FORM 2
THE PATENTS ACT, 1970 (39 OF 1970) & THE PATENT RULES, 2003
COMPLETE SPECIFICATION
(See section 10 and rule 13)
“METHOD IMPLEMENTED BY A NETWORK NODE FOR HANDLING HANDOVER 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 IMPLEMENTED BY A NETWORK NODE FOR HANDLING HANDOVER IN A COMMUNICATION NETWORK
FIELD OF THE DISCLOSURE
[0001] The present disclosure relates generally to the field of wireless
communication systems. More particularly, the present disclosure relates to method implemented by a network node for handling handover associated with a user equipment (UE) in a wireless communication network.
BACKGROUND
[0002] The following description of related art is intended to provide
background information pertaining to the field of the disclosure. This section may include certain implementations of the art that may be related to various features of the present disclosure. However, it should be appreciated that this section be used only to enhance the understanding of the reader with respect to the present disclosure, and not as admissions of prior art.
[0003] Wireless communication technology has rapidly evolved over the
past few decades, with each generation bringing significant improvements and advancements. The first generation of wireless communication technology was based on analog technology and offered only voice services. However, with the advent of the second-generation (2G) technology, digital communication and data services became possible, and text messaging was introduced. 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.
[0004] During establishment of a connection of a user equipment (UE) with
a communication network, a User Context is required that is stored at a network node, more particularly at an Access and Mobility Management Function (AMF) of the communication network, the user context contains information about the UE. When a user accessing a second network system such as a 5G system (5GS) (including but not limited to), and the user has to call another user, a handover of the connection takes place from a second network system i.e., the 5G system (5GS) to a first network system such as an Evolved Packet System (EPS) (including but not limited to) to handle the call. After the call, when the user has to switch back from the first network system to the second network system, a handover of the connection is done from the first network system to the second network system in order to allow the user to have the required bandwidth. In certain cases, the handover the first network system to the second network system is successful, but a Mobility Registration Request is not received at network node from the UE. This leads to non-assignment of an identifier such as, including but not limited to, 5G - Global Unique Temporary Identifier (GUTI), of the UE and thereby, the UE does not get registered in the second network system. The GUTI here refers to a temporary identifier used in 5G networks to identify a user equipment such as but not limited to a mobile device and its associated subscription information. In the existing solutions, this results in a stale session at the network node, a wastage of network resources and an inefficient network restoration and reducing performance of the network node. This scenario is handled at network node by deleting the user context of such users gracefully after running a small timer.

[0005] Further, over the period of time various solutions have been
developed to improve the performance of communication devices and to handle a handover of the connection from the first network system to the second network system. However, the conventionally available systems fail to handle the handover efficiently and reliably.
[0006] Thus, there exists an imperative need in the art of a method
implemented by the network node to handle the handover of the UE from the first network system to the second network system in an efficient and a reliable manner, which the present disclosure aims to address.
OBJECTS OF THE DISCLOSURE
[0007] Some of the objects of the present disclosure, which at least one
embodiment disclosed herein satisfies are listed herein below.
[0008] It is an object of the present disclosure to provide a method and a
system for handling handover in a communication network.
[0009] It is another object of the present disclosure to provide a solution
implemented by the network node to handle a handover of the UE from a first network system to a second network system.
[0010] It is another object of the present disclosure to provide a solution
that removes a context of the UE from the second network system to avoid stale sessions.
[0011] It is another object of the present disclosure to provide a solution
that initiates a timer to wait for a reception of a mobility registration request from the UE for a predetermined time period.

[0012] It is another object of the present disclosure to provide a solution
that stops, a timer in an event the mobility registration request is received in the predetermined time period, and registers, via the network node, the UE in the second network system and assign a Globally Unique Temporary Identifier (GUTI) to the UE.
[0013] It is another object of the present disclosure to provide a cost-
effective solution implemented by the network node for handling the handover of the UE.
[0014] It is yet another object of the present disclosure to provide a time-
efficient solution implemented by the network node for handling the handover of the UE.
SUMMARY OF THE DISCLOSURE
[0015] This section is provided to introduce certain implementations 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.
[0016] A first aspect of the present disclosure is related to a method
implemented by a network node for handling handover in a communication network. The method comprises verifying, by the network node via a processor, a reception of a mobility registration request from a user equipment (UE) after a successful handover of the UE from a first network system to a second network system. The method further comprises initiating, by the network node via the processor, a timer to wait for the reception of the mobility registration request for a predetermined time period. Thereafter, the method comprises removing, by the

network node via the processor, a context of the UE from the second network system in an event the reception of the mobility registration request fails in the predetermined time period.
[0017] Further according to an aspect of the present disclosure, the first
network system is an Evolved Packet System (EPS) and the second network system is a 5th Generation System (5GS).
[0018] Further according to an aspect of the present disclosure, the network
node is an Access and Mobility Management Function (AMF).
[0019] Further according to an aspect of the present disclosure, the method
encompasses registering, by the network node, the UE in the second network system by: stopping the timer in an event the mobility registration request is received in the predetermined time period; and registering, via the network node, the UE in the second network system and assign a Globally Unique Temporary Identifier (GUTI) to the UE.
[0020] Further according to an aspect of the present disclosure, the context
of the UE is removed from the second network system to avoid stale sessions. It is to be noted that the context of the UE is removed in the event the reception of the mobility registration request fails in the predetermined time period.
[0021] Further according to an aspect of the present disclosure, the context
corresponds to at least one from among user's identity, a set of service subscriptions, a set of network settings, a user existing session data, and a set of operational parameters necessary for the UE's connectivity and a communication within at least one of the first network system and the second network system.

