FORM 2
THE PATENTS ACT, 1970 (39 of 1970) THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
APPLICANT
of Office-101, Saffron, Nr. JIO PLATFORMS LIMITED
380006, Gujarat, India; Nationality : India
The following specification particularly describes
the invention and the manner in which
it is to be performed

RESERVATION OF RIGHTS
[0001] A portion of the disclosure of this patent document contains material,
which is subject to intellectual property rights such as, but are not limited to, copyright, design, trademark, Integrated Circuit (IC) layout design, and/or trade dress protection, belonging to Jio Platforms Limited (JPL) or its affiliates (hereinafter referred as owner). The owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all rights whatsoever. All rights to such intellectual property are fully reserved by the owner.
FIELD OF DISCLOSURE
[0002] The embodiments of the present disclosure generally relate to
communication networks. The present disclosure relates to a system and method for connecting a user equipment to a fallback network. In particular, present disclosure relates to a system and method for connecting a user equipment from a first network to a second network.
DEFINITION
[0003] As used in the present disclosure, the following terms are generally
intended to have the meaning as set forth below, except to the extent that the context
in which they are used to indicate otherwise.
[0004] The term PCRF as used herein, refers to a Policy and Charging Rules
Function. The PCRF plays a central role in controlling and enforcing policies
related to network resource allocation, quality of service (QoS), and charging for
subscriber sessions.
[0005] The term PCEF as used herein, refers to a Policy and Charging
Enforcement Function. The PCEF plays a central role in enforcing policy control
and charging rules for subscriber sessions, ensuring that service usage is managed
according to operator-defined policies and that subscribers are correctly charged for
their usage.

[0006] The term QCS as used herein, refers to an Online Charging System.
The OCS is responsible for real-time management of charging and policy
enforcement related to subscriber services in a network.
[0007] The term PGW as used herein, refers to a Packet Data Network
Gateway. The PGW serves as the interface between the mobile network and
external packet data networks, such as the internet or private corporate networks.
[0008] The term SPR as used herein, refers to subscriber profile repository.
The SPR is a database that contains subscriber or subscription information.
[0009] The term CCR as used herein, refers to Credit Control Request. The
CCR requests credit authorization and to convey session and service-related
information for a subscriber.
[0010] The term CCA as used herein, refers to Credit Control Answer. The
CCA message is sent in response to the CCR message, and it provides authorization
and policy decisions related to the subscriber sessions.
[0011] The term PGW as used herein, refers to a packet data network
gateway. The PGW acts as the interface between the LTE network and other packet
data networks.
[0012] The term PCID(s) as used herein, refers to Policy Control Identifiers.
These identifiers define which policies and rules should be applied to the
subscriber’s session, including aspects like quality of service (QoS), charging
limits, and service entitlements.
[0013] The term SLR as used herein, refers to a Spending Limit Request
message. The SLR requests information related to spending limits and associated
policy control identifiers (PCIDs) for a subscriber session.
[0014] The term SLA as used herein, refers to a Spending Limit Answer
message. The SLA requests information related to spending limits and associated
policy control identifiers (PCIDs) for a subscriber session.
BACKGROUND OF DISCLOSURE
[0015] The following description of 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 be used only to enhance the understanding of the reader with respect to the present disclosure, and not as admissions of prior art.
[0016] Wireless communication technology has rapidly evolved over the
past few decades. The first generation of wireless communication technology was
based on analog technology that offered only voice services. Further, when the
second-generation (2G) technology was introduced, text messaging and data
services became possible. The 3G technology marked the introduction of high¬
speed internet access, mobile video calling, and location-based services. The fourth
generation (4G) technology revolutionized the wireless communication with faster
data speeds, improved network coverage, and security. Currently, the fifth
generation (5G) technology is being deployed, with even faster data speeds, low
latency, and the ability to connect multiple devices simultaneously.
[0017] As wireless technologies are advancing, there is a need to cope with
the 5G requirements and deliver a high level of service to the subscribers. Technological development has outpaced the infrastructural development of cellular networks. While new generations of cellular networks are developed every decade, its corresponding infrastructure, and by implication its geographical coverage, has not kept pace. In many geographical regions, cellular networks of newer generations may not be available for service. In such regions, user equipment fallback to an older generation network, enabling telecommunication, albeit at lower speeds and costs.
[0018] Existing fallback solutions often involve communicating with some
network entities of the newer generation network for authentication and verification
of subscriber profiles. However, such verifications may be time-consuming,
unreliable, and may not provide optimal services to users.
[0019] There is, therefore, a need in the art to provide a method and a system
that can overcome the shortcomings of the existing prior arts.
SUMMARY

[0020] In an exemplary embodiment, the present invention discloses a
method for connecting a user equipment (UE) from a first network to a second
network. The method comprises receiving, at the second network, a request
associated with the UE from the first network. The method comprises triggering,
by a policy and charging rules function (PCRF), a service request towards an online
charging system (OCS) based on the received request. The method comprises
receiving, from the OCS, a response message at the PCRF based on the triggered
service request. The method comprises extracting, by the PCRF, one or more
attributes associated with the response message. The method comprises evaluating,
by the PCRF, one or more policies based on determining that one or more extracted
attributes meet at least one condition defined on a policy rule engine. The method
comprises connecting the UE to the second network based on the one or more
evaluated policies.
[0021] In an embodiment, the method further comprises querying by the
PCRF, a subscriber profile repository (SPR) for identifying details of a subscriber
profile associated with the UE.
[0022] In an embodiment, the method further comprises provisioning a flag
for the UE when the details of the subscriber profile are not identified in the SPR.
[0023] In an embodiment, the method further comprises creating a dummy
subscriber profile in the SPR when the provisioned flag is enabled.
[0024] In an embodiment, the method further comprises communicating an
error message to the first network when the provisioned flag is disabled.
[0025] In an embodiment, the one or more attributes include at least one of
a policy counter identifier (PCID) and a result code associated with the PCID.
[0026] In an embodiment, the at least one condition is defined on the policy
rule engine for the UE by a network operator.
[0027] In an embodiment, the first network is a fifth generation (5G)
network, and the second network is a fourth generation (4G) network.
[0028] In an exemplary embodiment, the present invention discloses a
system for connecting a user equipment (UE) from a first network to a second
network. The system comprising a receiving unit configured to receive, at the

