through replication channel, which is used for duplication. RPC makes sure that the data is synchronized or consistent in real-time or almost real-time across all instances. The session data cache is a component of the state that the network functions maintain.

[0006] In order to support proper processing of requests on nodes other than the primary "Active" node, this session cache is to be synchronized throughout all the cluster nodes. Further, it is highly important to ensure that the Network Repository Function (NRF) subscriber notification is received on both primary Active instance and Spare Active instance. This is crucial in a split-brain scenario, wherein a spare instance becomes active due to a failure in the connectivity between the Primary site and remote site (i.e., spare instance). In the split-brain scenario both the Primary instance and Spare instance act as Active node and serve the necessary call flow requests, but typically the NRF only sends the subscriber notification on Spare Active instance. This is problematic as it may lead to interruption in services.
[0007] Thus, there exists an imperative need in the art to managing and handling subscriber notification on dual active instances Policy Control Function (PCF), which the present disclosure aims to address.
SUMMARY
[0008] This section is provided to introduce certain aspects of the present disclosure in a simplified form that are further described below in the detailed description. This summary is not intended to identify the key features or the scope of the claimed subject matter.
[0009] An aspect of the present disclosure may relate to a method for concurrently managing subscription notifications on one or more Network Functions (NFs). The method comprises receiving, by a transceiver unit at a first Network Function (NF), a data corresponding to a subscription request, wherein the subscription request is transmitted by a second NF to a Network Repository Function (NRF) during a process of subscribing the NRF. The method further comprises, in an event of an intermittent connectivity failure between the first NF and the second NF, transmitting, by a transceiver unit at the first NF, a new subscription request to the

NRF, wherein the new subscription request is used for subscribing the first NF with the NRF. The method further comprises receiving, by the transceiver unit at the first NF, a subscription notification from the NRF, while the NRF concurrently transmits a subscription notification to the second NF.
[0010] In an exemplary aspect of the present disclosure, the first Network Function (NF) is a spare Policy Control Function (PCF).
[0011] In an exemplary aspect of the present disclosure, the second Network Function (NF) is an active Policy Control Function (PCF).
[0012] In an exemplary aspect of the present disclosure, wherein the process of subscribing the second NF with the NRF comprises transmitting, by the second NF, the subscription request to the NRF; and receiving, by the second NF from the NRF, a subscription response corresponding to the subscription request, wherein the subscription response comprises a subscription identity information
[0013] In an exemplary aspect of the present disclosure, the new subscription request is based on the data received from the second NF.
[0014] In an exemplary aspect of the present disclosure, pursuant to transmitting, by the transceiver unit at the first NF, the new subscription request to the NRF, the method further comprises: receiving, by the transceiver unit at the first NF, a subscription response, wherein the subscription response comprises a subscription identity information associated with the new subscription request.
[0015] Another aspect of the present disclosure may relate to a system for concurrently managing subscription notifications on one or more Network Functions (NFs). The system comprise a first Network Function (NF). The first NF comprises a processing unit and a transceiver unit connected to at least the processing unit. The transceiver unit is configured to receive a data corresponding

to a subscription request, wherein the subscription request is transmitted by a second NF to a Network Repository Function (NRF) during a process of subscribing with the NRF. The transceiver unit is further configured to, in an event of an intermittent connectivity failure between the second NF and the first NF, transmit a new subscription request to the NRF. The new subscription request is used for subscribing the first NF with the NRF. The transceiver unit is further configured to receive a subscription notification from the NRF, while the NRF concurrently transmits a subscription notification to the second NF.
[0016] Yet another aspect of the present disclosure may relate to a non-transitory computer readable storage medium storing instructions for concurrently managing subscription notifications on one or more Network Functions (NFs). The instructions include executable code which, when executed by one or more units of a system, causes a transceiver unit, at a first NF, of the system to receive a data corresponding to a subscription request, wherein the subscription request is transmitted by a second NF to a Network Repository Function (NRF) during a process of subscribing with the NRF. Further, the instructions include executable code which, when executed, causes the transceiver unit, at the first NF, to transmit, to in an event of an intermittent connectivity failure between the second NF and the first NF, a new subscription request to the NRF, wherein the new subscription request is used for subscribing the first NF with the NRF. Further, the instructions include executable code which, when executed, causes the transceiver, at the first NF, to receive a subscription notification from the NRF, while the NRF concurrently transmits a subscription notification to the second NF.
OBJECTS OF THE DISCLOSURE
[0017] Some of the objects of the present disclosure, which at least one embodiment disclosed herein satisfies are listed herein below.

[0018] It is an object of the present disclosure to provide a system and a method for concurrently managing subscription notifications on one or more Network Functions (NFs).
[0019] It is an object of the present disclosure to provide a system and a method for managing and handling subscriber notification on dual active instances Policy Control Function (PCF).
[0020] It is another object of the present disclosure to provide a solution that manages a triggering event such as split-brain, which leads to activation of spare instance PCF.
DESCRIPTION OF THE DRAWINGS
[0021] The accompanying drawings, which are incorporated herein, and constitute a part of this disclosure, illustrate exemplary embodiments of the disclosed methods and systems in which like reference numerals refer to the same parts throughout the different drawings. Components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Also, the embodiments shown in the figures are not to be construed as limiting the disclosure, but the possible variants of the method and system according to the disclosure are illustrated herein to highlight the advantages of the disclosure. It will be appreciated by those skilled in the art that disclosure of such drawings includes disclosure of electrical components or circuitry commonly used to implement such components.
[0022] FIG. 1 illustrates an exemplary block diagram representation of 5th generation core (5GC) network architecture;

