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 HANDLING A RACE
CONDITION”
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.
2
METHOD AND SYSTEM FOR HANDLING A RACE CONDITION
FIELD OF THE DISCLOSURE
5 [0001] Embodiments of the present disclosure generally relate to call management
and session management in a telecommunication network. More particularly,
embodiments of the present disclosure relate to methods and systems for handling
a race condition.
10 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
15 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] When a mobile device or a user Equipment (UE) is switched on, it attempts
20 to make contact with a public land mobile network (PLMN). The particular PLMN
to be contacted may be selected either automatically or manually. The UE looks for
a suitable cell of the chosen PLMN and chooses that cell to provide available
services. The UE will then register its presence in the registration area of the chosen
cell, if necessary, by means of a location registration (LR), GPRS attach or IMSI
25 attach procedure. If the UE loses coverage of a cell, say during mobility, or finds a
more suitable cell, it reselects the most suitable cell of the selected PLMN. If the
new cell is in a different registration area, an LR request is performed. If the UE
loses coverage of a PLMN, either a new PLMN is selected automatically, or an
indication of which PLMNs are available is given to the user, so that a manual
30 selection can be made. A UE needs to register with the network to get authorized to
receive services, to enable mobility tracking and to enable reachability. The
3
Connection Management is used to establish and release the Control Plane
signalling connection between the UE and the AMF. The Registration Management
is used to register or deregister a UE/user with the 5GS and establish the user
context in the 5GS. The Mobility Management functions are used to keep track of
5 the current location of a UE.
[0004] The current scenario in the 5G network architecture poses a significant
challenge, when a 5G mobile device is connected to RAT type EUTRA and a PLMN
change occurs during an ongoing call. In such a scenario, both PCF and MME
10 initiate the mobile detach process upon call completion. This results in a race
condition within the network, causing the Terminate-Notify Request from PCF to
time out, with no response from SMF. This issue leads to a degradation in Key
Performance Indicators (KPIs) at the PCF end and may even result in
inconsistencies in PDU session states at SMF. Addressing this race condition and
15 ensuring a smoother transition during PLMN changes is imperative to maintain the
integrity and performance of the 5G network.
[0005] Thus, there exists an imperative need in the art to efficiently handle a
plurality of race conditions, which the present disclosure aims to address.
20
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.
25 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 handling a
race condition. The method comprises receiving, by a transceiver unit, at a Policy
30 Control Function (PCF), a Public Landline Mobile Network (PLMN) change
request associated with a user equipment (UE). The method comprises identifying,
4
by an identification unit, at the PCF, a call session status associated with a call from
the UE, based on the PLMN change request, wherein the call session status is one
of an active call session and a non-active call session. The method further comprises
generating, by a processing unit, at the PCF, an internal signal to send a message to
5 a Session Management Function (SMF) to be consumed when the call session status
is the non-active call session, in an event the call session status is the active call
session. The method further comprises detecting, by a detection unit, at the PCF, a
call completion event in the event the call session status is the active call session;
performing, by an execution unit, at the PCF, one of a first action, a second action,
10 a third action, and a fourth action, based on detecting the call completion event.
[0008] In an exemplary aspect of the present disclosure, the PLMN change request
is for a change from a first PLMN to a second PLMN, wherein the call associated
with the active call session initiates in first PLMN and completes in the second
15 PLMN.
[0009] In an exemplary aspect of the present disclosure, the first PLMN is
associated with a first Radio Access technology (RAT) type and the second PLMN
is associated with a second RAT type.
20
[0010] In another exemplary aspect of the present disclosure, generating the
internal signal to send a message to the SMF is based on a flag to support the active
call session in an event of PLMN change associated with the UE, wherein the flag
is set to true.
25
[0011] In an exemplary aspect of the present disclosure, the first action comprises
detecting, by the detection unit, at the PCF, if the first PLMN is same as the second
PLMN. Further, the first action comprises ignoring, by the processing unit, at the
PCF, the generated signal, in an event the first PLMN is same as the second PLMN.
30 The first action further comprises sending, by the transceiver unit from the PCF, a
first notification to the SMF.
5
[0012] In an exemplary aspect of the present disclosure, the second action
comprises detecting, by the detection unit, at the PCF, if the first RAT type is same
as the second RAT type. The second action then comprises ignoring, by the
5 processing unit, at the PCF, the generated signal, in an event the first RAT type is
same as the second RAT type and relates to Evolved Universal Terrestrial Radio
Access (EUTRA). The second action also comprises detaching, by the processing
unit, the UE from a Mobility Management Entity (MME) associated with the first
PLMN. Further, the second action comprises sending, by the transceiver unit from
10 the PCF, a first notification to the SMF.
[0013] In an exemplary aspect of the present disclosure, the first notification is an
update-notify request.
15 [0014] In an exemplary aspect of the present disclosure, the third action comprises
detecting, by the detection unit, if the first RAT type is same as the second RAT
type. The third action comprises detecting, by the detection unit, at the PCF, if the
first PLMN is different from the second PLMN. Also, the third action comprise
sending, by the transceiver unit, from the PCF, a second notification to trigger
20 network initiated detach process of the UE, to the SMF, in an event the first RAT
type is same as second RAT type and relates to New Radio (NR) and in an event
the first PLMN is different from the second PLMN.
[0015] In an exemplary aspect of the present disclosure, the fourth action comprises
25 detecting, by the detection unit, at the PCF, if the first RAT type is different from
the second RAT type. The fourth action further comprises detecting, by the
detection unit, at the PCF, if the first PLMN is different from the second PLMN.
Then the fourth action comprises sending, by the transceiver unit, from the PCF, a
second notification to trigger network initiated detach process of the UE, in an event
30 the first RAT type is different from the second RAT type and in an event the first
PLMN is different from the second PLMN.
6
[0016] In an exemplary aspect of the present disclosure, the second notification is
a terminate-notify request.
[0017] Another aspect of the present disclosure may relate to a system for handling
5 a race condition. The system comprises a transceiver unit, an identification unit, a
processing unit, a detection unit, and an execution unit connected with each other.
The transceiver unit is configured to receive at a Policy Control Function (PCF), a
Public Landline Mobile Network (PLMN) change request associated with a user
equipment (UE). The identification unit is configured to identify at the PCF, a call
10 session status associated with a call from the (UE), based on the PLMN change
request, wherein the call session status is one of an active call session and a nonactive call session. The processing unit is configured to generate at the PCF, an
internal signal to send a message to a Session Management Function (SMF) to be
consumed when the call session status is the non-active call session, in an event the
15 call session status is the active call session. The detection unit is configured to
configured to detect at the PCF, a call completion event in the event the call session
status is the active call session. The execution unit is configured to perform at the
PCF, one of a first action, a second action, a third action, and a fourth action, based
on detecting the call completion event.
20
[0018] Yet another aspect of the present disclosure may relate to a non-transitory
computer readable storage medium storing one or more instructions for handling a
race condition, the one or more instructions include executable code which, when
executed by one or more units of a system, cause the one or more units to perform
25 certain functions. The one or more instructions when executed cause a transceiver
unit of the system to receive at a Policy Control Function (PCF), a Public Landline
Mobile Network (PLMN) change request associated with a user equipment (UE).
The one or more instructions when executed further cause an identification unit of
the system to identify at the PCF, a call session status associated with a call from
30 the (UE), based on the PLMN change request, wherein the call session status is one
of an active call session and a non-active call session. The one or more instructions
7
when executed further cause a processing unit of the system to generate at the PCF,
an internal signal to send a message to a Session Management Function (SMF) to
be consumed when the call session status is the non-active call session, in an event
the call session status is the active call session. The one or more instructions when
5 executed further cause a detection unit of the system to detect at the PCF, a call
completion event in the event the call session status is the active call session. The
one or more instructions when executed further cause an execution unit of the
system to perform at the PCF, one of a first action, a second action, a third action,
and a fourth action, based on detecting the call completion event.
10
OBJECTS OF THE DISCLOSURE
[0019] Some of the objects of the present disclosure, which at least one
embodiment disclosed herein satisfies are listed herein below.
15
[0020] It is an object of the present disclosure to provide a system and a method for
handling a race condition.
[0021] It is another object of the present disclosure to provide a system and a
20 method for handling one or more race conditions.
[0022] It is another object of the present disclosure to provide a solution to avoid a
PDU session state inconsistency at core network functions which ensures there is
no requirement to change MME behavior on PLMN change.
25
[0023] It is yet another object of the present disclosure to provide a solution for
successfully identifying one or more call session conditions based on the non-active
call session, wherein the one or more call session conditions is at least one of a
PLMN change condition check, a Radio Access Technology (RAT) type change
30 condition check and a RAT type condition check.
