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 ASSIGNING A SLICE TO USER EQUIPMENT IN
A COMMUNICATION 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 ASSIGNING A SLICE TO USER EQUIPMENT IN A
COMMUNICATION NETWORK
FIELD OF INVENTION
[0001] Embodiments of the present disclosure generally relate to network performance
management systems. More particularly, embodiments of the present disclosure relate to methods and systems for assigning a slice to one or more user equipment (UEs) in a communication 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] 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 the 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. The third-generation (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. Further, reducing call drops and latency is of paramount importance in the telecommunications industry. Call drops can be frustrating for users, and they can also result in lost revenue for service providers. Latency, on the other hand, refers to the time it takes for data to travel from one device to another and can cause delays and disruptions in communication. The introduction
2

of 5G technology promises to address these issues by delivering ultra-low latency and high-speed data transmission. With 5G, call drops are going to be minimized, and users are going to experience seamless, uninterrupted communication. Additionally, 5G technology may enable the development of new applications and services that require high-speed, low-latency communication, such as remote surgeries, autonomous vehicles, and virtual reality. The reduction of call drops and latency is crucial in ensuring that users have access to reliable and efficient communication services, and the 5G technology is a significant step towards achieving this goal.
[0004] In the 5G communication system, a number of functional modules are provided,
for example an Access and Mobility Management Function (AMF), a Network Slice Selection Function (NSSF), and/or a Network Repository Function (NRF), etc., one or more of which interact with each other to implement multiple operations of the 5G communication system. One such operation relates to assigning of a slice for a user equipment (UE). For such operation, the UE sends a network slice selection request to an AMF. The AMF further sends the same request to the NSSF. The NSSF is thereafter required to select the slice for the UE, as per the eligibility of different UEs. The 5G communication system can deploy multiple Network Slice Instances delivering exactly the same features for different groups of UEs. The NSSF offers services to the AMF. Following are the key Network Slice Selection Function (NSSF) functionalities:
• Authorize the set of network slice instances for AMF Availability (Registration).
• Determining the Allowed NSSAI for selection of Slice.
• Determining the AMF Set /Candidate list to be used to serve the UE based on the AMF Availability registration.
[0005] Furthermore, there may be situations when the UE moves from the home Public
Land Mobile Network (HPLMN) to visited Public Land Mobile Network (VPLMN). In such conditions, the UE sends a registration request to the Visited Access and Mobility Function (v-AMF), wherein the v-AMF further sends a request for network slice selection to the visited NSSF (v-NSSF). It may be noted that the v-NSSF may or may not locally store a slice mapping data and even if the v-NSSF may have locally stored slice mapping data it does not have a real time or updated slice mapping data.

Thus, there exists an imperative need in the art to provide a system and method of assigning a slice in VPLMN to the UE, in the absence of slice mapping or real time slice mapping on the v-NSSF of the VPLMN, which the present disclosure aims to address.
SUMMARY
[0006] 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.
[0007] An aspect of the present disclosure may relate to a method for assigning a slice to
one or more user equipment (UEs) in a communication network. The method comprises receiving, at a visited access and mobility management function (v-AMF) unit, a registration request from the one or more UEs. The method further comprises transmitting, by the v-AMF unit, a slice selection request, to a visited network slice selection function (v-NSSF) unit, based on the registration request. The slice selection request comprises at least a Home Public Land Mobile Network (HPLMN) parameter.The method further comprises querying, by the v-NSSF unit, a home network slice selection function (h-NSSF) unit for the slice selection request based on the HPLMN parameter. The method further comprises receiving, at the v-NSSF unit, a slice selection response from the h-NSSF unit, wherein the slice selection response comprises one or more slice configurations for a visited network, and a slice mapping. The method further comprises determining, by the v-NSSF unit, an allowed slice configuration for the one or more UEs from the one or more slice configurations based on the slice mapping. The method further comprises transmitting, by the v-AMF unit, the allowed slice configuration to the one or more UEs.
[0008] In an exemplary aspect of the present disclosure, the method further comprises
registering, by the v-AMF unit, the one or more UEs to a visiting Public Land Mobile Network (VPLMN) based on the allowed slice configuration.
[0009] In an exemplary aspect of the present disclosure, the h-NSSF unit is part of a home
public land mobile network (HPLMN) where one or more profiles for the one or more UEs are subscribed.

[00010] In an exemplary aspect of the present disclosure, the method further comprises the
v-NSSF unit and the v-AMF unit is part of a visiting PLMN where the one or more UEs are in roaming.
[00011] In an exemplary aspect of the present disclosure, the method further comprises
storing, by the home network slice selection function (h-NSSF) unit, a slice mapping for one or more public land mobile network (PLMN).
[00012] In an exemplary aspect of the present disclosure, the method further comprises
extracting, by the h-NSSF unit, the slice mapping for the one or more PLMNs. The method further comprises determining, by the h-NSSF unit, one or more slice configurations based on the slice selection request, and the slice mapping. The method further comprises transmitting, by the h-NSSF unit, the one or more slice configurations, and the slice mapping to the v-NSSF unit in response to the slice selection request.
[00013] In an exemplary aspect of the present disclosure, the HPLMN parameter comprises
at least one of a Mobile Country Code (MCC), a Mobile Network Code (MNC), a user subscription information, and one or more network-specific settings that characterize a home network relevant to the one or more UEs.
[00014] In an exemplary aspect of the present disclosure, the determination comprises
analysing, by the v-NSSF unit, the received slice selection response comprising the one or more slice configurations for the visited network, and the slice mapping. The determination further comprises comparing, by the v-NSSF unit, the slice mapping against the registration request. The determination further comprises determining, by the v-NSSF unit, the allowed slice configuration from the one or more slice configurations based on a positive comparison.
[00015] Another aspect of the present disclosure may relate to a system for assigning a slice
to one or more user equipment (UEs) in a communication network, the system comprises a visited access and mobility management function (v-AMF) unit, a home network slice selection function (h-NSSF) unit, and a visited network slice selection function (v-NSSF) unit connected to each other. The v-AMF unit is configured to receive a registration request from the one or more UEs. The v-AMF unit is further configured to transmit a slice selection request, to the v-NSSF unit, based on the registration request, wherein the slice selection request comprises at