[0022] Another aspect of the present disclosure is related to a system
implemented by a network node for handling handover in a communication network. The system comprises a storage unit; and a processor coupled to the storage unit. Further, the processor further causes the network node to verify, a reception of a mobility registration request from a user equipment (UE) after a successful handover of the UE from a first network system to a second network system. Further, the processor further causes the network node to initiate, a timer to wait for the reception of the mobility registration request for a predetermined time period. Thereafter, the processor further causes the network node to remove, a context of the UE from the second network system in an event the reception of the mobility registration request fails in the predetermined time period.
[0023] Yet another aspect of the present disclosure relates to a non-
transitory computer readable storage medium storing instruction for handling handover in a communication network. The storage medium comprises executable code which, when executed by one or more units of a processor of a system implemented by a network node, may causes the network node to verify, a reception of a mobility registration request from a user equipment (UE) after a successful handover of the UE from a first network system to a second network system; initiate, a timer to wait for the reception of the mobility registration request for a predetermined time period; and remove, a context of the UE from the second network system in an event the reception of the mobility registration request fails in the predetermined time period.
[0024] Yet another aspect of the present disclosure relates to a user
equipment (UE) connected to a network node, for handling handover in a communication network. The UE is configured to send, a mobility registration request to the network node, after a successful handover of the UE from a first network system to a second network system for verification by the network node; wait, for the reception of the mobility registration request for a predetermined time

period, after an initialization of a timer by the network node; and exit, the second network system, upon removal of a context of the UE from the second network system in an event the reception of the mobility registration request fails in the predetermined period.
BRIEF DESCRIPTION OF DRAWINGS
[0025] The accompanying drawings, which are incorporated herein, and
constitute a part of this disclosure, illustrate exemplary implementations 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. Some drawings may indicate the components using block diagrams and may not represent the internal circuitry of each component. It will be appreciated by those skilled in the art that disclosure of such drawings includes disclosure of electrical components, electronic components or circuitry commonly used to implement such components.
[0026] FIG.1A illustrates an exemplary block diagram representation of a
5th generation core (5GC) network architecture.
[0027] FIG.1B illustrates an exemplary block diagram of a system [100]
implemented by a network node for handling handover in a communication network, in accordance with exemplary implementations of the present disclosure.
[0028] FIG.2 illustrates an exemplary method [200] flow diagram
indicating a process implemented by a network node for handling handover in a communication network, in accordance with exemplary implementations of the present disclosure.

[0029] FIG.3 illustrates an exemplary scenario signal flow [300] indicating
the process for handling handover in a communication network, in accordance with exemplary implementations of the present disclosure.
5 [0030] FIG.4 illustrates an exemplary block diagram of a computing device
upon which an embodiment of the present disclosure may be implemented, in accordance with exemplary embodiments of the present disclosure.
[0031] The foregoing shall be more apparent from the following more
10 detailed description of the disclosure.
DETAILED DESCRIPTION
[0032] In the following description, for the purposes of explanation, various
15 specific details are set forth in order to provide a thorough understanding of
implementations of the present disclosure. It will be apparent, however, that
implementations of the present disclosure may be practiced without these specific
details. Several features described hereafter can each be used independently of
one another or with any combination of other features. An individual feature may
20 not address any of the problems discussed above or might address only some of
the problems discussed above. Some of the problems discussed above might not
be fully addressed by any of the features described herein. Example
implementations of the present disclosure are described below, as illustrated in
various drawings in which like reference numerals refer to the same parts
25 throughout the different drawings.
[0033] The ensuing description provides exemplary implementations only,
and is not intended to limit the scope, applicability, or configuration of the
disclosure. Rather, the ensuing description of the exemplary implementations will
30 provide those skilled in the art with an enabling description for implementing an
9

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.
5 [0034] It should be noted that the terms "mobile device", "user equipment",
"user device", “communication device”, “device” and similar terms are used
interchangeably for the purpose of describing the disclosure. These terms are not
intended to limit the scope of the disclosure or imply any specific functionality or
limitations on the described implementations. The use of these terms is solely for
10 convenience and clarity of description. The disclosure is not limited to any
particular type of device or equipment, and it should be understood that other equivalent terms or variations thereof may be used interchangeably without departing from the scope of the disclosure as defined herein.
15 [0035] Specific details are given in the following description to provide a
thorough understanding of the implementations. However, it will be understood by one of ordinary skill in the art that the implementations may be practiced without these specific details. For example, circuits, systems, networks, processes, and other components may be shown as components in block diagram form in
20 order not to obscure the implementations in unnecessary detail. In other instances,
well-known circuits, processes, algorithms, structures, and technique may be shown without unnecessary detail in order to avoid obscuring the implementations.
25 [0036] Also, it is noted that individual implementations 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 can be performed in parallel or concurrently. In addition, the order of the operations may be re-
10