8
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The accompanying drawings, which are incorporated herein, and constitute
a part of this disclosure, illustrate exemplary embodiments of the disclosed methods
5 and systems in which like reference numerals refer to the same parts throughout the
different drawings. Components in the drawings are not necessarily to scale,
emphasis instead being placed upon clearly illustrating the principles of the present
disclosure. Also, the embodiments shown in the figures are not to be construed as
limiting the disclosure, but the possible variants of the method and system
10 according to the disclosure are illustrated herein to highlight the advantages of the
disclosure. It will be appreciated by those skilled in the art that disclosure of such
drawings includes disclosure of electrical components or circuitry commonly used
to implement such components.
[0025] FIG. 1 illustrates an exemplary block diagram representation of 5th 15
generation core (5GC) network architecture.
[0026] FIG. 2 illustrates an exemplary block diagram of a computing device upon
which the features of the present disclosure may be implemented in accordance with
20 exemplary implementation of the present disclosure.
[0027] FIG. 3 illustrates an exemplary block diagram of a system for handling a
race condition, in accordance with exemplary implementations of the present
disclosure.
25
[0028] FIG. 4 illustrates a method flow diagram for handling a race condition, in
accordance with exemplary implementations of the present disclosure.
[0029] FIG. 5 illustrates an exemplary signal flow diagram illustrating a scenario
30 for a race condition.
9
[0030] FIG. 6 illustrates another exemplary signal flow diagram providing a
solution for handling the race condition in case of a change in PLMN.
[0031] FIG. 7 illustrates another exemplary signal flow diagram providing a
5 solution for handling the race condition in case of a change in PLMN in a New
Radio.
[0032] FIG. 8 illustrates another exemplary signal flow diagram providing a
solution for handling the race condition in case of a change in PLMN and also a
10 change in a type of radio access network.
[0033] FIG. 9 illustrates another exemplary signal flow diagram providing a
solution for handling the race condition in case of a change in PLMN and then
reverting back to the earlier PLMN.
15
[0034] The foregoing shall be more apparent from the following more detailed
description of the disclosure.
DETAILED DESCRIPTION
20
[0035] In the following description, for the purposes of explanation, various
specific details are set forth in order to provide a thorough understanding of
embodiments of the present disclosure. It will be apparent, however, that
embodiments of the present disclosure may be practiced without these specific
25 details. Several features described hereafter may each be used independently of one
another or with any combination of other features. An individual feature may not
address any of the problems discussed above or might address only some of the
problems discussed above.
30 [0036] The ensuing description provides exemplary embodiments only, and is not
intended to limit the scope, applicability, or configuration of the disclosure. Rather,
10
the ensuing description of the exemplary embodiments will provide those skilled in
the art with an enabling description for implementing an exemplary embodiment.
It should be understood that various changes may be made in the function and
arrangement of elements without departing from the spirit and scope of the
5 disclosure as set forth.
[0037] Specific details are given in the following description to provide a thorough
understanding of the embodiments. However, it will be understood by one of
ordinary skill in the art that the embodiments may be practiced without these
10 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.
[0038] It should be noted that the terms "first", "second", "primary", "secondary",
15 "target" and the like, herein do not denote any order, ranking, quantity, or
importance, but rather are used to distinguish one element from another.
[0039] 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
20 diagram, or a block diagram. Although a flowchart may describe the operations as
a sequential process, many of the operations may be performed in parallel or
concurrently. In addition, the order of the operations may be re-arranged. A process
is terminated when its operations are completed but could have additional steps not
included in a figure.
25
[0040] The word “exemplary” and/or “demonstrative” is used herein to mean
serving as an example, instance, or illustration. For the avoidance of doubt, the
subject matter disclosed herein is not limited by such examples. In addition, any
aspect or design described herein as “exemplary” and/or “demonstrative” is not
30 necessarily to be construed as preferred or advantageous over other aspects or
designs, nor is it meant to preclude equivalent exemplary structures and techniques
11
known to those of ordinary skill in the art. Furthermore, to the extent that the terms
“includes,” “has,” “contains,” and other similar words are used in either the detailed
description or the claims, such terms are intended to be inclusive in a manner similar
to the term “comprising” as an open transition word without precluding any
5 additional or other elements.
[0041] As used herein, a “processing unit” or “processor” or “operating processor”
includes one or more processors, wherein processor refers to any logic circuitry for
processing instructions. A processor may be a general-purpose processor, a special
10 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 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,
15 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 processor.
[0042] As used herein, “a user equipment”, “a user device”, “a smart-user-device”,
20 “a smart-device”, “an electronic device”, “a mobile device”, “a handheld device”,
“a wireless communication device”, “a mobile communication device”, “a
communication device” may be any electrical, electronic and/or computing device
or equipment, capable of implementing the features of the present disclosure. The
user equipment/device may include, but is not limited to, a mobile phone, smart
25 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 unit(s) which
are required to implement the features of the present disclosure.
30
12
[0043] As used herein, “storage unit” or “memory unit” refers to a machine or
computer-readable medium including any mechanism for storing information in a
form readable by a computer or similar machine. For example, a computer-readable
medium includes read-only memory (“ROM”), random access memory (“RAM”),
5 magnetic disk storage media, optical storage media, flash memory devices or other
types of machine-accessible storage media. The storage unit stores at least the data
that may be required by one or more units of the system to perform their respective
functions.
10 [0044] As used herein “interface” or “user interface” refers to a shared boundary
across which two or more separate components of a system exchange information
or data. The 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
15 called.
[0045] 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
20 digital signal processor (DSP), a plurality of microprocessors, one or more
microprocessors in association with a DSP core, a controller, a microcontroller,
Application Specific Integrated Circuits (ASIC), Field Programmable Gate Array
circuits (FPGA), any other type of integrated circuits, etc.
25 [0046] As used herein the transceiver unit include 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 the system
and/or connected with the system.
30 [0047] As discussed in the background section, the current known solutions have
several shortcomings. The present disclosure aims to overcome the above-
13
mentioned and other existing problems in this field of technology by providing
method and system of handling a race condition.
[0048] FIG. 1 illustrates an exemplary block diagram representation of 5th
5 generation core (5GC) network architecture, in accordance with exemplary
implementation of the present disclosure. As shown in fig. 1, the 5GC network
architecture [100] includes a user equipment (UE) [102], a radio access network
(RAN) [104], an access and mobility management function (AMF) [106], a Session
Management Function (SMF) [108], a Service Communication Proxy (SCP) [110],
10 an Authentication Server Function (AUSF) [112], a Network Slice Specific
Authentication and Authorization Function (NSSAAF) [114], a Network Slice
Selection Function (NSSF) [116], a Network Exposure Function (NEF) [118], a
Network Repository Function (NRF) [120], a Policy Control Function (PCF) [122],
a Unified Data Management (UDM) [124], an application function (AF) [126], a
15 User Plane Function (UPF) [128], a data network (DN) [130], wherein all the
components are assumed to be connected to each other in a manner as obvious to
the person skilled in the art for implementing features of the present disclosure.
[0049] Radio Access Network (RAN) [104] is the part of a mobile
20 telecommunications system that connects user equipment (UE) [102] to the core
network (CN) and provides access to different types of networks (e.g., 5G network).
It consists of radio base stations and the radio access technologies that enable
wireless communication.
25 [0050] Access and Mobility Management Function (AMF) [106] is a 5G core
network function responsible for managing access and mobility aspects, such as UE
registration, connection, and reachability. It also handles mobility management
procedures like handovers and paging.
30 [0051] Session Management Function (SMF) [108] is a 5G core network function
responsible for managing session-related aspects, such as establishing, modifying,
14
and releasing sessions. It coordinates with the User Plane Function (UPF) for data
forwarding and handles IP address allocation and QoS enforcement.
[0052] Service Communication Proxy (SCP) [110] is a network function in the 5G
5 core network that facilitates communication between other network functions by
providing a secure and efficient messaging service. It acts as a mediator for servicebased interfaces.
[0053] Authentication Server Function (AUSF) [112] is a network function in the
10 5G core responsible for authenticating UEs during registration and providing
security services. It generates and verifies authentication vectors and tokens.
[0054] Network Slice Specific Authentication and Authorization Function
(NSSAAF) [114] is a network function that provides authentication and
15 authorization services specific to network slices. It ensures that UEs can access only
the slices for which they are authorized.
[0055] Network Slice Selection Function (NSSF) [116] is a network function
responsible for selecting the appropriate network slice for a UE based on factors
20 such as subscription, requested services, and network policies.
[0056] Network Exposure Function (NEF) [118] is a network function that exposes
capabilities and services of the 5G network to external applications, enabling
integration with third-party services and applications.
25
[0057] Network Repository Function (NRF) [120] is a network function that acts
as a central repository for information about available network functions and
services. It facilitates the discovery and dynamic registration of network functions.
15
[0058] Policy Control Function (PCF) [122] is a network function responsible for
policy control decisions, such as QoS, charging, and access control, based on
subscriber information and network policies.
5 [0059] Unified Data Management (UDM) [124] is a network function that
centralizes the management of subscriber data, including authentication,
authorization, and subscription information.
