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

METHOD AND SYSTEM FOR MANAGING A PACKET DATA UNIT SESSION ESTABLISHMENT IN A NETWORK
FIELD OF INVENTION
[0001] Embodiments of the present disclosure generally relate to wireless
communication systems. More particularly, embodiments of the present disclosure relate to method and system for managing a packet data unit (PDU) session establishment in a network.
BACKGROUND
[0002] The following description of the related art is intended to provide
background information pertaining to the field of the disclosure. This section may include certain aspects of the art that may be related to various features of the present disclosure. However, it should be appreciated that this section is used only to enhance the understanding of the reader with respect to the present disclosure, and not as admissions of the prior art.
[0003] 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 antilog 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. As the wireless communication technology has evolved to a great extent, the number of users/subscribers of the wireless networks has also increased to a great extent and it is important for the wireless networks to provide better and smooth services to its subscribers. Session management plays a critical role in providing better services to the customers/subscribers of a telecom network. Improved session management may lead to an improved customer experience. Also, an increased number of sessions for the subscribers may create various problems at a network end and hence impact the user experience and network performance. Therefore, it is required to provide a session management solution that can efficiently handle the sessions created for the subscribers.
[0004] Currently, 3GPP does not define any specific way to limit the
number of sessions that can be created for individual subscribers. This may create problems when network fluctuations occur where multiple sessions (SM Policy Sessions or PDU Binding Sessions) get created for an individual subscriber. Also, this may result in consuming all important resources of the NFs (PCF, BSF and CHF-PC) unnecessarily. Further, many of those created sessions would be stale sessions or non-live sessions which may also result in additional signalling traffic to be sent after stale session audit is done.
[0005] Thus, there exists an imperative need in the art to provide a solution:
(1) that can overcome the limitations of the existing solutions, and (2) by which NFs can avoid additional signalling and conserve the compute, memory and storage resources allocated to NF (PCF/ BSF/ CHF-PC), which the present disclosure aims to address.
SUMMARY

[0006] This section is provided to introduce certain aspects of the present
disclosure in a simplified form that are further described below in the detailed description. This summary is not intended to identify the key features or the scope of the claimed subject matter.
[0007] An aspect of the present disclosure may relate to a method for
managing a Packet Data Unit (PDU) session establishment in a network. The method comprises receiving the PDU session establishment request for a User Equipment (UE), by a first network function (NF). The method further comprises transmitting a policy control create request from the first NF to a second NF. The policy control create request comprises a set of attributes associated with the PDU session establishment request for the UE. Also, the method comprises determining, by the second NF, one of a presence and an absence of an existing policy session associated with the set of attributes for the UE. In addition, the method comprises receiving, by the second NF, maximum permitted policy sessions and a count of established policy sessions, associated with a subset of attributes from the set of attributes, in an event of the absence of the existing policy session. Also, the method comprises determining, by the second NF, whether the count of the established policy control sessions is one of: below and equal to the maximum permitted policy sessions associated with the subset of attributes. Further, the method comprises accepting, by the second NF, the PDU session establishment request from the UE, based on the determination that the count of established policy sessions is below the maximum permitted policy sessions.
[0008] In another exemplary aspect of the present disclosure, the method
further comprises deleting, by the second NF, the existing policy session for the UE, in an event of the presence of the existing policy session for the UE and accepting, by the second NF, the PDU session establishment request from the UE.
[0009] In another exemplary aspect of the present disclosure, the method
further comprises deleting, by the second NF, a policy session from the established

policy sessions, based on the determination that the count of established policy sessions is equal to the maximum permitted policy sessions.
[0010] In an exemplary aspect of the present disclosure, deleting the policy
session from the established policy sessions, is determined based on a timestamp associated with each of the policy session from the established policy sessions.
[0011] In yet another exemplary aspect of the present disclosure, the set of
attributes comprises a Subscription Permanent Identifier (SUPI), a Data Network Name (DNN), a network slice, and a PDU Session ID.
[0012] In another exemplary aspect of the present disclosure, the subset of
attributes of the set of attributes comprises at least the SUPI, DNN, and the network slice.
[0013] In another exemplary aspect of the present disclosure, the first NF is
a Session Management Function (SMF) in the network.
[0014] In yet another exemplary aspect of the present disclosure, the
method further comprises the second NF is a Policy Control Function (PCF) in the network.
[0015] In another exemplary aspect of the present disclosure, the method
further comprises transmitting, by the second NF, to a third NF, a management register request for the UE comprising the subset of attributes. The method further comprises receiving, by the third NF, a maximum permitted binding sessions for the subset of attributes. The method further comprises receiving, by the third NF, a count of existing binding sessions for the subset of attributes. The method comprises determining, by the third NF, whether the count of the existing binding sessions is one of below and equal to the maximum permitted binding sessions. The method further comprises accepting, by the third NF, the management register request from the second NF, based on the determining that the count of the existing binding sessions is below the maximum permitted binding sessions. In addition,

the method comprises transmitting, by the third NF, an acceptance response for the management register request, to the second NF.
[0016] In another exemplary aspect of the present disclosure, based on the
determination that the count of the existing binding sessions is equal to the maximum permitted binding sessions, the third NF determines one of a rejected response and an acceptance response based on a flag value in a user configurable table.
[0017] In another exemplary aspect of the present disclosure, the rejected
response is transmitted to the second NF, based on a true value of the flag in the user configurable table.
[0018] In another exemplary aspect of the present disclosure, the
acceptance response is transmitted to the second NF, based on a false value of the flag in the user configurable table.
[0019] In another exemplary aspect of the present disclosure, the
acceptance response comprises deleting a binding session of the existing binding sessions for the subset of attributes.
[0020] In yet another exemplary aspect of the present disclosure, deleting
the binding session from the existing binding sessions is determined based on a timestamp associated with each binding session of the existing binding sessions.
[0021] In another exemplary aspect of the present disclosure, the third NF
is a Binding Support Function (BSF) in the network.
[0022] In another exemplary aspect of the present disclosure, the method
comprises transmitting, by the second NF, to a fourth NF, a spending limit control session request associated with the subset of attributes. The method further comprises receiving, by the fourth NF, a maximum permitted spending limit control sessions for the subset of attributes. The method comprises receiving, by

the fourth NF, a count of existing spending limit control sessions for the subset of
attributes. Also, the method comprises determining, by the fourth NF, whether the
count of the existing spending limit control sessions is one of below and equal to
the maximum permitted spending limit control session. The method further
5 comprises accepting, by the fourth NF, the spending limit control session request
from the second NF, based on the determining that the count of the existing
spending limit control sessions is below the maximum permitted spending limit
control sessions. The method comprises transmitting, by the fourth NF, the
acceptance response for the spending limit control session request, to the second
10 NF.
[0023] In another exemplary aspect of the present disclosure, the method
further comprises deleting, by the fourth NF, a spending limit control session from the existing spending limit control sessions, based on the determination that the
15 count of the existing spending limit control sessions is equal to the maximum
permitted spending limit control sessions. The deleting of the spending limit control session from the existing spending limit control sessions is based on a timestamp associated each of the spending limit control session from the existing spending limit control sessions. Also, the method comprises accepting, by the
20 fourth NF, the spending limit control request, from the second NF. The method
further comprises transmitting, by the fourth NF, the acceptance response for the spending limit control session request, to the second NF.
[0024] In another exemplary aspect of the present disclosure, the fourth NF
25 is a Charging Function (CHF) in the network.
[0025] In another exemplary aspect of the present disclosure, the maximum
permitted policy sessions, associated with the subset of attributes is received from
a configurable table configured at the second NF.
30
[0026] In yet another exemplary aspect of the present disclosure, the
method further comprises transmitting, by the first NF, to the fourth NF, a
7

converged charging create request associated with the subset of attributes. The
method comprises receiving, by the fourth NF, a maximum permitted PDU
sessions for the subset of attributes. The method comprises receiving, by the fourth
NF, a count of existing PDU sessions for the subset of attributes. The method
5 further comprises determining, by the fourth NF, whether the count of the existing
PDU sessions is one of below and equal to the maximum permitted PDU sessions.
The method comprises accepting, by the fourth NF, the converged charging create
request from the first NF, based on the determining that the count of the existing
PDU sessions is below the maximum permitted PDU sessions. The method
10 comprises transmitting, an acceptance response for the converged charging create
request, to the first NF.
[0027] In another exemplary aspect of the present disclosure, the method
further comprises deleting, by the fourth NF, a PDU session from the existing
15 PDU sessions, based on the determining that the count of the existing PDU
sessions is equal to the maximum permitted PDU sessions. The deleting of the PDU session from the existing PDU sessions is based on a timestamp associated with each of the PDU session from the existing PDU sessions. Further, the method comprises accepting, by the fourth NF, the charging service request, from the first
20 NF. Also, the method comprises transmitting, an acceptance response for the
converged charging create request, to the first NF.
[0028] Another aspect of the present disclosure may relate to a system for
managing a Packet Data Unit (PDU) session establishment in a network. The
25 system comprises a first transceiver unit, at a first network function (NF),
configured to receive, the PDU session establishment request for a User Equipment (UE). The first transceiver unit is configured to transmit, from the first NF to a second NF, a policy control create request comprising a set of attributes associated with the PDU session establishment request for the UE. The system
30 further comprises a second processing unit, at the second NF, configured to
determine, one of a presence and an absence of an existing policy session
8