arranged. A process is terminated when its operations are completed but could have additional steps not included in a figure.
[0037] The word “exemplary” and/or “demonstrative” is used herein to
5 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 implementation or design described herein as “exemplary” and/or “demonstrative” is not necessarily to be construed as preferred or advantageous over other implementations or designs, nor is it meant to preclude equivalent
10 exemplary structures and technique 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
[0038] As used herein, an “electronic device”, or “portable electronic
device”, or “user device” or “communication device” or “user equipment” or “device” refers to any electrical, electronic, electromechanical and computing device. The user device is capable of receiving and/or transmitting one or
20 parameters, performing function/s, communicating with other user devices and
transmitting data to the other user devices. The user equipment may have a processor, a display, a memory, a battery and an input-means such as a hard keypad and/or a soft keypad. The user equipment may be capable of operating on any radio access technology including but not limited to IP-enabled
25 communication, Zig Bee, Bluetooth, Bluetooth Low Energy, Near Field
Communication, Z-Wave, Wi-Fi, Wi-Fi direct, etc. For instance, the user equipment may include, but not limited to, a mobile phone, smartphone, virtual reality (VR) devices, augmented reality (AR) devices, laptop, a general-purpose computer, desktop, personal digital assistant, tablet computer, mainframe
11

computer, or any other device as may be obvious to a person skilled in the art for implementation of the features of the present disclosure.
[0039] Further, the user equipment (UE) may also comprise a “processor”
5 or “processing unit” includes processing unit, wherein processor refers to any
logic circuitry for processing instructions. The processor may be a general-purpose processor, a special purpose processor, a conventional processor, a digital signal processor, a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, Application Specific
10 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 is a hardware processor.
15
[0040] As portable electronic devices and wireless technologies continue to
improve and grow in popularity, the advancing wireless technologies for data transfer are also expected to evolve and replace the older generations of technologies. In the field of wireless data communications, the dynamic
20 advancement of various generations of cellular technology are also seen. The
development, in this respect, has been incremental in the order of second generation (2G), third generation (3G), fourth generation (4G), and now fifth generation (5G), and more such generations are expected to continue in the forthcoming time.
25
[0041] Radio Access Technology (RAT) refers to the technology used by
mobile devices/ user equipment (UE) to connect to a cellular network. It refers to the specific protocol and standards that govern the way devices communicate with base stations, which are responsible for providing the wireless connection.
30 Further, each RAT has its own set of protocols and standards for communication,
12

which define the frequency bands, modulation technique, and other parameters
used for transmitting and receiving data. Examples of RATs include GSM (Global
System for Mobile Communications), CDMA (Code Division Multiple Access),
UMTS (Universal Mobile Telecommunications System), LTE (Long-Term
5 Evolution), and 5G. The choice of RAT depends on a variety of factors, including
the network infrastructure, the available spectrum, and the mobile device's/device's capabilities. Mobile devices often support multiple RATs, allowing them to connect to different types of networks and provide optimal performance based on the available network resources.
10
[0042] Example implementations of the present disclosure enable
implementation of enhanced features and functionalities in 5G systems. Implementations of the technology disclosed herein may be employed in the technical field of 5G systems and network slicing for communication systems.
15 More particularly, the implementations of the technology disclosed herein may
relate to 5G core network and 5G systems for AMF Selection for Isolated Network Slice in communication systems. Throughout the present disclosure, UE, wireless device, and mobile device are used interchangeably. Throughout the present disclosure, base station, (Radio) Access Network ((R)AN), Next Generation
20 Radio Access Network (NG-RAN), New radio Node B (gNB), Next Generation
eNodeB (ng-eNBs) are used interchangeably. Stale session is defined as a period of time in which transfer of data completely stops.
[0043] All modules, units, components used herein or unit(s) that are a part
25 of system [100] may be software modules configured via hardware
modules/processors, or hardware modules or hardware processors, the processors being a general-purpose processor, a special purpose processor, a conventional processor, a digital signal processor, a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller,
13

Application Specific Integrated Circuits, Field Programmable Gate Array circuits, any other type of integrated circuits, etc.
[0044] As discussed in the background section, the current known solutions
5 for handling a handover of a user equipment (UE) from a first network system
such as an Evolved Packet System (EPS) to a second network system such as, a
5G system (5GS), have several shortcomings and said current known fails to
handle the handover efficiently, reliably, and in a cost-effective manner which
results in hampering a user experience of the user. The failure of the handover
10 arises due to a radio frequency (RF) level failure, moving of the UE to another
Next Generation Radio Access Network (NG-RAN) in the handover, moving of the UE back to the EPS due to poor network coverage in the 5GS, and the like.
[0045] The present disclosure aims to overcome the above-mentioned and
15 other existing problems in this field of communication technology by providing a
method for handling handover in a communication network by a network node.
The present disclosure discloses a solution that deletes the context of a user device
to avoid and overcome stale sessions and frivolous capacity utilisation of network
functions. The present disclosure provides a solution that eradicates the hurdles in
20 the communication technology, such as the stale sessions, that impede network
performance. The present disclosure discloses a time period for which the network
node waits for said time period in an event the registration request of the user
device is not received during handover to implement the solution of the present
disclosure.
25
[0046] Hereinafter, exemplary implementations of the present
disclosure will be described with reference to the accompanying drawings.
[0047] FIG. 1A illustrates an exemplary block diagram representation of
30 5th generation core (5GC) network architecture, in accordance with exemplary
14

