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 AUTOMATICALLY FETCHING A SLICE AUTHORISATION DATA AT AMF OF A
NETWORK”
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 AUTOMATICALLY FETCHING A SLICE AUTHORISATION DATA AT AMF OF A NETWORK
FIELD OF INVENTION
[0001] Embodiments of the present disclosure generally relate to wireless communication systems. More particularly, embodiments of the present disclosure relate to approaches for automatically fetching a slice authorisation data at an Access and Mobility Management Function (AMF) of a network.
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] In the context of 5G network management, a significant challenge arises concerning AMF (Access and Mobility Management Function) slice availability data authorisation from NSSF (Network Slice Selection Function). The issue centers around instances where the AMF is initiated before the NSSF, causing a lack of synchronization in slice authorisation processes. This asymmetry necessitates manual intervention to establish proper authorisation. Operators are compelled to resort to command-line interface (CLI) commands or the restart of the AMF after NSSF initialization. This situation underscores the need for streamlined coordination between these network components to ensure seamless slice availability and data authorisation within the 5G infrastructure.

[0004] Thus, there exists an imperative need in the art to automatically fetch a slice authorisation data by an AMF upon detecting negative response at the startup, which the present disclosure aims to address.
SUMMARY
[0005] 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.
[0006] An aspect of the present disclosure may relate to a method for automatically fetching a slice authorisation data at an Access and Mobility Management Function (AMF) of a network. The method comprises transmitting, by a transceiver unit, a first slice availability authorisation request to a Network Slicing Selection Function (NSSF). The method further comprises receiving, by the transceiver unit, a negative response associated with the first slice availability authorisation request from the NSSF. Furthermore, the method comprises initiating, by a processing unit, a timer based on the negative response, wherein the timer is a dynamically configurable timer. The method further comprises detecting, by a detection unit, a timer expiry associated with the timer. Further, the method comprises transmitting, by the transceiver unit, a second slice availability authorisation request to the NSSF, based on the timer expiry. The method further comprises automatically fetching, by the processing unit, the slice authorisation data based on the second slice availability authorisation request from the NSSF.
[0007] In an exemplary aspect of the present disclosure, the method further comprises fetching, by the transceiver unit, at least a slice availability data based on the first slice availability authorisation request, wherein the slice availability data is fetched in response to detection of a startup event associated with the AMF.

[0008] In an exemplary aspect of the present disclosure, the negative response is received at the AMF from the NSSF in an event of a failed slice authorisation.
[0009] In an exemplary aspect of the present disclosure, the timer is configured based on one of a pre-defined time period or a dynamically defined time period.
[0010] In an exemplary aspect of the present disclosure, the timer expiry is detected at the AMF in an event a time period completion status associated with the timer is detected.
[0011] In an exemplary aspect of the present disclosure, the timer is re-initiated each time a negative response is received from the NSSF.
[0012] Another aspect of the present disclosure may relate to a system for automatically fetching a slice authorisation data at an Access and Mobility Management Function (AMF) of a network. The system comprises a transceiver unit. The transceiver unit is configured to transmit a first slice availability authorisation request to a Network Slicing Selection Function (NSSF). The transceiver unit is further configured to receive, a negative response associated with the first slice availability authorisation request from the NSSF. The system further comprises a processing unit connected to at least the transceiver unit. The processing unit is configured to initiate a timer based on the negative response. The timer is a dynamically configurable timer. The processing unit is further configured to detect a timer expiry associated with the timer. The transceiver unit is further configured to transmit a second slice availability authorisation request based on the timer expiry to NSSF. Furthermore, the transceiver unit is configured to automatically fetch the slice authorisation data based on the second slice availability authorisation request.
[0013] Yet another aspect of the present disclosure may relate to a non-transitory computer readable storage medium storing instructions for automatically fetching