second network, a request associated with the UE from the first network. The system comprising a database configured to store the received request. The system comprising a processing unit coupled with the receiving unit and the database. The processing unit is configured to receive the request from the database. The processing unit is configured to trigger, by a policy and charging rules function (PCRF), a service request towards an online charging system (OCS) based on the received request. The processing unit is configured to receive, from the OCS, a response message at the PCRF based on the triggered service request. The processing unit is configured to extract, by the PCRF, one or more attributes associated with the response message. The processing unit is configured to evaluate, by the PCRF, one or more policies based on determining that the one or more extracted attributes meet at least one condition defined on a policy rule engine. The processing unit is configured to connect the UE to the second network based on the one or more evaluated policies.
[0029] In an embodiment, the system is further configured to query, by the
PCRF, a subscriber profile repository (SPR) for identifying details of a subscriber profile associated with the UE.
[0030] In an embodiment, the system is further configured to provision a
flag for the UE when the details of the subscriber profile are not identified in the SPR.
[0031] In an embodiment, the system is further configured to create a
dummy subscriber profile in the SPR when the provisioned flag is enabled.
[0032] In an embodiment, the system is further configured to communicate
an error message to the first network when the provisioned flag is disabled.
[0033] In an embodiment, the one or more attributes include at least one of
a policy counter identifier (PCID) and a result code associated with the PCID.
[0034] In an embodiment, the at least one condition is defined for the UE
by a network operator.
[0035] In an embodiment, the first network is a fifth generation (5G)
network, and the second network is a fourth generation (4G) network.

[0036] In an exemplary embodiment, the present invention discloses a user
equipment (UE) communicatively coupled with a first network. The coupling
comprises steps of receiving, by the first network, a connection request from the
UE, sending, by the first network, an acknowledgment of the connection request to
the UE and transmitting a plurality of signals in response to the connection request.
The UE gets connected from the first network to a second network by a method
comprises receiving, at the second network, a request associated with the UE from
the first network. The method comprises triggering, by a policy and charging rules
function (PCRF), a service request towards an online charging system (OCS) based
on the received request. The method comprises receiving, from the OCS, a response
message at the PCRF based on the triggered service request. The method comprises
extracting, by the PCRF, one or more attributes associated with the response
message. The method comprises evaluating, by the PCRF, one or more policies
based on determining that one or more extracted attributes meet at least one
condition defined on a policy rule engine. The method comprises connecting the
UE to the second network based on the one or more evaluated policies.
[0037] The foregoing general description of the illustrative embodiments
and the following detailed description thereof are merely exemplary aspects of the teachings of this disclosure and are not restrictive.
OBJECTS OF THE PRESENT DISCLOSURE
[0038] Some of the objects of the present disclosure, which at least one
embodiment herein satisfies are as listed herein below.
[0039] An object of the present disclosure is to provide a system and a
method for connecting a user equipment to a fallback network.
[0040] An object of the present disclosure is to provide a system and a
method for connecting a user equipment from a first network to a second network.
[0041] Another object of the present disclosure is to provide a system and a
method that allows subscribers to fall back to older generations of networks.
[0042] Another object of the present disclosure is to provide a system and a
method that retains the performance of the older generation network.

[0043] Another object of the present disclosure is to provide a system and a
method that reduces a computational burden on a Policy Charging Function (PCF).
[0044] Another object of the present disclosure is to provide a system and a
method that allows newer generation subscribers to latch on to older generation 5 network where subscriber profile is not available.
BRIEF DESCRIPTION OF DRAWINGS
[0045] The accompanying drawings, which are incorporated herein, and
constitute a part of this disclosure, illustrate exemplary embodiments of the 10 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 15 component. It will be appreciated by those skilled in the art that disclosure of such
drawings includes the disclosure of electrical components, electronic components
or circuitry commonly used to implement such components.
[0046] FIG. 1 illustrates an exemplary network architecture for connecting
a user equipment (UE) from a first network to a second network, in accordance with 20 embodiments of the present disclosure.
[0047] FIG. 2 illustrates a block diagram of the system, in accordance with
embodiments of the present disclosure.
[0048] FIG. 3A illustrates a system architecture of the system, in accordance
with embodiments of the present disclosure.
25 [0049] FIG. 3B illustrates a flowchart for connecting the UE from the first
network to the second network, in accordance with embodiments of the present
disclosure.
[0050] FIG. 4 illustrates an exemplary computer system in which or with
which embodiments of the present disclosure may be implemented.
8

[0051] FIG. 5 illustrates an exemplary flow diagram of a method for
connecting the UE from the first network to the second network, in accordance with embodiments of the present disclosure.
[0052] The foregoing shall be more apparent from the following more
5 detailed description of the disclosure.
LIST OF REFERENCE NUMERALS
100 – Network Architecture
102 - User 10 104 – User Equipment (UE)
106 – First Network
108 – System
110 – Second Network
200 – Block diagram 15 202 – Processor(s)
204 – Memory
206 – Interface(s)
208 – Processing unit
210 – Database 20 212 – Receiving unit
214 – Generation unit
216 – Retrieval unit
218 – Other Engines/Units
300A – Block diagram 25 302 – eNodeB
304 – Policy and charging enforcement function (PCEF) + Packet data network
gateway (PGW)
306 – Policy and charging rules function (PCRF)
308 – Subscriber profile repository (SPR) 30 310 – Online charging system (OCS)
300B- Flow diagram
9