embodiment of the present disclosure. As shown in Figure 1A, the 5GC network
architecture [100A] includes a user equipment (UE) [102u], a radio access
network (RAN) [104r], an access and mobility management function (AMF)
[106a], a Session Management Function (SMF) [108s], a Service Communication
5 Proxy (SCP) [110s], an Authentication Server Function (AUSF) [112a], a
Network Slice Specific Authentication and Authorization Function (NSSAAF)
[114n], a Network Slice Selection Function (NSSF) [116n], a Network Exposure
Function (NEF) [118n], a Network Repository Function (NRF) [120n], a Policy
Control Function (PCF) [122p], a Unified Data Management (UDM) [124u], an
10 application function (AF) [126a], a User Plane Function (UPF) [128u], a data
network (DN) [130d], 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.
15 [0048] The User Equipment (UE) [102u] interfaces with the network via
the Radio Access Network (RAN) [104r]; the Access and Mobility Management Function (AMF) [106a] manages connectivity and mobility, while the Session Management Function (SMF) [108s] administers session control; the service communication proxy (SCP) [110s] routes and manages communication between
20 network services, enhancing efficiency and security, and the Authentication
Server Function (AUSF) [112a] handles user authentication; the Network Slice Specific Authentication and Authorization Function (NSSAAF) [114n] for integrating the 5G core network with existing 4G LTE networks i.e., to enable Non-Standalone (NSA) 5G deployments, the Network Slice Selection Function
25 (NSSF) [116n], Network Exposure Function (NEF) [118n], and Network
Repository Function (NRF) [120n] enable network customization, secure interfacing with external applications, and maintain network function registries respectively; the Policy Control Function (PCF) [122p] develops operational policies, and the Unified Data Management (UDM) [124u] manages subscriber
30 data; the Application Function (AF) [126a] enables application interaction, the
15

User Plane Function (UPF) [128u] processes and forwards user data, and the Data
Network (DN) [130d] connects to external internet resources; collectively, these
components are designed to enhance mobile broadband, ensure low-latency
communication, and support massive machine-type communication, solidifying
5 the 5GC as the infrastructure for next-generation mobile networks.
[0049] Radio Access Network (RAN) [104r] is the part of a mobile
telecommunications system that connects user equipment (UE) [102u] to the core
network (CN) and provides access to different types of networks (e.g., 5G
10 network). It consists of radio base stations and the radio access technologies that
enable wireless communication.
[0050] Access and Mobility Management Function (AMF) [106a] is a 5G
core network function responsible for managing access and mobility aspects, such
15 as UE registration, connection, and reachability. It also handles mobility
management procedures like handovers and paging.
[0051] Session Management Function (SMF) [108s] is a 5G core network
function responsible for managing session-related aspects, such as establishing,
20 modifying, and releasing sessions. It coordinates with the User Plane Function
(UPF) [128u] for data forwarding and handles IP address allocation and QoS enforcement.
[0052] Service Communication Proxy (SCP) [110s] is a network function
25 in the 5G core network that facilitates communication between other network
functions by providing a secure and efficient messaging service. It acts as a mediator for service-based interfaces.
[0053] Authentication Server Function (AUSF) [112a] is a network
30 function in the 5G core responsible for authenticating UEs during registration and
16

providing security services. It generates and verifies authentication vectors and tokens.
[0054] Network Slice Specific Authentication and Authorization Function
5 (NSSAAF) [114n] 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.
[0055] Network Slice Selection Function (NSSF) [116n] is a network
10 function responsible for selecting the appropriate network slice for a UE based on
factors such as subscription, requested services, and network policies.
[0056] Network Exposure Function (NEF) [118n] is a network function that
exposes capabilities and services of the 5G network to external applications,
15 enabling integration with third-party services and applications.
[0057] Network Repository Function (NRF) [120n] 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
20 functions.
[0058] Policy Control Function (PCF) [122p] is a network function
responsible for policy control decisions, such as QoS, charging, and access control, based on subscriber information and network policies. 25
[0059] Unified Data Management (UDM) [124u] is a network function that
centralizes the management of subscriber data, including authentication, authorization, and subscription information.
17