[0060] Application Function (AF) [126] is a network function that represents
10 external applications interfacing with the 5G core network to access network
capabilities and services.
[0061] User Plane Function (UPF) [128] is a network function responsible for
handling user data traffic, including packet routing, forwarding, and QoS
15 enforcement.
[0062] Data Network (DN) [130] refers to a network that provides data services to
user equipment (UE) in a telecommunications system. The data services may
include but are not limited to Internet services, private data network related services.
20
[0063] Binding Support Function (BSF) [132] is a component responsible for
storing the binding information for a certain PDU Session and discovering the
binding information (e.g. the address information of the selected PCF). The BSF
[132] allows NF service consumers (e.g. PCF [122]) to register, update and remove
25 the binding information, and allows NF service consumers (e.g. an application
function (AF) [126] or Network Exposure Function (NEF) [118]) to discover the
binding information (e.g. the address information of the selected PCF [122]). The
BSF [132] may be deployed standalone or may also be collocated with other
network functions, such as PCF [122], NRF [120] and SMF [108].
30
16
[0064] FIG. 2 illustrates an exemplary block diagram of a computing device [200]
upon which the features of the present disclosure may be implemented in
accordance with exemplary implementation of the present disclosure. In an
implementation, the computing device [200] may also implement a method for
5 handling a race condition utilising the system [300]. In another implementation, the
computing device [200] itself implements the method for handling the race
condition using one or more units configured within the computing device [200],
wherein said one or more units are capable of implementing the features as
disclosed in the present disclosure.
10
[0065] The computing device [200] may include a bus [202] or other
communication mechanism for communicating information, and a hardware
processor [204] coupled with bus [202] for processing information. The hardware
processor [204] may be, for example, a general-purpose microprocessor. The
15 computing device [200] may also include a main memory [206], such as a randomaccess memory (RAM), or other dynamic storage device, coupled to the bus [202]
for storing information and instructions to be executed by the processor [204]. The
main memory [206] also may be used for storing temporary variables or other
intermediate information during execution of the instructions to be executed by the
20 processor [204]. Such instructions, when stored in non-transitory storage media
accessible to the processor [204], render the computing device [200] into a specialpurpose machine that is customized to perform the operations specified in the
instructions. The computing device [200] further includes a read only memory
(ROM) [208] or other static storage device coupled to the bus [202] for storing static
25 information and instructions for the processor [204].
[0066] A storage device [210], such as a magnetic disk, optical disk, or solid-state
drive is provided and coupled to the bus [202] for storing information and
instructions. The computing device [200] may be coupled via the bus [202] to a
30 display [212], such as a cathode ray tube (CRT), Liquid crystal Display (LCD),
Light Emitting Diode (LED) display, Organic LED (OLED) display, etc. for
17
displaying information to a computer user. An input device [214], including
alphanumeric and other keys, touch screen input means, etc. may be coupled to the
bus [202] for communicating information and command selections to the processor
[204]. Another type of user input device may be a cursor controller [216], such as a
5 mouse, a trackball, or cursor direction keys, for communicating direction
information and command selections to the processor [204], and for controlling
cursor movement on the display [212]. The input device typically has two degrees
of freedom in two axes, a first axis (e.g., x) and a second axis (e.g., y), that allow
the device to specify positions in a plane.
10
[0067] The computing device [200] may implement the techniques described
herein using customized hard-wired logic, one or more ASICs or FPGAs, firmware
and/or program logic which in combination with the computing device [200] causes
or programs the computing device [200] to be a special-purpose machine.
15 According to one implementation, the techniques herein are performed by the
computing device [200] in response to the processor [204] executing one or more
sequences of one or more instructions contained in the main memory [206]. Such
instructions may be read into the main memory [206] from another storage medium,
such as the storage device [210]. Execution of the sequences of instructions
20 contained in the main memory [206] causes the processor [204] to perform the
process steps described herein. In alternative implementations of the present
disclosure, hard-wired circuitry may be used in place of or in combination with
software instructions.
25 [0068] The computing device [200] also may include a communication interface
[218] coupled to the bus [202]. The communication interface [218] provides a twoway data communication coupling to a network link [220] that is connected to a
local network [222]. For example, the communication interface [218] may be an
integrated services digital network (ISDN) card, cable modem, satellite modem, or
30 a modem to provide a data communication connection to a corresponding type of
telephone line. As another example, the communication interface [218] may be a
18
local area network (LAN) card to provide a data communication connection to a
compatible LAN. Wireless links may also be implemented. In any such
implementation, the communication interface [218] sends and receives electrical,
electromagnetic or optical signals that carry digital data streams representing
5 various types of information.
[0069] The computing device [200] can send messages and receive data, including
program code, through the network(s), the network link [220] and the
communication interface [218]. In the Internet example, a server [230] might
10 transmit a requested code for an application program through the Internet [228], the
ISP [226], the local network [222], a host [224] and the communication interface
[218]. The received code may be executed by the processor [204] as it is received,
and/or stored in the storage device [210], or other non-volatile storage for later
execution.
15
[0070] Referring to FIG. 3, an exemplary block diagram of a system [300] for
handling a race condition, is shown, in accordance with the exemplary
implementations of the present disclosure. The system [300] comprises at least one
transceiver unit [302], at least one identification unit [304], at least one processing
20 unit [306], at least one detection unit [308], and at least one execution unit [310].
Also, all of the components/ units of the system [300] are assumed to be connected
to each other unless otherwise indicated below. As shown in the figures all units
shown within the system [300] should also be assumed to be connected to each
other. Also, in Fig. 3 only a few units are shown, however, the system [300] may
25 comprise multiple such units or the system [300] may comprise any such numbers
of said units, as required to implement the features of the present disclosure.
Further, in an implementation, the system [300] may be present in a user device/
user equipment [102] to implement the features of the present disclosure. The
system [300] may be in communication with the user device [102] (may also
30 referred herein as a UE). In another implementation, the system [300] may reside
19
in a server or a network entity. In yet another implementation, the system [300] may
reside partly in the server/ network entity and partly in the user device.
[0071] The system [300] is configured for handling the race condition, with the
5 help of the interconnection between the components/units of the system [300].
[0072] As may be known, the race condition is an undesirable situation that occurs
when a device or system attempts to perform two or more operations at the same
time, but because of the nature of the device or system, the operations must be done
10 in the proper sequence to be done correctly. For example, in case of a request from
a network function such as the PCF [122] gets expired due to timeout and such
request is not responded from another network function such as the SMF [108]. The
race condition, also known as the race around condition, leads to degradation in
KPIs at the NF end (like PCF end) and may lead to inconsistency in a PDU session
15 state at the other NF end (like SMF).
[0073] The transceiver unit [302] as shown in FIG. 3, receives at a Policy Control
Function (PCF) [122], a Public Landline Mobile Network (PLMN) change request
associated with a user equipment (UE) [102]. The PLMN change request may refer
20 to a request for changing the PLMN in order to detach the UE [102], in case a user
or the UE [102] moves from one PLMN to another.
[0074] As would be understood the PLMN may refer to a collection of Mobile
Switching Centres (MSCs) areas in Circuit Switching (CS) domain and serving
25 General Packet Radio Service (GPRS) Support Node (SGSN) areas for GPRS and
SGSN or Mobility Management Entity (MME) areas for Evolved Packet Core
(EPC) in Packet Switching (PS) domain within a common numbering plan (e.g.
same National Destination Code) and a common routing plan. The PLMN may be
established and operated by an administration or Recognized Private Operating
30 Agency (RPOA) for the specific purpose of providing land mobile
telecommunications service services to the public. A PLMN may be regarded as an
20
extension of networks (e.g. Integrated Services Digital Network (ISDN), corporate
and public packet data network (PDNs), etc.). A PLMN is identified by a globally
unique PLMN code or an identifier, which consists of a MCC (Mobile Country
Code) and MNC (Mobile Network Code).
5
[0075] In certain implementations of the present disclosure, the PLMN change
request may be for a change from a first PLMN to a second PLMN. It may be noted
that in such implementations, the call associated with the active call session initiates
in first PLMN and completes in the second PLMN. Further, the PLMN change is
10 an event notification that contains the new PLMN Identifier for the ongoing call
session.
[0076] In further implementations of the present disclosure, the first PLMN may be
associated with a first Radio Access technology (RAT) type and the second PLMN
15 may be associated with a second RAT type. For example, the first RAT type may be
of a 5G network, and the second RAT type may be of a 4G network. The RAT type
indicates which Radio Access Technology is currently serving the UE. Some
common examples include UTRA (UMTS Terrestrial Radio Access), GSM (Global
System for Mobile Communications), CDMA (Code Division Multiple Access),
20 LTE (Long-Term Evolution), and 5G NR (New Radio). RAT type also includes EUTRA which is the air interface of 3rd Generation Partnership Project (3GPP) Long
Term Evolution (LTE) upgrade path for mobile networks. It is an acronym for
Evolved UMTS Terrestrial Radio Access, also known as the Evolved Universal
Terrestrial Radio Access. Further, a PLMN may support more than one radio access
25 technology.