400- A computer system 410 – External Storage Device 420 – Bus
430 – Main Memory 5 440 – Read Only Memory 450 – Mass Storage Device 460 – Communication Port 470 – Processor 500- Flow diagram
10
DETAILED DESCRIPTION OF DISCLOSURE
[0053] 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
15 embodiments 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 not address all of the problems discussed above or might address only some of the problems discussed above. Some of the problems discussed above might not be
20 fully addressed by any of the features described herein.
[0054] The ensuing description provides exemplary embodiments only, and
is not intended to limit the scope, applicability, or configuration of the disclosure. Rather, the ensuing description of the exemplary embodiments will provide those skilled in the art with an enabling description for implementing an exemplary
25 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.
[0055] Specific details are given in the following description to provide a
thorough understanding of the embodiments. However, it will be understood by one
30 of ordinary skill in the art that the embodiments may be practiced without these
10

specific details. For example, circuits, systems, networks, processes, and other components may be shown as components in block diagram form in order not to obscure the embodiments in unnecessary detail. In other instances, well-known circuits, processes, algorithms, structures, and techniques may be shown without 5 unnecessary detail in order to avoid obscuring the embodiments.
[0056] Also, it is noted that individual embodiments may be described as a
process which is depicted as a flowchart, a flow diagram, a data flow diagram, a structure diagram, or a block diagram. Although a flowchart may describe the operations as a sequential process, many of the operations can be performed in
10 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. A process may correspond to a method, a function, a procedure, a subroutine, a subprogram, etc. When a process corresponds to a function, its termination can correspond to a return of the function to the calling
15 function or the main function.
[0057] 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
20 necessarily to be construed as preferred or advantageous over other aspects or designs, nor is it meant to preclude equivalent exemplary structures and techniques known to those of ordinary skill in the art. Furthermore, to the extent that the terms “includes,” “has,” “contains,” and other similar words are used in either the detailed description or the claims, such terms are intended to be inclusive in a manner similar
25 to the term “comprising” as an open transition word without precluding any additional or other elements.
[0058] Reference throughout this specification to “one embodiment” or “an
embodiment” or “an instance” or “one instance” means that a particular feature, structure, or characteristic described in connection with the embodiment is included
30 in at least one embodiment of the present disclosure. Thus, the appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout
11

this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.
[0059] The terminology used herein is for the purpose of describing
5 particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations,
10 elements, and/or components, but do not preclude the presence or addition of one
or more other features, integers, steps, operations, elements, components, and/or
groups thereof. As used herein, the term “and/or” includes any and all combinations
of one or more of the associated listed items.
[0060] The present disclosure relates to a system and a method a user
15 equipment from a first network to a second network. The system receives a request to connect a network from a user equipment (UE). The UE may be a device belonging to a succeeding generation of the network. The request may include a set of unique identifier attributes of the UE. The one or more attributes include at least one of a policy counter identifier (PCID) and a result code associated with the
20 PCID. In an embodiment, the at least one condition is defined for the UE (104) by a network operator. The system generates a dummy subscriber profile based on the set unique identifier attributes and assigns a location access attribute thereto. The dummy subscriber profile may be generated when subscriber profile associated with the unique identifier attributes of the UE is unavailable in the Subscriber
25 Profile Repository (SPR). The SPR stores and manages subscriber-related information and profiles. These profiles contain various details about subscribers, such as their service subscriptions, preferences, access rights, billing information, and authentication credentials. The SPR acts as a centralized database or repository that network elements, such as the Home Subscriber Server (HSS) in mobile
30 networks or the Policy and Charging Rules Function (PCRF), can access to retrieve subscriber information as needed. The PCRF manages policy control, charging, and
12

service quality management in the network. The PCRF enables operators to deliver differentiated services, optimize network resource utilization, and ensure a high-quality user experience for subscribers. The system retrieves a Policy Counter ID (PCID) associated with the UE from an Online Charging System (OCS) based on 5 the set of unique identifier attributes by mapping the set of unique identifier attributes with a corresponding charging rule in the OCS. The OCS is responsible for real-time charging and credit management for various services offered to subscribers. The OCS enables operators to charge subscribers based on actual service usage and provides them with immediate access to services based on their
10 available credit balance. The PCID is an identifier associated with a specific policy change within the network. The PCID is used to track changes in policy rules or parameters applied to subscriber sessions. The system transmits policy and charging rules applicable for allowing cellular communication to the UE in the network.
15 [0061] The various embodiments throughout the disclosure will be
explained in more detail with reference to FIGs. 1-5.
[0062] FIG. 1 illustrates an exemplary network architecture for connecting
a user equipment (UE) from a first network to a second network, in accordance with embodiments of the present disclosure.
20 [0063] Referring to FIG. 1, the network architecture (100) may include a
computing device, or a user equipment (104) associated with a user (102) in an environment. A person of ordinary skill in the art will understand that the user (102) may be individually referred to as the user (102) and collectively referred to as the users (102). Similarly, a person of ordinary skill in the art will understand that user
25 equipment (104) may be individually referred to as the user equipment (104) and collectively referred to as the user equipments (104). A person of ordinary skill in the art will appreciate that the terms “computing device(s)” and “user equipment” may be used interchangeably throughout the disclosure. Although one user equipment (104) is depicted in FIG. 1, however any number of the user equipments
30 (104) may be included without departing from the scope of the ongoing description. In an embodiment, each of the user equipment may have a unique identifier attribute
13