a slice authorisation data at an Access and Mobility Management Function (AMF) of a network. The instructions include executable code which, when executed by one or more units of a system causes a transceiver unit of the system to transmit a first slice availability authorisation request to a Network Slicing Selection Function (NSSF). Further, the instructions include executable code which, when executed, causes the transceiver unit to receive a negative response associated with the first slice availability authorisation request from the NSSF. Further, the instructions include executable code which, when executed, causes a processing unit to initiate a timer based on the negative response. The timer is a dynamically configurable timer. Further, the instructions include executable code which, when executed, causes a detection unit to detect a timer expiry associated with the timer. Further, the instructions include executable code which, when executed, cause the transceiver unit to transmit a second slice availability authorisation request to the NSSF, based on the timer expiry. Further, the instructions include executable code which, when executed, causes the processing unit to automatically fetch the slice authorisation data based on the second slice availability authorisation request from the NSSF.
OBJECTS OF THE INVENTION
[0014] Some of the objects of the present disclosure, which at least one embodiment disclosed herein satisfies are listed herein below.
[0015] It is an object of the present disclosure to provide a system and a method for automatically fetching a slice authorisation data by an AMF.
[0016] It is another object of the present disclosure to provide a solution that enables the AMF to get authorisation data from NSSF for slice availability data without manual intervention even if AMF starts first and NSSF later to it.

[0017] It is yet another object of the present disclosure to provide a solution that detects a timer expiry associated with the timer and transmits from the Access and Mobility Management Function (AMF) to a Network Slicing Selection Function (NSSF), a second slice availability authorisation request based on detecting the timer expiry.
DESCRIPTION OF THE DRAWINGS
[0018] 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.
[0019] FIG. 1 illustrates an exemplary block diagram representation of 5th generation core (5GC) network architecture;
[0020] 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 an exemplary implementation of the present disclosure;
[0021] FIG. 3 illustrates an exemplary block diagram of a system for automatically fetching a slice authorisation data at an Access and Mobility Management Function (AMF) of a network, in accordance with an exemplary implementation of the present disclosure;

[0022] FIG. 4 illustrates an exemplary call flow diagram for automatically fetching a slice authorisation data at an Access and Mobility Management Function (AMF) of a network, in accordance with an exemplary implementation of the present subject matter; and
[0023] FIG. 5 illustrates a method flow diagram for automatically fetching a slice authorisation data at an Access and Mobility Management Function (AMF) of a network, in accordance with an exemplary implementation of the present disclosure.
[0024] The foregoing shall be more apparent from the following more detailed description of the disclosure.
DETAILED DESCRIPTION
[0025] 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.
[0026] 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. 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.
[0027] Specific details are given in the following description to provide a thorough 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.
[0028] 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 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.
[0029] The word “exemplary” and/or “demonstrative” is used herein to mean 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 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 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.

[0030] 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
5 of microprocessors, one or more microprocessors in association with a (Digital
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
10 the system according to the present disclosure. More specifically, the processor or
processing unit is a hardware processor.
[0031] 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”,
15 “a wireless communication device”, “a mobile communication device”, “a
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,
20 tablet computer, wearable device or any other computing device which is capable
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 at least one of a transceiver unit, a processing unit, a storage unit, a detection unit and any other such unit(s) which are required to implement the features of the present disclosure.
25
[0032] As used herein, “storage unit” or “memory unit” refers to a machine or computer-readable medium including any mechanism for storing information in a form readable by a computer or similar machine. For example, a computer-readable medium includes read-only memory (“ROM”), random access memory (“RAM”),
30 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
9

that may be required by one or more units of the system to perform their respective functions.
[0033] As used herein “interface” or “user interface” refers to a shared boundary
5 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 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.
10
[0034] All modules, units, components used herein, unless explicitly excluded 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
15 microprocessors in association with a DSP core, a controller, a microcontroller,
Application Specific Integrated Circuits (ASIC), Field Programmable Gate Array circuits (FPGA), any other type of integrated circuits, etc.
[0035] As used herein the transceiver unit include at least one receiver and at least
20 one transmitter configured respectively for receiving and transmitting data, signals,
information or a combination thereof between units/components within the system and/or connected with the system.
[0036] As discussed in the background section, the current known solutions have
25 several shortcomings. When the AMF is initiated before the NSSF, there is a lack
of synchronization in slice authorisation processes. This asymmetry necessitates
manual intervention to establish proper authorisation. Operators are compelled to
resort to command-line interface (CLI) commands or the restart of the AMF after
NSSF initialization. This situation underscores the need for streamlined
30 coordination between these network components to ensure seamless slice
availability and data authorisation within the 5G infrastructure.
10