[0077] On receiving the PLMN change request, the identification unit [304]
identifies at the PCF [122], a call session status associated with a call from the UE
[102], based on the PLMN change request, wherein the call session status is one of
30 an active call session and a non-active call session. The call session status may refer
to a status of a call session, for example, whether the call is ongoing or has ended.
21
The active call session may indicate that the call is currently ongoing, and the nonactive call session may indicate that the call has been ended. As would be
understood, the call may refer to an interaction between different users that are
availing the communication services through a voice or video call session.
5
[0078] Thereafter, the processing unit [306] generates at the PCF [122], an internal
signal to send a message to a Session Management Function (SMF) [108] to be
consumed when the call session status becomes the non-active call session, in an
event the call session status is the active call session. The internal signal may refer
10 to an indication for communicating the call session status to the SMF [108]. The
message may be in the form of a command or a timeout request, which may be
provided for communicating certain actions to be performed after completion of the
active call session. The completion of the active call session indicates that
completion of an ongoing call. It may be noted that the certain actions as specified
15 are to be performed only in the case when the call session status has been
determined to be non-active call session. Further, in an implementation, the internal
signal is an AAA (Authorization Authentication Answer) message and includes the
PLMN identifier and the RAT type information. The PLMN identifier is included
within a 3GPP-SGSNMCC-MNC AVP and the RAT type within a RAT-Type AVP.
20 Here, AVP stands for Attribute Value Pair and defines the value in the form of a
code for the respective attribute. The RAT-Type (AVP) (AVP code 1032) is of type
Enumerated and is used to identify the radio access technology that is serving the
UE.
25 [0079] In one of the implementations of the present disclosure, generation of the
internal signal may be based on a flag to support the active call session in an event
of PLMN change associated with the UE [102], wherein the flag is set to true. In
such an implementation, the flag is used for determining whether to support an
ongoing call on PLMN change event. If the flag is set to true, it means that the
30 ongoing call or the active call session has to be supported to let the call session
continue even if there is a PLMN change event detected.
22
[0080] Continuing further, after the internal signal is generated, the detection unit
[308] detects at the PCF [122], a call completion event in the event the call session
status is the active call session. The call completion event may refer to the event
5 that the call has been terminated. For detection of the call completion event the call
session status is checked and when the active call session is terminated, the call
session status becomes the non-active call session, which is identified as the call
completion event.
10 [0081] On detection of the call completion event, the execution unit [310] performs
at the PCF [122], one of a first action, a second action, a third action, and a fourth
action based on detecting the call completion event. The first action, the second
action, the third action, and the fourth action may refer to actions that are required
to be taken for handling the race condition.
15
[0082] The first action may refer to an action required to be taken in a case when
there is no change in the PLMN. The second action may refer to an action which is
required to be taken in a case where there is change in the PLMN and the PLMN is
associated with RAT type E-UTRA. The third action may refer to an action required
20 to be taken in a case of no change in the PLMN, and PLMN is associated with the
RAT type NR. The fourth action may refer to an action required to be taken in a
case of a change in the PLMN and a change in the RAT type(for example, change
from 5G to 4G).
25 [0083] It may be understood that the system [300] may fetch certain parameters for
identification of the PLMN and the RAT type used by the PLMN as may be obvious
to a person skilled in the art.
[0084] In an implementation of the present disclosure, in order to perform the first
30 action, the detection unit [308] is required to detect at the PCF [122], if the first
PLMN is same as the second PLMN. For detection of the PLMN, the detection unit
23
[308] matches certain parameters of the first PLMN with the second PLMN, and in
case the parameters are matched, then it is considered that the first PLMN is same
as the second PLMN. These parameters may be the unique PLMN code, which
consists of a MCC (Mobile Country Code) and MNC (Mobile Network Code). This
5 identification helps in checking the prerequisite whether the first action is required
to be executed or not. Then the processing unit [306] ignores, the generated signal
at the PCF [122], in an event the first PLMN is same as the second PLMN. It may
be noted that the ignoring of the generated signal is the first action that is performed
in case the first PLMN is same as the second PLMN. The transceiver unit [302]
10 sends, from the PCF [122], a first notification to the SMF [108]. The first
notification is sent for updating the SMF [108] that the session may be continued
and no change may be required in the session and only the PDU session needs to
be updated. PDU stands for Packet Data Unit. A PDU session establishment is the
process of establishing a data path between the UE and the 5G core network. A PDU
15 session is a logical connection between the UE and a data network, such as the
internet or a private network. It is used to carry user data and can support different
types of services, such as voice, video, and data.
[0085] In an implementation of the present disclosure, the first notification may be
20 an update-notify request. The update-notify request may refer to a request for
sending the information that the PDU session may be updated and is not required
to be terminated.
[0086] To explain the above described first action, let us consider an example.
25 When during an active call session, the detection unit [308] detects a PLMN change
when the first PLMN is different from the second PLMN, but later on the call
completion, the detection unit [308] detects at the PCF [122], that the first PLMN
is same as the second PLMN. This may happen when the UE hops into multiple
PLMNs, but finally returns to the PLMN at which the call initiated at the time of
30 completing the call. The processing unit [306] then, ignores at the PCF [122], the
generated signal in an event the first PLMN becomes same as the second PLMN on
24
the call completion event. Since, the PLMN has now been reverted back to the
original PLMN, there may not be any need for terminating the PDU session for the
same. Accordingly, the transceiver unit [302] sends from the PCF [122], the first
notification to the SMF [108]. As provided above, the first notification may be the
5 update notify request.
[0087] In another implementation of the present disclosure, in order to perform the
second action, the detection unit [308] detects, at the PCF [122], if the first RAT
type is same as the second RAT type. The detecting enables checking whether the
10 prerequisites of the performance of the second action are fulfilled. For detecting,
the detection unit [308] may match certain parameters of the first RAT type with
certain parameters of the second RAT type. In case the certain parameters of the
first RAT type match with the second RAT type, then it may be determined that the
first RAT type is same as the second RAT type. The RAT-Type (AVP) (AVP code
15 1032) is of type Enumerated and is used to identify the radio access technology that
is serving the UE. It may be noted that for identifying the type of RAT there may
be various codes allocated from 0 to 2999. The value of 1004 may provide an
indication that the RAT is EUTRAN, and similarly, the value of 1006 may indicate
that the RAT is NG-RAN. Accordingly, the value may be used for detecting the
20 RAT type and may also detect any change in RAT type. Thereafter, the processing
unit [306] ignores the generated signal at the PCF [122], in an event the first RAT
type is same as the second RAT type and relates to Evolved Universal Terrestrial
Radio Access (EUTRA). It may be noted that during the matching of the certain
parameters, the first RAT type and the second RAT type may be analysed for
25 determination of RAT type being related to EUTRA. After ignoring/discarding of
the generated signal, the processing unit [306] detaches the UE [102] from a
Mobility Management Entity (MME) associated with the first PLMN. As would be
known, the MME may refer to a key component of the 5G core network responsible
for managing the mobility of the user devices within the network. The MME
30 ensures seamless connectivity and handover between different cells or networks.
After detachment is completed, then the transceiver unit [302] sends from the PCF
25
[122], a first notification to the SMF [108]. As provided above, the first notification
may be sent for updating the SMF [108] and the session may be continued to be
used and no change should be required in the session except updating of the certain
parameters, such as updating the bearer context or access points and/or other
5 security parameters.
[0088] In another implementation of the present disclosure, in order to perform the
third action, the detection unit [308] detects if the first RAT type is same as the
second RAT type. Further, the detection unit [308] also detects at the PCF [122], if
10 the first PLMN is different from the second PLMN. For detecting, the detection unit
[308] may match certain parameters of the first PLMN and the first RAT type with
certain parameters of the second PLMN and the second RAT type. In case the
certain parameters of the first PLMN are matched with the second PLMN, then it
may be determined that the first PLMN is same as the second PLMN. Similarly, in
15 case the certain parameters of the first RAT type are not matched with the second
RAT type, then it may be determined that the first RAT type is different than the
second RAT type. The detecting enables checking of the prerequisites for the third
action. Thereafter, the transceiver unit [302] sends from the PCF [122], a second
notification to trigger network initiated detach process of the UE [102], to the SMF
20 [108], in an event the first RAT type is same as second RAT type and relates to New
Radio (NR) and in an event the first PLMN is different from the second PLMN.
[0089] As may be understood, the NR RAT type may refer to the Next Generation
or 5th generation of telecommunication technology. Further, the network initiated
25 detach process may refer to the process of detaching the UE [102] from the current
PLMN through the network end. It may be noted that for detaching the UE [102]
from the current PLMN, a detachment request may be sent to the serving gateway
which may release the resources allocated to the UE, such as radio resources, and
bearers. Then the serving gateway may send a notification to the MME about the
30 detachment and accordingly the MME updates the home subscriber server about
the detachment.