Application Function (AF) [126a] is a network function that represents external applications interfacing with the 5G core network to access network capabilities and services.
5 [0060] User Plane Function (UPF) [128u] is a network function responsible
for handling user data traffic, including packet routing, forwarding, and QoS enforcement.
[0061] Data Network (DN) [130d] refers to a network that provides data
10 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.
[0062] Referring to Fig. 1B, an exemplary block diagram of a system [100]
15 implemented by a network node [101], for handling handover in a communication
network comprising at least a first network and a second network, in accordance with exemplary implementations of the present disclosure. The network node [101] implements the system [100] comprising one at least one storage unit [102] and at least one processor [104] coupled to at least the storage unit [102]. The
20 processor [104] may be further connected to at least one verification unit [105], at
least one synchronizing unit [107] and at least one fetching unit [109] to implement the solution of the present disclosure. Also, all of the components/ units inside the processor [104] of the system [100] implemented by the network node [101] are assumed to be connected to each other unless otherwise indicated below.
25 Further, the said units can also exist independently outside of the processor [104]
inside the system [100]. Also, in Fig. 1 only a few units are shown, however, the system [100] may comprise multiple such units or the processor [104] may comprise any such numbers of said units, as required to implement the features of the present disclosure. Further, in an implementation, the system [100] may be
30 present in a server device configured at a network entity to implement the features
18

of the present disclosure. The system [100] may be a part of the server device / or
may be independent of but in communication with the server device. In another
implementation, the system [100] may reside in a server or a network entity. In
yet another implementation, the system [100] may reside partly in the server/
5 network entity. In an implementation of the present disclosure, the system [100]
implemented by the network node [101] is configured for handling the handover in the communication network, with the help of the interconnection between the components/units of the network node [101].
10 [0063] In order to handle the handover of the U in the communication
network, the processor [104] cause the network node [101] to verify, a reception of a mobility registration request from the user equipment (UE) after a successful handover of the UE from a first network system to a second network system. Further, the processor [104] may in conjunction with the verification unit [105]
15 verify, the reception of the mobility registration request from the UE after the
successful handover of the UE from the first network system to the second network system. The processor [104] is further configured to cause the network node [101] to initiate, a timer to wait for the reception of the mobility registration request for a predetermined time period. Further, in an implementation of the
20 present solution, the processor [104] may in conjunction with the synchronizing
unit [107] initiate the timer to wait for the reception of the mobility registration request for the predetermined time-period. And finally, the processor [104] is further configured to cause the network node [101] to remove, a context of the UE from the second network in an event the reception of the mobility registration
25 request fails in the predetermined period. Further, in a implementation of the
present solution, the processor [104] may in conjunction with the fetching unit [109] removes the context of the UE from the second network system in the event that the mobility registration request fails to be received in the predetermined time-period.
30
19

[0064] It is to be noted that the context of the UE may correspond to a data
or an information required to initiate a connection with a network such as the user
context may include but is not limited to information related to a Protocol Data
Unit (PDU) session, a Security Key, a Mobility Restriction List, a UE Radio
5 Capability and a UE Security Capabilities, and the like. It is further important to
note that the context of the UE may correspond to at least one from among user's
identity, a set of service subscriptions, a set of network settings, a user existing
session data, and a set of operational parameters necessary for the UE's
connectivity and a communication within at least one of the first network system
10 and the second network system.
[0065] The present disclosure also encompasses that the first network
system is an Evolved Packet System (EPS) and the second network system is a 5th Generation System (5GS). 15
[0066] The present disclosure also encompasses, the network node [101] is
an Access and Mobility Management Function (AMF).
[0067] The present disclosure also encompasses, in order to register the UE
20 in the second network system, the processor [104] is configured to cause the
network node [101] to stop, the timer in an event the mobility registration request
is received in the predetermined time period. In another implementation, the
processor [104] may in conjunction with the synchronizing unit [107] may stop
the timer in the event the mobility registration request is received in the
25 predetermined time period. Further, the processor [104] is also configured to cause
the network node [101] to register, the UE in the second network system and
assign a Globally Unique Temporary Identifier (GUTI) to the UE. In an
implementation, the processor [104] may in conjunction with the synchronizing
unit [107] may register the UE in the second network system and assign a Globally
30 Unique Temporary Identifier (GUTI) to the UE.
20

[0068] The present disclosure encompasses that the context of the UE is
removed from the second network system to avoid stale sessions. It is to be noted
that the context of the UE is removed in the event the reception of the mobility
5 registration request fails in the predetermined time period.
[0069] 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
10 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
15 encompassed within the scope of the present disclosure.
[0070] Yet another aspect of the present disclosure relates to a non-
transitory computer readable storage medium storing instruction for handling handover in wireless communication network. The storage medium comprises
20 executable code which, when executed by one or more units of a processor [104]
of a system [100] implemented by a network node [101], wherein the processor [104] causes the network node [101] to verify a reception of a mobility registration request from a user equipment (UE) after a successful handover of the UE from a first network system to a second network system. Further, the executable code
25 when executed, causes the network node [101] to initiate a timer to wait for the
reception of the mobility registration request for a predetermined time period. Further, the executable code when executed, causes the network node [101] to remove, a context of the UE from the second network system in an event the reception of the mobility registration request fails in the predetermined time
30 period.
21