associated with the set of attributes for the UE. Also, the system comprises a
second transceiver unit, at the second NF, configured to receive maximum
permitted policy sessions and a count of established policy sessions, associated
with a subset of attributes from the set of attributes, in an event of the absence of
5 the existing policy session. Further, the second processing unit, at the second NF,
is configured to determine, whether the count of established policy sessions is one
of below and equal to the maximum permitted policy sessions associated with the
subset of attributes. The system further comprises a second processing unit, at the
second NF, configured to accept the PDU session establishment request for the
10 UE, based on the determination that the count of established policy sessions is
below the maximum permitted policy sessions.
[0029] In another exemplary aspect of the present disclosure, the second
processing unit, at the second NF, is further configured to delete the existing
15 policy session for the UE, in an event of the presence of the existing policy session
for the UE and accept the PDU session establishment request from the UE.
[0030] In another exemplary aspect of the present disclosure, the second
processing unit, at the second NF, is further configured to delete, a policy session
20 from the established policy sessions, based on the determining that the count of
established policy sessions is equal to the maximum permitted policy sessions.
[0031] In yet another exemplary aspect of the present disclosure, the
deleting the policy session from the established policy sessions, is determined
25 based on a timestamp associated with each of the policy session from the
established policy sessions.
[0032] In another exemplary aspect of the present disclosure, the set of
attributes comprises a Subscription Permanent Identifier (SUPI), a Data Network
30 Name (DNN), a network slice, and a PDU Session ID.
9

[0033] In another exemplary aspect of the present disclosure, the subset of
attributes of the set of attributes comprises at least a SUPI, a DNN, and a network slice.
5 [0034] In another exemplary aspect of the present disclosure, the first NF is
a Session Management Function (SMF) in the network.
[0035] In another exemplary aspect of the present disclosure, the second NF
is a Policy Control Function (PCF) in the network.
10
[0036] In another exemplary aspect of the present disclosure, the system
further comprises the second transceiver unit, at the second NF, that is configured
to transmit, to a third NF, a management register request for the UE comprising
the subset of attributes. Also, the system comprises a third transceiver unit, at the
15 third NF, that is configured to receive, a maximum permitted binding sessions for
the subset of attributes and receive, a count of existing binding sessions for the subset of attributes. The system comprises a third processing unit, at the third NF, configured to determine, whether the count of the existing binding sessions is one of below and equal to the maximum permitted binding sessions and accept, the
20 management register request from the second NF, based on the determining that
the count of the existing binding sessions is below the maximum permitted
binding sessions. In addition, the system comprises the third transceiver unit, at
the third NF, that is further configured to transmit, an acceptance response for the
management register request, to the second NF.
25
[0037] In another exemplary aspect of the present disclosure, based on the
determination that the count of the existing binding sessions is equal to the
maximum permitted binding sessions, the third processing unit at the third NF,
determines one of a rejected response and an acceptance response based on a flag
30 value in a user configurable table.
10

[0038] In another exemplary aspect of the present disclosure, the rejected
response is transmitted by the third transceiver unit, to the second NF, based on a true value of the flag in the user configurable table.
5 [0039] In another exemplary aspect of the present disclosure, the
acceptance response is transmitted by the third transceiver unit, to the second NF, based on a false value of the flag in the user configurable table.
[0040] In another exemplary aspect of the present disclosure, the
10 acceptance response comprises deleting, by the third processing unit, at the third
NF, a binding session from the existing binding sessions for the subset of attributes.
[0041] In another exemplary aspect of the present disclosure, the deleting
15 of the binding session from the existing binding sessions is determined by the third
processing unit, based on a timestamp associated with each binding session of the existing binding sessions.
[0042] In an exemplary aspect of the present disclosure, the third NF is a
20 Binding Support Function (BSF) in the network.
[0043] In an exemplary aspect of the present disclosure, the system further
comprises the second transceiver unit, at the second NF, configured to transmit, to a fourth NF, a spending limit control session request associated with the subset
25 of attributes and a fourth transceiver unit, at the fourth NF, configured to receive,
a maximum permitted spending limit control sessions for the combination of the subset of attributes. The fourth transceiver unit is further configured to receive, a count of existing spending limit control sessions for the subset of attributes. Also, the system includes a third processing unit, at the fourth NF, configured to
30 determine, whether the count of the existing spending limit control sessions is one
of below and equal to the maximum permitted spending limit control sessions and accept, the spending limit control session request from the second NF, based on the determining that the count of the existing spending limit control sessions is
11

below the maximum permitted spending limit control sessions. Furthermore, the fourth transceiver unit, at the fourth NF, is configured to transmit, the acceptance response for the spending limit control session request, to the second NF.
5 [0044] In an exemplary aspect of the present disclosure, the system
comprises the third processing unit, at the fourth NF, that is further configured to delete, a spending limit control session from the existing spending limit control sessions, based on the determining that the count of the existing spending limit control sessions is equal to the maximum permitted spending limit control
10 sessions, wherein the deleting of the spending limit control session from the
existing spending limit control sessions is based on a timestamp associated with each of the spending limit control session from the existing spending limit control sessions and accept, the spending limit control request, from the second NF. Also, the system comprises the fourth transceiver unit, at the fourth NF, that is further
15 configured to transmit the acceptance response for the spending limit control
session request, to the second NF.
[0045] In an exemplary aspect of the present disclosure, the fourth NF is a
Charging Function (CHF) in the network.
20
[0046] In an exemplary aspect of the present disclosure, the maximum
permitted policy control sessions, associated with the subset of attributes is
received from a configurable table configured at the second NF.
25 [0047] In an exemplary aspect of the present disclosure, the system
comprises the first transceiver unit, at the First NF, is further configured to transmit, to the fourth NF, a converged charging create request associated with the subset of attributes. The system comprises the fourth transceiver unit, at the fourth NF, that is further configured to: receive a maximum permitted PDU sessions for
30 the subset of attributes, and a count of existing PDU sessions for the subset of
attributes. Further, the system comprises the third processing unit, at the fourth NF, that is configured to determine, whether the count of the existing PDU
12

sessions is one of below and equal to the maximum permitted PDU sessions, and
accept, the converged charging create request from the first NF, based on the
determining that the count of the existing PDU sessions is below the maximum
permitted PDU sessions. Also, the system comprises the fourth transceiver unit,
5 at the fourth NF, that is further configured to transmit an acceptance response for
the converged charging create request, to the first NF.
[0048] In an exemplary aspect of the present disclosure, the third processing
unit, at the fourth NF is further configured to delete a PDU session from the
10 existing PDU sessions, based on the determination that the count of the existing
PDU session is equal to the maximum permitted PDU session. Deleting the PDU session from the existing from the existing PDU sessions, is based on a timestamp associated with each of the PDU session from the existing PDU sessions. Further, the third processing unit is configured to accept, the charging service request, from
15 the first NF; and the fourth transceiver unit, at the fourth NF, is further configured
to transmit, an acceptance response for the converged charging create request, to the first NF.
[0049] Yet another aspect of the present disclosure may relate to a method
20 for managing a Packet Data Unit (PDU) session establishment in a network is
disclosed. The method comprises: receiving, by a network function (NF) service
consumer, the PDU session establishment request for a User Equipment (UE); and
connecting, by the first NF, to a second NF to process the PDU session
establishment request for the UE. Further, the method comprises transmitting, by
25 the first NF, to the second NF, a policy control create request comprising a set of
attributes associated with the PDU session establishment request for the UE. The
method comprises determining, by the second NF, one of a presence and an
absence of an existing policy association, associated with the set of attributes for
the UE. In addition, the method comprises identifying, by the second NF, a first
30 timestamp associated with the existing policy association, based on determining
the presence of the existing policy association. The method comprises identifying,
by the second NF, a second timestamp associated with the policy control create
13