associated therewith. In an embodiment, the unique identifier attribute may be indicative of Mobile Station International Subscriber Directory Number (MSISDN), International Mobile Equipment Identity (IMEI) number, International Mobile Subscriber Identity (IMSI), Subscriber Permanent Identifier (SUPI), and the 5 like.
[0064] In an embodiment, the user equipment (104) may include smart
devices operating in a smart environment, for example, an Internet of Things (IoT) system. In such an embodiment, the user equipment (104) may include, but is not limited to, smartphones, smart watches, smart sensors (e.g., mechanical, thermal,
10 electrical, magnetic, etc.), networked appliances, networked peripheral devices, networked lighting system, communication devices, networked vehicle accessories, networked vehicular devices, smart accessories, tablets, smart television (TV), computers, smart security system, smart home system, other devices for monitoring or interacting with or for the user (102) and/or entities, or any combination thereof.
15 A person of ordinary skill in the art will appreciate that the user equipment (104)
may include, but is not limited to, intelligent, multi-sensing, network-connected
devices, that can integrate seamlessly with each other and/or with a central server
or a cloud-computing system or any other device that is network-connected.
[0065] In an embodiment, the user equipment (104) may include, but is not
20 limited to, a handheld wireless communication device (e.g., a mobile phone, a smartphone, a phablet device, and so on), a wearable computer device(e.g., a head-mounted display computer device, a head-mounted camera device, a wristwatch computer device, and so on), a Global Positioning System (GPS) device, a laptop computer, a tablet computer, or another type of portable computer, a media playing
25 device, a portable gaming system, and/or any other type of computer device with wireless communication capabilities, and the like. In an embodiment, the user equipment (104) may include, but is not limited to, any electrical, electronic, electro-mechanical, or an equipment, or a combination of one or more of the above devices such as virtual reality (VR) devices, augmented reality (AR) devices,
30 laptop, a general-purpose computer, desktop, personal digital assistant, tablet computer, mainframe computer, or any other computing device, wherein the user
14

equipment (104) may include one or more in-built or externally coupled accessories including, but not limited to, a visual aid device such as a camera, an audio aid, a microphone, a keyboard, and input devices for receiving input from the user (102) or the entity such as touch pad, touch enabled screen, electronic pen, and the like. 5 A person of ordinary skill in the art will appreciate that the user equipment (104) may not be restricted to the mentioned devices and various other devices may be used.
[0066] Referring to FIG. 1, the user equipment (104) may communicate
with a system (108) via a first network (106) and a second network (110). In an
10 embodiment, the first network (106) and the second network (110) may include at least one of a Fifth Generation (5G) network, Sixth Generation (6G) network, or the like and Fourth Generation (4G) network, respectively. The first network (106) and the second network (110) may enable the user equipment (104) to communicate with other devices in the network architecture (100) and/or with the system (108).
15 The first network (106) and the second network (110) may include a wireless card or some other transceiver connection to facilitate this communication. In another embodiment, the first network (106) and the second network (110) may be implemented as or include any of a variety of different communication technologies such as a wide area network (WAN), a local area network (LAN), a wireless
20 network, a mobile network, a Virtual Private Network (VPN), the Internet, the Public Switched Telephone Network (PSTN), or the like. In an embodiment, the first network (106) and the second network (110) may include one or more base stations for facilitating communication between the UE (104) and the first network (106) and the second network (110). The UE (104) is communicatively coupled
25 with the first network. The coupling comprises steps of receiving, by the first
network, a connection request from the UE, sending, by the first network, an
acknowledgment of the connection request to the UE, and transmitting a plurality
of signals in response to the connection request.
[0067] The base station may be a network infrastructure that provides
30 wireless access to one or more terminals associated therewith. The base station may have coverage defined to be a predetermined geographic area based on the distance
15

over which a signal may be transmitted. The base station may include, but not be limited to, wireless access point, evolved NodeB (eNodeB), 5G node or next generation NodeB (gNB), wireless point, transmission/reception point (TRP), and the like. In an embodiment, the one or more operational units may include, but not 5 be limited to, transceivers, baseband unit (BBU), remote radio unit (RRU), antennae, mobile switching centres, radio network control units, and one or more processors associated thereto.
[0068] In an embodiment, the first network (106) and the second network
(110) may include one or more network entities that may include, but are not limited
10 to, Serving Gateway (SGW), Packet Data Network (PDN) Gateway (PGW), Mobility Management Entity (MME), and the like. In embodiments where the first network (106) is a 5G network, the first network (106) may further include a user plane, and a control plane having network entities such as an Access and Mobility Management Function (AMF) unit, Session Management Function (SMF) unit, and
15 Network Exposure Function (NEF) units, but not limited thereto. In an
embodiment, the network entities forming the first network (106) may be
implemented as a hardware component, software component, or any combination
thereof.
[0069] In an embodiment, the system (108) may be a network entity
20 indicative of the Policy and Charging Rules Function (PCRF), Policy Charging Function (PCF), or a combination thereof. In an embodiment, the PCRF may be configured to determine policy and charging rules associated with the UE (104) attempting to connect to the second network (110). In an embodiment, the system (108) may be configured to retrieve the charging rules from an Online Charging
25 System (OCS). In an embodiment, the system (108) and the OCS may communicate using the Diameter Protocol. In an embedment, the OCS may be configured to, on receiving a request from the system (108), retrieve a Policy Counter ID (PCID) based on the unique identifier attributes of the UE (104) requesting service. In an embodiment, the PCID may include one or more charging rules applicable to the
30 UE (104). In an embodiment, the system (108) may also be associated with a Charging Function (CHF) interface that monitors the subscriber usage
16

consumption. The subscriber usage consumption may be used by the OCS for determining the PCID.
[0070] In an example, the UE (104) may be associated with a plan to
consume 1 Gigabyte (GB) of data per day, with the speed of the connection 5 reducing after consuming the 1GB of data. The CHF, after monitoring the data, may cause the OCS to retrieve a corresponding PCID indicating that UE (104) has consumed the allocated quota, and must be provided services with a lower speed. The system (108) may fulfil the request for service from the UE (104) based on the PCID received from the OCS. In an example, the system (108) may cause the PGW
10 to allocate bandwidths for connection based on the PCID. In an embodiment, the OCS may have a predetermined set of PCIDs. In other embodiments, the PCIDs may be dynamically generated by the OCS.
[0071] In accordance with embodiments of the present disclosure, the
system (108) may be designed and configured for connecting user equipment to
15 fallback network. In an embodiment, the system (108) may optimize the number of
sessions created and maintained to fulfil requests for service from the UEs (104).
[0072] FIG. 2 illustrates a block diagram (200) of the system (108), in
accordance with embodiments of the present disclosure.
[0073] In an aspect, the system (108) may include one or more processor(s)
20 (202). The one or more processor(s) (202) may be implemented as one or more microprocessors, microcomputers, microcontrollers, edge or fog microcontrollers, digital signal processors, central processing units, logic circuitries, and/or any devices that process data based on operational instructions. Among other capabilities, the one or more processor(s) (202) may be configured to fetch and
25 execute computer-readable instructions stored in a memory (204) of the system (108). The memory (204) may be configured to store one or more computer-readable instructions or routines in a non-transitory computer readable storage medium, which may be fetched and executed to create or share data packets over a network service. The memory (204) may include any non-transitory storage device
30 including, for example, volatile memory such as Random Access Memory (RAM),
17