[0023] FIG. 2 illustrates an exemplary block diagram of a computing device upon which the features of the present disclosure may be implemented in accordance with exemplary implementation of the present disclosure;
[0024] FIG. 3 illustrates an exemplary block diagram of a system for concurrently managing subscription notifications on one or more Network Functions (NFs), in accordance with exemplary implementations of the present disclosure;
[0025] FIG. 4 illustrates an exemplary signalling call flow diagram for concurrently managing subscription notifications on one or more Network Functions (NFs), in accordance with exemplary implementations of the present disclosure; and
[0026] FIG. 5 illustrates a method flow diagram for concurrently managing subscription notifications on one or more Network Functions (NFs), in accordance with exemplary implementations of the present disclosure.
[0027] The foregoing shall be more apparent from the following more detailed description of the disclosure.
DETAILED DESCRIPTION
[0028] In the following description, for the purposes of explanation, various specific details are set forth in order to provide a thorough understanding of embodiments of the present disclosure. It will be apparent, however, that embodiments of the present disclosure may be practiced without these specific details. Several features described hereafter may each be used independently of one another or with any combination of other features. An individual feature may not address any of the problems discussed above or might address only some of the problems discussed above.

[0029] The ensuing description provides exemplary embodiments only, and is not
intended to limit the scope, applicability, or configuration of the disclosure. Rather,
the ensuing description of the exemplary embodiments will provide those skilled in
the art with an enabling description for implementing an exemplary embodiment.
5 It should be understood that various changes may be made in the function and
arrangement of elements without departing from the spirit and scope of the disclosure as set forth.
[0030] Specific details are given in the following description to provide a thorough
10 understanding of the embodiments. However, it will be understood by one of
ordinary skill in the art that the embodiments may be practiced without these specific details. For example, circuits, systems, processes, and other components may be shown as components in block diagram form in order not to obscure the embodiments in unnecessary detail. 15
[0031] Also, it is noted that individual embodiments may be described as a process
which is depicted as a flowchart, a flow diagram, a data flow diagram, a structure
diagram, or a block diagram. Although a flowchart may describe the operations as
a sequential process, many of the operations may be performed in parallel or
20 concurrently. In addition, the order of the operations may be re-arranged. A process
is terminated when its operations are completed but could have additional steps not included in a figure.
[0032] The word “exemplary” and/or “demonstrative” is used herein to mean
25 serving as an example, instance, or illustration. For the avoidance of doubt, the
subject matter disclosed herein is not limited by such examples. In addition, any
aspect or design described herein as “exemplary” and/or “demonstrative” is not
necessarily to be construed as preferred or advantageous over other aspects or
designs, nor is it meant to preclude equivalent exemplary structures and techniques
30 known to those of ordinary skill in the art. Furthermore, to the extent that the terms
“includes,” “has,” “contains,” and other similar words are used in either the detailed
9

description or the claims, such terms are intended to be inclusive—in a manner similar to the term “comprising” as an open transition word—without precluding any additional or other elements.
5 [0033] As used herein, a “processing unit” or “processor” or “operating processor”
includes one or more processors, wherein processor refers to any logic circuitry for processing instructions. A processor may be a general-purpose processor, a special purpose processor, a conventional processor, a digital signal processor, a plurality of microprocessors, one or more microprocessors in association with a Digital
10 Signal Processing (DSP) core, a controller, a microcontroller, Application Specific
Integrated Circuits, Field Programmable Gate Array circuits, any other type of integrated circuits, etc. The processor may perform signal coding data processing, input/output processing, and/or any other functionality that enables the working of the system according to the present disclosure. More specifically, the processor or
15 processing unit is a hardware processor.
[0034] As used herein, “a user equipment”, “a user device”, “a smart-user-device”, “a smart-device”, “an electronic device”, “a mobile device”, “a handheld device”, “a wireless communication device”, “a mobile communication device”, “a
20 communication device” may be any electrical, electronic and/or computing device
or equipment, capable of implementing the features of the present disclosure. The user equipment/device may include, but is not limited to, a mobile phone, smart phone, laptop, a general-purpose computer, desktop, personal digital assistant, tablet computer, wearable device or any other computing device which is capable
25 of implementing the features of the present disclosure. Also, the user device may
contain at least one input means configured to receive an input from unit(s) which are required to implement the features of the present disclosure.
[0035] As used herein, “storage unit” or “memory unit” refers to a machine or
30 computer-readable medium including any mechanism for storing information in a
form readable by a computer or similar machine. For example, a computer-readable
10

medium includes read-only memory (“ROM”), random access memory (“RAM”),
magnetic disk storage media, optical storage media, flash memory devices or other
types of machine-accessible storage media. The storage unit stores at least the data
that may be required by one or more units of the system to perform their respective
5 functions.
[0036] As used herein “interface” or “user interface refers to a shared boundary
across which two or more separate components of a system exchange information
or data. The interface may also be referred to a set of rules or protocols that define
10 communication or interaction of one or more modules or one or more units with
each other, which also includes the methods, functions, or procedures that may be called.
[0037] All modules, units, components used herein, unless explicitly excluded
15 herein, may be software modules or hardware processors, the processors being a
general-purpose processor, a special purpose processor, a conventional processor, a
digital signal processor (DSP), a plurality of microprocessors, one or more
microprocessors in association with a DSP core, a controller, a microcontroller,
Application Specific Integrated Circuits (ASIC), Field Programmable Gate Array
20 circuits (FPGA), any other type of integrated circuits, etc.
[0038] As used herein the transceiver unit include at least one receiver and at least
one transmitter configured respectively for receiving and transmitting data, signals,
information or a combination thereof between units/components within the system
25 and/or connected with the system.
[0039] As discussed in the background section, in the split-brain scenario both the
Primary instance and Spare instance of a NF act as Active node and serve the
necessary call flow requests, but typically NRF only sends the subscriber
30 notification on Spare Active instance. This is problematic as it may lead to
interruption in services.
11