least a Home Public Land Mobile Network (HPLMN) parameter. The v-NSSF unit is configured to query the h-NSSF unit for the slice selection request based on the HPLMN parameter. The v-NSSF unit is further configured to receive a slice selection response from the h-NSSF unit, wherein the slice selection response comprises one or more slice configurations for a visited network, and a slice mapping. The v-NSSF unit is further configured to determine an allowed slice configuration for the one or more UEs from the one or more slice configurations based on the slice mapping. The v-AMF unit is further configured to transmit the allowed slice configuration to the one or more UEs.
[00016] Another aspect of the present disclosure relates to a user equipment (UE) for
receiving an allowed slice configuration, the UE comprising a transceiver unit configured to: 1) transmit, a registration request to a visited access and mobility management function (v-AMF) unit of a system, and 2) receive, the allowed slice configuration from the v-AMF unit. Also, the allowed slice configuration is determined by the system based on: 1) receiving, at the visited access and mobility management function (v-AMF) unit of the system, the registration request from the UE, 2) transmitting, by the v-AMF unit, a slice selection request, to a visited network slice selection function (v-NSSF) unit of the system, based on the registration request, wherein the slice selection request comprises at least a Home Public Land Mobile Network (HPLMN) parameter, 3) querying, by the v-NSSF unit, a home network slice selection function (h-NSSF) unit of the system for the slice selection request based on the HPLMN parameter, 4) receiving, at the v-NSSF unit, a slice selection response from the h-NSSF unit, wherein the slice selection response comprises one or more slice configurations for a visited network, and a slice mapping, and 5) determining, by the v-NSSF unit, an allowed slice configuration for the UE from the one or more slice configurations based on the slice mapping.
[00017] Yet another aspect of the present disclosure may relate to a non-transitory computer
readable storage medium storing instructions for assigning a slice to one or more user equipment (UEs) in a communication network, the instructions include executable code which, when executed by one or more units of a system, causes: a visited access and mobility management function (v-AMF) unit of the system to receive a registration request from the one or more UEs; the v-AMF unit of the system to transmit a slice selection request, to a visited network slice selection function (v-NSSF) unit, based on the registration request, wherein the slice selection request comprises at least a Home Public Land Mobile Network (HPLMN) parameter; the v-NSSF unit of the system to query a home network slice selection function (h-

NSSF) unit for the slice selection request based on the HPLMN parameter; the v-NSSF unit of the system to receive a slice selection response from the h-NSSF unit, wherein the slice selection response comprises one or more slice configurations for a visited network, and a slice mapping; the v-NSSF unit of the system to determine an allowed slice configuration for the one or more UEs from the one or more slice configurations based on the slice mapping; the v-AMF unit of the system to transmit the allowed slice configuration to the one or more UEs.
OBJECTS OF THE DISCLOSURE
[00018] Some of the objects of the present disclosure, which at least one embodiment
disclosed herein satisfies are listed herein below.
[00019] It is an object of the present disclosure to provide a system and a method for
assigning a slice to one or more user equipment (UEs) in a communication network.
[00020] It is an object of the present disclosure to provide an assignment of the slice in the
absence of availability of slice mapping on the v-NSSF.
[00021] It is an object of the present disclosure to enhance the robustness of a roaming
system, and allow more flexibility in a roaming architecture of a communication network.
[00022] It is an object of the present disclosure to provide control to different network
operators, and provide flexibility in interconnection and roaming partnerships between the operators.
[00023] It is an object of the present disclosure to improve the efficiency and flexibility in
roaming registrations in visited networks.
[00024] It is an object of the present disclosure to eliminate the reliance on the visited
network's Network Slice Selection Function (NSSF) for storing slice mapping information and eliminate the requirement for local slice data mapping storage at the visited network, and also eliminate the need to update the local slice data mapping storage in case of any updates.

DESCRIPTION OF THE DRAWINGS
[00025] 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.
[00026] Figure 1 illustrates an exemplary block diagram representation of 5th generation
core (5GC) network architecture.
[00027] Figure 2 illustrates an exemplary scenario diagram of a Home Public Land Mobile
Network (HPLMN) and a Visited Public Land Mobile Network (VPLMN) illustrating a user equipment in roaming.
[00028] Figure 3 illustrates an exemplary block diagram of a system for assigning a slice to
one or more user equipment (UEs) in a communication network, in accordance with exemplary implementations of the present disclosure.
[00029] Figure 4 illustrates a method flow diagram for assigning a slice to one or more user
equipment (UEs) in a communication network in accordance with exemplary implementations of the present disclosure.
[00030] Figure 5 illustrates a method flow diagram for determining, one or more slice
configurations, based on a slice selection request, and a slice mapping, in accordance with exemplary implementations of the present disclosure.
[00031] Figure 6 illustrates a method flow diagram for determining the allowed slice
configuration in accordance with exemplary implementations of the present disclosure.

5
The foregoing shall be more apparent from the following more detailed description of the disclosure.
DETAILED DESCRIPTION
10
[00032] 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
15 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.
[00033] The ensuing description provides exemplary embodiments only, and is not
20 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. 25
[00034] 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
30 diagram form in order not to obscure the embodiments in unnecessary detail.
[00035] 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
35 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.
9

5 [00036] 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
10 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.
15
[00037] 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
20 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 the system according to the present disclosure. More specifically, the processor or
25 processing unit is a hardware processor.
[00038] 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 communication device” may
30 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 of implementing the features of the present disclosure. Also, the user device may contain at least
35 one input means configured to receive an input from unit(s) which are required to implement
the features of the present disclosure.
10

5 [00039] 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”), magnetic disk storage media, optical
storage media, flash memory devices or other types of machine-accessible storage media. The
10 storage unit stores at least the data that may be required by one or more units of the system to
perform their respective functions.
[00040] 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
15 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.
[00041] All modules, units, components used herein, unless explicitly excluded herein, may
20 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 circuits (FPGA), any other type of integrated circuits, etc. 25
[00042] As discussed in the background section, the current known solutions have several
shortcomings. The present disclosure aims to overcome the above-mentioned and other
existing problems in this field of technology by providing method and system of assigning a
slice to one or more user equipment (UEs) in a communication network. The present invention
30 provides a system and method that assigns one or more slices / provides relevant slice
configurations to the one or more user equipment (UEs) for providing in an effective and efficient manner various services to the one or more UEs in the visited network.
[00043] Figure 1 illustrates an exemplary block diagram representation of 5th generation
35 core (5GC) network architecture, in accordance with exemplary implementation of the present
disclosure. As shown in Figure 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 Management Function (SMF) [108], a Service
11

5 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], a Unified
Data Management (UDM) [124], an application function (AF) [126], a User Plane Function
10 (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.
[00044] Radio Access Network (RAN) [104] is the part of a mobile telecommunications
15 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.
[00045] Access and Mobility Management Function (AMF) [106] is a 5G core network
20 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.
[00046] Session Management Function (SMF) [108] is a 5G core network function
25 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.
[00047] Service Communication Proxy (SCP) [110] is a network function in the 5G core
30 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.
[00048] Authentication Server Function (AUSF) [112] is a network function in the 5G core
responsible for authenticating UEs during registration and providing security services. It
35 generates and verifies authentication vectors and tokens.
12

