FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
The Patent Rules, 2003
COMPLETE SPECIFICATION
(See section 10 & rule 13)
1. TITLE OF THE INVENTION
2.
SYSTEM AND METHOD OF NETWORK SWITCHING
2. APPLICANT (S)
NAME NATIONALITY ADDRESS
JIO PLATFORMS LIMITED IN
Office-101, Saffron, Nr. Centre Point,
Panchwati 5 Rasta, Ambawadi,
Ahmedabad - 380006, Gujarat, India.
3. PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is to
be performed.
2
RESERVATION OF RIGHTS
[0001] This application is a divisional patent application for Indian patent
application no. 202321023228, filed on date 29th March 2023. The complete
specification is incorporated herein by reference.
5 [0002] A portion of the disclosure of this patent document contains material,
which is subject to intellectual property rights such as, but are not limited to,
copyright, design, trademark, integrated circuit (IC) layout design, and/or trade
dress protection, belonging to Jio Platforms Limited (JPL) or its affiliates (herein
after referred as owner). The owner has no objection to the facsimile reproduction
10 by anyone of the patent document or the patent disclosure, as it appears in the Patent
and Trademark Office patent files or records, but otherwise reserves all rights
whatsoever. All rights to such intellectual property are fully reserved by the owner.
FIELD OF INVENTION
[0003] The present disclosure relates generally to the field of
15 telecommunications network. In particular, the present disclosure relates to
switchover by a user equipment (UE) in a wireless communication system.
DEFINITION
[0004] As used in the present disclosure, the following terms are generally
intended to have the meaning as set forth below, except to the extent that the context
20 in which they are used to indicate otherwise.
[0005] The term “network entity” used hereinafter in the specification refers
to an entity that serves a cellular network for providing voice services (i.e., calls)
and data services to a user equipment. The network entity may include, but not be
limited to, a base station controller, a base transceiver station, a cell site, a NodeB,
25 an eNodeB, a gNodeB, a radio network controller, and any such entity obvious to a
person skilled in the art.
[0006] The term “wireless device” or “user equipment (UE)” used
hereinafter in the specification refers to a computing device that is latched to the
3
network entity to receive voice and data services. The wireless device may refer to
any one of various cellular telephones, personal data assistants (PDA’s), palm-top
computers, laptop computers with wireless modems, wireless electronic mail
receivers, multimedia Internet enabled cellular telephones, and similar personal
5 electronic devices. A wireless device may include a programmable processor and
memory. In a preferred embodiment, the wireless device is a cellular handheld
device (e.g., a wireless device), which can communicate via a cellular telephone
communications network. A person of ordinary skill in the art will appreciate that
the terms “wireless device” and “user equipment (UE)” may be used
10 interchangeably throughout the disclosure.
[0007] The term “UE-Usage-Type (UUT)” used hereinafter in the
specification indicates the usage characteristics of the UE that enables the selection
of a specific dedicated core network (DCN) or data network. Different data
networks are deployed by network service providers to serve specific subsets of
15 subscribers. The DCN supports multiple RAN types and includes regular core
network nodes, such as the MME (Mobility Management Entity), S-GW (Serving
Gateway) and P-GW (PDN Gateway). UE-Usage-Type is stored in a HSS (Home
Subscriber Server) within the subscription information of the UE. Each UE can
have no more than one UE-Usage-Type. This functionality of selecting P-GW
20 based on UUT is used to latch the subscribers to different data networks by
assigning an appropriate UUT value.
[0008] The term “Attribute Value Pair (AVP)” used hereinafter in the
specification indicates a format used to represent information in various domains.
The Attribute Value Pair operates on a concept of key-value pairs. The attribute
25 serves as the key, while the value corresponds to the associated data. This structure
enables efficient storage, retrieval, and processing of information. An UUT AVP
includes a value corresponding to a UUT. For example, if UUT AVP has a value
corresponds to 5G, and the user equipment may be connected to the 5G network.
[0009] The term “Home Subscriber Server (HSS)” used hereinafter in the
30 specification indicates a function that is configured to manage subscriber
information that contains subscriber information, device profile, and state
4
information. HSS is configured to cater various tasks such as authentication,
authorization, and mobility management functions for various networks. The HSS
supports authentication and security procedures for network access by providing
credentials and keys towards network entities (MME). The HSS is a central
5 database that contains all relevant details about a subscriber’s information and user
authentication. HSS also provides information for calls and IP session set up. This
server makes it easier for service providers to manage the information of their
subscribers in real time.
[0010] The term “Mobility Management Entity (MME)” used hereinafter in
10 the specification is responsible for tasks such as user registration, session
management, handover coordination, security, and location tracking. The MME is
responsible for handling signals between active UEs and a network. It is also
responsible for signalling between eNodeB and the core network. For continuous
functionality, MME also keeps track of the UE’s location within the network. MME
15 authenticates UEs by communicating with the HSS.
[0011] The term “circle-wise global flag” used hereinafter in the
specification indicates a variable that signals a particular condition or state of circle
level. The circle-wise global flag variable is accessible and modifiable from any
part of a program.
20 [0012] The term “outage” used hereinafter in the specification indicates to
a temporary disruption or interruption in service. This can occur due to various
reasons such as natural disasters, equipment failure, or maintenance. During the
outage, a subscriber is unable to use the services such as data services, calling
facilities etc.
25 [0013] These definitions are in addition to those expressed in the art.