request. The method comprises comparing, by the second NF, the first timestamp and the second timestamp. Also, the method comprises accepting, by the second NF, the policy control create request based on the comparing.
5 [0050] In an exemplary aspect of the present disclosure, comparing the first
timestamp and the second timestamp comprises: determining, if the second timestamp is greater than the first timestamp.
[0051] In an exemplary aspect of the present disclosure, accepting the
10 policy control request is based on determining that the second timestamp is greater
than the first timestamp.
[0052] In an exemplary aspect of the present disclosure, accepting the
policy control create request, comprises deleting, the existing policy association.
15
[0053] In an exemplary aspect of the present disclosure, the set of attributes
comprises a Subscription Permanent Identifier (SUPI), a Data Network Name
(DNN), a network slice, and a PDU Session ID.
20 [0054] In another exemplary aspect of the present disclosure, the method
comprises receiving, by the second NF, a maximum permitted policy associations, associated with a subset of attributes from the set of attributes, in an event of the absence of the existing policy association. The method further comprises determining, by the second NF, a count of existing associations, associated with
25 the subset of attributes from the set of attributes. The method comprises rejecting,
by the second NF, the policy control create request based on determining that the count of existing associations has reached the maximum permitted policy associations.
30 [0055] In an exemplary aspect of the present disclosure, the subset of
attributes comprises at least the SUPI, a DNN, and a network slice.
14

[0056] Yet another aspect of the present disclosure relates to a system for
managing a Packet Data Unit (PDU) session establishment in a network. The
system comprises a first transceiver unit, at a network function (NF) service
consumer, configured to: receive the PDU session establishment request for a User
5 Equipment (UE). In addition, the first transceiver unit is configured to connect to
a second NF to process the PDU session establishment request from the UE. Also, the first transceiver unit is configured to transmit, to the second NF, a policy control create request comprising a set of attributes associated with the PDU session establishment request for the UE. The system comprises a second
10 processing unit, at the second NF, configured to: determine one of a presence and
an absence of an existing policy session associated with the set of attributes for the UE; and identify a first timestamp associated with the existing policy association, based on determining the presence of the existing policy association. The second processing unit is further configured to identify a second timestamp
15 associated with the policy control create request; and compare the first timestamp
with the second timestamp. Further, the second processing unit, at the second NF, is configured to accept the policy control create request based on the comparison of the first timestamp with the second timestamp.
20 [0057] In an exemplary aspect of the present disclosure, the second
processing, upon the comparison of the first timestamp with the second timestamp, is further configured to determine if the second timestamp is greater than the first timestamp.
25 [0058] In an exemplary aspect of the present disclosure, the second
processing unit is configured to accept the policy control request based on determining that the second timestamp is greater than the first timestamp.
[0059] In an exemplary aspect of the present disclosure, the second
30 processing unit is further configured to delete the existing policy association.
15

[0060] In an exemplary aspect of the present disclosure, the set of attributes
comprises a Subscription Permanent Identifier (SUPI), a Data Network Name (DNN), a network slice, and a PDU Session ID.
5 [0061] In an exemplary aspect of the present disclosure, the first transceiver
unit is further configured to receive, by the second NF, a maximum permitted
policy associations, associated with a subset of attributes from the set of attributes,
in an event of the absence of the existing policy association. Also, the first
transceiver unit is configured to determine a count of existing associations,
10 associated with the subset of attributes from the set of attributes; and reject the
policy control create request based on determining that the count of existing associations has reached the maximum permitted policy associations.
[0062] In an exemplary aspect of the present disclosure, the subset of
15 attributes comprises at least the SUPI, DNN, and the network slice.
[0063] Yet another aspect of the present disclosure may relate to a non-
transitory computer-readable storage medium for managing a Packet Data Unit (PDU) session establishment in a network, the storage medium comprising
20 executable code which, when executed by one or more units of a system, causes:
a first transceiver unit, at a first network function (NF), configured to receive, the PDU session establishment request for a User Equipment (UE) and transmit, from the first NF, to a second NF, a policy control create request comprising a set of attributes associated with the PDU session establishment request for the UE.
25 Further, the executable code which, when executed by the one or more units of
the system, causes: a second processing unit, at the second NF, configured to determine, one of a presence and an absence of an existing policy session associated with the set of attributes for the UE; and a second transceiver unit, at the second NF, to receive, maximum permitted policy sessions and a count of
30 established policy sessions, associated with a subset of attributes from the set of
attributes, in an event of the absence of the existing policy session. Further, the executable code which, when executed causes the second processing unit, at the
16

second NF, to determine, whether the count of established policy sessions is one
of below and equal to the maximum permitted policy sessions associated with the
subset of attributes; and the second processing unit, to accept, the PDU session
establishment request for the UE, based on the determination that the count of
5 established policy sessions is below the maximum permitted policy sessions.
[0064] Yet another aspect of the present disclosure may relate to a non-
transitory computer-readable storage medium storing instructions for managing a Packet Data Unit (PDU) session establishment in a network, the instructions
10 comprising executable code which, when executed by one or more units of a
system, causes: a first transceiver unit to receive the PDU session establishment request for a User Equipment (UE); connect to a second NF to process the PDU session establishment request from the UE; and transmit, to the second NF, a policy control create request comprising a set of attributes associated with the
15 PDU session establishment request for the UE. Further, the executable code when
executed by the one or more units of the system, causes a second processing unit to identify a first timestamp associated with the existing policy association, based on determining the presence of the existing policy association; to identify a second timestamp associated with the policy control create request; and to compare the
20 first timestamp with the second timestamp. Also, the executable code when
executed by the one or more units of the system, causes the second processing unit to accept the policy control create request based on the comparison of the first timestamp with the second timestamp.
25 OBJECTS OF THE INVENTION
[0065] Some of the objects of the present disclosure, which at least one
embodiment disclosed herein satisfies are listed herein below.
17

[0066] It is an object of the present disclosure to provide a system and a
method for managing a Packet Data Unit (PDU) session establishment in a network.
5 [0067] It is another object of the present disclosure to provide a solution to
control an increase in a number of stale sessions which in turn results in saving the signalling traffic that is sent for validation of stale sessions.
[0068] It is another object of the present disclosure to provide a solution to
10 remove the faulty devices or network components leading to creation of multiple
sessions.
[0069] It is yet another object of the present disclosure to provide a solution
that can optimize the resources (compute, memory and storage) used by Network
15 Function (NF) by deleting or overwriting old sessions which are no longer live in
network with assumption that devices in network have capabilities that are understood by service provider.
DESCRIPTION OF THE DRAWINGS
20
[0070] The accompanying drawings, which are incorporated herein, and
constitute a part of this disclosure, illustrate exemplary embodiments of the disclosed methods and systems in which like reference numerals refer to the same parts throughout the different drawings. Components in the drawings are not
25 necessarily to scale, emphasis instead being placed upon clearly illustrating the
principles of the present disclosure. Also, the embodiments shown in the figures are not to be construed as limiting the disclosure, but the possible variants of the method and system according to the disclosure are illustrated herein to highlight the advantages of the disclosure. It will be appreciated by those skilled in the art
30 that disclosure of such drawings includes disclosure of electrical components or
circuitry commonly used to implement such components.
18

[0071] FIG. 1 illustrates an exemplary block diagram of a system for
managing a Packet Data Unit (PDU) session establishment in a network, in accordance with exemplary embodiments of the present disclosure. 5
[0072] FIG. 2 illustrates an exemplary system architecture depicting
various network elements for managing the PDU session establishment in the network, in accordance with exemplary implementation of the present disclosure.
10 [0073] FIG. 3A and FIG. 3B illustrate an exemplary process flow diagram
of the system, in accordance with exemplary implementations of the present disclosure.
[0074] FIG. 4A and FIG. 4B illustrate another exemplary process flow
15 diagram of the system, in accordance with exemplary implementations of the
present disclosure.
[0075] FIG. 5 illustrates a method flow diagram for managing the Packet
Data Unit (PDU) session establishment in the network, in accordance with
20 exemplary implementations of the present disclosure.
[0076] FIG. 6 illustrates another method flow diagram for managing the
Packet Data Unit (PDU) session establishment in the network, in accordance with exemplary implementations of the present disclosure 25
[0077] The foregoing shall be more apparent from the following more
detailed description of the disclosure.
30
DETAILED DESCRIPTION
19