5 [00049] 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.
[00050] Network Slice Selection Function (NSSF) [116] is a network function responsible
10 for selecting the appropriate network slice for a UE based on factors such as subscription,
requested services, and network policies.
[00051] Network Exposure Function (NEF) [118] is a network function that exposes
capabilities and services of the 5G network to external applications, enabling integration with
15 third-party services and applications.
[00052] 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. 20
[00053] 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.
25 [00054] Unified Data Management (UDM) [124] is a network function that centralizes the
management of subscriber data, including authentication, authorization, and subscription information.
[00055] Application Function (AF) [126] is a network function that represents external
30 applications interfacing with the 5G core network to access network capabilities and services.
[00056] User Plane Function (UPF) [128] is a network function responsible for handling
user data traffic, including packet routing, forwarding, and QoS enforcement.
35 [00057] 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.
13

5 [00058] Figure 2 illustrates an exemplary scenario for a home public land mobile network
(HPLMN) [202] and a visited public land mobile network (VPLMN) [204]. A Public Land Mobile Network (PLMN) is the geographical area covered by a mobile network operator for providing services to one or more user equipment (UEs) [102]. The PLMN connects to the other PLMNs for providing inter-operators roaming, messaging, and data services. The
10 HPLMN [202] is the Public Land Mobile Network (PLMN) in which the user equipment [102]
has registered primarily. The users are able to use the services from the PLMN when outside the HPLMN [202] by connecting with other PLMN which are known as VPLMN [204]. The connection with the VPLMN [204] is also known as roaming. The scenario illustrated in the figure shows that the user equipment [102] is roaming in the VPLMN [204]. The VPLMN
15 [204] comprises at least a visited Access and Mobility Management Function (v-AMF) [208],
and a visited Network Slice Selection Function (v-NSSF) [210]. The HPLMN [202] comprises at least a home Network Slice Selection Function (h-NSSF) [206]. The v-AMF [208] is a network function responsible for managing access and mobility aspects, such as UE registration, connection, and reachability in the VPLMN [204]. It also handles mobility
20 management procedures like handovers and paging in the VPLMN [204]. The v-NSSF [210]
is a network function responsible for selecting the appropriate network slice, in the VPLMN [204], for the one or more UEs [102] based on factors such as subscription, requested services, and/or network policies etc. The h-NSSF [206] is a network function responsible for selecting the appropriate network slice, in the HPLMN [202], for the one or more UEs [102] based on
25 factors such as subscription, requested services, and/or network policies etc.
[00059] Referring to Figure 3, an exemplary block diagram of a system [300] for assigning
a slice to one or more user equipment (UEs) [102] in a communication network, is shown, in accordance with the exemplary implementations of the present disclosure. The system [300]
30 comprises at least one visited access and mobility management function (v-AMF) unit [302],
at least one visited network slice selection function (v-NSSF) unit [304], and at least one home network slice selection function (h-NSSF) unit [306]. Also, all of the components/ units of the system [300] are assumed to be connected to each other unless otherwise indicated below. Also, in Figure 3 only a few units are shown, however, the system [300] may comprise multiple such
35 units or the system [300] may comprise any such numbers of said units, as required to
implement the features of the present disclosure. In an implementation, the system [300] may reside in a network entity.
14

5 [00060] The system [300] is configured for assigning the slice to the one or more user
equipment (UEs) [102] in the communication network, with the help of the interconnection
between the components/units of the system [300]. The slice may be a virtualised network
created in a shared physical infrastructure, wherein the slice may be a customisable portion of
the communication network where such customisable portion can also be an isolated end-to-
10 end network tailored to fulfil diverse requirements requested by a particular application of the
one or more UEs [102]. The one or more UEs [102] registers with one or more slices in the
communication network to access various services provided by the communication network.
More specifically, based on the implementation of features as disclosed in the present
disclosure, the system [300] assigns one or more slices to the one or more UEs [102] for the
15 registration of said one or more UEs [102] with said one or more slices. Therefore, the system
[300] via its components provides appropriate slice(s) which would provide the service(s) to
the one or more UEs [102].
[00061] The functionalities of the units/components of the system [300] is described as
20 below for assigning the slice to the one or more user equipment (UEs) [102] in the
communication network.
[00062] Initially, the visited access and mobility management function (v-AMF) unit [302]
of the system [300] is configured to receive a registration request from the one or more UEs
25 [102]. The registration request from the one or more UEs [102] is a request to register the one
or more UEs [102] in a visited network in order to avail different kinds of network services, wherein the visited network is a network: 1) that is different from a home network of the one or more UEs, and 2) where the one or more UEs are roaming. The visited network may also be referred herein as a visited Public Land Mobile Network (VPLMN) [204] and the VPLMN
30 [204] is a network used by the one or more UEs while roaming outside of their Home Public
Mobile Network (HPLMN) which is a network from a network operator by which the one or more UEs have a subscription to handle the user's subscription and services. Also, the v-AMF unit [302] is a unit responsible for managing access and mobility aspects, such as UE registration, connection, and reachability in the VPLMN [204]. The v-AMF unit [302] also
35 handles mobility management procedures like handovers and paging in the VPLMN [204].
[00063] Once, the registration request is received, then the visited access and mobility
management function (v-AMF) unit [302] is configured to transmit a slice selection request, to
15