[0071] Yet another aspect of the present disclosure relates to a user
equipment (UE) connected to a network node [101], for handling handover in a
communication network. The UE is configured to send, a mobility registration
request to the network node [101], after a successful handover of the UE from a
5 first network system to a second network system for verification by the network
node [101]; wait, for the reception of the mobility registration request for a
predetermined time period, after an initialization of a timer by the network node
[101]; and exit, the second network system, upon removal of a context of the UE
from the second network system in an event the reception of the mobility
10 registration request fails in the predetermined period.
[0072] Referring to Fig. 2 method [200] flow diagram indicating a process
implemented by a network node [101] for handling handover in a communication
network, in accordance with exemplary implementations of the present disclosure
15 is shown. In an implementation the method [200] is performed by the system
[100]. As shown in Fig. 2, the method [200] starts at step [202].
[0073] At step [204], the method [200] as disclosed by the present
disclosure comprises verifying, by the network node [101] via a processor [104],
20 a reception of a mobility registration request from a user equipment (UE) after a
successful handover of the UE from a first network system to a second network system. It is important to note that the first network system is an Evolved Packet System (EPS) and the second network system is a 5th Generation System (5GS). It is further important to note that the network node [101] is an Access and
25 Mobility Management Function (AMF).
[0074] In an implementation of the present disclosure, the method [200]
may comprise verifying, the reception of the mobility registration request from the UE after the successful handover of the UE from the first network system to
22

the second network system by the processor [104] in conjunction with a verification unit [105].
[0075] Next, at step [206], the method [200] as disclosed by the present
5 disclosure comprises initiating, by the network node [101] via the processor [104],
a timer to wait for the reception of the mobility registration request for a predetermined time period.
[0076] Further, in an implementation of the present disclosure, the method
10 [200] may further comprises registering, by the network node [101], the UE in the
second network system by stopping by the network node [101], the timer in an
event the mobility registration request is received in the predetermined time
period. Further, for the registering the UE in the second network system, the
present disclosure further comprises registering, via the network node [101], the
15 UE in the second network system and assign a Globally Unique Temporary
Identifier (GUTI) to the UE. The GUTI here refers to a temporary identifier used in 5G networks to identify a user equipment and its associated subscription information.
20 [0077] In an implementation, the timer is initiated by the processor [104] in
conjunction with a synchronizing unit [107] to wait for the reception of the mobility registration request for the predetermined time period. In another implementation, the UE is registered in the second network system, by the processor [104] in conjunction with the synchronizing unit [107], by stopping the
25 timer in the event the mobility registration request is received in the predetermined
time period, and based on said event registering the UE in the second network system and assign the GUTI to the UE.
[0078] Next, at step [208], the method [200] as disclosed by the present
30 disclosure comprises by the network node [101] via the processor [104], a context
23

of the UE from the second network system in an event the reception of the mobility
registration request fails in the predetermined time period. The present disclosure
encompasses that the context of the UE is removed from the second network
system to avoid stale sessions. It is important to note that the context corresponds
5 to at least one from among user's identity, a set of service subscriptions, a set of
network settings, a user existing session data, and a set of operational parameters
necessary for the UE's connectivity and a communication within at least one of
the first network system and the second network system. It further noted that the
context of the UE is removed in the event the reception of the mobility registration
10 request fails in the predetermined time period.
[0079] In an implementation of the present solution, the context of the UE
is removed from the second network system by the processor [104] in conjunction with a fetching unit [109]in the event the reception of the mobility registration
15 request fails in the predetermined time period It is important to note that the
reception of the mobility registration request fails in the handover due to radio frequency (RF) level failures, movement of the UE to another Next Generation Radio Access Network (NG-RAN) or the movement of the UE back to the EPS (Evolved Packet System) due to poor network coverage in the 5G network and the
20 like.
[0080] It is further important to note that the above method [200] steps for
handling handover in wireless communication network may be performed by the
verification unit [105], a synchronizing unit [107] and a fetching unit [109] of the
25 processor [104] that may work in tandem with the processor [104] to enable the
network node [101] to perform the above mentioned method [200].
[0081] Thereafter, the method terminates at step [210].
24

[0082] Referring to Fig. 3, an exemplary scenario signal flow [300]
indicating the process for handling handover in a communication network
(preferably a 5G communication network) is shown, in accordance with
exemplary implementations of the present disclosure. As depicted in Figure 3, a
5 User Equipment (UE) [301], a Next Generation Radio Access Network (NG-
RAN) [302], a Access and Mobility Management Function (AMF) [303], and a
Session Management Function [304] and Packet Data Network Gateway Control
Plane Function [305] (SMF and PGW-C) work together to enable seamless
connectivity, session management, and data transmission in the communication
10 network. The UE [301] communicates with the NG-RAN [302] for access to the
5G network. The NG-RAN [302] comprises base stations (gNBs) (not shown) responsible for wireless communication and the NG-RAN [302] thereby provides access to the 5G network, facilitating the transmission of data between the UE(s) [301] and the core network.
15
[0083] The AMF [303] is a core network function responsible for access
and mobility management in the communication network which is responsible for
authenticating the UE [301], allocating resources, and handling mobility-related
procedures such as registration, handover, and mobility state management. The
20 SMF [304] and PGW-C [305] work in combination to manage session
establishment, modification, and termination for user data sessions. The SMF [304] handles session management, policy enforcement, and QoS management, while the PGW-C [305] manages control plane signalling for packet data services. After a successful handover of the UE [301] from a first network system to a
25 second network system, at step [S 1], the UE [301] sends a mobility registration
request to the AMF [303] while the AMF [303] starts the mobility registration request wait timer for a fixed period of time.
[0084] Once the fixed period of time is expired or complete, the AMF [303],
30 at step [S2], starts deleting user context (i.e., details including but not limited to
user's identity, a set of service subscriptions, a set of network settings, a user
25