[0078] In the following description, for the purposes of explanation, various
specific details are set forth to provide a thorough understanding of embodiments
of the present disclosure. It will be apparent, however, that embodiments of the
present disclosure may be practiced without these specific details. Several features
5 described hereafter may each be used independently of one another or with any
combination of other features. An individual feature may not address any of the problems discussed above or might address only some of the problems discussed above.
10 [0079] The ensuing description provides exemplary embodiments only, and
is not intended to limit the scope, applicability, or configuration of the disclosure. Rather, the ensuing description of the exemplary embodiments will provide those skilled in the art with an enabling description for implementing an exemplary embodiment. It should be understood that various changes may be made in the
15 function and arrangement of elements without departing from the spirit and scope
of the disclosure as set forth.
[0080] Specific details are given in the following description to provide a
thorough understanding of the embodiments. However, it will be understood by
20 one of ordinary skill in the art that the embodiments may be practiced without
these specific details. For example, circuits, systems, processes, and other components may be shown as components in block diagram form in order not to obscure the embodiments in unnecessary detail.
25 [0081] Also, it is noted that individual embodiments may be described as a
process which is depicted as a flowchart, a flow diagram, a data flow diagram, a
structure diagram, or a block diagram. Although a flowchart may describe the
operations as a sequential process, many of the operations may be performed in
parallel or concurrently. In addition, the order of the operations may be re-
30 arranged. A process is terminated when its operations are completed but could
have additional steps not included in a figure.
20

[0082] 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,
5 any aspect or design described herein as “exemplary” and/or “demonstrative” is
not necessarily to be construed as preferred or advantageous over other aspects or
designs, nor is it meant to preclude equivalent exemplary structures and
techniques known to those of ordinary skill in the art. Furthermore, to the extent
that the terms “includes”, “has”, “contains” and other similar words are used in
10 either the detailed description or the claims, such terms are intended to be
inclusive in a manner like the term “comprising” as an open transition word without precluding any additional or other elements.
[0083] As used herein, a “processing unit” or “processor” or “operating
15 processor” includes one or more processors, wherein processor refers to any logic
circuitry for processing instructions. A processor may be a general-purpose
processor, a special purpose processor, a conventional processor, a digital signal
processor, a plurality of microprocessors, one or more microprocessors in
association with a (Digital Signal Processing) DSP core, a controller, a
20 microcontroller, Application Specific Integrated Circuits, Field Programmable
Gate Array circuits, any other type of integrated circuits, etc. The processor may
perform signal coding data processing, input/output processing, and/or any other
functionality that enables the working of the system according to the present
disclosure. More specifically, the processor or processing unit is a hardware
25 processor.
[0084] As used herein, “a user equipment”, “a user device”, “a smart-user-
device”, “a smart-device”, “an electronic device”, “a mobile device”, “a handheld
device”, “a wireless communication device”, “a mobile communication device”,
30 “a communication device” may be any electrical, electronic and/or computing
device or equipment, capable of implementing the features of the present disclosure. The user equipment/device may include, but is not limited to, a mobile
21

phone, smart phone, laptop, a general-purpose computer, desktop, personal digital
assistant, tablet computer, wearable device or any other computing device which
is capable of implementing the features of the present disclosure. Also, the user
device may contain at least one input means configured to receive an input from
5 at least one of a transceiver unit, a processing unit, a storage unit, a detection unit
and any other such unit(s) which are required to implement the features of the present disclosure.
[0085] As used herein, “storage unit” or “memory unit” refers to a machine
10 or computer-readable medium including any mechanism for storing information
in a form readable by a computer or similar machine. For example, a computer-
readable medium includes read-only memory (“ROM”), random access memory
(“RAM”), magnetic disk storage media, optical storage media, flash memory
devices or other types of machine-accessible storage media. The storage unit
15 stores at least the data that may be required by one or more units of the system to
perform their respective functions.
[0086] As used herein “interface” or “user interface refers to a shared
boundary across which two or more separate components of a system exchange
20 information or data. The interface may also be referred to a set of rules or protocols
that define communication or interaction of one or more modules or one or more units with each other, which also includes the methods, functions, or procedures that may be called.
25 [0087] All modules, units, components used herein, unless explicitly
excluded herein, may be software modules or hardware processors, the processors being a general-purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a
30 microcontroller, Application Specific Integrated Circuits (ASIC), Field
Programmable Gate Array circuits (FPGA), any other type of integrated circuits, etc.
22

[0088] As used herein the transceiver unit includes at least one receiver and
at least one transmitter configured respectively for receiving and transmitting data,
signals, information or a combination thereof between units/components within
5 the system and/or connected with the system.
[0089] As discussed in the background section, the current known solutions
have several shortcomings. Currently, 3GPP does not define any specific way to limit the number of sessions that can be created for individual subscribers. This
10 may create problems when network fluctuations occur where multiple sessions
(SM Policy Sessions or PDU Binding Sessions or Spending Limit Control) are created for an individual subscriber. Also, this may result in consuming all important resources of the NFs (PCF, BSF and CHF-PC) unnecessarily. Further, many of those created sessions would be stale sessions or non-live sessions which
15 may also result in additional signalling traffic to be sent after stale session audit is
done. The present disclosure aims to overcome the problems mentioned in the background section and other existing problems in this field of technology by providing method and system for managing a Packet Data Unit (PDU) session establishment in a network
20
[0090] FIG. 1 illustrates an exemplary block diagram of a system [100] for
managing a Packet Data Unit (PDU) session establishment in a network, in accordance with exemplary embodiments of the present disclosure. The network may be a 5G core network, 6G core network and the like. As shown in FIG. 1, the
25 system [100] includes a First NF (SMF) [204] comprising a first transceiver unit
[102], a first processing unit [104 and a first storage unit [106]. The system [100] further includes a Second NF (PCF) [216] comprising a second transceiver unit [108], a second processing unit [110], and a second storage unit [112]. The system [100] further includes a Third NF (BSF) [208] comprising a third transceiver unit
30 [114], a third processing unit [116] and a third storage unit [118]. The system
[100] further includes a Fourth NF (CHF) [206] comprising a fourth transceiver
23

unit [120], a fourth processing unit [122] and a fourth storage unit [124]. Further,
the first storage unit [106] is associated with the first transceiver unit [102]. The
second storage unit [112] is associated with the second transceiver unit [108]. The
third storage unit [118] is associated with the third transceiver unit [114] and the
5 fourth storage unit [124] is associated with the fourth transceiver unit [120].
[0091] Further, the exemplary block diagram of the system [100] as shown
in FIG. 1 is intended to be read in conjunction with an exemplary architecture
[200] as shown in FIG. 2. The FIG. 1 and FIG. 2 complement each other.
10
[0092] It is to be noted that the number of transceiver units may not be
limited to the mentioned number of units and may be more or less than four. It is
to be noted that the number of the processing units may not be limited to the
mentioned number of units and may be more or less than four. It is to be noted
15 that the number of the storage units may not be limited to the mentioned number
of units and may be more or less than four. All the components of the system [100]
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.
20 [0093] The first transceiver unit [102], at a first network function (NF), is
configured to receive the PDU session establishment request for a User Equipment (UE). In general, PDU session establishment is a process of establishing a data path between the UE and the network. Further, a PDU session is a logical connection between the UE and the network, such as the internet or a private
25 network. The PDU session is used to carry user data and may support different
types of services, such as voice, video, and data. The PDU session establishment request may include information about the type of service that the UE wants to use, and a type of network traffic (such as real-time network traffic or non-real-time network traffic). Further, the first NF is a Session Management Function
30 (SMF) [204] in the network. In general, the first NF/SMF [204] is a core network
function responsible for managing session-related aspects, such as establishing, modifying, and releasing sessions. The SMF [204] coordinates with a User Plane
24