5 a visited network slice selection function (v-NSSF) unit [304], based on the registration request,
wherein the slice selection request comprises at least a Home Public Land Mobile Network (HPLMN) parameter. More specifically, in an implementation, the slice selection request is a request for selection of one or more appropriate slices which have been requested by the one or more UEs [102]. Also, the v-NSSF unit [304] is a unit responsible for selecting the one or
10 more appropriate network slices, in the VPLMN [204], for the one or more UEs [102] based
on factors such as subscription, requested services, and network policies. It is pertinent to note that the v-NSSF unit [304] and the v-AMF unit [302] are a part of the visiting PLMN [204] where the one or more UEs [102] are in roaming. The one or more UEs [102] are able to use various services when they are outside the HPLMN [202] (i.e., while the UE(s) are roaming in
15 geographical areas other than the HPLMN [202]) by connecting with the PLMN(s) of the
roaming geographical area known as the VPLMN [204].
[00064] Furthermore, the HPLMN parameter present in the slice selection request
comprises at least one of a Mobile Country Code (MCC), a Mobile Network Code (MNC), a
20 user subscription information. and one or more network-specific settings that characterize a
home network relevant (i.e., the HPLMN [202]) to the one or more UEs [102]. The MCC is a three-digit code which identifies the country where the network operates. The MNC is a two-digit or three-digit code which signifies a specific mobile network operator within that country. The user subscription information relates to an information pertaining to details of one or more
25 subscriptions associated with the one or more UEs [102] such as including but not limiting to
at least one of one or more subscriber identities, one or more service plan details, a billing information, and an activation status, etc. The one or more network-specific settings may refer to one or more network settings related to slicing.. Also, it is pertinent to note that the home network relevant to the one or more UEs [102] may also be referred herein as the HPLMN
30 [202].
[00065] Further, once the slice selection request is transmitted by the v-AMF unit [302] to
the v-NSSF unit [304], then the v-NSSF unit [304] is configured to query a home network slice
selection function (h-NSSF) unit [306] for the slice selection request based on the HPLMN
35 parameter, wherein the h-NSSF unit [306] is part of the home public land mobile network
(HPLMN) [202] where one or more profiles for the one or more UEs [102] are subscribed. The one or more profiles for the one or more UEs [102] may include an information that may be stored in the home network/ HPLMN [202], where such information may be at least one of a
16

5 subscriber identification detail, one or more subscription details, one or more authentication
and security credentials, one or more network access configurations, one or more service preferences, and a management and status information etc. Therefore, the v-NSSF unit [304] queries the h-NSSF unit [306] for the slice selection request based on at least one of the Mobile Country Code (MCC), the Mobile Network Code (MNC), the user subscription information;
10 and the one or more network-specific settings that characterize the home network relevant to
the one or more UEs [102]. For instance, the v-NSSF unit [304] checks with the h-NSSF unit [306] and seeks a response from the h-NSSF unit [306] for fetching an information with regard to one or more slice instances, wherein such one or more slice instances are capable of catering one or more services that may be requested by the one or more UEs. This querying may also
15 help in checking with the h-NSSF unit [306] regarding an authentication or validation of the
HPLMN parameter. Thus, the h-NSSF unit [306] is a unit responsible for selecting one or more appropriate network slices, in the HPLMN [202], for the one or more UEs [102] based on factors such as subscription, requested services, and/or network policies etc.
20 [00066] After the querying the h-NSSF unit [306] for the slice selection request, the v-NSSF
unit [304] is configured to receive a slice selection response from the h-NSSF unit [306], wherein the slice selection response comprises one or more slice configurations for the visited network (i.e., the VPLMN [204]), and a slice mapping. Therefore, the slice selection response is the response for the query raised by the v-NSSF unit [304]. The slice selection response
25 provides information related to the one or more slice configurations for the visited network,
and the slice mapping. The one or more slice configurations may include information related to one or more configured slices, wherein such information related to the one or more configured slices is used to provide one or more allowed slices, to the one or more UEs [102] in the visited network. The one or more allowed slices are those slices that allows the one or
30 more UEs [102] to register in the visited network. The information related to the one or more
configured slices includes a detail of the one or more slices that are authorised by the h-NSSF unit [306]. The slice mapping may refer to a mapping of one or more slice instances/slices with one or more services that are subscribed by the one or more UEs [102] associated with their corresponding one or more HPLMNs [202]. Therefore, the slice selection response
35 includes the slice mapping and the information related to the one or more configured slices to
identify the one or more allowed slices by the v-NSSF unit [304] in the visited network.
17

5 [00067] The present disclosure further discloses that the h-NSSF unit [306] is further
configured to store a slice mapping for one or more public land mobile network (PLMNs). The
h-NSSF unit [306] may also comprise a storage for storing the slice mapping for the one or
more PLMNs. In an implementation said one or more PLMNs may be one or more PLMNs
that are currently active throughout the globe and are associated with the one or more UEs
10 [102]. Furthermore, this storage provides a database of an information associated with one or
more slices of the one or more PLMNs, wherein such database can be accessed during the querying of the h-NSSF unit [306] for the slice selection request and during the generation of the slice selection response.
15 [00068] The present disclosure further discloses that the h-NSSF unit [306] is also
configured to extract the slice mapping for the one or more PLMNs. Therefore, the h-NSSF unit [306] extracts a mapping of one or more slice instances/slices with one or more services that are subscribed via the one or more PLMNs. Then after the extraction of the slice mapping, the h-NSSF unit [306] is further configured to determine one or more slice configurations based
20 on the slice selection request, and the slice mapping. For example, the one or more slice
configurations are determined based on one or more services requested by the one or more UEs [102] and one or more services offered by one or more slices / slice instance associated with the slice mapping.
25 [00069] Further, once the one or more slice configurations are determined, the h-NSSF unit
[306] is further configured to transmit the one or more slice configurations and the slice mapping to the v-NSSF unit [304] in response to the slice selection request. In an implementation the h-NSSF unit [306] is configured to transmit the one or more slice configurations and the slice mapping to the v-NSSF unit [304] based on the HPLMN parameter
30 present in the slice selection request (i.e., based on at least one of the Mobile Country Code
(MCC), the Mobile Network Code (MNC), the user subscription information; and the one or more network-specific settings that characterize a home network relevant (i.e., the HPLMN [202]) to the one or more UEs [102]). Thereafter, the one or more slice configurations which are to be used by the one or more UEs [102] in the VPLMN [202] are sent to the v-NSSF unit
35 [304] which may be then later transferred to the one or more UEs [102].
[00070] Once, the slice selection response is received, then the v-NSSF unit [304] is
configured to determine an allowed slice configuration for the one or more UEs [102] from the
18

5 one or more slice configurations based on the slice mapping. Therefore, the v-NSSF unit [304]
is configured to determine an allowed slice configuration for the one or more UEs [102] from the one or more slice configurations based on the mapping of one or more slice instances/slices with the one or more services that are subscribed by the one or more UEs via the one or more PLMNs. Furthermore, the allowed slice configuration is a slice configuration from the one or
10 more slice configurations which is allowed to be used by the one or more UEs [102] for availing
the one or more services. Therefore, the determination of whether the one or more slice configurations are allowed to be used by the one or more UEs [102] is based on analysis of the slice mapping (i.e., analysis of the mapping of the one or more slice instances/slices with the one or more services that are subscribed by the one or more UEs [102] via the one or more
15 PLMNs).
[00071] The present disclosure further discloses that for the determination of the allowed
slice configuration for the one or more UEs [102], the v-NSSF unit [304] is configured to
analyse the received slice selection response comprising the one or more slice configurations
20 for the visited network, and the slice mapping. Therefore, the one or more slice configurations
of the visited network and the slice mapping are received in the slice selection response, and information associated with both are analysed to determine the allowed slice configuration for the one or more UEs [102].
25 [00072] Then for determining the allowed slice configuration for the one or more UEs
[102], the v-NSSF unit [304] is further configured to compare the slice mapping against the registration request of the one or more UEs [102]. For this purpose, in an instance an information associated with the slice mapping and an information associated with the registration request are compared. For example, comparison is made to check if services which
30 the one or more UEs [102] have requested are same as services provided by one or more
slices/slice instances present in the slice mapping, wherein the one or more slices/slice instance are associated with the one or more slice configurations. If the services requested by the one or more UEs [102] are same as the services provided by one or more slices/slice instances present in in the slice mapping, then it may yield a result as a positive comparison. However, if the
35 comparison provides that the services are not same then it would lead to a negative comparison.
[00073] Then based on the comparison, the v-NSSF unit [304] is further configured to
determine the allowed slice configuration from the one or more slice configurations based on
19