[0040] The present disclosure aims to overcome the above-mentioned and other
existing problems in this field of technology by the implementation of unsubscribe
handling at Spare instance PCF, during a triggering event such as the split-brain
5 situation.
[0041] Hereinafter, exemplary embodiments of the present disclosure will be described with reference to the accompanying drawings.
10 [0042] FIG. 1 illustrates an exemplary block diagram representation of 5th
generation core (5GC) network architecture, in accordance with exemplary implementation of the present disclosure. As shown in FIG. 1, the 5GC network architecture [100] includes a user equipment (UE) [102], a radio access network (RAN) [104], an access and mobility management function (AMF) [106], a Session
15 Management Function (SMF) [108], a Service Communication Proxy (SCP) [110],
an Authentication Server Function (AUSF) [112], a Network Slice Specific Authentication and Authorization Function (NSSAAF) [114], a Network Slice Selection Function (NSSF) [116], a Network Exposure Function (NEF) [118], a Network Repository Function (NRF) [120], a Policy Control Function (PCF) [122],
20 a Unified Data Management (UDM) [124], an application function (AF) [126], a
User Plane Function (UPF) [128], a data network (DN) [130], wherein all the components are assumed to be connected to each other in a manner as obvious to the person skilled in the art for implementing features of the present disclosure.
25 [0043] Radio Access Network (RAN) [104] is the part of a mobile
telecommunications system that connects user equipment (UE) [102] to the core network (CN) and provides access to different types of networks (e.g., 5G network). It consists of radio base stations and the radio access technologies that enable wireless communication.
30
12

[0044] Access and Mobility Management Function (AMF) [106] is a 5G core network function responsible for managing access and mobility aspects, such as UE registration, connection, and reachability. It also handles mobility management procedures like handovers and paging. 5
[0045] Session Management Function (SMF) [108] is a 5G core network function responsible for managing session-related aspects, such as establishing, modifying, and releasing sessions. It coordinates with the User Plane Function (UPF) for data forwarding and handles IP address allocation and QoS enforcement.
10
[0046] Service Communication Proxy (SCP) [110] is a network function in the 5G core network that facilitates communication between other network functions by providing a secure and efficient messaging service. It acts as a mediator for service-based interfaces.
15
[0047] Authentication Server Function (AUSF) [112] is a network function in the 5G core responsible for authenticating UEs during registration and providing security services. It generates and verifies authentication vectors and tokens.
20 [0048] Network Slice Specific Authentication and Authorization Function
(NSSAAF) [114] is a network function that provides authentication and authorization services specific to network slices. It ensures that UEs can access only the slices for which they are authorized.
25 [0049] Network Slice Selection Function (NSSF) [116] is a network function
responsible for selecting the appropriate network slice for a UE based on factors such as subscription, requested services, and network policies.
[0050] Network Exposure Function (NEF) [118] is a network function that
30 exposes capabilities and services of the 5G network to external applications,
enabling integration with third-party services and applications.
13

[0051] Network Repository Function (NRF) [120] is a network function that acts as a central repository for information about available network functions and services. It facilitates the discovery and dynamic registration of network functions. 5
[0052] Policy Control Function (PCF) [122] is a network function responsible for policy control decisions, such as QoS, charging, and access control, based on subscriber information and network policies.
10 [0053] Unified Data Management (UDM) [124] is a network function that
centralizes the management of subscriber data, including authentication, authorization, and subscription information.
[0054] Application Function (AF) [126] is a network function that represents
15 external applications interfacing with the 5G core network to access network
capabilities and services.
[0055] User Plane Function (UPF) [128] is a network function responsible for
handling user data traffic, including packet routing, forwarding, and QoS
20 enforcement.
[0056] Data Network (DN) [130] refers to a network that provides data services to user equipment (UE) in a telecommunications system. The data services may include but are not limited to Internet services, private data network related services.
25
[0057] FIG. 2 illustrates an exemplary block diagram of a computing device [200] upon which the features of the present disclosure may be implemented in accordance with exemplary implementation of the present disclosure. In an implementation, the computing device [200] may also implement a method for
30 concurrently managing subscription notifications on one or more Network
Functions (NFs), utilising the system. In another implementation, the computing
14