26
[0090] Further, in certain implementations of the present disclosure, the second
notification may be a terminate-notify request. The terminate-notify request may
refer to a request used to provide notification of the termination of the PDU session.
5
[0091] In another implementation of the present disclosure, for performing the
fourth action, the detection unit [308] detects at the PCF [122], if the first RAT type
is different from the second RAT type. Also, the detection unit [308] detects at the
PCF [122], if the first PLMN is different from the second PLMN. As provided
10 above, for detecting, the detection unit [308] may match certain parameters of the
first PLMN and the first RAT type with certain parameters of the second PLMN
and the second RAT type. In case the certain parameters of the first PLMN are not
matched with the second PLMN, then it may be determined that the first PLMN is
different than the second PLMN. Similarly, in case the certain parameters of the
15 first RAT type are not matched with the second RAT type, then it may be determined
that the first RAT type is different than the second RAT type. The transceiver unit
[302], sends from the PCF [122], a second notification to trigger network initiated
detach process of the UE [102], in an event the first RAT type is different from the
second RAT type and in an event the first PLMN is different from the second
20 PLMN.
[0092] Referring to FIG. 4, an exemplary method flow diagram [400] for handling
a race condition, in accordance with exemplary implementations of the present
disclosure is shown. In an implementation the method [400] is performed by the
25 system [300]. Further, in an implementation, the system [300] may be present in a
server device to implement the features of the present disclosure. Also, as shown in
FIG. 4, the method [400] starts at step [402].
[0093] As may be known, the race condition is an undesirable situation that occurs
30 when a device or system attempts to perform two or more operations at the same
time, but because of the nature of the device or system, the operations must be done
27
in a proper sequence to be done correctly. For example, in case of a request from a
network function such as the PCF [122] gets expired due to timeout and such
request is not responded from another network function such as the SMF [108]. The
race condition, also known as the race around condition, leads to degradation in
5 KPIs at the NF end (like PCF end) and may lead to inconsistency in a PDU session
state at the other NF end (like SMF).
[0094] Then at step [404], the method [400] involves receiving, by a transceiver
unit [302], at a Policy Control Function (PCF) [122], a Public Landline Mobile
10 Network (PLMN) change request associated with a user equipment (UE) [102]. The
PLMN change request may refer to a request for changing the PLMN in order to
detach the UE [102], in case a user or the UE [102] moves from one PLMN to
another.
15 [0095] As would be understood the PLMN may refer to a collection of Mobile
Switching Centres (MSCs) areas in Circuit Switching (CS) domain and Serving
General Packet Radio Service (GPRS) Support Node (SGSN) areas for GPRS and
SGSN or Mobility Management Entity (MME) areas for Evolved Packet Core
(EPC) in Packet Switching (PS) domain within a common numbering plan (e.g.
20 same National Destination Code) and a common routing plan. The PLMN may be
established and operated by an administration or Recognized Private Operating
Agency (RPOA) for the specific purpose of providing land mobile
telecommunications service services to the public. A PLMN may be regarded as an
extension of networks (e.g. Integrated Services Digital Network (ISDN), corporate
25 and public packet data network (PDNs), etc.). A PLMN is identified by a globally
unique PLMN code, which consists of a MCC (Mobile Country Code) and MNC
(Mobile Network Code).
[0096] In certain implementations of the present disclosure, the PLMN change
30 request may be for a change from a first PLMN to a second PLMN. It may be noted
that in such implementations, the call associated with the active call session initiates
28
in first PLMN and completes in the second PLMN. Further, the PLMN change is
an event notification that contains the new PLMN Identifier for the ongoing call
session.
5 [0097] In further implementations of the present disclosure, the first PLMN may be
associated with a first Radio Access technology (RAT) type and the second PLMN
may be associated with a second RAT type. For example, the first RAT type may be
of a 5G network, and the second RAT type may be of a 4G network. The RAT type
indicates which Radio Access Technology is currently serving the UE. Some
10 common examples include UTRA (UMTS Terrestrial Radio Access), GSM (Global
System for Mobile Communications), CDMA (Code Division Multiple Access),
LTE (Long-Term Evolution), and 5G NR (New Radio). RAT type also includes EUTRA which is the air interface of 3rd Generation Partnership Project (3GPP) Long
Term Evolution (LTE) upgrade path for mobile networks. It is an acronym for
15 Evolved UMTS Terrestrial Radio Access, also known as the Evolved Universal
Terrestrial Radio Access. Further, a PLMN may support more than one radio access
technology.
[0098] On receiving the PLMN change request, at step [406], the method [400]
20 involves identifying, by an identification unit [304], at the PCF [122], a call session
status associated with a call from the UE [102], based on the PLMN change request,
wherein the call session status is one of an active call session and a non-active call
session. The call session status may refer to a status of a call session, for example,
whether the call is ongoing or has ended. The active call session may indicate that
25 the call is currently ongoing, and the non-active call session may indicate that the
call has been ended. As would be understood, the call may refer to an interaction
between different users that are availing the communication services through a
voice or video call session.
30 [0099] On identification of the call session status, then at step [408], the method
[400] comprises generating, by a processing unit [306], at the PCF [122], an internal
29
signal to send a message to a Session Management Function (SMF) [108] to be
consumed when the call session status becomes the non-active call session, in an
event the call session status is the active call session. The internal signal may refer
to an indication for communicating the call session status to the SMF [108]. The
5 message may be in the form of a command or a timeout request, which may be
provided for communicating certain actions to be performed after completion of a
certain event. For example, the certain event may be a completion of the call. It may
be noted that the certain action as specified is required to be performed only in the
case when the call session status has been determined to be non-active call session.
10
[0100] In one of the implementations of the present disclosure, generation of the
internal signal may be based on a flag to support the active call session in an event
of PLMN change associated with the UE [102], wherein the flag is set to true. In
such an implementation, the flag is used for determining whether to support an
15 ongoing call on PLMN change event. If the flag is set to true, it means that the
ongoing call or the active call session has to be supported to let the call session
continue even if there is a PLMN change event detected.
[0101] Further, at step [410], the method [400] involves detecting, by a detection
20 unit [308], at the PCF [122], a call completion event in the event the call session
status is the active call session. The call completion event may refer to the event
that the call has been terminated. For detection of the call completion event the call
session status is checked and when the active call session is terminated, the call
session status becomes the non-active call session, which is identified as the call
25 completion event.
[0102] On detection of call completion event, then at step [412], the method [400]
comprises performing, by an execution unit [310], at the PCF [122], one of a first
action, a second action, a third action, and a fourth action, based on detecting the
30 call completion event.
30
[0103] The first action may refer to an action required to be taken in a case when
there is no change in the PLMN. The second action may refer to an action which is
required to be taken in a case where there is no change in the PLMN and the PLMN
is associated with RAT type E-UTRA. The third action may refer to an action
5 required to be taken in a case of no change in the PLMN, and PLMN is associated
with the RAT type NR. The fourth action may refer to an action required to be taken
in a case of a change in the PLMN and a change in the RAT type (for example,
change from 5G to 4G).
10 [0104] It may be understood that the system [300] may fetch certain parameters for
identification of the PLMN and the RAT type used by the PLMN as may be obvious
to a person skilled in the art.
[0105] In an implementation of the present disclosure, the first action may comprise
15 detecting, by the detection unit [308], at the PCF [122], if the first PLMN is same
as the second PLMN. The first action further comprises ignoring, by the processing
unit [306], at the PCF [122], the generated signal, in an event the first PLMN is
same as the second PLMN. The first action further comprises sending, by the
transceiver unit [302], from the PCF [122], a first notification to the SMF [108].
20 For detection of the PLMN, the detection unit [308] matches certain parameters of
the first PLMN with the second PLMN, and in case the parameters are matched,
then it is considered that the first PLMN is same as the second PLMN. These
parameters may be the unique PLMN code, which consists of a MCC (Mobile
Country Code) and MNC (Mobile Network Code). This identification helps in
25 checking the prerequisite whether the first action is required to be executed or not.
It may be noted that the ignoring of the generated signal is the first action that is
performed in case the first PLMN is same as the second PLMN. The first
notification is sent for updating the SMF [108] and the session may be continued to
be used and no change may be required in the session and only the PDU session
30 needs to be updated.
31
[0106] In an implementation of the present disclosure, the first notification may be
an update-notify request. The update-notify request may refer to a request for
sending the information that the PDU session may be updated and is not required
to be terminated.
5
[0107] To explain the above described first action, let us consider an example.
When during an active call session, the detection unit [308] detects a PLMN change
when the first PLMN is different from the second PLMN, but later on the call
completion, the detection unit [308] detects at the PCF [122], that the first PLMN
10 is same as the second PLMN. This may happen when the UE hops into multiple
PLMNs, but finally returns to the PLMN at which the call initiated at the time of
completing the call. The processing unit [306] then, ignores at the PCF [122], the
generated signal in an event the first PLMN becomes same as the second PLMN on
the call completion event. Since, the PLMN has now been reverted back to the
15 original PLMN, there may not be any need for terminating the PDU session for the
same. Accordingly, the transceiver unit [302] sends from the PCF [122], the first
notification to the SMF [108]. As provided above, the first notification may be the
update notify request.