BACKGROUND OF INVENTION
[0014] The following description of related art is intended to provide
background information pertaining to the field of the disclosure. This section may
include certain aspects of the art that may be related to various features of the
30 present disclosure. However, it should be appreciated that this section be used only
5
to enhance the understanding of the reader with respect to the present disclosure,
and not as admissions of prior art.
[0015] Network experience may vary for different locations. The network
availability may be down at various levels like at circle level or super core levels,
5 which may affect the subscriber-registered services. The network availability may
sometimes be down due to outages. The outages may be at the circle level like
access and mobility management function (AMF), session management function
(SMF), or user plane function (UPF) may be affected. The other outage may be at
super core level like policy control function (PCF), or other network functions or
10 data center may be affected. In another case, outage may be at both at circle level
and super core level.
[0016] In conventional systems and methods, few subscribers may move to
fifth generation (5G) services and others may still be on 4G. 5G subscribers, in
absence of the 5G network must get at least 4G services. Moreover, as soon the 5G
15 network is available, the 5G services must restore back. This transition between the
networks is not spontaneous, smooth, and transparent to users in the conventional
systems and methods.
[0017] Therefore, there is a well-felt need for an improved and efficient
mechanism for switching of users between networks that addresses at least the
20 above-mentioned issues and shortcomings.
OBJECTS OF THE INVENTION
[0018] An object of the present disclosure is to provide an efficient approach
towards switchover of user equipment(s) between networks.
[0019] An object of the present disclosure is to switch users seamlessly and
25 gradually between networks (for example, 4G, 5G, 6G) if there is an issue in the
serving network, thereby avoiding spikes in traffic.
[0020] An object of the present disclosure is to ensure that subscriber
profiles are not duplicated due of switchover of the user equipment(s).
[0021] An object of the present disclosure is to ensure that subscriber
30 profiles are not duplicated due of switchover of the user equipment(s).
6
SUMMARY
[0022] The present disclosure discloses a system (900) for switching at least
one user equipment (UE) connected with a first network to a second network on
detection of an outage in the first network at a circle level or a super core level. The
5 system (900) includes a home subscriber server (HSS) (116/134) and a mobility
management entity (MME) (120). The HSS (116/134) is configured to enable a
global flag when circle-level nodes and super core-level nodes are impacted
responsive to an outage in the first network. The global flag sets a UE-usage-type
(UUT) attribute-value-pair (AVP) to indicate the second network for user
10 equipments latched in the impacted circle-level nodes and for user equipments
belonging to circles parented by the impacted super core-level nodes. The MME
(120) is configured to receive the value of the UUT from the HSS (116/134) and to
switch at least one UE to the second network when the UUT AVP value indicates
the second network, wherein UEs latched in the impacted circle-level nodes and the
15 impacted super core-level nodes are served in the second network.
[0023] In an embodiment, the circle-level nodes that are impacted in the first
network comprise a session management function (SMF) (110) and a user plane
function (UPF) (112), and the super core-level nodes that are impacted comprise a
policy control function (PCF) (114).
20 [0024] In an embodiment, when the UPF (112) of a first location is not
serviceable and the PCF (114) of a second location is unavailable, the HSS
(116/134) is configured to set the value of the UUT as the second network for all
said UEs latched in the first location, including said UEs of other circles roaming
in the first location, and for all said UEs with home public land mobile network
25 (PLMN) belonging to the second location as well as circles parented to the second
location.
[0025] In an embodiment, the HSS (116/134) is configured to return the
value of the UUT to the impacted circle’s MMEs (120), such that the UEs latched
in the impacted circle-level nodes and the impacted super core-level nodes are
30 served in the second network core.
7
[0026] In an embodiment, the HSS (116/134) is configured to update or set
flags for a table having the UUT as an attribute and a value as a network type
selected from the second network, the first network, or a 6G network for operations
including adjusting server parameters, adjusting options, and configuring and
5 tuning an instance for outage detection.
[0027] In an embodiment, when the HSS (116/134) sets, removes, or
modifies the global flag for outage detection, the table is restarted, and the global
flag value is persisted for the instance until the HSS (116/134) removes it.
[0028] In an embodiment, upon restoration of the impacted super core-level
10 nodes, the global flag settings of the HSS (116/134) overwrite the value of the UUT
and return the value of the UUT as the first network to the affected MMEs (120),
and for all impacted first-network UEs, the affected MMEs (120) select the first
network (100-1) for new attach requests coming from said UEs (102) over secondnetwork radio.
15 [0029] In an embodiment, upon restoration of the impacted circle-level
nodes, the HSS (116/134) overwrites the value of the UUT and returns the value of
the UUT as the first network to the MMEs (120) of the impacted location, and for
allsaid first network UEs in the impacted location, the MMEs (120) gradually select
the first network (100-1) for new attach requests coming from said UEs (102) over
20 second-network radio.
[0030] In an embodiment, the HSS (116/134) is configured to maintain a
list of impacted PLMNs to override a value of the UUT from the first network to
the second network and is configured to check for visited PLMN IDs in an update
location request and for home PLMN from an IMSI prefix as well as PLMNs for
25 all circles served by the respective super core (PCF).
[0031] The present disclosure further discloses a method for switching at
least one UE connected with a first network to a second network on detection of an
outage in the first network. The method includes enabling, by the HSS (116/134),
a global flag when circle-level nodes and super core-level nodes are impacted
30 responsive to an outage in the first network; setting, by the HSS (116/134), a UUT
AVP to indicate the second network for UEs latched in the impacted circle-level
8
nodes and for UEs belonging to circles parented by the impacted super core-level
nodes, receiving, by the MME (120), the value of the UUT from the HSS (116/134),
and switching, by the MME (120), at least one UE to the second network when the
UUT AVP value indicates the second network, wherein UEs latched in the impacted
5 circle-level nodes and the impacted super core-level nodes are served in the second
network.