existing session data, and a set of operational parameters necessary for the UE's
connectivity and communication). Thereafter, at step [S3], a SMContext (Session
Management Context) Release Request is sent by the AMF [303] to release the
session associated with the UE [301]. When the UE's session, (such as a data
5 session or a voice call) is terminated or becomes inactive, the AMF [303] initiates
the release of the SMContext Release Request to free up resources and optimize
network utilization. The SMContext Release Request includes relevant
information (such as session identifiers and context parameters) about the session
to be released. Upon receiving the SMContext Release Request, the SMF [304]
10 and PGW-C [305] release the associated resources and terminate the session
thereby ensuring efficient management of network resources and improving overall network performance.
[0085] At step [S4], a SMContext Release Response confirms the
15 successful release of the resources by the SMF [304] and PGW-C [305]. This
message ensures that all network elements involved in the session management process are synchronized and that the resources associated with the terminated session are appropriately released. It is important to note that SM context refers may include but not limited to session identifiers and context parameters etc. Next,
20 at step [S5], a UEContext Release Command is sent by the AMF [303] in the
communication network. The UEContext Release Command is a message to instruct the connected UE [301] to release its context and resources associated with the ongoing session or connection. UEContext Release Command is triggered when the communication network determines that the UE's context
25 needs to be released in such as when the UE [301] is moving out of network
coverage or when the session is terminated. After that step [S6] is performed, wherein a UEContext Release Complete is sent by the UE [301] to acknowledge the UEContext Release Command and thereby confirms the successful release of its context and resources. Upon receiving the UEContext Release Command, the
30 UE [301] releases the context and performs any necessary cleanup procedures.
26

The UE [301] then sends the UEContext Release Complete message back to the AMF [303] in the communication network to indicate that the release process has been completed.
5 [0086] Fig. 4 illustrates an exemplary block diagram of a computing device
[1000] upon which an embodiment of the present disclosure may be implemented.
In an implementation, the computing device [1000] implements the method [200]
for handling handover in wireless communication network by utilising the system
[100]. In another implementation, the computing device [1000] itself implements
10 the method [200] handling handover in wireless communication network in a
multi-network environment using one or more units configured within the computing device [1000], wherein said one or more units are capable of implementing the features as disclosed in the present disclosure.
15 [0087] The computing device [1000] may include a bus [1002] or other
communication mechanism for communicating information, and a hardware processor [1004] coupled with bus [1002] for processing information. The hardware processor [1004] may be, for example, a general purpose microprocessor. The computing device [1000] may also include a main memory
20 [1006], such as a random access memory (RAM), or other dynamic storage
device, coupled to the bus [1002] for storing information and instructions to be executed by the processor [1004]. The main memory [1006] also may be used for storing temporary variables or other intermediate information during execution of the instructions to be executed by the processor [1004]. Such instructions, when
25 stored in non-transitory storage media accessible to the processor [1004], render
the computing device [1000] into a special-purpose machine that is customized to perform the operations specified in the instructions. The computing device [1000] further includes a read only memory (ROM) [1008] or other static storage device coupled to the bus [1002] for storing static information and instructions for the
30 processor [1004].
27

[0088] A storage device [1010], such as a magnetic disk, optical disk, or
solid-state drive is provided and coupled to the bus [1002] for storing information
and instructions. The computing device [1000] may be coupled via the bus [1002]
5 to a display [1012], 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 [1014], including alphanumeric and other keys, touch screen input means, etc. may be coupled to the bus [1002] for communicating information and command selections to the
10 processor [1004]. Another type of user input device may be a cursor controller
[1016], such as a mouse, a trackball, or cursor direction keys, for communicating direction information and command selections to the processor [1004], and for controlling cursor movement on the display [1012]. This input device typically has two degrees of freedom in two axes, a first axis (e.g., x) and a second axis
15 (e.g., y), that allow the device to specify positions in a plane.
[0089] The computing device [1000] 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
20 device [1000] causes or programs the computing device [1000] to be a special-
purpose machine. According to one embodiment, the techniques herein are performed by the computing device [1000] in response to the processor [1004] executing one or more sequences of one or more instructions contained in the main memory [1006]. Such instructions may be read into the main memory [1006] from
25 another storage medium, such as the storage device [1010]. Execution of the
sequences of instructions contained in the main memory [1006] causes the processor [1004] to perform the process steps described herein. In alternative embodiments, hard-wired circuitry may be used in place of or in combination with software instructions.
30
28