[0037] The present disclosure aims to overcome the above-mentioned and other
existing problems in this field of technology by providing method and system for
automatically fetching a slice authorisation data at an Access and Mobility
5 Management Function (AMF) of a network.
[0038] 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
10 architecture [100] includes a user equipment (UE) [102], a radio access network
(RAN) [104], an access and mobility management function (AMF) [106], a Session Management Function (SMF) [108], a Service Communication Proxy (SCP) [110], an Authentication Server Function (AUSF) [112], a Network Slice Specific Authentication and Authorisation Function (NSSAAF) [114], a Network Slice
15 Selection Function (NSSF) [116], a Network Exposure Function (NEF) [118], a
Network Repository Function (NRF) [120], a Policy Control Function (PCF) [122], 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
20 the person skilled in the art for implementing features of the present disclosure.
[0039] 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).
25 It consists of radio base stations and the radio access technologies that enable
wireless communication.
[0040] Access and Mobility Management Function (AMF) [106] is a 5G core
network function responsible for managing access and mobility aspects, such as UE
30 registration, connection, and reachability. It also handles mobility management
procedures like handovers and paging.
11

[0041] 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
5 forwarding and handles IP address allocation and QoS enforcement.
[0042] 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
10 service-based interfaces.
[0043] 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. 15
[0044] Network Slice Specific Authentication and Authorisation Function (NSSAAF) [114] is a network function that provides authentication and authorisation services specific to network slices. It ensures that UEs can access only the slices for which they are authorised. 20
[0045] 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.
25 [0046] Network Exposure Function (NEF) [118] is a network function that
exposes capabilities and services of the 5G network to external applications, enabling integration with third-party services and applications.
[0047] Network Repository Function (NRF) [120] is a network function that acts
30 as a central repository for information about available network functions and
services. It facilitates the discovery and dynamic registration of network functions.
12

[0048] 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. 5
[0049] Unified Data Management (UDM) [124] is a network function that centralizes the management of subscriber data, including authentication, authorisation, and subscription information.
10 [0050] Application Function (AF) [126] is a network function that represents
external applications interfacing with the 5G core network to access network capabilities and services.
[0051] User Plane Function (UPF) [128] is a network function responsible for
15 handling user data traffic, including packet routing, forwarding, and QoS
enforcement.
[0052] Data Network (DN) [130] refers to a network that provides data services
to user equipment (UE) in a telecommunications system. The data services may
20 include but are not limited to Internet services, private data network related services.
[0053] The 5GC network architecture also comprises a plurality of interfaces for connecting the network functions with a network entity for performing the network functions. The NSSF [116] is connected with the network entity via the interface
25 denoted as (Nnssf) interface in FIG. 1. The NEF [118] is connected with the
network entity via the interface denoted as (Nnef) interface in FIG. 1. The NRF [120] is connected with the network entity via the interface denoted as (Nnrf) interface in FIG. 1. The PCF [122] is connected with the network entity via the interface denoted as (Npcf) interface in FIG. 1. The UDM [124] is connected with
30 the network entity via the interface denoted as (Nudm) interface in FIG. 1. The AF
[126] is connected with the network entity via the interface denoted as (Naf)
13