[0032] In an embodiment, the method includes setting, by the HSS
(116/134), the value of the UUT as the second network for all said UEs latched in
a first location when the UPF (112) of the first location is not serviceable and the
10 PCF (114) of a second location is unavailable, including said UEs of other circles
roaming in the first location and said UEs with home PLMN belonging to the
second location and circles parented to the second location.
[0033] In an embodiment, the method includes returning, by the HSS
(116/134), the value of the UUT to the MMEs (120) of an impacted circle such that
15 the said UEs latched in the impacted circle are served in the second network core.
[0034] In an embodiment, the method includes updating or setting, by the
HSS (116/134), flags for a table having the UUT as an attribute and a value as a
network type selected from the second network, the first network, or 6G for
operations including adjusting server parameters, adjusting options, and
20 configuring and tuning an instance for outage detection.
[0035] In an embodiment, the method includes restarting, by the HSS
(116/134), the table when the HSS sets, removes, or modifies the global flag for
outage detection, and persisting the global flag value for the instance until the HSS
removes it.
25 [0036] In an embodiment, the method includes overwriting, by the HSS
(116/134), the value of the UUT as the first network upon restoration of the
impacted super core-level nodes and returning the value of the UUT to the affected
MMEs (120), wherein the affected MMEs (120) select the first network for new
attach requests coming from said UEs (102) over second-network radio.
30 [0037] In an embodiment, the method includes overwriting, by the HSS
(116/134), the value of the UUT as the first network upon restoration of the
9
impacted circle-level nodes and returning the value of the UUT to the MMEs (120)
of the impacted location, wherein the MMEs (120) gradually select the first network
for new attach requests coming from said UEs (102) over second-network radio.
[0038] In an embodiment, the method includes maintaining, by the HSS
5 (116/134), a list of impacted PLMNs to override a value of the UUT from the first
network to the second network and checking, by the HSS, for visited PLMN IDs in
an update location request and for home PLMN from an IMSI prefix as well as
PLMNs for all circles served by the respective super core (PCF).
[0039] The present disclosure further discloses a user equipment (UE) (102)
10 configured to switch from a first network to a second network on detection of an
outage in the first network. The user equipment (102) includes a processor and a
computer-readable storage medium storing programming for execution by the
processor. The programming includes instructions to receive, from the HSS
(116/134), a UUT AVP value indicating the second network, wherein the HSS
15 (116/134) is configured to enable a global flag when circle-level nodes and super
core-level nodes are impacted responsive to an outage in the first network and to
set the UUT AVP to indicate the second network for said UEs latched in the
impacted circle-level nodes and for said UEs belonging to circles parented by the
impacted super core-level nodes. The programming further includes instructions to
20 initiate, responsive to the received UUT AVP value indicating the second network,
attachment or reattachment to the second network, wherein the UE (102) is served
in the second network until restoration of the first network.
BRIEF DESCRIPTION OF DRAWINGS
[0040] The accompanying drawings, which are incorporated herein, and
25 constitute a part of this invention, illustrate exemplary embodiments of the
disclosed methods and systems in which like reference numerals refer to the same
parts throughout the different drawings. Components in the drawings are not
necessarily to scale, emphasis instead being placed upon clearly illustrating the
principles of the present invention. Some drawings may indicate the components
30 using block diagrams and may not represent the internal circuitry of each
10
component. It will be appreciated by those skilled in the art that invention of such
drawings includes the invention of electrical components, electronic components or
circuitry commonly used to implement such components.
[0041] FIG. 1 illustrates an exemplary architecture of a system for
5 performing switchover between a first network and a second network, in
accordance with an embodiment of the present disclosure.
[0042] FIG. 2 illustrates an exemplary representation of a connection
between a user equipment (UE) and a network entity, in accordance with an
embodiment of the present disclosure.
10 [0043] FIGS. 3A-3B illustrate exemplary signal flow diagrams for
implementing a switchover of the UE between networks (a first network and a
second network), in accordance with embodiments of the present disclosure.
[0044] FIG. 4 illustrates an exemplary representation of communication
between a mobility management entity (MME), a home subscriber server (HSS),
15 and network entry points, in accordance with an embodiment of the present
disclosure.
[0045] FIG. 5 illustrates an exemplary architecture of a system for
implementing a circle level service impact (outage) for a Policy Control Function
(PCF), a session management function (SMF), and a user plane function (UPF), in
20 accordance with an embodiment of the present disclosure.
[0046] FIGS. 6A-6B illustrate an exemplary sequence flow diagrams of a
method for implementing a circle level service impact for PCF, SMF, and UPF
network functions, in accordance with embodiments of the present disclosure.
[0047] FIG. 7 illustrates an exemplary architecture of a system for
25 implementing a super core level service impact, in accordance with an embodiment
of the present disclosure.
[0048] FIGS. 8A-B illustrate exemplary sequence flow diagrams of a
method for implementing a super core level service impact, in accordance with
embodiments of the present disclosure.
11
[0049] FIG. 9 illustrates an exemplary architecture of a system for
implementing a circle level service impact as well as a super core level service
impact, in accordance with an embodiment of the present disclosure.