device [200] itself implements the method for concurrently managing subscription notifications on one or more Network Functions (NFs), using one or more units configured within the computing device [200], wherein said one or more units are capable of implementing the features as disclosed in the present disclosure. 5
[0058] The computing device [200] may include a bus [202] or other communication mechanism for communicating information, and a hardware processor [204] coupled with bus [202] for processing information. The hardware processor [204] may be, for example, a general-purpose microprocessor. The
10 computing device [200] may also include a main memory [206], such as a random-
access memory (RAM), or other dynamic storage device, coupled to the bus [202] for storing information and instructions to be executed by the processor [204]. The main memory [206] also may be used for storing temporary variables or other intermediate information during execution of the instructions to be executed by the
15 processor [204]. Such instructions, when stored in non-transitory storage media
accessible to the processor [204], render the computing device [200] into a special-purpose machine that is customized to perform the operations specified in the instructions. The computing device [200] further includes a read only memory (ROM) [208] or other static storage device coupled to the bus [202] for storing static
20 information and instructions for the processor [204].
[0059] A storage device [210], such as a magnetic disk, optical disk, or solid-state drive is provided and coupled to the bus [202] for storing information and instructions. The computing device [200] may be coupled via the bus [202] to a
25 display [212], such as a cathode ray tube (CRT), Liquid crystal Display (LCD),
Light Emitting Diode (LED) display, Organic LED (OLED) display, etc. for displaying information to a computer user. An input device [214], including alphanumeric and other keys, touch screen input means, etc. may be coupled to the bus [202] for communicating information and command selections to the processor
30 [204]. Another type of user input device may be a cursor controller [216], such as a
mouse, a trackball, or cursor direction keys, for communicating direction
15

information and command selections to the processor [204], and for controlling cursor movement on the display [212]. This input device typically has two degrees of freedom in two axes, a first axis (e.g., x) and a second axis (e.g., y), that allow the device to specify positions in a plane. 5
[0060] The computing device [200] may implement the techniques described herein using customized hard-wired logic, one or more ASICs or FPGAs, firmware and/or program logic which in combination with the computing device [200] causes or programs the computing device [200] to be a special-purpose machine.
10 According to one implementation, the techniques herein are performed by the
computing device [200] in response to the processor [204] executing one or more sequences of one or more instructions contained in the main memory [206]. Such instructions may be read into the main memory [206] from another storage medium, such as the storage device [210]. Execution of the sequences of instructions
15 contained in the main memory [206] causes the processor [204] to perform the
process steps described herein. In alternative implementations of the present disclosure, hard-wired circuitry may be used in place of or in combination with software instructions.
20 [0061] The computing device [200] also may include a communication interface
[218] coupled to the bus [202]. The communication interface [218] provides a two-way data communication coupling to a network link [220] that is connected to a local network [222]. For example, the communication interface [218] may be an integrated services digital network (ISDN) card, cable modem, satellite modem, or
25 a modem to provide a data communication connection to a corresponding type of
telephone line. As another example, the communication interface [218] may be a local area network (LAN) card to provide a data communication connection to a compatible LAN. Wireless links may also be implemented. In any such implementation, the communication interface [218] sends and receives electrical,
30 electromagnetic or optical signals that carry digital data streams representing
various types of information.
16

[0062] The computing device [200] can send messages and receive data, including
program code, through the network(s), the network link [220] and the
communication interface [218]. In the Internet example, a server [230] might
5 transmit a requested code for an application program through the Internet [228], the
ISP [226], the local network [222], the host [224] and the communication interface [218]. The received code may be executed by the processor [204] as it is received, and/or stored in the storage device [210], or other non-volatile storage for later execution.
10 [0063] Referring to FIG. 3, an exemplary block diagram of a system [300] for
concurrently managing subscription notifications on one or more Network Functions (NFs), in accordance with the exemplary implementations of the present disclosure, is shown. In one example, such NF may be implemented as a Policy Control Function (PCF). Such PCF has been explained in conjunction with FIG. 1,
15 as PCF [122]. The same explanation has not been repeated here for the sake of
brevity. In another example, the NF may be implemented as any other Network Function as well, such as the AMF [106], the SMF [108], the SCP [110], the AUSF [112], the NSSAAF [114], the NSSF [116], the NEF [118], the UDM [124], the AF [126] and the UPF [128]. The corresponding explanation of all these components
20 have been explained in conjunction with FIG. 1.
[0064] In one example, the system [300] may be in communication with other network entities/components known to a person skilled in the art. Such network entities/components have not been depicted in FIG. 3 and have not been explained here for the sake of brevity.
25 [0065] Further, FIG. 4 illustrates an exemplary signalling call flow diagram for
concurrently managing subscription notifications on one or more Network Functions (NFs), in accordance with exemplary implementations of the present disclosure.
17

[0066] It may be noted that FIG. 3 and FIG. 4 have been explained simultaneously and may be read in conjunction with each other.
[0067] As depicted in FIG 3, the system [300] comprises at least one processing
unit [302],at least one transceiver unit [304] and at least one storage unit [306]. In
5 one example, the system [300] may be implemented as a Network Function (NF),
referred to as first Network Function (NF). In such cases, the various
aforementioned units, as shown in FIG. 3, may be a part of the first Network
Function (NF). In another example, the system [300] may be implemented within a
Network Function (NF). In such cases, various aforementioned units may be a part
10 of the system [300] and the system [300] may be in communication with various
other components of the Network Function (NF).
[0068] In yet another example, as depicted in FIG. 3, the system [300] may include
a Network Function (NF), referred to as the first Network Function (NF) [300A],
along with other components in communication with the first NF [300A] (not
15 depicted in FIG. 3). In such cases, as depicted in FIG 3, the various units may be a
part of the first Network Function [300A].
[0069] Continuing further, also, all of the components/ units of the system [300] are assumed to be connected to each other unless otherwise indicated below. As shown in FIG. 3, all units shown within the system [300] should also be assumed
20 to be connected to each other. Also, in FIG. 3, only a few units are shown, however,
the system [300] may comprise multiple such units or the system [300] may comprise any such numbers of said units, as required to implement the features of the present disclosure. Further, in an implementation, the system [300] may be present in a user device/ user equipment [102] to implement the features of the
25 present disclosure.
[0070] The system [300] is configured for concurrently managing subscription notifications on one or more Network Functions (NFs), with the help of the interconnection between the components/units of the system [300].
18