Function (UPF) for data forwarding and handles IP address allocation and Quality
of Service (QoS) enforcement. In an implementation, the first transceiver unit
[102] is configured to connect with a second NF to process the PDU session
establishment request from the UE.
5
[0094] Also, the first transceiver unit [102] is configured to transmit, from
the first NF to the second NF, a policy control create request comprising a set of
attributes associated with the PDU session establishment request for the UE. The
policy control create request may be a request to create a new policy control
10 session or update an existing one. The second NF is a Policy Control Function
(PCF) [216] in the network. The PCF is responsible for policy control decisions and flow-based charging control functionalities. The second NF/PCF [216] provides policies for policies application and service data flow detection, gating, QoS, flow-based charging, traffic steering control, usage monitoring control,
15 access traffic steering, switching and steering within a PDU Session, access
network information report, Time Sensitive Networking (TSN) Bridge management Container (BMIC), TSN port management information container, TSN TSCAI input container and RAN support information to the SMF [204]. Further, the SMF [204] facilitates enforcement of session management related
20 policy decisions from the PCF [216], related to service flow detection, QoS,
charging, gating, traffic usage reporting, traffic steering and access traffic steering, switching and splitting within a PDU Session. Further, when the second NF/PCF [216] accepts the policy control create request from the first NF/SMF [204], the related policy rules associated with the UE are processed by the first processing
25 unit [104] at the first NF/SMF [204] and stored in the first storage unit [106].
[0095] The second transceiver unit [108], at the second NF, is configured
to receive the PDU session establishment request from the first NF. The second
transceiver unit [108] may be associated with the second processing unit [110].
30 The second processing unit [110] at the second NF, is configured to determine one
of a presence and an absence of an existing policy session associated with the set of attributes for the UE. In an embodiment, information associated with the
25

presence and the absence of the existing policy session may be stored in the second
storage unit [112]. Further, any information associated with the second transceiver
unit [108] may be stored in the second storage unit [112]. The set of attributes
comprises a Subscription Permanent Identifier (SUPI), a Data Network Name
5 (DNN), a network slice, and a PDU Session ID. In general, SUPI is a unique
identifier used to represent a subscriber's permanent identity in a 5G network. SUPI replaces the International Mobile Subscriber Identity (IMSI) used in 4G networks and is designed to provide enhanced privacy and security features. Further, the DNN is the counterpart of Access Point Name (APN) in LTE. The
10 DNN is used to identify and route traffic to a specific network slice, which can be
customized with specific QoS requirements for different services and applications. The network slice is a logical network that provides specific network capabilities and network characteristics, supporting various service properties for network slice customers or users. Further, the PDU Session ID is an identifier used
15 to uniquely identify one of a UE's PDU Sessions.
[0096] Further, the second transceiver unit [108], at the second NF, is
configured to receive maximum permitted policy sessions and a count of established policy sessions, associated with a subset of attributes from the set of
20 attributes in an event of the absence of the existing policy session. The maximum
permitted policy sessions refer to the maximum number of policy sessions that can be active. The second processing unit [110] is further configured to determine whether the count of established policy sessions is one of below and equal to the maximum permitted policy sessions associated with the subset of attributes. The
25 subset of attributes of the set of attributes comprises at least the SUPI, the DNN,
and the network slice.
[0097] Further, the second processing unit [110] may be associated with the
second processing unit [110]. The second processing unit [110] at the second NF,
30 is configured to accept the PDU session establishment request for the UE, based
on the determination that the count of established policy sessions is below the
26

maximum permitted policy sessions. Further, in one implementation, the second
processing unit [110] at the second NF, is configured to delete the existing policy
session for the UE, in an event of the presence of the existing policy session for
the UE and accept the PDU session establishment request.
5
[0098] The second processing unit [110] is further configured to delete a
policy session from the established policy sessions, based on the determination
that the count of established policy sessions is equal to the maximum permitted
policy sessions. The deleting of the policy session from the established policy
10 sessions, is determined or performed based on a timestamp associated with each
of the policy session from the established policy sessions.
[0099] In an alternative embodiment, the second processing unit [110] at
15 the second NF is configured to determine one of a presence and an absence of an
existing policy association, associated with the set of attributes for the UE. The
second processing unit [110] is further configured to identify a first timestamp
associated with the existing policy association, based on determination of the
presence of the existing policy association. In addition, the second processing unit
20 [110] is configured to identify a second timestamp associated with the policy
control create request. Further, the second processing unit [110] is configured to
compare the first timestamp with the second timestamp. In an embodiment, the
second processing unit [110] may be configured to accept the policy control create
request based on the comparison of the first timestamp with the second timestamp.
25 The second processing unit [110], upon the comparison of the first timestamp with
the second timestamp, is further configured to determine if the second timestamp
is greater than the first timestamp. The second processing unit [110] is configured
to accept the policy control request based on determining that the second
timestamp is greater than the first timestamp.
30
[0100] In an alternative embodiment, the second transceiver unit [108] is
further configured to receive, by the second NF, a maximum permitted policy
27

associations, associated with a subset of attributes from the set of attributes, in an
event of the absence of the existing policy association. Also, the second processing
unit [110] is configured to determine a count of existing associations, associated
with the subset of attributes from the set of attributes; and reject the policy control
5 create request based on determining that the count of existing associations has
reached the maximum permitted policy associations. During the PDU session establishment, the second NF/PCF [216] may receive information from a Unified Data Repository (UDR) about the maximum permitted policy associations such as total allowed usage per DNN / S-NSSAI combination and the UE, i.e. the
10 overall amount of allowed traffic volume and/or time of usage that are to be
monitored per DNN / S-NSSAI combination and UE and/or the total allowed usage for Monitoring key(s) per DNN / S-NSSAI combination and UE. S-NSSAI refers to Single – Network Slice Selection Assistance Information. S-NSSAI is sent to the network by the UE to assist the network in selecting a particular
15 network slice.
[0101] Referring again to the second transceiver unit [108], at the second
NF, is further configured to transmit a management register request to a third NF, for the UE comprising the subset of attributes. The third NF is a Binding Support
20 Function (BSF) [208] in the network. The third NF/BSF [208] enables
policy/charging (PCF/CHF) scaling of the 5G network while ensuring session correlation for Hyper Text Transfer Protocol (HTTP). The BSF is configured to track sessions that are located anywhere in the network, but share common criteria, such as subscriber identifiers. The third NF/BSF [208] enables correlation
25 of sessions across multiple policy servers. In general, the third NF/BSF [208] is
configured to find binding information such as address information of a selected second NF/PCF [216], then allow the second NF/PCF [216]to register, update and remove the binding information and allows Application Function (AF) or Network Exposure Function (NEF) to discover the binding information. Further,
30 the NEF is a function that facilitates secure, robust, developer-friendly access to
exposed network services and provides customers capabilities that are provided
28

by 3GPP 5G network functions. The exposure may be an internal exposure or re-
exposure. In general, the NEF may be connected to network ecosystems since its
applications are data-rich and resourceful. This means that access to network data
and resources for different ecosystems is enriched with enterprise applications.
5 Data transportation within signalling messages is enabled by the NEF via a control
plane which eliminates user plane connection which is costly.
[0102] The second transceiver unit [108] may be associated with the third
transceiver unit [114]. The third transceiver unit [114], at the third NF, is
10 configured to receive, a maximum permitted binding sessions for the subset of
attributes and to receive, a count of existing binding sessions for the subset of attributes. The third transceiver unit [114] may be associated with the third processing unit [116]. Further, the third processing unit [116] is configured to determine whether the count of the existing binding sessions is one of below and
15 equal to the maximum permitted binding sessions. In general, the maximum
permitted binding sessions refer to maximum number of simultaneous bindings or associations that a network entity allows with other entities. Also, the third processing unit [116] is configured to accept, the management register request from the second NF, based on the determination that the count of the existing
20 binding sessions is below the maximum permitted binding sessions. The
management register request may be a request to register or deregister a UE/user with the network and establish the user context in the network.
[0103] In addition, the third transceiver unit [114], at the third NF, is further
25 configured to transmit, an acceptance response for the management register
request, to the second NF. Based on the determination that the count of the existing
binding sessions is equal to the maximum permitted binding sessions, the third
processing unit [116] at the third NF, determines one of the rejected response and
the acceptance response based on a flag value in a user configurable table.
30 Generally, flag value is a binary indicator (often represented as a boolean or
integer) that signifies presence or absence of a particular condition or setting. In addition, flag value in a user configurable table refers to a specific data structure
29

or setting within a table that allows users or administrators to configure or control
certain behaviours, options, or conditions within the system [100]. The rejected
response is transmitted by the third transceiver unit [114], to the second NF, based
on a true value of the flag in the user configurable table. Further, the acceptance
5 response is transmitted by the third transceiver unit [114], to the second NF, based
on a false value of the flag in the user configurable table. The acceptance response comprises deleting, by the third processing unit [116], at the third NF, a binding session from the existing binding sessions for the subset of attributes. The deleting of the binding session from the existing binding sessions is determined by the third
10 processing unit [116], based on a timestamp associated with each binding session
of the existing binding sessions. In an embodiment, the acceptance response and the rejected response is stored in the third storage unit [118]. Further, any information associated with the third transceiver unit [114] may be stored in the third storage unit [118].
15
[0104] The second transceiver unit [108], at the second NF, is configured
to transmit to a fourth NF, a spending limit control session request associated with the subset of attributes. The second transceiver unit [108] and the third transceiver unit [114] may be associated with the fourth transceiver unit [120]. The fourth
20 transceiver unit [120], at a fourth NF, is configured to receive a maximum
permitted spending limit control sessions for the subset of attributes and a count of existing spending limit control sessions for the subset of attributes. The fourth NF is a Charging Function (CHF) [206] in the network. The fourth NF/CHF [206] acts as a gateway into a charging system, supporting both session-based charging
25 and event-based charging scenarios, with or without unit reservation, including
new 5G capabilities such as network slicing.
[0105] The fourth transceiver unit [120] may be associated with the fourth
processing unit [122]. The fourth processing unit [122], at the fourth NF, is
30 configured to delete, a spending limit control session from the existing spending
limit control sessions, based on the determination that the count of the existing
30