5 the positive comparison. More specifically, a slice configuration from the one or more slice
configurations is identified as the allowed slice configuration in an event such slice configuration is of a slice that caters to the same services that are requested by the one or more UEs [102]. This enables a verification between the v-NSSF unit [304] and the h-NSSF unit [306] with regard to the allowed slice configuration from the one or more slice configurations.
10
[00074] Once, the allowed slice configuration is determined, then the v-AMF unit [302] is
further configured to transmit the allowed slice configuration to the one or more UEs [102]. The transmission of the allowed slice configuration to the one or more UEs [102] enables the one or more UEs to avail the requested services.
15
[00075] More specifically, the present disclosure discloses that after the allowed slice
configuration is transmitted to the one or more UEs [102], the v-AMF unit [302] is configured to register the one or more UEs [102] to the visiting Public Land Mobile Network (VPLMN) [204] based on the allowed slice configuration. This enables the one or more UEs [102] to be
20 connected with the VPLMN [204] and avail the allowed services provided by the VPLMN
[204].
[00076] Therefore, it is clear from the above disclosure that when the one or more UEs
[102] in the visited network attempts to connect to the network, they need a mapped slice (i.e.,
25 the slice mapping) in the serving network that corresponds to a network slice in the home
network (i.e., the HPLMN [202]). The v-NSSF unit [304] supports functionalities for this by querying the h-NSSF unit [306] based on the received HPLMN [202] in the slice selection request during initial registration. The h-NSSF unit [306] may store the list of HPLMNs in memory, and therefore it compares the received HPLMN with the stored data, and determines
30 whether to query a representative h-NSSF as per the agreement with a roaming partner (i.e.,
network operator of the visited network). This functionality aids in dynamically updating of the slice mapping without the need for defining the mapping in local storage of the v-NSSF unit [304].
35 [00077] Therefore, it is clear from the above disclosure that system [300] assigns one or
more slices / provides relevant slice configurations to the one or more user equipment (UEs) [102] in the communication network for providing various services to the one or more UEs [102] in an effective and efficient manner in the visited network.
20

5 [00078] Referring to Figure 4, an exemplary method flow diagram [400] for assigning a
slice to one or more user equipment (UEs) [102] in a communication network, in accordance
with exemplary implementations of the present disclosure is shown. In an implementation the
method [400] is performed by the system [300]. Further, in an implementation, the system
[300] is present in the communication network to implement the features of the present
10 disclosure.
[00079] Moreover, the method [400] for assigning the slice to the one or more user
equipment (UEs) [102] in the communication network is performed with the help of the interconnection between the components/units of the system [300]. The slice may be a
15 virtualised network created in a shared physical infrastructure, wherein the slice may be a
customisable portion of the communication network where such customisable portion can also be an isolated end-to-end network tailored to fulfil diverse requirements requested by a particular application of the one or more UEs [102]. The one or more UEs [102] registers with one or more slices in the communication network to access various services provided by the
20 communication network. More specifically, based on the implementation of features as
disclosed in the present disclosure, the system [300] assigns one or more slices to the one or more UEs [102] for the registration of said one or more UEs [102] with said one or more slices. Therefore, the system [300] via its components provides appropriate slice(s) which would provide the service(s) to the one or more UEs [102].
25
[00080] The method [400] as performed by the system [300] is described as below for
assigning the slice to the one or more user equipment (UEs) [102] in the communication network.
30 [00081] As shown in Figure 4, the method [400] starts at step [402]. Next, at step 404, the
method [400] comprises receiving, at a visited access and mobility management function (v-AMF) unit [302] of the system [300], a registration request from the one or more UEs [102]. The registration request from the one or more UEs [102] is a request to register the one or more UEs [102] in a visited network in order to avail different kinds of network services, wherein
35 the visited network is a network: 1) that is different from a home network of the one or more
UEs, and 2) where the one or more UEs are roaming. The visited network may also be referred herein as a visited Public Land Mobile Network (VPLMN) [204] and the VPLMN [204] is a network used by the one or more UEs while roaming outside of their Home Public Mobile
21

5 Network (HPLMN) which is a network from a network operator by which the one or more UEs
have a subscription to handle the user's subscription and services. Also, the v-AMF unit [302] is a unit responsible for managing access and mobility aspects, such as UE registration, connection, and reachability in the VPLMN [204]. The v-AMF unit [302] also handles mobility management procedures like handovers and paging in the VPLMN [204].
10
[00082] Once, the registration request is received, then next at step [406], the method [400]
comprises transmitting, by the v-AMF unit [302], a slice selection request, to a visited network slice selection function (v-NSSF) unit [304], based on the registration request, wherein the slice selection request comprises at least a Home Public Land Mobile Network (HPLMN) parameter.
15 More specifically, in an implementation, the slice selection request is a request for selection of
one or more appropriate slices which have been requested by the one or more UEs [102]. Also, the v-NSSF unit [304] is a unit responsible for selecting the one or more appropriate network slices, in the VPLMN [204], for the one or more UEs [102] based on factors such as subscription, requested services, and network policies. The v-NSSF unit [304] and the v-AMF
20 unit [302] are a part of the visiting PLMN [204] where the one or more UEs [102] are in
roaming. The one or more UEs [102] are able to use various services when they are outside the HPLMN [202] (i.e., while the UE(s) are roaming in geographical areas other than the HPLMN [202]) by connecting with the PLMN(s) of the roaming geographical area known as the VPLMN [204].
25
[00083] Furthermore, the HPLMN parameter present in the slice selection request
comprises at least one of a Mobile Country Code (MCC), a Mobile Network Code (MNC), a user subscription information, and one or more network-specific settings that characterize a home network relevant (i.e., the HPLMN [202]) to the one or more UEs [102]. The MCC is a
30 three-digit code which identifies the country where the network operates. The MNC is a two-
digit or three-digit code which signifies a specific mobile network operator within that country. The user subscription information relates to an information pertaining to details of one or more subscriptions associated with the one or more UEs [102] such as including but not limiting to at least one of one or more subscriber identities, one or more service plan details, a billing
35 information, and an activation status, etc. The one or more network-specific settings may refer
to one or more network settings related to slicing. Also, it is pertinent to note that the home network relevant to the one or more UEs [102] may also be referred herein as the HPLMN [202].
22