20 [0108] In another implementation of the present disclosure, the second action
comprises detecting, by the detection unit [308], at the PCF [122], if the first RAT
type is same as the second RAT type. The second action further comprises ignoring,
by the processing unit [306], at the PCF [122], the generated signal, in an event the
first RAT type is same as the second RAT type and relates to Evolved Universal
25 Terrestrial Radio Access (EUTRA). Furthermore, the second action further
comprises detaching, by the processing unit [306], the UE [102] from a Mobility
Management Entity (MME) associated with the first PLMN. Then the second action
comprises sending, by the transceiver unit [302] from the PCF [122], a first
notification to the SMF [108]. The detecting enables checking whether the
30 prerequisites of the performance of the second action are fulfilled. For detecting,
the detection unit [308] may match certain parameters of the first RAT type with
32
certain parameters of the second RAT type. In case the certain parameters of the
first RAT type are matched with the second RAT type, then it may be determined
that the first RAT type is same as the second RAT type. The RAT type AVP (AVP
code 1032) is of type Enumerated and is used to identify the radio access technology
5 that is serving the UE. It may be noted that for identifying the type of RAT there
may be various codes allocated from 0 to 2999. The value of 1004 may provide an
indication that the RAT is EUTRAN, and similarly, the value of 1006 may indicate
that the RAT is NG-RAN. Accordingly, the value may be used for detecting the
RAT type and may also detect any change in RAT type. It may be noted that during
10 the matching of the certain parameters, the first RAT type and the second RAT type
may be analysed for determination of RAT type being related to EUTRA. After
ignoring/discarding of the generated signal, the processing unit [306] detaches the
UE [102] from a Mobility Management Entity (MME) associated with the first
PLMN. As would be known, the MME may refer to a key component of the 5G
15 core network responsible for managing the mobility of the user devices within the
network. The MME ensures seamless connectivity and handover between different
cells or networks. As provided above, the first notification may be sent for updating
the SMF [108] and the session may be continued to be used and no change should
be required in the session except updating of the certain parameters, such as
20 updating the bearer context or access points and/or other security parameters.
[0109] In another implementation of the present disclosure, the third action
comprises detecting, by the detection unit [308], if the first RAT type is same as the
second RAT type. Then the third action further comprises detecting, by the detection
25 unit [308], at the PCF [122], if the first PLMN is different from the second PLMN.
Also, the third action comprises sending, by the transceiver unit [302], from the
PCF [122], a second notification to trigger network initiated detach process of the
UE [102], to the SMF [108], in an event the first RAT type is same as second RAT
type and relates to New Radio (NR) and in an event the first PLMN is different
30 from the second PLMN. For detecting, the detection unit [308] may match certain
parameters of the first PLMN and the first RAT type with certain parameters of the
33
second PLMN and the second RAT type. In case the certain parameters of the first
PLMN are matched with the second PLMN, then it may be determined that the first
PLMN is same as the second PLMN. Similarly, in case the certain parameters of
the first RAT type are not matched with the second RAT type, then it may be
5 determined that the first RAT type is different than the second RAT type. The
detecting enables checking of the prerequisites for the third action.
[0110] As may be understood, the NR RAT type may refer to the Next Generation
or 5th generation of telecommunication technology. Further, the network initiated
10 detach process may refer to the process of detaching the UE [102] from the current
PLMN through the network end. It may be noted that for detaching the UE [102]
from the current PLMN, a detachment request may be sent to the serving gateway
which may release the resources allocated to the UE, such as radio resources, and
bearers. Then the serving gateway may send a notification to the MME about the
15 detachment and accordingly the MME updates the home subscriber server about
the detachment.
[0111] Further, in an implementation of the present disclosure, the second
notification may be a terminate-notify request. The terminate-notify request may
20 refer to a request used to provide notification of the termination of the PDU session.
[0112] In another implementation of the present disclosure, the fourth action
comprises detecting, by the detection unit [308], at the PCF [122], if the first RAT
type is different from the second RAT type. Then the fourth action comprises
25 detecting, by the detection unit [308], at the PCF [122], if the first PLMN is different
from the second PLMN. Further, the fourth action involves sending, by the
transceiver unit [302], from the PCF [122], a second notification to trigger network
initiated detach process of the UE [102], in an event the first RAT type is different
from the second RAT type and in an event the first PLMN is different from the
30 second PLMN. As provided above, for detecting, the detection unit [308] may
match certain parameters of the first PLMN and the first RAT type with certain
34
parameters of the second PLMN and the second RAT type. In case the certain
parameters of the first PLMN are not matched with the second PLMN, then it may
be determined that the first PLMN is different than the second PLMN. Similarly, in
case the certain parameters of the first RAT type are not matched with the second
5 RAT type, then it may be determined that the first RAT type is different than the
second RAT type.
[0113] Thereafter, at step [414], the method [400] terminates.
10 [0114] FIG. 5 illustrates an exemplary signal flow diagram [500] illustrating a
scenario for a race condition. As per the signal flow [500], at step [502], the MME
or the AMF [106] sends an attach request to the SMF [108]. Then, at step [504], the
SMF [108] sends a request for creation of a PDU session to the PCF [122]. PDU
stands for Packet Data Unit. A PDU session establishment is the process of
15 establishing a data path between the UE and the 5G core network. A PDU session
is a logical connection between the UE and a data network, such as the internet or
a private network. It is used to carry user data and can support different types of
services, such as voice, video, and data.
20 [0115] Based on the request, then at step [506], the PCF [122] accordingly creates
the PDU session and sends back its respective information in the response to the
SMF [108]. After the SMF [108] receives the PDU session, it accordingly, at step
[508], sends its information to the MME or the AMF [106]. Then the attachment of
the UE [102] becomes successful. It may be known that the attachments of the UE
25 may refer to establishment of the connection between the UE [102] and the
telecommunication network. Thereafter, at step [510], the BSF [132] may enable
initiation of a call by sending an AA (Authorization Authentication) Request (AAR)
command for providing the session information. The AAR command, indicated by
the Command-Code field set to 265 and the ‘R’ bit set in the Command Flags field,
30 provides the session information. Thereafter, at step [512], the process involves
installation of certain dynamic PCC rules that are a collection of parameters that
35
enable IP traffic flows to be identified, QoS parameters and filtering actions to be
applied to these flows and charging to be performed on them. After the installation
is successful, then, at step [514], the SMF [108] sends to the PCF [122], a success
indication for the installation of the PCC rules. Then at step [516], the call is
5 established, and an AA answer (AAA) is sent. The AAA command, indicated by the
Command-Code field set to 265 and the ‘R’ bit cleared in the Command Flags field,
is sent in response to the AAR command.
[0116] Now, at step [518], there is a change detected in the PLMN at the MME or
10 the AMF [106], and the same is reported to the SMF [108], and then eventually at
step [520], the same is reported to the PCF [122]. After, the call is completed, at
step [522], a session termination request (STR) is sent to the PCF [122] by the BSF
[132], and at step [524], a session termination answer (STA) is sent back to the BSF
[132].
15
[0117] Now, as provided in the background and the present figure, a race condition
or a race around condition arises when at step [522], the PCF [122] sends a
terminate-notify request to the SMF [108]. Also, at step [524], the MME sends the
detach request to the SMF [108]. Due to this the SMF [108] receives multiple
20 requests due to which a race around condition happens and the SMF [108] may
become unable to make a decision regarding which request should be catered to.
[0118] Referring to FIG. 6, the signal flow diagram [600] provides a solution for
handling the race condition. The signal flow [600] relates to a scenario for handing
25 race condition in case of a change in PLMN. As per the signal flow [600], at step
[602], the MME or the AMF [106] sends an attach request to the SMF [108]. Then,
at step [604], the SMF [108] sends a request for creation of a PDU session to the
PCF [122]. Based on the request, then at step [606], the PCF [122] accordingly
creates the PDU session and sends back its respective information in the response
30 to the SMF [108]. After the SMF [108] receives the PDU session, it accordingly, at
step [608], sends its information to the MME or the AMF [106]. Then the
36
attachment of the UE [102] becomes successful. Thereafter, at step [610], the BSF
[132] may enable initiation of a call by sending an AA Request (AAR) command
for providing the session information. Thereafter, at step [612], the process involves
installation of certain dynamic PCC rules that are a collection of parameters that
5 enable IP traffic flows to be identified, QoS parameters and filtering actions to be
applied to these flows, and charging to be performed on them. After the installation
is successful, then at step [614], the SMF [108] sends to the PCF [122], a success
indication for the same. Then at step [616], the call is established and an AA answer
(AAA) is sent.