or non-volatile memory such as Erasable Programmable Read-Only Memory (EPROM), flash memory, and the like.
[0074] Referring to FIG. 2, the system (108) may include an interface(s)
(206). The interface(s) (206) may include a variety of interfaces, for example, 5 interfaces for data input and output devices, referred to as I/O devices, storage devices, and the like. The interface(s) (206) may facilitate communication to/from the system (108). The interface(s) (206) may also provide a communication pathway for one or more components of the system (108). Examples of such components include, but are not limited to, processing unit (208) and a database
10 (210).
[0075] In an embodiment, the processing unit (208) may be implemented as
a combination of hardware and programming (for example, programmable instructions) to implement one or more functionalities of the processing unit (208). In examples described herein, such combinations of hardware and programming
15 may be implemented in several different ways. For example, the programming for the processing unit (208) may be processor-executable instructions stored on a non-transitory machine-readable storage medium and the hardware for the processing unit (208) may include a processing resource (for example, one or more processors), to execute such instructions. In the present examples, the machine-readable storage
20 medium may store instructions that, when executed by the processing resource, implement the processing unit (208). In such examples, the system (108) may include the machine-readable storage medium storing the instructions and the processing resource to execute the instructions, or the machine-readable storage medium may be separate but accessible to the system (108) and the processing
25 resource. In other examples, the processing unit (208) may be implemented by electronic circuitry.
[0076] In an embodiment, the database (210) may include data that may be
either stored or generated as a result of functionalities implemented by any of the components of the processor (202) or the processing unit (208). In an embodiment,
30 the database (210) may be separate from the system (108). In an embodiment, the database (210) may be indicative of including, but not limited to, a relational
18

database, a distributed database, a cloud-based database, or the like. In an
embodiment, the system (108) may include a receiving unit (212).
[0077] In an exemplary embodiment, the processing unit (208) may include
one or more units selected from any of a generation unit (214), a retrieval unit (216) 5 and other engines (218) having functions that may include, but are not limited to, testing, storage, and peripheral functions, such as wireless communication unit for remote operation, audio unit for alerts, and the like.
[0078] In an embodiment, the receiving unit (212) is configured to receive,
at the second network (110), a request associated with the UE (104) from the first
10 network (106). The UE may be a device of a succeeding generation of the network. The request may include a set of unique identifier attributes of the UE (104). In an embodiment, the request may include, but not be limited to, Access Point Name (APN), International Mobile Subscriber Identity (IMSI)/ Subscription Permanent Identifier (SUPI) Range, Mobile Station International Subscriber Directory
15 Number (MSISDN) Range, location attribute, and the like. In an embodiment, the
request may also include the first unique identifier attributes of the UE (104)
requesting service. In an embodiment, the request may be made using a Credit
Control Request (CCR) message.
[0079] The database (210) is configured to store the received request. The
20 processing unit (208) is configured to receive the request from the database (210). The processing unit (208) is configured to trigger, by PCRF, a service request towards the OCS based on the received request. The processing unit (208) is configured to receive, from the OCS, a response message at the PCRF based on the triggered service request. The processing unit (208) is configured to extract, by the
25 PCRF, one or more attributes associated with the response message. The processing unit (208) is configured to evaluate, by the PCRF, one or more policies based on determining that the one or more extracted attributes meet at least one condition defined on a policy rule engine. The processing unit (208) is configured to connect the UE (104) to the second network (110) based on the one or more evaluated
30 policies. In an example, the condition may be related to the UE, for example, the UE (104) may be associated with a plan to consume 1 Gigabytes (GB) of data per
19

day, with a speed of the connection reducing after consuming the 1GB of data so allocating. The CHF, after monitoring the data, may cause the OCS to retrieve a corresponding PCID indicating that UE (104) has consumed the allocated quota, and must be provided services with a lower speed. The system (108) may fulfil the 5 request for service from the UE (104) based on the PCID received from the OCS. In an example, the system (108) may cause the PGW to allocate bandwidths for connection based on the PCID. In an embodiment, the OCS may have a predetermined set of PCIDs. In other embodiments, the PCIDs may be dynamically generated by the OCS.
10 [0080] In an embodiment, the generation unit (214) may generate a dummy
subscriber profile based on the set of unique identifier attributes and assign a location access attribute thereto. The dummy subscriber profile may be generated when the subscriber profile associated with the unique identifier attributes of the UE is unavailable in the SPR. In an embodiment, the SPR may be a database, or a
15 repository of subscriber profiles associated with corresponding policy and charging rules. In an embodiment, the dummy subscriber profiles may also include one or more attributes that may be required for the first network (106) to fulfil requests for service. In an embodiment, the dummy profile may be saved as a cache for subsequent use by the network elements of the first network (106).
20 [0081] In an embodiment, the retrieval unit (216) may retrieve the PCID
associated with the UE from OCS based on the set of unique identifier attributes by mapping the set of unique identifier attributes with a corresponding charging rule in the OCS. In an embodiment, the first network (106) may share the OCS with the succeeding generation of networks. In an example, the first network (106)
25 indicative of a 4G network may share the OCS with a 5G network. The retrieval unit (216) may transmit a response message to the UE (104). In an embodiment, the response message may be indicative of a Credit Control Answer (CCA) message having the policy and charging rules retrieved using the dummy profile. In an embodiment, the CCA message may indicate policy and charging rules applicable
30 for allowing cellular communication to the UE in the network.
20