interface in FIG. 1. The NSSAAF [114] is connected with the network entity via
the interface denoted as (Nnssaaf) interface in FIG. 1. The AUSF [112] is connected
with the network entity via the interface denoted as (Nausf) interface in FIG. 1. The
AMF [106] is connected with the network entity via the interface denoted as (Namf)
5 interface in FIG. 1. The SMF [108] is connected with the network entity via the
interface denoted as (Nsmf) interface in FIG. 1. The SMF [108] is connected with the UPF [128] via the interface denoted as (N4) interface in FIG. 1. The UPF [128] is connected with the RAN [104] via the interface denoted as (N3) interface in FIG. 1. The UPF [128] is connected with the DN [130] via the interface denoted as (N6)
10 interface in FIG. 1. The RAN [104] is connected with the AMF [106] via the
interface denoted as (N2). The AMF [106] is connected with the RAN [104] via the interface denoted as (N1). The UPF [128] is connected with other UPF [128] via the interface denoted as (N9). The interfaces such as Nnssf, Nnef, Nnrf, Npcf, Nudm, Naf, Nnssaaf, Nausf, Namf, Nsmf, N9, N6, N4, N3, N2, and N1 can be
15 referred to as a communication channel between one or more functions or modules
for enabling exchange of data or information between such functions or modules, and network entities.
[0054] FIG. 2 illustrates an exemplary block diagram of a computing device [200]
20 upon which the features of the present disclosure may be implemented in
accordance with an exemplary implementation of the present disclosure. In an
implementation, the computing device [200] may also implement a method for
automatically fetching a slice authorisation data at an Access and Mobility
Management Function (AMF) of a network, utilising a system. In another
25 implementation, the computing device [200] itself implements the method
automatically fetching a slice authorisation data at an Access and Mobility
Management Function (AMF) of a network, 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.
30
14

[0055] 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
5 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
10 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
15 information and instructions for the processor [204].
[0056] 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
20 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
25 [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 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
30 the device to specify positions in a plane.
15

[0057] 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.
5 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
10 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.
15 [0058] 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
20 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,
25 electromagnetic or optical signals that carry digital data streams representing
various types of information.
[0059] The computing device [200] can send messages and receive data, including
program code, through the network(s), the network link [220] and the
30 communication interface [218]. In the Internet example, a server [230] might
transmit a requested code for an application program through the Internet [228], the
16

ISP [226], the local network [222], a 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. 5
[0060] The present disclosure is implemented by a system [300] (as shown in FIG. 3). In an implementation, the system [300] may include the computing device [200] (as shown in FIG. 2). It is further noted that the computing device [200] is able to perform the steps of a method [500] (as shown in FIG. 5).
10
[0061] Referring to FIG. 3, an exemplary block diagram of a system [300] for automatically fetching a slice authorisation data at an Access and Mobility Management Function (AMF) of a network, in accordance with an exemplary implementation of the present disclosure, is shown. In one example, the system
15 [300] may be implemented as or within the Access and Mobility Management
Function (AMF). In another 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 explained here for the sake of brevity.
20
[0062] FIG. 4 illustrates an exemplary call flow diagram for automatically fetching a slice authorisation data at an Access and Mobility Management Function (AMF) of a network, in accordance with an exemplary implementation of the present subject matter.
25
[0063] It may be noted that FIG. 3 and FIG. 4 have been explained simultaneously and may be read in conjunction with each other.
[0064] As depicted in FIG. 3, the system [300] comprises at least one transceiver
30 unit [302], at least one processing unit [304], and at least one detection unit [306].
In cases where the system [300] is implemented as an Access and Mobility
17

Management Function (AMF), the various aforementioned units may be part of the AMF.
[0065] Continuing further, also, all of the components/ units of the system [300]
5 are assumed to be connected to each other unless otherwise indicated below. As
shown in FIG. 3, all units shown within the system should also be assumed 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
10 disclosure.
[0066] Further, in an implementation, the system [300] may be present in a user
device to implement the features of the present disclosure. The system [300] may
be a part of the user device / or may be independent of but in communication with
15 the user device (may also referred herein as a UE). In another implementation, the
system [300] may reside in a server or a network entity. In yet another implementation, the system [300] may reside partly in the server/ network entity and partly in the user device.
20 [0067] The system [300] is configured for automatically fetching a slice
authorisation data at an Access and Mobility Management Function (AMF) of a network, with the help of the interconnection between the components/units of the system [300]. The slice authorisation data refers to a successful return of the authorised network slice information selected for a corresponding slice
25 authorisation request.
[0068] In operation, the transceiver unit [302] may transmit a first slice availability authorisation request to a Network Slicing Selection Function (NSSF) [116]. This has been depicted by Step 402 in FIG. 4.
30
18