[0071] In an implementation of the present disclosure, the concurrent management
of subscription notification refers to managing notifications related to subscriptions
across several network functions at once. The Network Function (NF) is a
5 component within a network that performs specific tasks, such as handling calls,
managing data sessions, or maintaining connectivity.
[0072] In one example, a Network Function (NF), referred to as Second Network
Function (NF) [300B] in the context of the present application, may be
10 communicating with and undergoing a process of subscribing with the Network
Repository Function (NRF) [120].
[0073] In one example, the second NF may be an active Policy Control Function (PCF). As would be understood, an active NF, such as an active PCF, may refer to
15 a network function that is currently operational, registered, and actively providing
its services within the 5G Core (5GC) network. The active NF, second NF [300B] in the context of the present example, is the primary unit responsible for making real time policy decisions within the network. It manages and applies rules related to resource allocation, quality of service, and other critical network policies for
20 users and services.
[0074] The Network Repository Function (NRF) is a function within the network
that stores and retrieves network functions related information, such as NF Profile
comprising, but not limited to, identity information, network addresses, network
25 capacity, and offered services.
[0075] As would be understood, a Network Function (NF), e.g. a Policy Control
Function (PCF), may subscribe with the NRF to receive notifications about specific
events (registration, deregistration, profile change) related to target NF instance
30 located in the network or changes in status (such as location updates, changes in
access authorization, roaming status, etc.). When an event or change occurs, all the
19

subscribed NFs may be notified about the event or change. This may ensure that all relevant parts of the network are updated and can take appropriate actions in a timely manner.
5 [0076] In the context of the present example, i.e., in cases where the NF is a PCF,
when there is an event in a network or a change in the status of the network function, the PCF may need to adjust the policy rules that dictate how the different aspects of the network would be operating.
10 [0077] Continuing further, the second NF [300B], for subscribing with the NRF
[120], may transmit a subscription request to the NRF [120]. This has been depicted as Step 402 in FIG. 4
[0078] The subscription request is a message sent by the second Network Function
15 (NF) [300B] to the Network Repository Function (NRF) [120] to establish, update,
or manage a subscription of the second NF [300B] with the NRF [120] within the network. In one example, the subscription request may include the type of subscription being requested, such as notifications for specific events or a specific type of change in the target network function instance. 20
[0079] In another example, the subscription request may also include additional
parameters, such as a list of network attributes in the target NF’s NF Profile to be
monitored (or to be excluded from monitoring), in order to determine whether a
notification from the NRF should be sent, or not, when there is any change in said
25 attributes of the target network function’s NF Profile.
[0080] In an exemplary of the present invention, the subscription request
(NFStatusSubscribe service operation) is sent by consumer network function
(herein PCF) to create a subscription resource at the NRF, where the subscription
30 request bodymay include ‘SubscriptionData’ data object. Further, the
‘SubscriptionData’ object includes attributes such as, but not limited to,
20

‘subscrCond’ containing conditions identifying set of NF instances whose status is requested to be monitored. If this attribute is not present, it means that the NF Service Consumer requests a subscription to all NFs in the NRF
5 [0081] In an implementation, the subscription request ‘SubscriptionData’ may
include attribute name ‘plmnId’ which contains the target PLMN ID of the NF Instance(s) whose status is requested to be monitored.
[0082] In an implementation, the subscription request may include attribute name
10 ‘nrfSupportedFeatures’ which refers, to features supported by the NRF in the
Nnrf_NFManagement service.
[0083] In yet another, the subscription request may also include subscriber
information, which identifies associated with the network function, or service
15 associated with the subscription. The request may also specify event triggers, which
are the conditions under which the NRF should notify the NF. These triggers could be related to network state changes, policy updates, or resource availability.
[0084] On receiving the subscription request from the second NF [300B], the NRF
20 [120] processes this request and sends back a subscription response to the second
NF [300B]. This has been depicted as Step 404 in FIG. 4. The subscription response
may refer to a message or outcome that is sent from the NRF, back to the second
NF [300B] after said second NF has made the subscription request. Such
subscription response contains essential information, including a subscription
25 identity information, which uniquely identifies the subscription within the network.
[0085] In an exemplary of the present invention, the subscription response comprises data related to the created subscription returned in ‘SubscriptionData’ object. 30
21