[0082] The following example is described in the context of where the
system (108) may require interaction with the OCS to provide services to a 5G UE
(104) in the 4G network (110). For instance, the system (108) may receive a Credit
Control Request (CCR) message from a PGW associated with a 4G eNodeB.
5 [0083] In an example, when a 5G subscriber latches on to the 4G network
(110) with the corresponding UE (104), a credit control request may be received on
the PCRF from a Policy and Charging Enforcement Function (PCEF). In such
examples, the system (108) may be indicative of the PCRF.
[0084] In an example, the PCRF may query the corresponding subscriber
10 profile associated with the UE (104) on the SPR interaction. Since the subscriber profile of a UE (104) of a 5G network may be unavailable on the SPR of a 4G network, a 5030-error response may be generated, indicating that the user is unknown. In an example, a configuration flag may be added to support such subscribers to allow services through the 4G network (110). If the flag is enabled,
15 then PCRF may create the dummy subscriber profile. In an example, the OCS may be queried with the dummy subscriber profile. The dummy subscriber profile may be generated substantially based on the unique identifier attributes of the UE (104). In an example, the query may be transmitted as a Spending Limit Request (SLR) message.
20 [0085] When the OCS receives the SLR message, the OCS may respond
with a Spending Limited Answer (SLA) message having the corresponding PCID and a result code. The PCRF may implement the policy and charging rules so retrieved from the PCID. The PCRF may send these policies or charging rules in the CCA answer message.
25 [0086] In an example, the PCRF may be implemented on the APNs or base
stations. In an example, the PCRF may also support voice calls for those subscribers through Rx interface in the 4G network.
[0087] FIG. 3A illustrates a system architecture (300A) of the system (108),
in accordance with embodiments of the present disclosure.
30 [0088] The system (108) includes an eNodeB (302) associated with the first
network (106). The UE (104) is connected to the first network (106). The eNodeB
21

(302) sends a request to Policy and Charging Enforcement Function (PCEF) + Packet Data Network Gateway (PGW) (304) for connecting the user from the first network (106) to a second network (110). The PCEF+PGW (304) communicates the request to the PCRF (306) of the second network. In an example, the PCRF 5 (306) may query the corresponding subscriber profile associated with the UE (104) on the SPR interaction. Since the subscriber profile of the UE (104) of a 5G network may be unavailable on the SPR (308) of a 4G network, a 5030-error response may be generated indicating that the user is unknown. In an example, a configuration flag may be added to support such subscribers to allow services through the 4G
10 network (106). If the flag is enabled, then PCRF (306) may create the dummy subscriber profile. In an example, the OCS (310) may be queried with the dummy subscriber profile. The dummy subscriber profile may be generated substantially based on the unique identifier attributes of the UE (104). In an example, the query may be transmitted as a Spending Limit Request (SLR) message. When the OCS
15 (310) receives the SLR message, the OCS may respond with a Spending Limited Answer (SLA) message having the corresponding PCID and a result code. The PCRF (306) may implement the policy and charging rules so retrieved from the PCID. The PCRF (306) may send these policies or charging rules in the CCA answer message.
20 [0089] FIG. 3B illustrates a flowchart (300B) for connecting the user
equipment (UE) from a first network (106) to a second network (110), in accordance with embodiments of the present disclosure.
[0090] At step 312: A CCR message is received on the PCRF (306) from
the PCEF+PGW (304). The PCRF (306) extracts one or more attributes from the
25 received request.
[0091] At step 314: The PCRF (306) may query the corresponding
subscriber profile associated with the UE (104).
[0092] At step 316: The PCRF (306) fails to find the subscriber profile of
the UE on the SPR (308).
30 [0093] At step 318, The PCRF (306) determines if the 4G network is
configured to support 5G roamer subscribers.
22

[0094] At step 320: When step 318 is non affirmative and the 4G network
is not configured to support 5G out roamer subscribers, the PCRF (306) sends a
5030 error response to the 4G network (110) indicating that the user is unknown.
The error response may be communicated in the CCA message.
5 [0095] At step 322: When step 318 is affirmative, the PCRF (306) creates a
dummy subscriber profile for 5G out roamer subscriber and trigger a Spending Limit Request (SLR) message to the OCS (310).
[0096] At step 324: The OCS (310) communicates the response message
towards PCRF (306) with PCIDs and a result code associated with the PCIDs in the
10 Spending Limited Answer (SLA) message. In an embodiment, the result code may provide a status information regarding the processing of the SLR request. In an embodiment, the result code may include a “DIAMETER_SUCCESS” that indicates successful processing of the SLR message. In an embodiment, the “DIAMETER_SUCCESS” may indicate the PCIDs with their status. The status
15 may comprise an active status or an inactive status. The status of a PCID (active or inactive) indicates whether the associated policy rules and parameters are currently enforced and applicable. In an embodiment, the result code may include error codes such as 5030 (subscriber not found), 5012 (Diameter Unable to Comply), and 3002 (Diameter Unable to Deliver). The 5030 error code indicates challenges such as
20 subscriber identification issues, potentially due to data inconsistencies or user
account discrepancies. Error codes like 5012 and 3002 highlight broader network
or system limitations that may temporarily prevent fulfilling requests or delivering
messages.
[0097] At step 326: The PCRF evaluates the rules of the policy engine based
25 on the attributes of the received request, and policies will be applied when the
attributes get matched with the condition defined on the policy rule engine. PCRF
will send these policies or corresponding rules in CCA answer message.
[0098] FIG. 4 illustrates an exemplary computer system (400) in which or
with which embodiments of the present disclosure may be implemented. As shown
30 in FIG. 4, the computer system (400) may include an external storage device (410), a bus (420), a main memory (430), a read only memory (440), a mass storage device
23