[0050] FIGS. 10A-10B illustrate exemplary sequence flow diagrams of a
5 method for implementing a circle level service impact as well as a super core level
service impact, in accordance with embodiments of the present disclosure.
[0051] FIG. 11 illustrates an exemplary computer system in which or with
which embodiments of the present disclosure may be implemented.
[0052] The foregoing shall be more apparent from the following more
10 detailed description of the disclosure.
LIST OF REFERENCE NUMERALS
100 – System
100-1 – First Network
100-2 – Second Network
15 102, 202 – User Equipment (UE)
104 – First Network Entity
106 – Second Network Entity
108 – Access and Mobility Management Function (AMF)
110 – Session Management Function (SMF)
20 112 – User Plane Function (UPF)
114 – Policy Control Function (PCF)
116, 134 – Home Subscriber Server (HSS)
118 –5G network functions (NFs)
120 – Mobility Management Entity (MME)
25 122– Serving Gateway (SGW)
124 – Packet Network Data Gateway (PGW)
126 – Policy And Charging Rules Function (PCRF)
128– Diameter Routing Agent (DRA) / Subscriber Location Function (SLF)
130 – Evolved Packet Core (EPC) Nodes
30 132-1, 132-2 – Data Network
12
204 – Network Entity
1110 – External Storage Device
1120 – Bus
1130 – Main Memory
5 1140 – Read Only Memory
1150 – Mass Storage Device
1160 – Communication Port
1170 – Processor
BRIEF DESCRIPTION OF THE INVENTION
10 [0053] In the following description, for the purposes of explanation, various
specific details are set forth in order to provide a thorough understanding of
embodiments of the present disclosure. It will be apparent, however, that
embodiments of the present disclosure may be practiced without these specific
details. Several features described hereafter can each be used independently of one
15 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. Some of the problems discussed above might not be
fully addressed by any of the features described herein. Example embodiments of
the present disclosure are described below, as illustrated in various drawings in
20 which like reference numerals refer to the same parts throughout the different
drawings.
[0054] The ensuing description provides exemplary embodiments only, and
is not intended to limit the scope, applicability, or configuration of the disclosure.
Rather, the ensuing description of the exemplary embodiments will provide those
25 skilled in the art with an enabling description for implementing an exemplary
embodiment. It should be understood that various changes may be made in the
function and arrangement of elements without departing from the spirit and scope
of the disclosure as set forth.
[0055] Specific details are given in the following description to provide a
30 thorough understanding of the embodiments. However, it will be understood by one
13
of ordinary skill in the art that the embodiments may be practiced without these
specific details. For example, circuits, systems, networks, processes, and other
components may be shown as components in block diagram form in order not to
obscure the embodiments in unnecessary detail. In other instances, well-known
5 circuits, processes, algorithms, structures, and techniques may be shown without
unnecessary detail in order to avoid obscuring the embodiments.
[0056] Also, it is noted that individual embodiments may be described as a
process that is depicted as a flowchart, a flow diagram, a data flow diagram, a
structure diagram, or a block diagram. Although a flowchart may describe the
10 operations as a sequential process, many of the operations can be performed in
parallel or concurrently. In addition, the order of the operations may be re-arranged.
A process is terminated when its operations are completed but could have additional
steps not included in a figure. A process may correspond to a method, a function, a
procedure, a subroutine, a subprogram, etc. When a process corresponds to a
15 function, its termination can correspond to a return of the function to the calling
function or the main function.
[0057] The word “exemplary” and/or “demonstrative” is used herein to
mean serving as an example, instance, or illustration. For the avoidance of doubt,
the subject matter disclosed herein is not limited by such examples. In addition, any
20 aspect or design described herein as “exemplary” and/or “demonstrative” is not
necessarily to be construed as preferred or advantageous over other aspects or
designs, nor is it meant to preclude equivalent exemplary structures and techniques
known to those of ordinary skill in the art. Furthermore, to the extent that the terms
“includes,” “has,” “contains,” and other similar words are used in either the detailed
25 description or the claims, such terms are intended to be inclusive like the term
“comprising” as an open transition word without precluding any additional or other
elements.
[0058] Reference throughout this specification to “one embodiment” or “an
embodiment” or “an instance” or “one instance” means that a particular feature,
30 structure, or characteristic described in connection with the embodiment is included
in at least one embodiment of the present disclosure. Thus, the appearances of the
14
phrases “in one embodiment” or “in an embodiment” in various places throughout
this specification are not necessarily all referring to the same embodiment.
Furthermore, the particular features, structures, or characteristics may be combined
in any suitable manner in one or more embodiments.
5 [0059] The terminology used herein is to describe particular embodiments
only and is not intended to be limiting the disclosure. As used herein, the singular
forms “a”, “an”, and “the” are intended to include the plural forms as well, unless
the context indicates otherwise. It will be further understood that the terms
“comprises” and/or “comprising,” when used in this specification, specify the
10 presence of stated features, integers, steps, operations, elements, and/or
components, but do not preclude the presence or addition of one or more other
features, integers, steps, operations, elements, components, and/or groups thereof.
As used herein, the term “and/or” includes any combinations of one or more of the
associated listed items. It should be noted that the terms “mobile device”, “user
15 equipment”, “user device”, “communication device”, “device” and similar terms
are used interchangeably for the purpose of describing the invention. These terms
are not intended to limit the scope of the invention or imply any specific
functionality or limitations on the described embodiments. The use of these terms
is solely for convenience and clarity of description. The invention is not limited to
20 any particular type of device or equipment, and it should be understood that other
equivalent terms or variations thereof may be used interchangeably without
departing from the scope of the invention as defined herein.