[0069] The first slice availability authorisation request may include one or more
parameters. Examples of such parameters may include, but are not limited to, a
requested Network Slice Selection Assistance Information (NSSAI), a subscribed
Single-NSSAI(s), a Public Land Mobile Network identifier (PLMN ID) of a
5 Subscription Permanent Identifier (SUPI), a Tracking Area Identifier (TAI), a
Network Function (NF) type of the NF service consumer, a requester identifier (ID).
[0070] The requested NSSAI refers to a request for identifying an appropriate network slice for the request. The Single- NSSAI(s) refers to the NSSAI which may
10 represent a single network slice in the 5th Generation Core network. The PLMN ID
refers to a unique identifier to identify a network to which a user may be subscribed. The SUPI refers to a unique identifier assigned to the user of the network. The TAI refers to an identifier to identify a specific geographical area in the network. The NF type refers to the network function consuming the network. The requester ID
15 refers to the identity of the user equipment or user making the slice availability
authorisation request to the NSSF [116].
[0071] In one example, the transceiver unit [302] may continuously monitor the network slice to detect a status of the network. It may be the cases that the
20 transceiver unit [302] may detect a failure of the network, referred to as a startup
event. In such cases, based on the first slice availability authorisation request, the transceiver unit [302] may fetch, at least a slice availability data. The slice availability data may be fetched in response to detection of the startup event associated with the AMF [106].
25
[0072] Continuing further, pursuant to transmitting the first slice availability authorisation request to the NSSF [116], the AMF [106] may receive a response for the slice availability authorisation request from the NSSF [116]. The response may be one of a positive and a negative response.
30
19

[0073] In one example, the transceiver unit [302] receives the positive response
when the NSSF [116] detects the slice authorised data for the slice availability
authorisation request. This has been depicted as Step 404 in FIG. 4. The positive
response may refer to a response which includes the slice authorisation data. The
5 positive response may indicate that the fetching of the slice authorisation data has
been completed.
[0074] In one example, a "200 OK" may be sent to the transceiver unit [302] in the
positive response. The positive response may further include an information, where
10 the information may contain at least an authorised NSSAI, a target AMF Set or a
list of AMF(s); the information may additionally contain a target AMF Service Set.
[0075] However, in another example, the transceiver unit [302] may receive a
negative response associated with the first slice availability authorisation request
15 from the NSSF [116]. In one example, the negative response may include a ‘403
Forbidden response’ with "Details of the issue". The details of the issue may be "NSSAI_NOT_SUPPORTED".
[0076] The negative response is associated with a slice availability data received at
20 the AMF [106] from the NSSF [116], in an event of a failed slice authorisation. In
such events, the AMF [106] may retransmit the slice authorisation request to the
NSSF [116]. The AMF [106] may keep transmitting the slice authorisation request
again, every time the negative response is received, till the time positive response
is received from the NSSF [116]. These steps have been depicted as Step 406 and
25 Step 408 in FIG. 4, in dotted block. It may be noted that the Steps 406 and Steps
408, as depicted in dotted block in FIG. 4 are optional, and not necessarily be
performed as a part of the present subject matter. It may be the case that upon
transmitting the slice availability authorisation request by the AMF [106] to the
NSSF [116], a positive response may be received, and the process may be
30 considered complete. The Steps 406 and 408 may only happen in cases where a
negative response is received from the NSSF [116].
20