[0086] In an implementation, the subscription response may include attribute name ‘subscriptionId’ which contain the subscription ID for the newly created resource.
[0087] In an implementation, the subscription response may include attribute name
5 ‘validityTime’ which refers time instant after which the subscription becomes
invalid. This parameter may be sent by the client, as a hint to the server, but it shall be always sent back by the server (regardless of the presence of the attribute in the request) in the response to the subscription creation request.
10 [0088] In one example, upon receiving the subscription identity information, the
first NF [300A] stores the information in the storage unit [306].
[0089] In operation, as per approaches of the present subject matter, the transceiver unit [304] of the first NF [300A] may receive a data corresponding to the
15 subscription request. This process may be referred to as ‘Data Replication’, and has
been indicated by Step 406 in FIG. 4. In one example, the first Network Function (NF) [300A] may be a spare Policy Control Function (PCF). A "spare NF" acts as a backup unit, which can take over functions if a primary NF, i.e., the second NF [300B] in the context of the present invention, fails or if there is a need for
20 additional capacity.
[0090] As described previously, said subscription request may be transmitted by
the second NF [300B] to the NRF [120] during a process of subscribing with the
NRF [120]. It may be noted that such data, received from the second NF [300B],
25 may allow the first NF [300A] to determine what information or events the second
NF [300B] was monitoring, the conditions under which the second NF [300B] was requesting the notifications from the NRF [120], the manner in which the information was requested by the second NF [300B] from the NRF, etc.
30 [0091] Continuing further, it may happen that there may be an intermittent
connectivity failure between the second NF [300B] and the first NF [300A]. In the
22

event of intermitted connectivity failure, the spare NF, i.e., the first NF [300A] to become active. This has been depicted by Step 408 in FIG. 4.
[0092] In an implementation of the present disclosure, the intermittent connectivity
5 failure refers to a temporary disruption in the communication link between the two
NFs. In another implementation, the intermittent connectivity failure between the two NFs may occur when the replication channel fails. If such a failure occurs, the transceiver unit [304] within the first NF [300A] (which is the spare NF) is configured to transmit a new subscription request to the NRF. This has been
10 depicted by Step 410 in FIG. 4. The new subscription request may be used for
subscribing the first NF [300A] with the NRF [120]. This action confirms that the subscription information of the NF, PCF in the context of the present example, remains up-to-date, so that the PCF can implement policies accordingly and the network can continue to function correctly despite the connectivity issues. The new
15 subscription request is based on the data received from the second NF [300B],
thereby ensuring that the first NF [300A] accurately replicates the second NF [300B].
[0093] In response, on receiving the new subscription request from the first NF
20 [300A], the NRF [120] processes this new request similarly, sending back a
subscription response to the now-active spare NF, i.e., the first NF [300A] again including the necessary subscription identity information and related information. This has been depicted by Step 412 in FIG. 4.
25 [0094] Continuing further, during such process of intermittent connectivity failure
between the second NF and the first NF, it may be possible that the connectivity between the first NF and the second NF may resume subsequently. As a result, the second NF may also being active, without being aware of the fact that the network has also activated spare NF, i.e., the first NF [300A]. As a result, ‘Split-brain
30 condition’ may occur in the network. As would be understood, ‘split-brain
condition’ may refer to a scenario where the network detects that the active NF, i.e.,
23

the second NF [300B] is no longer the only active instance, and multiple instances, such as second NF and the first NF, are now active.
[0095] Continuing further, when there are changes in the subscribed request, the
5 NRF [120] may transmit a subscription notification to the first NF [300A], as well
as concurrently transmits the subscription notification to the second NF [300B]. This has been depicted by Step 414 in FIG. 4.
[0096] In one example, the subscription notification may include certain
10 notification data (NotificationData), such as ‘event’ which refers to notification
type. It may take the values "NF_REGISTERED", "NF_DEREGISTERED" or "NF_PROFILE_CHANGED".
[0097] In an example, the subscription notification may include ‘nfInstanceURI’
15 which refers to Uri of the NF Instance associated to the notification event.
[0098] In an example, the subscription notification may include ‘nfProfile’ refers
to New NF Profile or Updated NF Profile; it shall be present when the notification
type is "NF_REGISTERED" and it may be present when the notification type is
20 "NF_PROFILE_CHANGED"
[0099] In an example, the subscription notification may include ‘profileChanges’
refers to list of changes on the profile of the NF Instance associated to the
notification event; it may be present when the notification type is
25 "NF_PROFILE_CHANGED".
[0100] In an example, the subscription notification may include ‘conditionEvent’
refers to the type of event indicating whether a change of NF Profile results in that
the NF Instance starts or stops being part of a given set of NF Instances, as indicated
30 in the subscription condition. It can take the value "NF_ADDED" (if the NF
24

Instance starts being part of a given set) or "NF_REMOVED" (if the NF Instance stops being part of a given set).
[0101] As would be noted and appreciated, this ensures that both NFs are
5 synchronized with the latest subscription information, maintaining consistency
across the network functions. This dual communication from the NRF is essential for confirming that both NFs are up-to-date and can manage network policies effectively, even in cases of failover or redundancy scenarios.
10 [0102] In an example, this is important in conditions where the NFs need to manage
subscription notifications concurrently, even if connectivity between them is unstable.
[0103] Referring to FIG. 5, an exemplary method flow diagram [500] for
15 concurrently managing subscription notifications on one or more Network
Functions (NFs), in accordance with exemplary implementations of the present
disclosure is shown. In an implementation the method [500] is performed by the
system [300]. Further, in an implementation, the system [300] may be present in a
server device to implement the features of the present disclosure. Also, as shown in
20 FIG. 4, the method [500] starts at step [502].
[0104] At step [504], the method [500] comprises receiving, by a transceiver unit
[304] at a first Network Function (NF) [300A], a data corresponding to a
subscription request, wherein the subscription request is transmitted by a second
25 NF to a Network Repository Function (NRF) during a process of subscribing with
the NRF.
[0105] In one example, a Network Function (NF), referred to as Second Network
Function (NF) [300B] in the context of the present application, may be
30 communicating with and undergoing a process of subscribing with the Network
Repository Function (NRF) [120]. In one example, the second NF may be an active
25