[0060] As used herein, an “electronic device”, or “portable electronic
device”, or “user device” or “communication device” or “user equipment” or
25 “device” refers to any electrical, electronic, electromechanical, and computing
device. The user device is capable of receiving and/or transmitting one or
parameters, performing function/s, communicating with other user devices, and
transmitting data to the other user devices. The user equipment may have a
processor, a display, a memory, a battery, and an input-means such as a hard keypad
30 and/or a soft keypad. The user equipment may be capable of operating on any radio
access technology including but not limited to IP-enabled communication, Zig Bee,
15
Bluetooth, Bluetooth Low Energy, Near Field Communication, Z-Wave, Wi-Fi,
Wi-Fi direct, etc. For instance, the user equipment may include, but not limited to,
a mobile phone, smartphone, virtual reality (VR) devices, augmented reality (AR)
devices, laptop, a general-purpose computer, desktop, personal digital assistant,
5 tablet computer, mainframe computer, or any other device as may be obvious to a
person skilled in the art for implementation of the features of the present disclosure.
[0061] Further, the user device may also comprise a “processor” or
“processing unit” includes processing unit, wherein processor refers to any logic
circuitry for processing instructions. The processor may be a general-purpose
10 processor, a special purpose processor, a conventional processor, a digital signal
processor, a plurality of microprocessors, one or more microprocessors in
association with a DSP core, a controller, a microcontroller, Application Specific
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 is
a hardware processor.
[0062] As portable electronic devices and wireless technologies continue to
improve and grow in popularity, the advancing wireless technologies for data
20 transfer are also expected to evolve and replace the older generations of
technologies. In the field of wireless data communications, the dynamic
advancement of various generations of cellular technology are also seen. The
development, in this respect, has been incremental in the order of second generation
(2G), third generation (3G), fourth generation (4G), fifth generation (5G), and now
25 sixth generation (6G), and more such generations are expected to continue in the
forthcoming time.
[0063] While considerable emphasis has been placed herein on the
components and component parts of the preferred embodiments, it will be
appreciated that many embodiments can be made and that many changes can be
30 made in the preferred embodiments without departing from the principles of the
disclosure. These and other changes in the preferred embodiment as well as other
16
embodiments of the disclosure will be apparent to those skilled in the art from the
disclosure herein, whereby it is to be distinctly understood that the foregoing
descriptive matter is to be interpreted merely as illustrative of the disclosure and
not as a limitation.
5 [0064] The present disclosure relates to systems and methods for network
switching of a user equipment. As an example, fourth generation (4G) and 5G
networks exist in tandem. In an aspect, the system is applicable for sixth generation
(6G) network also. The 5G core is a combo-core which serves migrated customers
from the 4G network when they are in 5G or 4G coverage alike. The present
10 disclosure provides a spontaneous, smooth, and transparent approach towards
switching over of the user equipment between different communication networks
(4G, 5G and 6G). The changeover happens without touching the provisioning
architecture of network entities or nodes. The subscriber profiles are not duplicated.
[0065] In an embodiment, a user equipment (UE) usage type (UUT), stored
15 in a home subscriber server (HSS), is be used by a serving network, for example,
mobility management entity (MME) to select a core network that should serve the
UE. The HSS provides the UUT value in subscription information of the UE to the
MME. Based on UUT to network mapping, the MME selects one of the multiple
the core networks deployed. As an example, but not limitation, Table 1 shows the
20 UUT to network mapping that is referred to by the MME while selectin the core
network for the UE.
UUT from HSS Gateway (GW) selection
5G
1. One of the GWs mapped to UUT=5G is selected (e.g.,
combo SMF/GW-C).
2. If no GW with UUT=5G is mapped, one of the GWs
with UUT=NO is selected (e.g., 4G Only GW).
3. If no GW is mapped to UUT=5G or UUT=NO, then
GW selection fails.
17
No UUT (4G
Only Subscriber)
1. One of the GWs mapped to UUT=NO is selected (e.g.,
4G Only GW).
2. If no GW is mapped to UUT=NO, then GW selection
fails. GW with any other mapped UUT value will not be
selected.
UUT Value with
no mapping in
MME
1. One of the GWs mapped to UUT=NO is selected (e.g.,
4G Only GW).
2. If no GW is defined and mapped to UUT=NO, then
GW selection fails. GW with any UUT value mapped will
not be selected.
Table 1
[0066] The various embodiments throughout the disclosure will be
explained in more detail with reference to FIG. 1- FIG. 11.
[0067] FIG. 1 illustrates an exemplary architecture of a system 100 for
5 switching at least one user equipment (UE) 102 from a first network (100-1) to a
second network (100-2) on detection of an outage in the first network, in accordance
with an embodiment of the present disclosure. In an aspect, the first network is a
5G network or a combination of 4G and 5G cellular networks. In another example,
the second network is a 4G network. In another aspect, the first network is a 6G
10 network or a combination of 5G and 6G cellular networks. In another example, the
second network is a 5G network.
[0068] Referring to FIG. 1, the system 100 includes a user equipment (UE)
102, a first network entity 104, and a second network entity 106. In an embodiment,
the first network entity 104 may correspond to a gNodeB in a 4G/5G combination
15 core network 100-1 (first network). In an embodiment, the second network entity
106 may correspond to an eNodeB in a 4G core network 100-2 (second network).