[0077] Continuing further with the present example, in the event of receiving a negative response, the processing unit [304] may then initiate a timer based on the negative response. This has been depicted by Step 408 in FIG. 4. 5
[0078] For example, on receiving the negative response (as depicted by Step 406 in FIG. 4), to retrieve the slice authorised data, the user may have to initiate a second slice availability authorisation request manually. In another example, the user may have to restart the AMF [106] after the NSSF [116] restarts. To enable the AMF
10 [106] to retrieve the slice authorisation data without intervention of the user, and
without the need of the NSSF [116] to restart before the AMF [106], the present disclosure discloses the timer to be initiated at the AMF [106], if the negative response to the first slice authorisation request is received (as depicted by Step 408 in FIG. 4).
15
[0079] Continuing further, the processing unit [304] may then detect a timer expiry associated with the timer. The timer expiry is detected at the AMF [106] in an event a time period completion status associated with the timer is detected. The timer expiry may initiate the second slice availability authorisation request. The timer
20 expiry refers to a predefined interval of time after which a subsequent slice
availability authorisation request may be initiated if the negative response for a previous slice availability authorisation request is received.
[0080] In one example, the timer may be a dynamically configurable timer. In an
25 implementation of the present disclosure, the timer may be changed or adjusted
during runtime. The timer may not be fixed at initialisation of the system [300]. In an example, the user or the processing unit [304] may set the timeout of the timer for every slice availability authorisation request.
30 [0081] It may be noted that, when the transceiver unit [302] receives the negative
response for the first slice availability authorisation request, the timer may be
21

initiated by the processing unit [304]. It may be again noted and appreciated that, as depicted in FIG. 4, the timer is re-initiated each time the negative response is received from the NSSF [116].
5 [0082] The transceiver unit [302] is further configured to transmit the second slice
availability authorisation request based on the timer expiry to NSSF [116]. In an
implementation of the present disclosure, the second slice availability authorisation
request may be the same as the first slice availability authorisation request (as
depicted in FIG. 4). In another embodiment, the second slice availability
10 authorisation request may be an update in the first slice availability authorisation
request.
[0083] Further, the transceiver unit [302] is configured to automatically fetch, the slice authorisation data based on the second slice availability authorisation request.
15 When the transceiver unit [302] receives the second slice availability authorisation
request, the transceiver unit [302] may be configured to trigger and fetch the slice authorisation data. In an implementation of the present disclosure, if the NSSF [116] detects the slice authorisation data for the second slice availability request, the positive response may be sent to the transceiver unit [302]. This has been
20 depicted as Step 404 in FIG. 4. A ‘200 OK’ response may be sent to the transceiver
unit [302] along with the slice authorisation data response. The positive response may further include an information, where the information may contain at least an authorised NSSAI, a target AMF Set or a list of AMF(s); the information may additionally contain a target AMF Service Set.
25
[0084] However, if the negative response is received, the timer may be initiated again (as depicted by the arrow in FIG. 4). The method may loop back to sending the slice availability authorisation request again and may keep sending the same for every time a negative response is received, till the time a positive response is
30 received.
22

[0085] Referring to FIG. 5, an exemplary method flow diagram [500] for automatically fetching a slice authorisation data at an Access and Mobility Management Function (AMF) of a network, in accordance with an exemplary implementation 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 FIG. 5, the method [500] starts at step [502].
[0086] At step [504], the method comprises transmitting, by a transceiver unit [302], a first slice availability authorisation request to a Network Slicing Selection Function (NSSF) [116]. The first slice availability authorisation request may include one or more parameters. Examples of such parameters may include, but are not limited to, a requested Network Slice Selection Assistance Information (NSSAI), a subscribed Single-NSSAI(s), a Public Land Mobile Network identifier (PLMN ID) of a Subscription Permanent Identifier (SUPI), a Tracking Area Identifier (TAI), a Network Function (NF) type of the NF service consumer, a requester identifier (ID). The requested NSSAI refers to a request for identifying an appropriate network slice for the request. The Single- NSSAI(s) refers to the NSSAI which may represent a single network slice in the 5th Generation Core network. The PLMN ID refers to a unique identifier to identify a network to which a user may be subscribed. The SUPI refers to a unique identifier assigned to the user of the network. The TAI refers to an identifier to identify a specific geographical area in the network. The NF type refers to the network function consuming the network. The requester ID refers to the identity of the user equipment or user making the slice availability authorisation request to the NSSF [116].
[0087] Next, at step [506], the method comprises receiving, by the transceiver unit [302], a negative response associated with the first slice availability authorisation request from the NSSF [116]. For example, the AMF [106] may receive a response for the slice availability authorisation request from the NSSF [116]. The negative response is associated with a slice availability data received at the AMF [106] from