[0090] The computing device [1000] also may include a communication
interface [1028] coupled to the bus [1002]. The communication interface [1028]
provides a two-way data communication coupling to a network link [1020] that is
connected to a local network [1022]. The local network [1022] may be connected
5 a host [1024]. For example, the communication interface [1028] may be an
integrated services digital network (ISDN) card, cable modem, satellite modem,
or a modem to provide a data communication connection to a corresponding type
of telephone line. As another example, the communication interface [1028] may
be a local area network (LAN) card to provide a data communication connection
10 to a compatible LAN. Wireless links may also be implemented. In any such
implementation, the communication interface [1028] sends and receives electrical, electromagnetic or optical signals that carry digital data streams representing various types of information.
15 [0091] The computing device [1000] can send messages and receive data,
including program code, through the network(s), the network link [1020] and the communication interface 1028. In the Internet example, a server [1030] might transmit a requested code for an application program through the Internet [1028], the ISP [1026], the local network [1022] and the communication interface [1028].
20 The received code may be executed by the processor [1004] as it is received,
and/or stored in the storage device [1010], or other non-volatile storage for later execution.
[0092] As is evident from the above, the present disclosure provides a
25 technically advanced solution for a method [200] implemented by a system [100].
Thus, the present disclosure involves restoration of the network of the affected UEs; gives a time-efficient system to restore network during the handover of the connection from the first network system to the second network system; helps in avoiding formation of stale sessions; improves overall performance of the
29

network; deletes the existing user context gracefully while ensuring unnecessary capacity utilization of the network.
[0093] While considerable emphasis has been placed herein on the
5 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
10 be implemented is illustrative and non-limiting.
30

We Claim
1. A method [200] implemented by a network node [101] for handling
handover in a communication network, the method [200] comprising:
verifying, by the network node [101] via a processor [104], a reception of a mobility registration request from a user equipment (UE) after a successful handover of the UE from a first network system to a second network system;
initiating, by the network node [101] via the processor [104], a timer to wait for the reception of the mobility registration request for a predetermined time period; and
removing, by the network node [101] via the processor [104], a context of the UE from the second network system in an event the reception of the mobility registration request fails in the predetermined time period.
2. The method [200] as claimed in claim 1, wherein the first network system is an Evolved Packet System (EPS) and the second network system is a 5th Generation System (5GS).
3. The method [200] as claimed in claim 1, wherein the network node [101] is an Access and Mobility Management Function (AMF).
4. The method [200] as claimed in claim 1, wherein the method [200] further comprises registering, by the network node [101], the UE in the second network system by:

- stopping, by the network node [101], the timer in an event the mobility registration request is received in the predetermined time period, and
- registering, via the network node [101], the UE in the second network system and assign a Globally Unique Temporary Identifier (GUTI) to the UE.
5. The method [200] as claimed in claim 1, wherein the context of the UE is
removed from the second network system to avoid stale sessions, and
wherein the context of the UE is removed in the event the reception of the
mobility registration request fails in the predetermined time period.

6. The method [200] as claimed in claim 1, wherein the context corresponds to at least one from among user's identity, a set of service subscriptions, a set of network settings, a user existing session data, and a set of operational parameters necessary for the UE's connectivity and a communication within at least one of the first network system and the second network system.
7. A system [100] implemented by a network node [101] for handling handover in a communication network, the system [100] comprises:
a storage unit [102]; and
a processor [104], coupled to the storage unit [102], the processor [104] causes the network node [101] to:
verify, a reception of a mobility registration request from a user equipment (UE) after a successful handover of the UE from a first network system to a second network system;
initiate, a timer to wait for the reception of the mobility registration request for a predetermined time period; and
remove, a context of the UE from the second network system in an event the reception of the mobility registration request fails in the predetermined time period.
8. The system [100] as claimed in claim 7, wherein the first network system is an Evolved Packet System (EPS) and the second network system is a 5th Generation System (5GS).
9. The system [100] as claimed in claim 7, wherein the network node [101] is an Access and Mobility Management Function (AMF).
10. The system [100] as claimed in claim 7, wherein the processor [104] further causes the network node [101] to register, the UE in the second network system to:
o stop, the timer in an event the mobility registration request is received in the predetermined time period, and
o register, the UE in the second network system and assign a Globally Unique Temporary Identifier (GUTI) to the UE.

11. The system [100] as claimed in claim 7, wherein the context of the UE is removed from the second network system to avoid stale sessions, an wherein the context of the UE is removed in the event the reception of the mobility registration request fails in the predetermined time period.
12. The system [100] as claimed in claim 7, wherein the context corresponds to at least one from among user's identity, a set of service subscriptions, a set of network settings, a user existing session data, and a set of operational parameters necessary for the UE's connectivity and a communication within at least one of the first network system and the second network system.
13. A user equipment (UE) connected to a network node [101], for handling handover in a communication network,
the UE being configured to:
send, a mobility registration request to the network node [101], after a successful handover of the UE from a first network system to a second network system, for verification by the network node [101];
wait, for the reception of the mobility registration request for a predetermined time period, after an initialization of a timer by the network node [101]; and
exit, the second network system, upon removal of a context of the UE from the second network system in an event the reception of the mobility registration request fails in the predetermined period.