In an embodiment, the first network entity 104 and the second network entity 106
are configured to provide a cellular network to the user equipment 102 present in a
cellular coverage range of either of the first network entity 104 or the second
20 network entity 106 and thereby, the user equipment 102 avails voice and data
services using the cellular network.
18
[0069] Further, the first network 100-1 includes various components such
as an access and mobility management function (AMF) 108, a session management
function (SMF) / gateway-control plane (GW-C) 110, user plane function (UPF) /
gateway-user plane (GW-U) 112, a policy control function (PCF) 114, a unified
5 data manager (UDM) / home subscriber server (HSS) 116, and other 5G network
functions (NFs) 118.
[0070] Furthermore, the second network 100-2 may include a mobility
management entity (MME) 120, a serving gateway (SGW) 122, a packet network
data gateway (PGW) 124, a policy and charging rules function (PCRF) 126, a
10 Diameter routing agent (DRA) / subscriber location function (SLF) 128, HSS 134,
and other evolved packet core (EPC) nodes 130. The serving gateway (SGW) 122
handles the user data traffic, but isn’t responsible for the signaling data used. It
transports IP data from UE’s to the LTE network. The SGW also routes incoming
and outgoing IP packets and serves as an anchor for the UE when it moves from
15 one eNodeB to another. The PGW 124 is the network node that connects an evolved
packet core (EPC), to external IP networks. The PGW 124 routes packets to and
from external IP networks. The PGW 124 also allocates an IP address to all UEs
and enforces different policies regarding IP user traffic such as packet filtering. As
depicted in FIG. 1, the network functions in the first network 100-1 are
20 communicatively coupled over a data network 132-1. Similarly, the EPC nodes in
the 4G core network 100-2 are communicatively coupled over a data network 132-
2.
[0071] The home-subscriber-server (HSS) 116 is a database that stores and
manages the subscriber profiles and service data. The HSS 116 contains
25 information such as the subscriber's identity, authentication parameters, service
preferences, location, and contact details. The HSS 116 also assigns an IP
Multimedia Private Identity (IMPI) and one or more IP Multimedia Public Identities
(IMPUs) to each subscriber, which are used for registration and authentication
purposes.
30 [0072] The MME 120 is configured to manage the mobility of user
equipments within the network. By managing the movement of user equipments,
19
the MME ensures that they remain connected to the network and can continue to
communicate seamlessly and without interruption.
[0073] As depicted in FIG. 1, the system 100 is employed at edge locations,
a circle level, and a super core level. The user equipment 102 is in the coverage area
5 of the 5G network, and therefore, attached to the 5G network. In an embodiment,
where a current location of the user equipment 102 does not have 5G coverage, then
the user equipment 102 may latch to the 4G network 100-2. In an embodiment,
services to the user equipment 102 may be served by the 4G/5G combination core
network 100-1 or the 4G core network 100-2 based on a UE-usage-type (UUT)
10 attribute value pair (AVP) value. In an embodiment, the UUT AVP value is
maintained/stored by the HSS 116. In an example, the UUT AVP value further
includes an updated location value of the at least one UE.
[0074] Referring to FIG. 1, in an embodiment, the HSS 116 and/or the HSS
134 are queried by the MME 120 to decide whether the user equipment 102 is 4G
15 only or migrated to the 4G/5G combination core network 100-1. The HSS 116
and/or the HSS 134 determine the UUT AVP value and return this information to
the MME 120. In an embodiment, if the user equipment 102 is 4G only, the MME
120 is configured to select the 4G GW-C and GW-U. In another embodiment, if the
user equipment 102 is migrated to the 4G/5G combination core, the MME 120 is
20 configured to select the SMF and the UPF.
[0075] In such an embodiment, if any issue is anticipated in the 5G core
network, then the circle-wise global flag in the HSS 116 is configured to return 4G
as the UUT AVP value to the MME 120. Therefore, the MME 120 is configured to
always select the 4G core network 100-2 and the user equipment 102 may latch on
25 to the 4G core network 100-2. When the user equipment 102 is configured to
transfer back to the 5G core network, when the circle-wise global flag is removed
from the HSS 116 for that particular circle, and therefore, the user equipment 102
is configured to move back to the 5G core network.
[0076] In an embodiment, if any issue is anticipated in the 6G core network,
30 then the circle-wise global flag in the HSS 116 is configured to return 5G as the
UUT AVP value to the MME 120. Therefore, the MME 120 is configured to always
20
select the 5G core network and the user equipment 102 may latch on to the 5G core
network. When the user equipment 102 is configured to transfer back to the 6G core
network, when the circle-wise global flag is removed from the HSS 116 for that
particular circle, and therefore, the user equipment 102 is configured to move back
5 to the 6G core network.
[0077] In an operative aspect, the mobility management entity (MME) is
configured to send a query to the home subscriber server (HSS) for the UE usage
type (UUT) of at least one UE. The HSS is configured to generate a UE-usage-type
(UUT) attribute value pair (AVP) value corresponding to the at least one UE. The
10 UUT AVP value may refer to a defined aspect or attribute related to the User
Equipment (UE) and its usage type within a telecommunication network. In some
implementations, the UUT AVP parameter may refer to the generation of cellular
network (4G, 5G, 6G, etc.) that the UE is using or capable of connecting with. In
an example, the HSS is configured to store UUT AVP values of the UEs connected
15 to the network entity. The MME receives the UUT value in subscription
information of the UE provided by the HSS. The mobility management entity
(MME) is further configured to determine a type of the at least one UE based on
the received UUT AVP value and switch the UE to the second network based on
the determined type of the at least one UE. In an example, the determined type is a
20 fourth-generation (4G) UE, or a fifth-generation (5G) UE, or a sixth-generation
(6G) UE. The MME is configured to select a gateway-control plane (GW-C) or a
gateway-user plane (GW-U) if the determined type of the at least one UE is 4G.