spending limit control sessions is equal to the maximum permitted spending limit
control sessions. The deleting of the spending limit control session from the
existing spending limit control sessions is based on a timestamp associated with
each of the spending limit control session from the existing spending limit control
5 sessions. In general, timestamp is a digital record of the time at which an event
occurred. The fourth processing unit [122] is further configured to accept the spending limit control request, from the second NF. The fourth transceiver unit [120], at the fourth NF, is further configured to transmit, the acceptance response for the spending limit control session request, to the second NF. The maximum
10 permitted policy control sessions, associated with the subset of attributes are
received from a configurable table configured at the second NF. The spending limit control request enables the First NF to retrieve policy counter status information. In an embodiment, any information related to the spending limit control session may be stored in the fourth storage unit [124]. Further, any
15 information associated with the fourth transceiver unit [120] may be stored in the
fourth storage unit [124].
[0106] Referring to the first transceiver unit [102], at the first NF, that is
further configured to transmit to the fourth NF, a converged charging create
20 request associated with the subset of attributes. The fourth transceiver unit [120],
at the fourth NF, is further configured to receive, a maximum permitted PDU sessions for the subset of attributes and a count of existing PDU sessions for the subset of attributes from the fourth storage unit [124]. In addition, the fourth processing unit [122], at the fourth NF, determines, whether the count of the
25 existing PDU sessions is one of below and equal to the maximum permitted PDU
sessions. Further, the fourth processing unit [122] accepts the converged charging create request from the first NF, based on the determination that the count of the existing PDU sessions is below the maximum permitted PDU sessions. Furthermore, the fourth transceiver unit [120], at the fourth NF, is further
30 configured to transmit an acceptance response for the converged charging create
31

alternate embodiment, an incoming “Npcf_SMPolicyControl_Create” service
request shall be considered as more recent than an existing SM Policy Association
and be accepted if no 3gpp-Sbi-Origination-Timestamp header is provided for at
least one of the two SM Policy Associations.
5
[0159] At step [618], the method [600] includes accepting, by the second
NF, the policy control create request based on the comparing. The accepting the
policy control request is based on determining that the second timestamp is greater
than the first timestamp. Further, the accepting the policy control request
10 comprises deleting the existing policy association.
[0160] In an alternate embodiment, the method [600] includes that the PCF
[216] may reject an incoming request whose timestamp is less recent than the
timestamp of the existing SM Policy Association with the HTTP status code "403
15 Forbidden" and the application error "LATE_OVERLAPPING_REQUEST". The
HTTP status code “403 Forbidden” and the application error
“LATE_OVERLAPPING_REQUEST” depicts that the request is rejected
because it collides with an existing policy association with a more recent
originating timestamp.
20
[0161] The method [600] further comprises receiving, by the second NF,
maximum permitted policy associations, associated with a subset of attributes
from the set of attributes, in an event of the absence of the existing policy
association. During the PDU session establishment, the PCF [216] may receive
25 information from a Unified Data Repository (UDR) about the maximum permitted
policy associations such as total the allowed usage per DNN / S-NSSAI combination and the UE, i.e. the overall amount of allowed traffic volume and/or time of usage that are to be monitored per DNN / S-NSSAI combination and UE and/or the total allowed usage for Monitoring key(s) per DNN / S-NSSAI
30 combination and UE.
47

[0162] The method [600] further comprises determining, by the second NF,
a count of existing associations, associated with the subset of attributes from the
set of attributes. Also, the method [600] comprises rejecting, by the second NF,
the policy control create request based on determining that the count of existing
5 associations has reached the maximum permitted policy associations.
[0163] The method [600] terminates at step [620].
[0164] The present disclosure further discloses a non-transitory computer
10 readable storage medium storing instructions for managing a Packet Data Unit
(PDU) session establishment in a network, the instructions include executable code which, when executed by a one or more units of a system [100], causes: a first transceiver unit [102] to receive the PDU session establishment request for a User Equipment (UE); and transmit, from the first NF, to a second NF, a policy
15 control create request comprising a set of attributes associated with the PDU
session establishment request for the UE. The executable code which, when executed by the one or more units of the system [100], causes: a second processing unit [110], at the second NF, to determine, one of a presence and an absence of an existing policy session associated with the set of attributes for the UE; a second
20 transceiver unit [108], at the second NF, to: receive, maximum permitted policy
sessions and a count of established policy sessions, associated with a subset of attributes from the set of attributes, in an event of the absence of the existing policy session; and the second processing unit [110], at the NF, to determine, whether the count of established policy sessions is one of below and equal to the maximum
25 permitted policy sessions associated with the subset of attributes. The executable
code which, when executed by the one or more units of the system, causes: a second processing unit [110], at the NF, to accept, the PDU session establishment request for the UE, based on the determination that the count of established policy sessions is below the maximum permitted policy sessions.
30
[0165] Yet another aspect of the present disclosure may relate to a non-
transitory computer-readable storage medium storing instructions for managing a
48

Packet Data Unit (PDU) session establishment in a network, the instructions
comprising executable code which, when executed by one or more units of a
system, causes: a first transceiver unit [102] to receive the PDU session
establishment request for a User Equipment (UE); connect to a second NF to
5 process the PDU session establishment request from the UE; and transmit, to the
second NF, a policy control create request comprising a set of attributes associated with the PDU session establishment request for the UE. Further, the executable code when executed by the one or more units of the system [100], causes a second processing unit [110] to identify a first timestamp associated with the existing
10 policy association, based on determining the presence of the existing policy
association; to identify a second timestamp associated with the policy control create request; and to compare the first timestamp with the second timestamp. Also, the executable code when executed by the one or more units of the system, causes a second processing unit [110] to accept the policy control create request
15 based on the comparison of the first timestamp with the second timestamp.
[0166] As is evident from the above, the present disclosure provides a
technically advanced solution for managing a Packet Data Unit (PDU) session establishment in a network. The present disclosure provides a solution to control
20 an increase in a number of stale sessions which in turn results in saving the
signalling traffic that is sent for validation of stale sessions. Also, the present disclosure provides a solution that can optimize the resources (compute, memory and storage) used by NF by deleting or overwriting old sessions which are no longer live in network with assumption that devices in network have capabilities
25 that are understood by service provider.
[0167] 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
30 embodiments may disclose a particular functionality of these units for clarity, it is
recognized that various configurations and combinations thereof are within the
49

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
5 encompassed within the scope of the present disclosure.
[0168] While considerable emphasis has been placed herein on the
disclosed implementations, it will be appreciated that many implementations can
be made and that many changes can be made to the implementations without
10 departing from the principles of the present disclosure. These and other changes
in the implementations of the present disclosure will be apparent to those skilled in the art, whereby it is to be understood that the foregoing descriptive matter to be implemented is illustrative and non-limiting.
15 [0169] Further, in accordance with the present disclosure, it is to be
acknowledged that the functionality described for the various components/units can be implemented interchangeably. While specific embodiments may disclose a particular functionality of these units for clarity, it is recognized that various configurations and combinations thereof are within the scope of the disclosure.
20 The functionality of specific units as disclosed in the disclosure should not be
construed as limiting the scope of the present disclosure. Consequently, alternative arrangements and substitutions of units, provided they achieve the intended functionality described herein, are considered to be encompassed within the scope of the present disclosure.
50

WE CLAIM:
1. A method [500] for managing a Packet Data Unit (PDU) session
establishment in a network, the method comprising:
- receiving, by a first network function (NF), a PDU session establishment request for a User Equipment (UE);
- transmitting, from the first NF, to a second NF, a policy control create request comprising a set of attributes associated with the PDU session establishment request for the UE;
- determining, by the second NF, one of a presence and an absence of an existing policy session associated with the set of attributes for the UE;
- receiving, by the second NF, a maximum permitted policy sessions and a count of established policy sessions, associated with a subset of attributes from the set of attributes, in an event of the absence of the existing policy session;
- determining, by the second NF, whether the count of established policy control sessions is one of below and equal to the maximum permitted policy sessions associated with the subset of attributes; and
- accepting, by the second NF, the PDU session establishment request from the UE, based on the determination that the count of established policy sessions is below the maximum permitted policy sessions; and
- processing, by the first NF, one or more policy rules received from the second NF, in response to accepting the policy control create request.
2. The method [500] as claimed in claim 1, further comprising:
- deleting, by the second NF, the existing policy session for the UE, in an event of the presence of the existing policy session for the UE; and
- accepting, by the second NF, the PDU session establishment request from the UE.