Policy Control Function (PCF). As would be understood, an active NF, such as an active PCF, may refer to a network function that is currently operational, registered, and actively providing its services within the 5G Core (5GC) network.
5 [0106] As would be understood, a Network Function (NF), e.g. a Policy Control
Function (PCF), may subscribe with the NRF to receive notifications about specific
events (registration, deregistration, profile change) related to target NF instance
located in the network or changes in status (such as location updates, changes in
access authorization, roaming status, etc.). When an event or change occurs, all the
10 subscribed NFs may be notified about the event or change. This may ensure that all
relevant parts of the network are updated and can take appropriate actions in a timely manner.
[0107] Continuing further, the second NF [300B], for subscribing with the NRF
15 [120], may transmit a subscription request to the NRF [120].
[0108] The subscription request is a message sent by the second Network Function
(NF) [300B] to the Network Repository Function (NRF) [120] to establish, update,
or manage a subscription of the second NF [300B] with the NRF [120] within the
20 network. In one example, the subscription request may include the type of
subscription being requested, such as notifications for specific events or a specific type of change in the target network function instance .
[0109] On receiving the subscription request from the second NF [300B], the NRF
25 [120] processes this request and sends back a subscription response to the second
NF [300B]. The subscription response may refer to a message or outcome that is sent from the NRF, back to the second NF [300B] after said second NF has made the subscription request.
30 [0110] In one example, upon receiving the subscription identity information, the
first NF [300A] stores the information in the storage unit [306].
26

[0111] In operation, as per approaches of the present subject matter, the transceiver
unit [304] of the first NF [300A] may receive a data corresponding to the
subscription request. This process may be referred to as ‘Data Replication’. In one
5 example, the first Network Function (NF) [300A] may be a spare Policy Control
Function (PCF).
[0112] As described previously, said subscription request may be transmitted by the second NF [300B] to the NRF [120] during a process of subscribing with the
10 NRF [120]. It may be noted that such data, received from the second NF [300B],
may allow the first NF [300A] to determine what information or events the second NF [300B] was monitoring, the conditions under which the second NF [300B] was requesting the notifications from the NRF [120], the manner in which the information was requested by the second NF [300B] from the NRF, etc.
15
[0113] At step [506], the method [500] comprises transmitting [506], by a transceiver unit [304] at the first NF [300A], a new subscription request to the NRF in an event of an intermittent connectivity failure between the first NF and the second NF, wherein the new subscription request is used for subscribing the first
20 NF with the NRF.
[0114] Continuing further, it may happen that there may be an intermittent
connectivity failure between the second NF [300B] and the first NF [300A]. In the
event of intermitted connectivity failure, the spare NF, i.e., the first NF [300A] to
25 become active. This has been depicted by Step 408 in FIG. 4.
[0115] In an implementation of the present disclosure, the intermittent connectivity
failure refers to a temporary disruption in the communication link between the two
NFs. In another implementation, the intermittent connectivity failure between the
30 two NFs may occur when the replication channel fails. If such a failure occurs, the
transceiver unit [304] within the first NF [300A] (which is the spare NF) is
27

configured to transmit a new subscription request to the NRF. The new subscription request may be used for subscribing the first NF [300A] with the NRF [120]. This action confirms that the subscription information of the NF, PCF in the context of the present example, remains up-to-date, so that the PCF can implement policies accordingly and the network can continue to function correctly despite the connectivity issues. The new subscription request is based on the data received from the second NF [300B], thereby ensuring that the first NF [300A] accurately replicates the second NF [300B].
[0116] In response, on receiving the new subscription request from the first NF [300A], the NRF [120] processes this new request similarly, sending back a subscription response to the now-active spare NF, i.e., the first NF [300A] again including the necessary subscription identity information and related information.
[0117] At block [508], the method [500] comprises receiving, by the transceiver unit [304] at the first NF [300A], a subscription notification from the NRF, while the NRF concurrently transmits a subscription notification to the second NF.
[0118] Continuing further, during such process of intermittent connectivity failure between the second NF and the first NF, it may be possible that the connectivity between the first NF and the second NF may resume subsequently. As a result, the second NF may also being active, without being aware of the fact that the network has also activated spare NF, i.e., the first NF [300A]. As a result, ‘Split-brain condition’ may occur in the network. As would be understood, ‘split-brain condition’ may refer to a scenario where the network detects that the active NF, i.e., the second NF [300B] is no longer the only active instance, and multiple instances, such as second NF and the first NF, are now active.
[0119] Continuing further, when there are changes in the subscribed request, the NRF [120] may transmit a subscription notification to the first NF [300A], as well as concurrently transmits the subscription notification to the second NF [300B].