The MME is configured to select a session management function (SMF) or a user
plane function (UPF) if the determined type of the at least one UE is migrated to
25 the 4G/5G. The MME is configured to map the UUT AVP value with a set of
predefined UUT values stored in a table (Table 1) corresponding to a number of
gateway planes connected with the first network and the second network. In an
example, the number of gateway planes include a gateway-control plane (GW-C),
a fully qualified domain name (FQDN), a gateway-user plane (GW-U), a session
30 management function (SMF) or a user plane function (UPF).
21
[0078] If the received UUT AVP value is corresponds to NO and is mapped
with at least one UUT values from the set of predefined UUT values stored in Table
1, the MME is configured to select at least one of the gateway-control plane (GWC), the fully qualified domain name (FQDN), and the gateway-user plane (GW-U)
5 connected with the second network.
[0079] If the received UUT AVP value is corresponds to 5G and mapped
with at least one UUT values from the set of UUT values stored in Table 1, the
MME is configured to select at least one of the gateway-control plane (GW-C) and
the session management function (SMF) connected with the first network.
10 [0080] In an operative aspect, the system is configured to detect the outage
based on a number of parameters. The outage includes an unexpected hardware or
software outage of at least one serving cell in the first network. In an aspect, the
hardware outages or software outages occur when components like servers, storage
devices, or networking equipment fail or experience disruptions. Factors
15 contributing to the hardware outages include component failure, power issues,
overheating, natural disasters, human error, and software bugs. In an example, the
number of parameters includes a reference signal received power (RSRP), a
reference signal received quality (RSRQ), a received signal strength indicator
(RSSI), and a signal-to-interference-plus-noise ratio (SINR). The RSRP is a
20 parameter used in wireless communication systems to measure the quality of a
received signal. The RSRP represents the power of a reference signal received by a
receiver (UE), normalized to the power of a transmitted signal. A higher RSRP
indicates a stronger signal, while a lower RSRP indicates a weaker signal. RSRP is
commonly used to evaluate the quality of a received signal and estimate the amount
25 of data that can be transmitted without errors. The UE usually measures RSRP or
RSRQ based on the direction (RRC message) from the network and report the value.
RSSI indicates the strength of the signal received by UE. RSSI considers not only
the useful signal of a cell, but also all the secondary signal in the measured
frequency range. For example, the RSSI value includes the signal of neighbouring
30 base stations, internal and external interference, and noise. SINR measures signal
quality by comparing a strength of a required signal compared to the unnecessary
22
interference and noise. Mobile network operators seek to maximize SINR at all sites
to deliver the best possible customer experience, either by transmitting at a higher
power, or by minimizing the interference and noise.
[0081] In an aspect, the system is configured to detect the outage on edge
5 location level, a circle level, and a super core level. In an example, if the outage is
detected in a circle level node(s), then the HSS is configured to enable a circle-wise
global flag and sets the UUT AVP value as 4G for the user equipments latched to
the circle level node(s). In an example, the circle level node(s) includes a public
land mobile network (PLMN). The HSS is configured to update/set flags for a table
10 (having UUT as attributes and values as network (4G or 5G) for many operations,
including adjusting server parameters, adjusting options, and configuring and
tuning an instance (outage detection on circle level). When the HSS sets, removes,
or modifies a flag (for example, circle-wise global flag) for the outage detection,
the table might be restarted. The flag value is then persisted for the instance until
15 the HSS remove it. In an operative aspect, if any issue is anticipated in the 5G core
network, then the circle-wise global flag in the HSS 116 always return 4G as the
UUT AVP value to the MME 120. Therefore, the MME 120 always selects the 4G
core network 100-2 and the user equipment 102 will be latched on to the 4G core
network 100-2.
20 [0082] Further, the HSS is configured to disable the circle-wise global flag
on resolving the outage in the circle level node(s), thereby enabling transfer of the
UEs to the circle level node(s). When the user equipment 102 may have to be
brought back to the 5G core network, then the circle-wise global flag may be
removed from the HSS 116 for that particular circle, and therefore, the user
25 equipment 102 may move back to the 5G core network. In an aspect, the super core
level includes at least one data center. The system is configured to detect the
hardware and software outages in the data center.
[0083] In an example, if the outage is detected in super core level node(s),
the HSS is configured to enable a global flag and sets the UUT AVP value as 4G
23
for the user equipments latched to the super core level node(s). The HSS is
configured to update/set flags for the table (having UUT as attributes and value as
network (4G or 5G or 6G) for many operations, including adjusting server
parameters, adjusting options, and configuring and tuning an instance (outage
5 detection). When the HSS sets, removes, or modifies a flag (for example, global
flag) for the outage detection, the table might be restarted. The flag value is then
persisted for the instance until the HSS remove it. The UUT AVP value indicates
the usage characteristics of the UE that enables the selection of a core network. The
global flag may set a value of the UUT as 4G for all subscribers such as the user
10 equipment 102 latched in that particular circle as well as for subscribers belonging
to circles parented by the impacted super core location. For example, if UPF 112 of
location 1 is not serviceable and PCF 114 of location 2 is also unavailable, the HSS
116/134 is configured to set the value of the UUT as 4G for all subscribers latched
in the location 1, which is configured to also include subscribers of other circles
15 roaming in the location 1, and for all subscribers with home PLMN belonging to
the location 2 as well as circles parented to the location 2. In this scenario, the value
of the UUT is returned to the impacted circle’s MMEs 120, in this example, to the
MMEs of location 1. Hence, subscribers latched in location 1 are served in 4G core
network. Further, the HSS 116/134 returns the value of the UUT to the MMEs 120
20 affected because of PCF at location 2 not being serviceable.