(450), a communication port (460), and a processor (470). A person skilled in the
art will appreciate that the computer system (400) may include more than one
processor (470) and communication ports (460). Processor (470) may include
various modules associated with embodiments of the present disclosure.
5 [0099] In an embodiment, the communication port (460) may be any of an
RS-232 port for use with a modem-based dialup connection, a 10/100 Ethernet port, a Gigabit or 10 Gigabit port using copper or fiber, a serial port, a parallel port, or other existing or future ports. The communication port (460) may be chosen depending on a network, such a Local Area Network (LAN), Wide Area Network
10 (WAN), or any network to which the computer system (400) connects.
[00100] In an embodiment, the memory (430) may be Random Access
Memory (RAM), or any other dynamic storage device commonly known in the art. Read-only memory (440) may be any static storage device(s) e.g., but not limited to, a Programmable Read Only Memory (PROM) chips for storing static
15 information e.g., start-up or Basic Input/Output System (BIOS) instructions for the processor (470).
[00101] In an embodiment, the mass storage (450) may be any current or
future mass storage solution, which may be used to store information and/or instructions. Exemplary mass storage solutions include, but are not limited to,
20 Parallel Advanced Technology Attachment (PATA) or Serial Advanced Technology Attachment (SATA) hard disk drives or solid-state drives (internal or external, e.g., having Universal Serial Bus (USB) and/or Firewire interfaces), one or more optical discs, Redundant Array of Independent Disks (RAID) storage, e.g., an array of disks (e.g., SATA arrays).
25 [00102] In an embodiment, the bus (420) communicatively couples the
processor(s) (470) with the other memory, storage, and communication blocks. The bus (420) may be, e.g., a Peripheral Component Interconnect (PCI)/PCI Extended (PCI-X) bus, Small Computer System Interface (SCSI), Universal Serial Bus (USB) or the like, for connecting expansion cards, drives and other subsystems as well as
30 other buses, such a front side bus (FSB), which connects the processor (470) to the computer system (400).
24

[00103] Optionally, operator and administrative interfaces, e.g., a display,
keyboard, joystick, and a cursor control device, may also be coupled to the bus
(420) to support direct operator interaction with the computer system (400). Other
operator and administrative interfaces may be provided through network
5 connections connected through the communication port (460). Components
described above are meant only to exemplify various possibilities. In no way should
the aforementioned exemplary computer system (400) limit the scope of the present
disclosure.
[00104] FIG. 5 illustrates an exemplary flow diagram of a method (500) for
10 connecting the user equipment (UE) (104) from a first network (106) to a second network (110).
[00105] At step 502, the method (500) comprises receiving, at the second
network (110), a request associated with the UE (104) from the first network (106).
[00106] At step 504, the method (500) comprises triggering, by a policy and
15 charging rules function (PCRF) (306), a service request towards an online charging system (OCS) (310) based on the received request.
[00107] At step 506, the method (500) comprises receiving, from the OCS
(310), a response message at the PCRF (306) based on the triggered service request.
[00108] At step 508, the method (500) comprises extracting, by the PCRF
20 (306), one or more attributes associated with the response message.
[00109] At step 510, the method (500) comprises evaluating, by the PCRF
(306), one or more policies based on determining that the one or more extracted
attributes meet at least one condition defined on a policy rule engine.
[00110] At step 512, the method (500) comprises connecting the UE (104) to
25 the second network (110) based on the one or more evaluated policies.
[00111] In an embodiment, the method further comprises querying by the
PCRF (306), a subscriber profile repository (SPR) (308) for identifying details of a subscriber profile associated with the UE (104). In an embodiment, the method further comprises provisioning a flag for the UE (104) when the details of the
30 subscriber profile are not identified in the SPR (308). In an embodiment, the method further comprises creating a dummy subscriber profile in the SPR (308) when the
25

provisioned flag is enabled. In an embodiment, the method further comprises
communicating an error message to the first network (106) when the provisioned
flag is disabled. In an embodiment, the one or more attributes include at least one
of a policy counter identifier (PCID) and a result code associated with the PCID. In
5 an embodiment, the at least one condition is defined for the UE (104) by a network
operator. In an embodiment, the first network (106) is a fifth generation (5G)
network, and the second network (110) is a fourth generation (4G) network.
[00112] In an exemplary embodiment, the present invention discloses a
system (108) for connecting a user equipment (UE) (104) from a first network (106)
10 to a second network (110). The system comprising a receiving unit (212) configured to receive, at the second network (110), a request associated with the UE (104) from the first network (106). The system comprising a database (210) configured to store the received request. The system comprising a processing unit (208) coupled with the receiving unit (212) and the database (210). The processing unit (208) is
15 configured to receive the request from the database (210). The processing unit (208) is configured to trigger, by a policy and charging rules function (PCRF) (306), a service request towards an online charging system (OCS) (310) based on the received request. The processing unit (208) is configured to receive, from the OCS (310), a response message at the PCRF (306) based on the triggered service request.
20 The processing unit (208) is configured to extract, by the PCRF (306), one or more attributes associated with the response message. The processing unit (208) is configured to evaluate, by the PCRF (306), one or more policies based on determining that the one or more extracted attributes meet at least one condition defined on a policy rule engine. The processing unit (208) is configured to connect
25 the UE (104) to the second network (110) based on the one or more evaluated policies.
[00113] In an exemplary embodiment, the present invention discloses a user
equipment (UE) (104) communicatively coupled with a first network (106). The coupling comprises steps of receiving, by the first network (106), a connection
30 request from the UE (104), sending, by the first network (106), an acknowledgment of the connection request to the UE (104), and transmitting a plurality of signals in
26