the NSSF [116], in an event of a failed slice authorisation. In one example, the negative response includes a ‘403 Forbidden response’ with "Details of the issue". The details of the issue may be "NSSAI_NOT_SUPPORTED".
[0088] Next, at step [508], the method comprises initiating, by a processing unit [304], a timer based on the negative response, wherein the timer is a dynamically configurable timer. For example, on receiving the negative response, to enable the AMF [106] to retrieve the slice authorisation data without intervention of the user, and without the need of the NSSF [116] to restart before the AMF [106], the present disclosure discloses the timer to be initiated at the AMF [106].
[0089] Further, at step [510], the method comprises detecting, by a detection unit, a timer expiry associated with the timer. The timer expiry is detected at the AMF [106] in an event a time period completion status associated with the timer is detected. The timer expiry may initiate the second slice availability authorisation request. The timer expiry refers to a predefined interval of time after which a subsequent slice availability authorisation request may be initiated if the negative response for a previous slice availability authorisation request is received. The timer may be a dynamically configurable timer. In an implementation of the present disclosure, the timer may be changed or adjusted during runtime. The timer may not be fixed at initialisation of the system [300]. In an example, the user or the processing unit [304] may set the timeout of the timer for every slice availability authorisation request.
[0090] The timer is re-initiated each time the negative response is received from the NSSF [116].
[0091] Further, at step [512], the method encompasses transmitting, by the transceiver unit [302], a second slice availability authorisation request to the NSSF [116], based on the timer expiry. In an implementation of the present disclosure, the second slice availability authorisation request may be the same as the first slice

availability authorisation request. In another embodiment, the second slice availability authorisation request may be an update in the first slice availability authorisation request.
[0092] Further, at step [514], the method comprises automatically fetching, by the processing unit [304], the slice authorisation data based on the second slice availability authorisation request from the NSSF [116]. When the transceiver unit [302] receives the second slice availability authorisation request, the transceiver unit [302] may be configured to trigger and fetch the slice authorisation data. In an implementation of the present disclosure, if the NSSF [116] detects the slice authorisation data for the second slice availability request, the positive response may be sent to the transceiver unit [302]. A ‘200 OK’ response may be sent to the transceiver unit [302] along with the slice authorisation data response. The positive response may further include an information, where the information may contain at least an authorised NSSAI, a target AMF Set or a list of AMF(s); the information may additionally contain a target AMF Service Set.
[0093] The method terminates at step [516].
[0094] The present disclosure further discloses a non-transitory computer readable storage medium storing instructions for automatically fetching a slice authorisation data at an Access and Mobility Management Function (AMF) of a network. The instructions include executable code which, when executed by one or more units of a system [300] causes a transceiver unit [302] of the system [300] to transmit a first slice availability authorisation request to a Network Slicing Selection Function (NSSF) [116]. Further, the instructions include executable code which, when executed, causes the transceiver unit [302] to receive a negative response associated with the first slice availability authorisation request from the NSSF [116]. Further, the instructions include executable code which, when executed, causes a processing unit [304] to initiate a timer based on the negative response. The timer is a dynamically configurable timer. Further, the instructions include executable code