5
[00084] Once, the slice selection request is transmitted by the v-AMF unit [302] to the v-
NSSF unit [304], then at step [408], the method [400] further comprises querying, by the v-NSSF unit [304], a home network slice selection function (h-NSSF) unit [306] for the slice selection request based on the HPLMN parameter, wherein the h-NSSF unit [306] is part of a
10 home public land mobile network (HPLMN) [202] where one or more profiles for the one or
more UEs [102] are subscribed. The one or more profiles for the one or more UEs [102] may include an information that may be stored in the home network/ HPLMN [202], where such information may be at least one of a subscriber identification detail, one or more subscription details, one or more authentication and security credentials, one or more network access
15 configurations, one or more service preferences, and a management and status information etc.
Therefore, the v-NSSF unit [304] queries the h-NSSF unit [306] for the slice selection request based on at least one of the Mobile Country Code (MCC), the Mobile Network Code (MNC), the user subscription information; and the one or more network-specific settings that characterize the home network relevant to the one or more UEs [102]. For instance, the v-NSSF
20 unit [304] checks with the h-NSSF unit [306] and seeks a response from the h-NSSF unit [306]
for fetching an information with regard to one or more slice instances, wherein such one or more slice instances are capable of catering one or more services that may be requested by the one or more UEs. This querying may also help in checking with the h-NSSF unit [306] regarding an authentication or validation of the HPLMN parameter. Thus, the h-NSSF unit
25 [306] is a unit responsible for selecting one or more appropriate network slices, in the HPLMN
[202], for the one or more UEs [102] based on factors such as subscription, requested services, and/or network policies etc.
[00085] After querying the h-NSSF unit [306] for the slice selection request, next at step
30 [410], the method [400] further comprises receiving, at the v-NSSF unit [304], a slice selection
response from the h-NSSF unit [306], wherein the slice selection response comprises one or
more slice configurations for the visited network (i.e., the VPLMN [204]), and a slice mapping.
Therefore, the slice selection response is the response for the query raised by the v-NSSF unit
[304]. The slice selection response provides information related to the one or more slice
35 configurations for the visited network, and the slice mapping. The one or more slice
configurations may include information related to one or more configured slices, wherein such information related to the one or more configured slices is used to provide one or more allowed slices, to the one or more UEs [102] in the visited network. The one or more allowed slices are
23

5 those slices that allows the one or more UEs [102] to register in the visited network. The
information related to the one or more configured slices includes a detail of the one or more
slices that are authorised by the v-NSSF unit [304] in the visited network. The slice mapping
may refer to a mapping of one or more slice instances/slices with one or more services that are
subscribed by the one or more UEs [102] associated with their corresponding one or more
10 HPLMNs [202]. Therefore, the slice selection response includes the slice mapping and the
information related to the one or more configured slices to identify the one or more allowed slices by the v-NSSF unit [304] in the visited network.
[00086] The present disclosure further discloses that the method further comprises storing,
15 by the home network slice selection function (h-NSSF) unit [306], a slice mapping for one or
more public land mobile network (PLMN). The h-NSSF unit [306] may also comprise a storage
for storing the slice mapping for the one or more PLMNs. In an implementation said one or
more PLMNs may be one or more PLMNs that are currently active throughout the globe and
are associated with the one or more UEs [102]. Furthermore, this storage provides a database
20 of an information associated with one or more slices of the one or more PLMNs, wherein such
database can be accessed during the querying of the h-NSSF unit [306] for the slice selection request and during the generation of the slice selection response.
[00087] The present disclosure further discloses that for determination of the one or more
25 slice configurations, as shown in Figure 5, the method at step [502] comprises extracting, by
the h-NSSF unit [306], the slice mapping for the one or more PLMNs. Therefore, the h-NSSF
unit [306] extracts a mapping of one or more slice instances/slices with one or more services
that are subscribed via the one or more PLMNs. The present disclosure further discloses that
the method further at step [504] comprises determining, by the h-NSSF unit [306], one or more
30 slice configurations based on the slice selection request, and the slice mapping. For example,
the one or more slice configurations are determined based on one or more services requested
by the one or more UEs [102] and one or more services offered by one or more slices / slice
instance associated with the slice mapping. The present disclosure further discloses that the
method further at step [506] comprises transmitting, by the h-NSSF unit [306], the one or more
35 slice configurations, and the slice mapping to the v-NSSF unit [304] in response to the slice
selection request. In an implementation the h-NSSF unit [306] is configured to transmit the one or more slice configurations and the slice mapping to the v-NSSF unit [304] based on the HPLMN parameter present in the slice selection request (i.e., based on at least one of the
24

5 Mobile Country Code (MCC), the Mobile Network Code (MNC), the user subscription
information; and the one or more network-specific settings that characterize a home network
relevant (i.e., the HPLMN [202]) to the one or more UEs [102]). Thereafter, the one or more
slice configurations which are to be used by the one or more UEs [102] in the VPLMN [202]
are sent to the v-NSSF unit [304] which may be then later transferred to the one or more UEs
10 [102].
[00088] Once, the slice selection response is received, then next at step [412], the method
[400] further comprises determining, by the v-NSSF unit [304], an allowed slice configuration for the one or more UEs [102] from the one or more slice configurations based on the slice
15 mapping. Therefore, the v-NSSF unit [304] is configured to determine an allowed slice
configuration for the one or more UEs [102] from the one or more slice configurations based on the mapping of one or more slice instances/slices with the one or more services that are subscribed by the one or more UEs via the one or more PLMNs. Furthermore, the allowed slice configuration is a slice configuration from the one or more slice configurations which is
20 allowed to be used by the one or more UEs [102] for availing the one or more services.
Therefore, the determination of whether the one or more slice configurations are allowed to be used by the one or more UEs [102] is based on analysis of the slice mapping (i.e., analysis of the mapping of the one or more slice instances/slices with the one or more services that are subscribed by the one or more UEs [102] via the one or more PLMNs).
25
[00089] The present disclosure further discloses that the determination of the allowed slice
configuration for the one or more UEs [102], as shown in Figure 6, at step [602] comprises analysing, by the v-NSSF unit [304], the received slice selection response comprising the one or more slice configurations for the visited network, and the slice mapping. Therefore, the one
30 or more slice configurations of the visited network and the slice mapping are received in the
slice selection response, and information associated with both are analysed to determine the allowed slice configuration for the one or more UEs [102].
[00090] The present disclosure further discloses that for determination of the allowed slice
35 configuration for the one or more UEs [102], the method at step [604] further comprises
comparing, by the v-NSSF unit [304], the slice mapping against the registration request of the one or more UEs [102]. For this purpose, in an instance an information associated with the slice mapping and an information associated with the registration request are compared. For
25