10
[0119] Now, at step [618], there is a change detected in the PLMN at the MME or
the AMF [106], and the same is reported to the SMF [108], and then eventually at
step [620], the same is reported to the PCF [122]. After, the call is completed, at
step [622], a session termination request (STR) is sent to the PCF [122] by the BSF
15 [132], and at step [624], a session termination answer (STA) is sent back to the BSF
[132].
[0120] Accordingly, at step [626], in order to handle race condition, a request is
sent to ensure that the dynamic PCC rules are removed. Then at step [628], a
20 response may be received indicating that the PCC rules are removed successfully.
Thereafter, at step [620], a detach request may be received in order to detach the
UE [102].
[0121] Referring to FIG. 7, the signal flow diagram [700] provides a solution for
25 handling the race condition. The signal flow [700] relates to a scenario for handing
race condition in case of a change in PLMN and the RAT type is a NR RAT type.
As per the signal flow [700], at step [702], the AMF [106] sends an attach request
to the SMF [108]. Then, at step [704], the SMF [108] sends a request for creation
of a PDU session to the PCF [122]. Based on the request, then at step [706], the
30 PCF [122] accordingly creates the PDU session and sends back its respective
information in the response to the SMF [108]. After the SMF [108] receives the
37
PDU session, it accordingly, at step [708], sends its information to the AMF [106].
Then the attachment of the UE [102] becomes successful. Thereafter, at step [710],
the BSF [132] may enable initiation of a call by sending an AA Request (AAR)
command for providing the session information. Thereafter, at step [712], the
5 process involves installation of certain dynamic PCC rules that are a collection of
parameters that enable IP traffic flows to be identified, QoS parameters and filtering
actions to be applied to these flows and charging to be performed on them. After
the installation is successful, then at step [714], the SMF [108] sends to the PCF
[122], a success indication for the same. Then at step [716], the call is established,
10 and an AA answer (AAA) is sent.
[0122] Now, at step [718], there is a change detected in the PLMN at the AMF
[106], then the same is communicated to the SMF [108]. Then at step [720], this
PLMN change is conveyed to the PCF [122]. Accordingly, on receipt of the STR at
15 the PCF [122] at step [722], when the call is completed and STR is sent by the BSF
[132] to the PCF [122], then at step [724], the PCF [122] sends an STA to the BSF
[132]. Also, at step [726], the PCF [122] sends a terminate-notify request for
terminating the PDU session to the SMF [108], accordingly, at step [728], the SMF
[108] sends a response confirming the termination of the PDU session. Then, at
20 step [730], the SMF [108] sends a request for deleting the PDU session, to which
the PCF [122], at step [732], sends back a response after confirming the deletion of
the PDU session.
[0123] Referring to FIG. 8, the signal flow diagram [800] provides a solution for
25 handling the race condition. The signal flow [800] relates to a scenario for handing
race condition in case of a change in PLMN and also a change in RAT type. As per
the signal flow [800], at step [802], the MME or the AMF [106] sends an attach
request to the SMF [108]. Then, at step [804], the SMF [108] sends a request for
creation of a PDU session to the PCF [122]. Based on the request, then at step [806],
30 the PCF [122] accordingly creates the PDU session and sends back its respective
information in the response to the SMF [108]. After the SMF [108] receives the
38
PDU session, it accordingly, at step [808], sends its information to the MME or the
AMF [106]. Then the attachment of the UE [102] becomes successful. Thereafter,
at step [810], the BSF [132] may enable initiation of a call by sending an AA
Request (AAR) command for providing the session information. Thereafter, at step
5 [812], the process involves installation of certain dynamic PCC rules that are a
collection of parameters that enable IP traffic flows to be identified, QoS parameters
and filtering actions to be applied to these flows and charging to be performed on
them. After the installation is successful, then at step [814], the SMF [108] sends
to the PCF [122], a success indication for the same. Then at step [816], the call is
10 established, and an AA answer (AAA) is sent.
[0124] Now, at step [818], there is a change detected in the PLMN at the MME or
the AMF [106], then the same is communicated to the SMF [108]. Then at step
[820], this PLMN change is conveyed to the PCF [122]. Also, at step [822], the
15 MME/AMF detects change in the RAT type, and reports the same to the SMF [108].
Accordingly, on receipt of the STR at the PCF [122] at step [826], when the call is
completed and STR is sent by the BSF [132] to the PCF [122], then at step [828],
the PCF [122] sends an STA to the BSF [132]. Also, at step [830], the PCF [122]
sends a terminate-notify request for terminating the PDU session to the SMF [108],
20 accordingly, at step [832], the SMF [108] sends a response confirming the
termination of the PDU session. Then, at step [834], the SMF [108] sends a request
for deleting the PDU session, to which the PCF [122], at step [836], sends back a
response after confirming the deletion of the PDU session.
25 [0125] Referring to FIG. 9, the signal flow diagram [900] provides a solution for
handling the race condition. The signal flow [900] relates to a scenario for handing
race condition in case of a change in PLMN and then the PLMN reverts back to the
earlier PLMN. As per the signal flow [900], at step [902], the MME or the AMF
[106] sends an attach request to the SMF [108]. Then, at step [904], the SMF [108]
30 sends a request for creation of a PDU session to the PCF [122] at the PLMN to
which the UE is already connected, for example PLMN A. Based on the request,
39
then at step [906], the PCF [122] accordingly creates the PDU session and sends
back its respective information in the response to the SMF [108]. After the SMF
[108] receives the PDU session, it accordingly, at step [908], sends its information
to the MME or the AMF [106]. Then the attachment of the UE [102] becomes
5 successful. Thereafter, at step [910], the BSF [132] may enable initiation of a call
by sending an AA Request (AAR) command for providing the session information.
Thereafter, at step [912], the process involves installation of certain dynamic PCC
rules that are a collection of parameters that enable IP traffic flows to be identified,
QoS parameters and filtering actions to be applied to these flows and charging to
10 be performed on them. After the installation is successful, then at step [914], the
SMF [108] sends to the PCF [122], a success indication for the same. Then at step
[916], the call is established, and an AA answer (AAA) is sent.
[0126] Now, at step [918], there is a change detected in the PLMN at the MME or
15 the AMF [106], for example change from PLMN A to PLMN B, then the same is
communicated to the SMF [108]. Then at step [920], this PLMN change is
conveyed to the PCF [122]. Then in a scenario, where the PLMN is again changed,
but now the PLMN changes back to the PLMN under which the call was initiated,
i.e., the PLMN changes back to PLMN A. Then at step [922], another PLMN
20 change is reported to the SMF [108], which conveys the same to the PCF [122] at
step [924]. Accordingly, on receipt of the STR at the PCF [122] at step [926], when
the call is completed and STR is sent by the BSF [132] to the PCF [122]. Then at
step [928], the PCF [122] sends an STA to the BSF [132]. Then, at step [930], the
SMF [108] sends a request to the SMF [108] for removing the dynamic PCC rules.
25 Then after the PCC rules are successfully removed, then at step [932], a
confirmation response conveying success or removal of the PCC rules.
[0127] The present disclosure further discloses a non-transitory computer readable
storage medium storing one or more instructions for handling a race condition, the
30 one or more instructions include executable code which, when executed by one or
more units of a system [300], cause the one or more units to perform certain
40
functions. The one or more instructions when executed cause a transceiver unit
[302] of the system [300] to receive at a Policy Control Function (PCF) [122], a
Public Landline Mobile Network (PLMN) change request associated with a user
equipment (UE) [102]. The one or more instructions when executed further cause
5 an identification unit [304] of the system [300] to identify at the PCF, a call session
status associated with a call from the (UE), based on the PLMN change request,
wherein the call session status is one of an active call session and a non-active call
session. The one or more instructions when executed further cause a processing unit
[306] of the system [300] to generate at the PCF [122], an internal signal to send a
10 message to a Session Management Function (SMF) [108] to be consumed when the
call session status is the non-active call session, in an event the call session status
is the active call session. The one or more instructions when executed further cause
a detection unit [308] of the system [300] to detect at the PCF [122], a call
completion event in the event the call session status is the active call session. The
15 one or more instructions when executed further cause an execution unit [310] of the
system [300] to perform at the PCF [122], one of a first action, a second action, a
third action, and a fourth action, based on detecting the call completion event.