response to the connection request. The UE (104) gets connected from the first network (106) to a second network (110) by a method (500) comprises receiving, at the second network (110), a request associated with the UE (104) from the first network (106). The method (500) comprises triggering, by a policy and charging 5 rules function (PCRF) (306), a service request towards an online charging system (OCS) (310) based on the received request. The method (500) comprises receiving, from the OCS (310), a response message at the PCRF (306) based on the triggered service request. The method (500) comprises extracting, by the PCRF (306), one or more attributes associated with the response message. The method (500) comprises
10 evaluating, by the PCRF (306), one or more policies based on determining that one
or more extracted attributes meet at least one condition defined on a policy rule
engine. The method (500) comprises connecting the UE (104) to the second
network (110) based on one or more evaluated policies.
[00114] The present disclosure provides technical advancement related to
15 improving performance of the network. This advancement addresses the limitations of existing solutions by providing a system and method for connecting a subscriber from a first network to a second network when the coverage of the first network is not available. By initiating an Sy message (SLR) to the OCS rather than immediately returning an error code to the PCEF, the PCRF ensures that service
20 continuity is maintained even in scenarios where subscriber profile information is temporarily inaccessible. This approach not only enhances subscriber experience by reducing instances of denied service due to profile unavailability but also enables the PCRF to make informed policy decisions based on real-time subscriber context provided by the OCS. Thus, the present disclosure optimizes network performance,
25 resource allocation and network utilization, ensuring efficient handling of service
requests while adhering to defined policies and regulatory requirements.
[00115] While considerable emphasis has been placed herein on the preferred
embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from
30 the principles of the disclosure. These and other changes in the preferred embodiments of the disclosure will be apparent to those skilled in the art from the
27

disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter to be implemented merely as illustrative of the disclosure and not as limitation.
5 ADVANTAGES OF THE PRESENT DISCLOSURE
[00116] The present disclosure provides a system and a method for
connecting user equipment to fallback network.
[00117] The present disclosure provides provide a system and a method for
connecting a user equipment from a first network to a second network.
10 [00118] The present disclosure provides a system and a method that allows
subscribers to fallback to older generation of networks.
[00119] The present disclosure provides a system and a method that retains
performance of the of the older generation network.
[00120] The present disclosure provides a system and a method that reduces
15 computational burden on the Policy Charging Function (PCF).
[00121] The present disclosure provides a system and a method that allows
newer generation subscribers to latch on to older generation network where
subscriber profile is not available.
28

We Claim:
1. A method (500) for connecting a user equipment (UE) (104) from a first
network (106) to a second network (110), the method (500) comprising:
receiving (502), at the second network (110), a request associated with the UE (104) from the first network (106);
triggering (504), by a policy and charging rules function (PCRF) (306), a service request towards an online charging system (OCS) (310) based on the received request;
receiving (506), from the OCS (310), a response message at the PCRF (306) based on the triggered service request;
extracting (508), by the PCRF (306), one or more attributes associated with the response message;
evaluating (510), by the PCRF (306), one or more policies based on determining that the one or more extracted attributes meet at least one condition defined on a policy rule engine; and
connecting (512) the UE (104) to the second network (110) based on the one or more evaluated policies.
2. The method (500) as claimed in claim 1, further comprising querying, by the PCRF (306), a subscriber profile repository (SPR) (308) for identifying details of a subscriber profile associated with the UE (104).
3. The method (500) as claimed in claim 2 further comprises provisioning a flag for the UE (104) when the details of the subscriber profile are not identified in the SPR (308).
4. The method (500) as claimed in claim 3, further comprising creating a dummy subscriber profile in the SPR (308) when the provisioned flag is enabled.

5. The method (500) as claimed in claim 3, further comprising communicating an error message to the first network (106) when the provisioned flag is disabled.
6. The method (500) as claimed in claim 1, wherein the one or more attributes include at least one of a policy counter identifier (PCID) and a result code associated with the PCID.
7. The method (500) as claimed in claim 1, wherein the at least one condition is defined on the policy rule engine for the UE (104) by a network operator.
8. The method (500) as claimed in claim 1, wherein the first network (106) is a fifth generation (5G) network, and the second network (110) is a fourth generation (4G) network.
9. A system (108) for connecting a user equipment (UE) (104) from a first network (106) to a second network (110), the system (108) comprising:
a receiving unit (212) configured to:
receive, at the second network (110), a request associated with the UE (104) from the first network (106);
a database (210) configured to store the received request;
a processing unit (208) coupled with the receiving unit (212) and the database (210) and is configured to:
receive the request from the database (210);
trigger, by a policy and charging rules function (PCRF) (306), a service request towards an online charging system (OCS) (310) based on the received request;
receive, from the OCS (310), a response message at the PCRF (306) based on the triggered service request;
extract, by the PCRF (306), one or more attributes associated with the response message;

evaluate, by the PCRF (306), one or more policies based on determining that the one or more extracted attributes meet at least one condition defined on a policy rule engine; and
connect the UE (104) to the second network (110) based on the one or more evaluated policies.
10. The system (108) as claimed in claim 9, further configured to query, by the PCRF (306), a subscriber profile repository (SPR) (308) for identifying details of a subscriber profile associated with the UE (104).
11. The system (108) as claimed in claim 10, further configured to provision a flag for the UE (104) when the details of the subscriber profile are not identified in the SPR (308).
12. The system (108) as claimed in claim 11, further configured to create a dummy subscriber profile in the SPR (308) when the provisioned flag is enabled.
13. The system (108) as claimed in claim 11, further configured to communicate an error message to the first network (106) when the provisioned flag is disabled.
14. The system (108) as claimed in claim 9, wherein the one or more attributes include at least one of a policy counter identifier (PCID) and a result code associated with the PCID.
15. The system (108) as claimed in claim 9, wherein the at least one condition is defined on the policy rule engine for the UE (104) by a network operator.

16. The system (108) as claimed in claim 9, wherein the first network (106) is a fifth generation (5G) network, and the second network (110) is a fourth generation (4G) network.
17. A user equipment (UE) (104) communicatively coupled with a first network (106), the coupling comprises steps of:
receiving, by the first network (106), a connection request from the UE (104);
sending, by the first network (106), an acknowledgment of the connection request to the UE (104); and
transmitting a plurality of signals in response to the connection request, wherein the UE (104) gets connected from the first network (106) to a second network (110) by a method (500) as claimed in claim 1.