[0120] This ensures that both NFs are synchronized with the latest subscription information, maintaining consistency across the network functions. This dual communication from the NRF is essential for confirming that both NFs are up-to-date and can manage network policies effectively, even in cases of failover or redundancy scenarios.
[0121] Thereafter, the method terminates at step [510].
[0122] The present disclosure further discloses a non-transitory computer readable storage medium storing instructions for concurrently managing subscription notifications on one or more Network Functions (NFs). The instructions include executable code which, when executed by one or more units of a system, causes a transceiver unit, at a first NF, of the system to receive a data corresponding to a subscription request, wherein the subscription request is transmitted by a second NF to a Network Repository Function (NRF) during a process of subscribing with the NRF. Further, the instructions include executable code which, when executed, causes the transceiver unit, at the first NF, to transmit, to in an event of an intermittent connectivity failure between the second NF and the first NF, a new subscription request to the NRF, wherein the new subscription request is used for subscribing the first NF with the NRF. Further, the instructions include executable code which, when executed, causes the transceiver, at the first NF, to receive a subscription notification from the NRF, while the NRF concurrently transmits a subscription notification to the second NF.
[0123] As is evident from the above, the present disclosure provides a technically advanced solution for concurrently managing subscription notifications on one or more Network Functions (NFs). The present solution many technical advantages, some of the advantages are as follows:

[0124] The present solution efficiently manages network call flows landing on both primary Active instance PCF and Spare Active instance PCF. The present solution prevents network congestion/outages and smoothens the overall network experience for the end user. The present solution avoid re-attachment to only Spare Active instance PCF as service request is processed on both primary active instance PCF and spare active instance PCF site.
[0125] While considerable emphasis has been placed herein on the disclosed implementations, it will be appreciated that many implementations can be made and that many changes can be made to the implementations without departing from the principles of the present disclosure. These and other changes in the implementations of the present disclosure will be apparent to those skilled in the art, whereby it is to be understood that the foregoing descriptive matter to be implemented is illustrative and non-limiting.
[0126] Further, in accordance with the present disclosure, it is to be acknowledged that the functionality described for the various components/units can be implemented interchangeably. While specific embodiments may disclose a particular functionality of these units for clarity, it is recognized that various configurations and combinations thereof are within the scope of the disclosure. The functionality of specific units as disclosed in the disclosure should not be construed as limiting the scope of the present disclosure. Consequently, alternative arrangements and substitutions of units, provided they achieve the intended functionality described herein, are considered to be encompassed within the scope of the present disclosure.

We Claim:
1. A method [500] for concurrently managing subscription notifications on one
or more Network Functions (NFs), the method [500] comprising:
- receiving [504], by a transceiver unit [304] at a first Network Function (NF) [300A], a data corresponding to a subscription request, wherein the subscription request is transmitted by a second NF [300B] to a Network Repository Function (NRF) during a process of subscribing with the NRF;
- in an event of an intermittent connectivity failure between the first NF [300A] and the second NF [300B], transmitting [506], by a transceiver unit [304] at the first NF [300A], a new subscription request to the NRF, wherein the new subscription request is used for subscribing the first NF [300A] with the NRF; and
- receiving [508], by the transceiver unit [304] at the first NF [300A], a subscription notification from the NRF, while the NRF concurrently transmits a subscription notification to the second NF [300B].

2. The method [500] as claimed in claim 1, wherein the first Network Function (NF) is a spare Policy Control Function (PCF).
3. The method [500] as claimed in claim 1, wherein the second Network Function (NF) is an active Policy Control Function (PCF).
4. The method [500] as claimed in claim 1, wherein the process of subscribing the second NF with the NRF comprises:

- transmitting, by the second NF, the subscription request to the NRF; and
- receiving, by the second NF from the NRF, a subscription response corresponding to the subscription request, wherein the subscription response comprises a subscription identity information.

5. The method [500] as claimed in claim 1, wherein the new subscription request is based on the data received from the second NF.
6. The method [500] as claimed in claim 1, wherein pursuant to transmitting [506], by the transceiver unit [304] at the first NF [300A], the new subscription request to the NRF, the method [500] further comprises:
- receiving, by the transceiver unit [304] at the first NF [300A], a
subscription response, wherein the subscription response comprises a
subscription identity information associated with the new subscription
request.
7. A system [300] for concurrently managing subscription notifications on one
or more Network Functions (NFs), the system [300] comprising a first Network
Function (NF) [300A], the first NF [300A] comprising:
- a processing unit [302];
- a transceiver unit [304] connected to at least the processing unit [302], wherein the transceiver unit [304] is configured to:
o receive a data corresponding to a subscription request, wherein the subscription request is transmitted by a second NF to a Network Repository Function (NRF) during a process of subscribing with the NRF;
o in an event of an intermittent connectivity failure between the first NF and the second NF, transmit a new subscription request to the NRF, wherein the new subscription request is used for subscribing the first NF with the NRF; and
o receive a subscription notification from the NRF, while the NRF concurrently transmits a subscription notification to the second NF.
8. The system [300] as claimed in claim 7, wherein the first Network Function
(NF) is a spare Policy Control Function (PCF).

9. The system [300] as claimed in claim 7, wherein the second Network Function (NF) is an active Policy Control Function (PCF).
10. The system [300] as claimed in claim 7, wherein the process of subscribing the second NF with the NRF comprises:

- transmitting, by the second NF, the subscription request to the NRF; and
- receiving, by the second NF from the NRF, a subscription response corresponding to the subscription request, wherein the subscription response comprises a subscription identity information.

11. The system [300] as claimed in claim 7, wherein the new subscription request is based on the data received from the second NF.
12. The system [300] as claimed in claim 7, wherein pursuant to transmitting the new subscription request to the NRF, the transceiver unit [304], at the first NF [300A], is further configured to:
- receive a subscription response, wherein the subscription response
comprises a subscription identity information associated with the new
subscription request.