5 example, comparison is made to check if services which the one or more UEs [102] have
requested are same as services provided by one or more slices/slice instances present in the
slice mapping, wherein the one or more slices/slice instance are associated with the one or more
slice configurations. If the services requested by the one or more UEs [102] are same as the
services provided by one or more slices/slice instances present in in the slice mapping, then it
10 may yield a result as a positive comparison. However, if the comparison provides that the
services are not same then it would lead to a negative comparison.
[00091] The present disclosure further discloses that based on the comparison, the method
further at step [606] comprises determining, by the v-NSSF unit [304], the allowed slice
15 configuration from the one or more slice configurations based on the positive comparison.
More specifically, a slice configuration from the one or more slice configurations is identified as the allowed slice configuration in an event such slice configuration is of a slice that caters to the same services that are requested by the one or more UEs [102]. This enables a verification between the v-NSSF unit [304] and the h-NSSF unit [306] with regard to the allowed slice
20 configuration from the one or more slice configurations.
[00092] Once, the allowed slice configuration is determined, then next at step [414], the
method [400] further comprises transmitting, by the v-AMF unit [302], the allowed slice
configuration to the one or more UEs [102]. The transmission of the allowed slice configuration
25 to the one or more UEs [102] enables the one or more UEs to avail the requested services.
[00093] The present disclosure further discloses that after the allowed slice configuration is
transmitted to the one or more UEs [102], the method further comprises registering, by the v-
AMF unit [302], the one or more UEs [102] to the visiting Public Land Mobile Network
30 (VPLMN) [204] based on the allowed slice configuration. This enables the one or more UEs
[102] to be connected with the VPLMN [204] and avail the allowed services provided by the VPLMN [204].
[00094] Thereafter, at step [416], the method [400] is terminated.
35
[00095] Therefore, it is clear from the above disclosure that the method [400] assigns one
or more slices and provides relevant slice configurations to the one or more user equipment
26

5 (UEs) [102] for providing in the visited network, various services to the one or more UEs [102]
in an effective and efficient manner.
[00096] The present disclosure further discloses a non-transitory computer readable storage
medium storing instructions for assigning a slice to one or more user equipment (UEs) [102]
10 in a communication network, the instructions include executable code which, when executed
by one or more units of a system [300], causes: a visited access and mobility management function (v-AMF) unit [302] of the system [300] to receive a registration request from the one or more UEs [102]; the v-AMF unit [302] of the system [300] to transmit a slice selection request, to a visited network slice selection function (v-NSSF) unit [304], based on the
15 registration request, wherein the slice selection request comprises at least a Home Public Land
Mobile Network (HPLMN) parameter; the v-NSSF unit [304] of the system [300] to query a home network slice selection function (h-NSSF) unit [306] for the slice selection request based on the HPLMN parameter; the v-NSSF unit [304] of the system [300] to receive a slice selection response from the h-NSSF unit [306], wherein the slice selection response comprises
20 one or more slice configurations for a visited network, and a slice mapping; the v-NSSF unit
[304] of the system [300] to determine an allowed slice configuration for the one or more UEs [102] from the one or more slice configurations based on the slice mapping; the v-AMF unit [302] of the system [300] to transmit the allowed slice configuration to the one or more UEs [102].
25
[00097] Also, the present disclosure discloses a user equipment (UE) [102] for receiving an
allowed slice configuration, the UE comprising a transceiver unit configured to: 1) transmit, a registration request to a visited access and mobility management function (v-AMF) unit [302] of a system [300], and 2) receive, the allowed slice configuration from the v-AMF unit [302].
30 Also, the allowed slice configuration is determined by the system [300] based on: 1) receiving,
at the visited access and mobility management function (v-AMF) unit [302] of the system [300], the registration request from the UE [102], 2) transmitting, by the v-AMF unit [302], a slice selection request, to a visited network slice selection function (v-NSSF) unit [304] of the system [300], based on the registration request, wherein the slice selection request comprises
35 at least a Home Public Land Mobile Network (HPLMN) parameter, 3) querying, by the v-
NSSF unit [304], a home network slice selection function (h-NSSF) unit [306] of the system [300] for the slice selection request based on the HPLMN parameter, 4) receiving, at the v-NSSF unit [304], a slice selection response from the h-NSSF unit [306], wherein the slice
27

selection response comprises one or more slice configurations for a visited network, and a slice mapping, and 5) determining, by the v-NSSF unit [304], an allowed slice configuration for the UE [102] from the one or more slice configurations based on the slice mapping.
[00098] As is evident from the above, the present disclosure provides a technically
advanced solution for assigning a slice to one or more user equipment (UEs) [102] in a communication network when the user is roaming outside the home network. The present solution provides assignment of the slice even in the absence of slice mapping available on the v-NSSF unit [304]. By decentralizing the slice mapping retrieval process, the present disclosure enhances the robustness of the roaming system. Enhanced flexibility of direct querying approach allows for more flexibility in the roaming architecture. It enables different network operators to have control over their own NSSFs and make direct queries to the Roaming Partner NSSF. This flexibility facilitates efficient interconnection and roaming partnerships between operators, enabling customized solution for international roamers. The present disclosure improves the efficiency and flexibility of the roaming registration by the one or more UEs [102] in the visited PLMNs. It eliminates the reliance on the visited network's NSSF for storing slice mapping information. By allowing the visited network to fetch the mapping from home network, the invention eliminates local slice data mapping storage at V-NSSF unit [304] without making any roaming partner agreement. For assigning a slice to one or more user equipment (UEs) [102] in a communication network when the user is roaming outside the home network only connection with h-NSSF unit [306] is needed. If any changes in slice mapping is done in roaming partner network, there is no need to update it locally in the visited network. This disclosure makes the NSSF query home network for slice mapping and makes it independent and hence provides a solution that is technically advanced over the existing solutions.
[00099] 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.