3. The method [500] as claimed in claim 1, wherein the method further
comprises, deleting, by the second NF, a policy session from the established
policy sessions, based on the determination that the count of established
policy sessions is equal to the maximum permitted policy sessions.
4. The method [500] as claimed in claim 3, wherein, the deleting the policy
session from the established policy sessions, is determined based on a
timestamp associated with each of the policy session from the established
policy sessions.
5. The method [500] as claimed in claim 1, wherein the set of attributes comprises a Subscription Permanent Identifier (SUPI), a Data Network Name (DNN), a network slice, and a PDU Session ID.
6. The method [500] as claimed in claim 5, wherein the subset of attributes of the set of attributes comprises at least a SUPI, a DNN, and a network slice.
7. The method [500] as claimed in claim 1, wherein the first NF is a Session Management Function (SMF) [204] in the network.
8. The method [500] as claimed in claim 1, wherein the second NF is a Policy Control Function [216] in the network.
9. The method [500] as claimed in claim 1, further comprises:

- transmitting, by the second NF, to a third NF, a management register request for the UE comprising the subset of attributes;
- receiving, by the third NF, a maximum permitted binding sessions for the subset of attributes;
- receiving, by the third NF, a count of existing binding sessions for the subset of attributes;

- determining, by the third NF, whether the count of the existing binding sessions is one of below and equal to the maximum permitted binding sessions;
- accepting, by the third NF, the management register request from the second NF, based on the determining that the count of the existing binding sessions is below the maximum permitted binding sessions; and
- transmitting, by the third NF, an acceptance response for the management register request, to the second NF.

10. The method [500] as claimed in claim 9, wherein, based on the determination that the count of the existing binding sessions is equal to the maximum permitted binding sessions, the third NF, determines one of a rejected response and an acceptance response based on a flag in a user configurable table.
11. The method [500] as claimed in claim 10, wherein the rejected response is transmitted to the second NF, based on a true value of the flag in the user configurable table.
12. The method [500] as claimed in claim 10, wherein the acceptance response is transmitted to the second NF, based on a false value of the flag in the user configurable table.
13. The method [500] as claimed in claim 12, wherein the acceptance response comprises deleting a binding session of the existing binding sessions for the subset of attributes.
14. The method [500] as claimed in claim 13, wherein deleting the binding session from the existing binding sessions is determined based on a timestamp associated with each binding session of the existing binding sessions.

15. The method [500] as claimed in claim 9, wherein the third NF is a Binding Support Function (BSF) [208] in the network.
16. The method [500] as claimed in claim 1, further comprises:

- transmitting, by the second NF, to a fourth NF, a spending limit control session request associated with the subset of attributes;
- receiving, by the fourth NF, a maximum permitted spending limit control sessions for the subset of attributes;
- receiving, by the fourth NF, a count of existing spending limit control sessions for the subset of attributes;
- determining, by the fourth NF, whether the count of the existing spending limit control sessions is one of below and equal to the maximum permitted spending limit control sessions;
- accepting, by the fourth NF, the spending limit control session request from the second NF, based on the determining that the count of the existing spending limit control sessions is below the maximum permitted spending limit control sessions; and
- transmitting, by the fourth NF, an acceptance response for the spending limit control session request, to the second NF.
17. The method [500] as claimed in claim 16, further comprises:
- deleting, by the fourth NF, a spending limit control session from the existing spending limit control sessions, based on the determination that the count of the existing spending limit control sessions is equal to the maximum permitted spending limit control sessions, wherein deleting the spending limit control session from the existing spending limit control sessions is based on a timestamp associated each of the spending limit control session from the existing spending limit control sessions;
- accepting, by the fourth NF, the spending limit control session request, from the second NF; and

- transmitting, by the fourth NF, the acceptance response for the
spending limit control session request, to the second NF.
18. The method [500] as claimed in claim 16, wherein the fourth NF is a Charging Function (CHF) [206] in the network.
19. The method [500] as claimed in claim 1, wherein the maximum permitted policy sessions, associated with the subset of attributes is received from a configurable table configured at the second NF.
20. The method [500] as claimed in claim 16, wherein the method further
comprises:
- transmitting, by the first NF, to the fourth NF, a converged charging create request associated with the subset of attributes;
- receiving, by the fourth NF, a maximum permitted PDU sessions for the subset of attributes;
- receiving, by the fourth NF, a count of existing PDU sessions for the subset of attributes;
- determining, by the fourth NF, whether the count of the existing PDU sessions is one of below and equal to the maximum permitted PDU sessions;
- accepting, by the fourth NF, the converged charging create request from the first NF, based on the determining that the count of the existing PDU sessions is below the maximum permitted PDU sessions; and
- transmitting, an acceptance response for the converged charging create request, to the first NF.
21. The method [500] as claimed in claim 20, further comprising:
- deleting, by the fourth NF, a PDU session from the existing PDU
sessions, based on the determining that the count of the existing PDU
sessions is equal to the maximum permitted PDU sessions, wherein

deleting of the PDU session from the existing PDU sessions is based on a timestamp associated with each of the PDU session from the existing PDU sessions;
- accepting, by the fourth NF, the converged charging create request, from the first NF; and
- transmitting, an acceptance response for the converged charging create request, to the first NF.
22. A system [100] for managing a Packet Data Unit (PDU) session establishment in a network, the system comprising:
- a first transceiver unit [102], at a first network function (NF), configured
to:
o receive, a PDU session establishment request for a User
Equipment (UE); o transmit, from the first NF to a second NF, a policy control create
request comprising a set of attributes associated with the PDU
session establishment request for the UE;
- a second processing unit [110], at the second NF, configured to:
o determine, one of a presence and an absence of an existing policy session associated with the set of attributes for the UE;
- a second transceiver unit [108], at the second NF, configured to:
o receive, maximum permitted policy sessions and a count of established policy sessions, associated with a subset of attributes from the set of attributes, in an event of the absence of the existing policy session;
- the second processing unit [110], at the second NF, further configured
to:
o determine, whether the count of established policy sessions is one of below and equal to the maximum permitted policy sessions associated with the subset of attributes;

o accept, the PDU session establishment request for the UE, based on the determination that the count of established policy sessions is below the maximum permitted policy sessions; and
- a first processing unit [ 104], at the first NF, configured to:
o process, one or more policy rules received from the second NF in response to accepting the policy control create request.
23. The system [100] as claimed in claim 22, wherein,
- the second processing unit [110], at the second NF, is further configured
to:
■ delete the existing policy session for the UE, in an event of the presence of the existing policy session for the UE; and
■ accept the PDU session establishment request from the UE.
24. The system [100] as claimed in claim 22, wherein the second processing unit
[110], at the second NF, is further configured to:
- delete, a policy session from the established policy sessions, based on
the determination that the count of established policy sessions is equal
to the maximum permitted policy sessions.
25. The system [100] as claimed in claim 24, wherein, the deleting the policy session from the established policy sessions, is determined based on a timestamp associated with each of the policy session from the established policy sessions.
26. The system [100] as claimed in claim 22, wherein the set of attributes comprises a Subscription Permanent Identifier (SUPI), a Data Network Name (DNN), a network slice, and a PDU Session ID.

27. The system [100] as claimed in claim 26, wherein the subset of attributes of the set of attributes comprises at least a SUPI, a DNN, and a network slice.
28. The system [100] as claimed in claim 22, wherein the first NF is a Session Management Function (SMF) in the network.
29. The system [100] as claimed in claim 22, wherein the second NF is a Policy Control Function in the network.
30. The system [100] as claimed in claim 22, wherein the system [100] further comprises:
- the second transceiver unit [108], at the second NF, further configured
to:
o transmit, to a third NF, a management register request for the UE comprising the subset of attributes;
- a third transceiver unit [114], at the third NF, configured to:
o receive, a maximum permitted binding sessions for the subset of
attributes; o receive, a count of existing binding sessions for the subset of
attributes;
- a third processing unit [116], at the third NF, configured to:
o determine, whether the count of the existing binding sessions is one of below and equal to the maximum permitted binding sessions;
o accept, the management register request from the second NF, based on the determination that the count of the existing binding sessions is below the maximum permitted binding sessions; and
- the third transceiver unit [114], at the third NF, further configured to
transmit, an acceptance response for the management register request,
to the second NF.