which, when executed, causes a detection unit [306] to detect a timer expiry associated with the timer. Further, the instructions include executable code which, when executed, cause the transceiver unit [302] to transmit a second slice availability authorisation request to the NSSF [116], based on the timer expiry. Further, the instructions include executable code which, when executed, causes the processing unit [304] to automatically fetch the slice authorisation data based on the second slice availability authorisation request from the NSSF [116].
[0095] As is evident from the above, the present disclosure provides a technically advanced solution for automatically fetching a slice authorisation data at an Access and Mobility Management Function (AMF) of a network. The present solution provides a system and a method for automatically fetching a slice authorisation data by an AMF. The present solution further provides a solution that enables the AMF to get authorisation data from NSSF for slice availability data without manual intervention even if AMF starts first and NSSF later to it. Furthermore, the present disclosure provides a solution to detect a timer expiry associated with the timer and transmits from the Access and Mobility Management Function (AMF) to a Network Slicing Selection Function (NSSF), a second slice availability authorisation request based on detecting the timer expiry.
[0096] 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.
[0097] 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 automatically fetching a slice authorisation data at an
Access and Mobility Management Function (AMF) [106] of a network, the
method [500] comprising:
- transmitting [504], by a transceiver unit [302], a first slice availability authorisation request to a Network Slicing Selection Function (NSSF) [116];
- receiving [506], by the transceiver unit [302], a negative response associated with the first slice availability authorisation request from the NSSF [116];
- initiating [508], by a processing unit [304], a timer based on the negative response, wherein the timer is a dynamically configurable timer;
- detecting [510], by a detection unit [306], a timer expiry associated with the timer;
- transmitting [512], by the transceiver unit [302], a second slice availability authorisation request to the NSSF [116], based on the timer expiry; and
- automatically fetching [514], by the processing unit [304], the slice authorisation data based on the second slice availability authorisation request from the NSSF [116].

2. The method [500] as claimed in claim 1, further comprising: fetching, by the transceiver unit [302], at least a slice availability data based on the first slice availability authorisation request, wherein the slice availability data is fetched in response to detection of a startup event associated with the AMF [106].
3. The method [500] as claimed in claim 1, wherein the negative response is received at the AMF [106] from the NSSF [116] in an event of a failed slice authorisation.
4. The method [500] as claimed in claim 1, wherein the timer is configured based on one of a pre-defined time period or a dynamically defined time period.

5. The method [500] as claimed in claim 1, wherein the timer expiry is detected at the AMF [106] in an event a time period completion status associated with the timer is detected.
6. The method [500] as claimed in claim 1, wherein the timer is re-initiated each time a negative response is received from the NSSF [116].
7. A system [300] for automatically fetching a slice authorisation data at an Access and Mobility Management Function (AMF) [106] of a network, the system [300] comprising:
- a transceiver unit [302], wherein the transceiver unit [302] is configured to:
• transmit a first slice availability authorisation request to a Network Slicing Selection Function (NSSF) [116],
• receive a negative response associated with the first slice availability authorisation request from the NSSF [116]; and
- a processing unit [304] connected to at least the transceiver unit [302], wherein
the processing unit [304] is configured to:
• initiate a timer based on the negative response, wherein the timer is a dynamically configurable timer, and
• detect a timer expiry associated with the timer;
- the transceiver unit [302] further configured to:
• transmit a second slice availability authorisation request based on the timer expiry to NSSF [116], and
• automatically fetch the slice authorisation data based on the second slice availability authorisation request.
8. The system [300] as claimed in claim 7, wherein the transceiver unit [302] is
further configured to fetch, at least a slice availability data based on the first
slice availability authorisation request, wherein the slice availability data is
fetched in response to detection of a startup event associated with the AMF
[106].

9. The system [300] as claimed in claim 7, wherein the negative response is associated with a slice availability data received at the AMF [106] from the NSSF [116], in an event of a failed slice authorisation.
10. The system [300] as claimed in claim 7, wherein the timer is configured based on one of a pre-defined time period or a dynamically defined time period.
11. The system [300] as claimed in claim 7, wherein the timer expiry is detected at the AMF [106] in an event a time period completion status associated with the timer is detected.
12. The system [300] as claimed in claim 7, wherein the timer is re-initiated each time a negative response is received from the NSSF [116].