[000100] Further, in accordance with the present disclosure, it is to be acknowledged that the functionality described for the various the 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 for assigning a slice to one or more user equipment (UEs) [102] in a
communication network, the method comprising:
receiving, at a visited access and mobility management function (v-AMF) unit [302], a registration request from the one or more UEs [102];
transmitting, by the v-AMF unit [302], a slice selection request, to a visited network slice selection function (v-NSSF) unit [304], based on the registration request, wherein the slice selection request comprises at least a Home Public Land Mobile Network (HPLMN) parameter;
querying, by the v-NSSF unit [304], a home network slice selection function (h-NSSF) unit [306] for the slice selection request based on the HPLMN parameter;
receiving, at the v-NSSF unit [304], a slice selection response from the h-NSSF unit [306], wherein the slice selection response comprises one or more slice configurations for a visited network, and a slice mapping;
determining, by the v-NSSF unit [304], an allowed slice configuration for the one or more UEs [102] from the one or more slice configurations based on the slice mapping; and
transmitting, by the v-AMF unit [302], the allowed slice configuration to the one or more UEs [102].
2. The method as claimed in claim 1, the method further comprising registering, by the v-AMF unit [302], the one or more UEs [102] to a visiting Public Land Mobile Network (VPLMN) [204] based on the allowed slice configuration.
3. The method as claimed in claim 1, wherein the h-NSSF unit [304] is part of a home public land mobile network (HPLMN) [202] where one or more profiles for the one or more UEs [102] are subscribed.
4. The method as claimed in claim 1, wherein the v-NSSF unit [304] and the v-AMF unit [302] is part of a visiting PLMN [204] where the one or more UEs [102] are in roaming.

5. The method as claimed in claim 1, the method further comprising storing, by the home network slice selection function (h-NSSF) unit [306], a slice mapping for one or more public land mobile network (PLMN).
6. The method as claimed in claim 5, the method further comprising:
extracting, by the h-NSSF unit [306], the slice mapping for the one or more PLMNs;
determining, by the h-NSSF unit [306], one or more slice configurations based on the slice selection request, and the slice mapping; and
transmitting, by the h-NSSF unit [306], the one or more slice configurations, and the slice mapping to the v-NSSF unit [304] in response to the slice selection request.
7. The method as claimed in claim 1, wherein the HPLMN parameter comprises at least one of a Mobile Country Code (MCC), a Mobile Network Code (MNC), a user subscription information, and one or more network-specific settings that characterize a home network relevant to the one or more UEs [102].
8. The method as claimed in claim 1, wherein the determination comprises:
analysing, by the v-NSSF unit [304], the received slice selection response comprising the one or more slice configurations for the visited network, and the slice mapping;
comparing, by the v-NSSF unit [304], the slice mapping against the registration request;
determining, by the v-NSSF unit [304], the allowed slice configuration from the one or more slice configurations based on a positive comparison.
9. A system [300] for assigning a slice to one or more user equipment (UEs) [102] in a
communication network, the system [300] comprising:
- a visited access and mobility management function (v-AMF) unit [302] configured to:
o receive a registration request from the one or more UEs [102], and o transmit a slice selection request, to a visited network slice selection function (v-NSSF) unit [304], based on the registration request, wherein the

slice selection request comprises at least a Home Public Land Mobile Network (HPLMN) parameter; and
- the v-NSSF unit [304] connected to at least the v-AMF unit [302], wherein the v-
NSSF unit [304] is configured to:
query a home network slice selection function (h-NSSF) unit [306] for the slice selection request based on the HPLMN parameter,
receive a slice selection response from the h-NSSF unit [306], wherein the slice selection response comprises one or more slice configurations for a visited network, and a slice mapping, and
determine an allowed slice configuration for the one or more UEs [102] from the one or more slice configurations based on the slice mapping; and
- the v-AMF unit [302] is further configured to transmit the allowed slice
configuration to the one or more UEs [102].
10. The system as claimed in claim 9, wherein the v-AMF unit [302] is further configured to register the one or more UEs [102] to a visiting Public Land Mobile Network (VPLMN) [204] based on the allowed slice configuration.
11. The system as claimed in claim 9, wherein the h-NSSF unit [306] is part of a home public land mobile network (HPLMN) [202] where one or more profiles for the one or more UEs [102] are subscribed.
12. The system as claimed in claim 9, wherein the v-NSSF unit [304] and the v-AMF unit [302] is part of a visiting PLMN [204] where the one or more UEs [102] are in roaming.
13. The system as claimed in claim 9, wherein the h-NSSF unit [306] is further configured to store a slice mapping for one or more public land mobile network (PLMNs).
14. The system as claimed in claim 13, wherein the h-NSSF unit [306] is further configured to:
extract the slice mapping for the one or more PLMNs;
determine one or more slice configurations based on the slice selection request, and the slice mapping; and

transmit the one or more slice configurations and the slice mapping to the v-NSSF unit [304] in response to the slice selection request.
15. The system as claimed in claim 9, wherein the HPLMN parameter comprises at least one of a Mobile Country Code (MCC), a Mobile Network Code (MNC), a user subscription information, and one or more network-specific settings that characterize a home network relevant to the one or more UEs [102].
16. The system as claimed in claim 9, wherein for the determination, the v-NSSF unit [304] is further configured to:
analyse the received slice selection response comprising the one or more slice configurations for the visited network, and the slice mapping;
compare the slice mapping against the registration request of the one or more UEs [102];
determine the allowed slice configuration from the one or more slice configurations based on a positive comparison.
17. A user equipment (UE) [102] for receiving an allowed slice configuration, the UE
comprising:
- a transceiver unit configured to:
transmit, a registration request to a visited access and mobility management
function (v-AMF) unit [302] of a system [300], and
receive, the allowed slice configuration from the v-AMF unit [302], wherein the
allowed slice configuration is determined by the system [300] based on:
receiving, at the visited access and mobility management function (v-AMF) unit [302] of the system [300], the registration request from the UE [102],
transmitting, by the v-AMF unit [302], a slice selection request, to a visited network slice selection function (v-NSSF) unit [304] of the system [300], based on the registration request, wherein the slice selection request comprises at least a Home Public Land Mobile Network (HPLMN) parameter,

querying, by the v-NSSF unit [304], a home network slice selection
function (h-NSSF) unit [306] of the system [300] for the slice selection
request based on the HPLMN parameter,
receiving, at the v-NSSF unit [304], a slice selection response from the
h-NSSF unit [306], wherein the slice selection response comprises one
or more slice configurations for a visited network, and a slice mapping,
and
determining, by the v-NSSF unit [304], an allowed slice configuration
for the UE [102] from the one or more slice configurations based on the
slice mapping.