[0128] As is evident from the above, the present disclosure provides a technically
20 advanced solution for handling a race condition. The present solution provides
various technical advantages of handling the race around condition at the Policy
Control Function (PCF). Firstly, this approach ensures there is no Key Performance
Indicator (KPI) degradation at the PCF, as it prevents the occurrence of TerminateNotify timeouts. This means that network performance metrics remain stable and
25 reliable. Secondly, it eliminates the potential for inconsistencies in the Packet Data
Unit (PDU) session state at the Session Management Function (SMF) and other
core network functions, enhancing overall network integrity. Importantly, there is
no need to alter the behavior of the Mobility Management Entity (MME) in
response to PLMN changes, simplifying network management. Additionally, PCF
30 takes the initiative to send Terminate-Notify requests for mobile device detachment
during PLMN changes only when MME is not already triggering the process. This
41
optimizes detachment procedures. Furthermore, the solution extends its support to
scenarios involving frequent PLMN change requests in bordering areas. For
instance, when a call is initiated in PLMN A, the device moves to PLMN B and
subsequently returns to PLMN A during the call, the detachment process is
5 suppressed after call completion. This intelligent handling prevents unnecessary
signaling on the control plane, ensuring a smoother experience for mobile device
attachment and detachment in the same PLMN. This comprehensive approach
showcases the technical prowess and efficiency gained from managing the race
around condition at the PCF level.
10
[0129] While considerable emphasis has been placed herein on the disclosed
implementations, it will be appreciated that many implementations can be made and
that many changes can be made to the implementations without departing from the
principles of the present disclosure. These and other changes in the implementations
15 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.
[0130] Further, in accordance with the present disclosure, it is to be acknowledged
20 that the functionality described for the various components/units can be
implemented interchangeably. While specific embodiments may disclose a
particular functionality of these units for clarity, it is recognized that various
configurations and combinations thereof are within the scope of the disclosure. The
functionality of specific units as disclosed in the disclosure should not be construed
25 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.
42
We Claim:
1. A method for handling a race condition, the method comprising:
- receiving, by a transceiver unit [302], at a Policy Control Function (PCF)
[122], a Public Landline Mobile Network (PLMN) change request
5 associated with a user equipment (UE) [102];
- identifying, by an identification unit [304], at the PCF [122], a call
session status associated with a call from the UE [102], based on the
PLMN change request, wherein the call session status is one of an active
call session and a non-active call session;
10 - generating, by a processing unit [306], at the PCF [122], an internal
signal to send a message to a Session Management Function (SMF)
[108] to be consumed when the call session status is the non-active call
session, in an event the call session status is the active call session;
- detecting, by a detection unit [308], at the PCF [122], a call completion
15 event in the event the call session status is the active call session;
- performing, by an execution unit [310], at the PCF [122], one of a first
action, a second action, a third action and a fourth action based on
detecting the call completion event.
20 2. The method as claimed in claim 1, wherein the PLMN change request is for
a change from a first PLMN to a second PLMN, wherein the call associated
with the active call session initiates in first PLMN and completes in the
second PLMN.
25 3. The method as claimed in claim 2, wherein the first PLMN is associated
with a first Radio Access technology (RAT) type and the second PLMN is
associated with a second RAT type.
4. The method as claimed in claim 1, wherein generating the internal signal to
30 send a message to the SMF [108] is based on a flag to support the active call
43
session in an event of PLMN change associated with the UE [102], wherein
the flag is set to true.
5. The method as claimed in claim 2, wherein the first action comprises:
5 - detecting, by the detection unit [308], at the PCF [122], if the first PLMN
is same as the second PLMN;
- ignoring, by the processing unit [306], at the PCF [122], the generated
signal, in an event the first PLMN is same as the second PLMN;
- sending, by the transceiver unit [302], from the PCF [122], a first
10 notification to the SMF [108].
6. The method as claimed in claim 3, wherein the second action comprises:
- detecting, by the detection unit [308], at the PCF [122], if the first RAT
type is same as the second RAT type;
15 - ignoring, by the processing unit [306], at the PCF [122], the generated
signal, in an event the first RAT type is same as the second RAT type
and relates to Evolved Universal Terrestrial Radio Access (EUTRA);
- detaching, by the processing unit [306], the UE [102] from a Mobility
Management Entity (MME) associated with the first PLMN;
20 - sending, by the transceiver unit [302] from the PCF [122], a first
notification to the SMF [108].
7. The method as claimed in claim 6, wherein the first notification is an updatenotify request.
25
8. The method as claimed in claim 3, wherein the third action comprises:
- detecting, by the detection unit [308], if the first RAT type is same as
the second RAT type;
- detecting, by the detection unit [308], at the PCF [122], if the first PLMN
30 is different from the second PLMN;
44
- sending, by the transceiver unit [302], from the PCF [122], a second
notification to trigger network initiated detach process of the UE [102],
to the SMF [108], in an event the first RAT type is same as second RAT
type and relates to New Radio (NR) and in an event the first PLMN is
5 different from the second PLMN.
9. The method as claimed in claim 3, wherein the fourth action comprises:
- detecting, by the detection unit [308], at the PCF [122], if the first RAT
type is different from the second RAT type;
10 - detecting, by the detection unit [308], at the PCF [122], if the first PLMN
is different from the second PLMN;
- sending, by the transceiver unit [302], from the PCF [122], a second
notification to trigger network initiated detach process of the UE [102],
in an event the first RAT type is different from the second RAT type and
15 in an event the first PLMN is different from the second PLMN.
10. The method as claimed in claim 9, wherein the second notification is a
terminate-notify request.
20 11. A system [300] for handling a race condition, the system [300] comprising:
- a transceiver unit [302], configured to receive at a Policy Control
Function (PCF) [122], a Public Landline Mobile Network (PLMN)
change request associated with a user equipment (UE) [102];
- an identification unit [304] connected at least to the transceiver unit
25 [302], the identification unit [304] configured to identify at the PCF, a
call session status associated with a call from the (UE), based on the
PLMN change request, wherein the call session status is one of an active
call session and a non-active call session;
- a processing unit [306] connected at least to the transceiver unit [302],
30 the processing unit [306] configured to generate at the PCF [122], an
internal signal to send a message to a Session Management Function
45
(SMF) [108] to be consumed when the call session status is the nonactive call session, in an event the call session status is the active call
session;
- a detection unit [308] connected at least to the transceiver unit [302], the
5 detection unit [308] configured to detect at the PCF [122], a call
completion event in the event the call session status is the active call
session;
- an execution unit [310] connected at least to the transceiver unit [302],
the execution unit [310] configured to perform at the PCF [122], one of
10 a first action, a second action, a third action and a fourth action based on
detecting the call completion event.
12. The system [300] as claimed in claim 11, wherein the PLMN change request
is for a change from a first PLMN to a second PLMN, wherein the call
15 associated with the active call session initiates in first PLMN and completes
in the second PLMN.
13. The system [300] as claimed in claim 12, wherein the first PLMN is
associated with a first Radio Access technology (RAT) type and the second
20 PLMN is associated with a second RAT type.
14. The system [300] as claimed in claim 11, wherein generating the internal
signal to send a message to the SMF [108] is based on a flag to support the
active call session in an event of PLMN change associated with the UE
25 [102], wherein the flag is set to true.
15. The system [300] as claimed in claim 12, wherein to perform the first action,
the system [300] comprises:
- the detection unit [308], further configured to detect at the PCF [122], if
30 the first PLMN is same as the second PLMN;
46
- the processing unit [306], further configured to ignore at the PCF [122],
the generated signal, in an event the first PLMN is same as the second
PLMN;
- the transceiver unit [302], further configured to send from the PCF
5 [122], a first notification to the SMF [108].
16. The system [300] as claimed in claim 13, wherein for performing the second
action, the system [300] comprises:
- the detection unit [308], further configured to detect at the PCF [122], if
10 the first RAT type is same as the second RAT type;
- the processing unit [306], further configured to ignore at the PCF [122],
the generated signal, in an event the first RAT type is same as the second
RAT type and relates to Evolved Universal Terrestrial Radio Access
(EUTRA);
15 - the processing unit [306], further configured to detach the UE [102]
from a Mobility Management Entity (MME) associated with the first
PLMN;
- the transceiver unit [302], further configured to send from the PCF
[122], a first notification to the SMF [108].
20
17. The system [300] as claimed in claim 16, wherein the first notification is an
update-notify request.
18. The system [300] as claimed in claim 13, wherein for performing the third
25 action, the system [300] comprises:
- the detection unit [308], further configured to detect if the first RAT type
is same as the second RAT type;
- the detection unit [308], further configured to detect at the PCF [122], if
the first PLMN is different from the second PLMN;
30 - the transceiver unit [302], further configured to send from the PCF
[122], a second notification to trigger network initiated detach process
47
of the UE [102], to the SMF [108], in an event the first RAT type is same
as second RAT type and relates to New Radio (NR) and in an event the
first PLMN is different from the second PLMN.
5 19. The system [300] as claimed in claim 13, wherein for performing the fourth
action, the system [300] comprises:
- the detection unit [308], further configured to detect at the PCF [122], if
the first RAT type is different from the second RAT type;
- the detection unit [308], further configured to detect at the PCF [122], if
10 the first PLMN is different from the second PLMN;
- the transceiver unit [302], further configured to send from the PCF
[122], a second notification to trigger network initiated detach process
of the UE [102], in an event the first RAT type is different from the
second RAT type and in an event the first PLMN is different from the
15 second PLMN.
20. The system [300] as claimed in claim 18, wherein the second notification is a terminate-notify request.