31. The system [100] as claimed in claim 30, wherein, based on the determination that the count of the existing binding sessions is equal to the maximum permitted binding sessions, the third processing unit [116] at the third NF, determines one of a rejected response and an acceptance response, based on a flag value in a user configurable table.
32. The system [100] as claimed in claim 31, wherein the rejected response is transmitted by the third transceiver unit [114], to the second NF, based on a true value of the flag in the user configurable table.
33. The system [100] as claimed in claim 31, wherein, the acceptance response is transmitted by the third transceiver unit [114], to the second NF, based on a false value of the flag in the user configurable table.
34. The system [100] as claimed in claim 31, wherein the acceptance response comprises deleting, by the third processing unit [118], at the third NF, a binding session from the existing binding sessions for the subset of attributes.
35. The system [100] as claimed in claim 34, wherein the deleting of the binding session from the existing binding sessions is determined by the third processing unit [116], based on a timestamp associated with each binding session of the existing binding sessions.
36. The system [100] as claimed in claim 30, wherein the third NF is a Binding
Support Function (BSF) [208] in the network.
37. The system [100] as claimed in claim 22, wherein the system [100] further
comprises:
the second transceiver unit [108], at the second NF, configured to:

o transmit, to a fourth NF, a spending limit control session request associated with the subset of attributes; a fourth transceiver unit [120], at the fourth NF, configured to:
o receive, a maximum permitted spending limit control sessions
for the subset of attributes; o receive, a count of existing spending limit control sessions for the subset of attributes; a fourth processing unit [122], at the fourth NF, configured to:
o determine, whether the count of the existing spending limit control sessions is one of below and equal to the maximum permitted spending limit control sessions; o accept, the spending limit control session request from the second NF, based on the determining that the count of the existing spending limit control sessions is below the maximum permitted spending limit control sessions; and the fourth transceiver unit [120], at the fourth NF, further configured to transmit, an acceptance response for the spending limit control session request, to the second NF.
38. The system [100] as claimed in claim 37, wherein the system [100] further comprises:
the fourth processing unit [122], at the fourth NF, is further configured to:
o delete, a spending limit control session from the existing spending limit control sessions, based on the determination that the count of the existing spending limit control sessions is equal to the maximum permitted spending limit control sessions, wherein the deleting of the spending limit control session from the existing spending limit control sessions is based on a timestamp associated with each of the spending limit control session from the existing spending limit control sessions;

o accept, the spending limit control request, from the second NF;
and the fourth transceiver unit [120], at the fourth NF, further configured to: o transmit, the acceptance response for the spending limit control
session request, to the second NF.
39. The system [100] as claimed in claim 37, wherein the fourth NF is a Charging Function (CHF) in the network.
40. The system [100] as claimed in claim 22, wherein the maximum permitted policy control sessions, associated with the subset of attributes are received from a configurable table configured at the second NF.
41. The system [100] as claimed in claim 37, wherein the system further comprises:
the first transceiver unit [102], at the first NF, further configured to:
o transmit, to the fourth NF, a converged charging create request associated with the subset of attributes; the fourth transceiver unit [120], at the fourth NF, further configured to:
o receive, a maximum permitted PDU sessions for the subset of
attributes; o receive, a count of existing PDU sessions for the subset of attributes; the fourth processing unit [122], at the fourth NF, further configured to:
o determine, whether the count of the existing PDU sessions is one
of below and equal to the maximum permitted PDU sessions; o accept, the converged charging create request from the first NF, based on the determination that the count of the existing PDU sessions is below the maximum permitted PDU sessions; and

the fourth transceiver unit [120], at the fourth NF, further configured to transmit an acceptance response for the converged charging create request, to the first NF.
42. The system [100] as claimed in claim 41, wherein, the system further
comprises:
the fourth processing unit [122], at the fourth NF, further configured to:
- delete, a PDU session from the existing PDU sessions, based on the determination that the count of the existing PDU sessions is equal to the maximum permitted PDU sessions, wherein deleting the PDU session from the existing PDU sessions, is based on a timestamp associated with each of the PDU session from the existing PDU sessions.
- accept, the charging service request, from the first NF; and
the fourth transceiver unit [120], at the fourth NF, further configured to:
- transmit, an acceptance response for the converged charging create
request, to the first NF.
43. A method [600] for managing a Packet Data Unit (PDU) session
establishment in a network, the method comprising:
- receiving, by a first network function (NF), a PDU session establishment request for a User Equipment (UE);
- connecting, by the first NF, to a second NF to process the PDU session establishment request for the UE;
- transmitting, by the first NF, to the second NF, a policy control create request comprising a set of attributes associated with the PDU session establishment request for the UE;
- determining, by the second NF, one of a presence and an absence of an existing policy association, associated with the set of attributes for the UE;

- identifying, by the second NF, a first timestamp associated with the existing policy association, based on determining the presence of the existing policy association;
- identifying, by the second NF, a second timestamp associated with the policy control create request;
- comparing, by the second NF, the first timestamp and the second timestamp;
- accepting, by the second NF, the policy control create request based on the comparing; and
- processing, by the first NF, one or more policy rules received from the second NF, in response to accepting the policy control create request.

44. The method [600] as claimed in claim 43, wherein, the comparing by the second NF, the first timestamp and the second timestamp comprises: determining, if the second timestamp is greater than the first timestamp.
45. The method [600] as claimed in claim 44, wherein accepting the policy control create request is based on determining that the second timestamp is greater than the first timestamp.
46. The method [600] as claimed in claim 43, wherein, accepting by the second NF, the policy control create request, comprises:
deleting, the existing policy association.
47. The method [600] as claimed in claim 43, wherein the set of attributes comprises a Subscription Permanent Identifier (SUPI), a Data Network Name (DNN), a network slice, and a PDU Session ID.
48. The method [600] as claimed in claim 47, further comprises:

- receiving, by the second NF, a maximum permitted policy associations, associated with a subset of attributes from the set of attributes, in an event of the absence of the existing policy association;
- determining, by the second NF, a count of existing policy associations, associated with the subset of attributes from the set of attributes; and
- rejecting, by the second NF, the policy control create request based on determining that the count of existing policy associations has reached the maximum permitted policy associations.
49. The method [600] as claimed in claim 48, wherein the subset of attributes
comprises at least a SUPI, a DNN, and a network slice.
50. A system [100] for managing a Packet Data Unit (PDU) session
establishment in a network, the system comprising:
- a first transceiver unit [102], at a first network function (NF), configured
to:
o receive a PDU session establishment request for a User
Equipment (UE); o connect to a second NF to process the PDU session
establishment request from the UE; o transmit, to the second NF, a policy control create request
comprising a set of attributes associated with the PDU session
establishment request for the UE;
- a second processing unit [110], at the second NF, configured to:
o determine one of a presence and an absence of an existing policy
association associated with the set of attributes for the UE; o identify a first timestamp associated with the existing policy
association, based on determination of the presence of the
existing policy association; o identify a second timestamp associated with the policy control
create request; and

o compare the first timestamp with the second timestamp. o accept the policy control create request based on the comparison of the first timestamp with the second timestamp; and
- a first processing unit [104], at the first NF, configured to:
o process, one or more policy rules received from the second NF, in response to accepting the policy control create request.
51. The system [100] as claimed in claim 50, wherein the second processing unit [110], at the second NF, upon the comparison of the first timestamp with the second timestamp, is further configured to determine if the second timestamp is greater than the first timestamp.
52. The system [100] as claimed in claim 51, wherein the second processing unit [110] at the second NF, is configured to accept the policy control request based on determining that the second timestamp is greater than the first timestamp.
53. The system [100] as claimed in claim 50, wherein the second processing unit [110] at the second NF, is further configured to delete the existing policy association.
54. The system [100] as claimed in claim 50, wherein the set of attributes comprises a Subscription Permanent Identifier (SUPI), a Data Network Name (DNN), a network slice, and a PDU Session ID.
55. The system [100] as claimed in claim 54, wherein the system further comprises a second transceiver unit [108] at the second NF, configured to:

- receive, a maximum permitted policy associations, associated with a subset of attributes from the set of attributes, in an event of the absence of the existing policy association;
- determine a count of existing policy associations, associated with the subset of attributes from the set of attributes; and

- reject the policy control create request based on determining that the
count of existing policy associations has reached the maximum permitted policy associations.
56. The system [100] as claimed in claim 55, wherein the subset of attributes comprises at least the SUPI, DNN, and the network slice.