[0084] The HSS is configured to disable the global flag on resolving the
outage in the super core level node(s), thereby enabling transfer of the at least one
UE to the super core level node(s). In an embodiment, on restoration of the impacted
super core level nodes, i.e. the PCF 114, global flag (settings) of the HSS 116/134
25 again overwrite the value of the UUT and return the value of the UUT as 5G to the
affected MMEs 120. For all impacted 5G subscribers, the affected MMEs 120
gradually selects the 5G core network (i.e. 100-1) for new attach requests coming
from user equipments such as 102 over 4G radio.
[0085] Although FIG. 1 shows exemplary components of the system 100,
30 in other embodiments, the system 100 may include fewer components, different
24
components, differently arranged components, or additional functional components
than depicted in FIG. 1. Additionally, or alternatively, one or more components of
the system 100 may perform functions described as being performed by one or more
other components of the system 100.
5 [0086] FIG. 2 illustrates an exemplary representation 200 of a connection
between a user equipment and a network, in accordance with an embodiment of the
present disclosure.
[0087] Referring to FIG. 2, a user equipment 202 is connected to a network
entity 204 such as the gNodeB. In an embodiment, when all 5G core network NFs
10 206 are available and there exists no issue, the UDM / HSS 208 returns the UUT
AVP value as 5G, and therefore, the user equipment 202 is connected to the 5G
network. It is appreciated that the user equipment 202, the network entity 204, and
the UDM/HSS 208 are similar to the user equipment 102, the network entity 104,
and the UDM/HSS 116 of FIG. 1, respectively, in their functionality. Further, the
15 5G NFs 206 are similar to the network functions displayed in 100-1 of FIG. 1 in
their functionality.
[0088] FIGS. 3A-3B illustrate exemplary signal flow diagrams (300-1, 300-
2) for implementing a switchover of the UE between the networks, in accordance
with embodiments of the present disclosure.
20 [0089] Referring to FIG. 3A, step A1 includes determining that a user
equipment 302 is present in a coverage area of a 4G network. Further, at step A2, a
random access procedure is initiated, where a radio resource control (RRC)
connection is established between the user equipment 302 and an MME 306. In an
embodiment, at step A2, an attach and authentication procedure is also initiated. In
25 an embodiment, the user equipment 302 is communicatively coupled to the MME
306 via a network entity 304 such as the eNodeB.
[0090] Furthermore, at step A3, the MME 306 is configured to send an
authentication information request to DRA/SLF 308. In an embodiment, the
25
DRA/SLF 308 determines whether the user equipment 302 is 4G only or migrated
to 4G/5G combination core network. Based on the determination, the DRA/SLF
308 transmits the authentication information request to the respective HSS in the
core network. For example, if the DRA/SLF 308 determines that the user equipment
5 302 is migrated to 4G/5G combination core, then the DRA/SLF 308 transmits the
authentication information request to a 4G/5G combination core network 312 at
step A3a. In another embodiment, the if DRA/SLF 308 determined that the user
equipment 302 is 4G only, then the DRA/SLF 308 transmits the authentication
information request to a 4G core network 310 at step B3a, which is explained with
10 reference to FIG. 3B.
[0091] Referring to FIG. 3A, in response to receiving the authentication
information request, UDM/HSS in the 4G/5G combination core network 312 is
configured to retrieve and provide relevant authentication vectors to the DRA/SLF
308 in an authentication information answer at step A3b. Thereafter, at step A4, the
15 DRA/SLF 308 is configured to send the authentication information answer to the
MME 306. Based on the authentication information answer, the MME 306 is
configured to send a ciphered options request to the user equipment 302 at step A5.
In response, at step A6, the user equipment 302 is configured to send a ciphered
options response to the MME 306.
20 [0092] Further, at step A7, the MME 306 is configured to send an update
location request to the DRA/SLF 308. In this embodiment, the DRA/SLF 308 is
configured to send the update location request to the 4G/5G combination core
network 312, and specifically to the UDM/HSS within the 4G/5G combination core
network 312 at step A7a. In an embodiment, the UDM/HSS is configured to retrieve
25 and provide UUT AVP value as an update location answer to the DRA/SLF 308 at
step A7b. In this particular scenario, the UUT AVP value is 5G. Furthermore, the
DRA/SLF 308 is configured to send the update location answer to the MME 306 at
step A8. In an embodiment, based on the update location answer (i.e. the UUT AVP
value), the MME 306 is configured to select the 4G/5G combination core network
26
312 for the user equipment 302, and at step A9, the user equipment 302 is
successfully latched on to the 4G/5G combination core network 312.
[0093] Referring to FIG. 3B, if at step A3, the DRA/SLF 308 determines
that the user equipment 302 is 4G only, then the DRA/SLF 308 transmits the
5 authentication information request to the 4G core network 310 at step B3a. In
response to receiving the authentication information request, the existing HSS (for
example, the HSS 134 of FIG. 1) in the 4G core network 310 is configured to
retrieve and provide relevant authentication vectors to the DRA/SLF 308 in an
authentication information answer at step B3b. Thereafter, at step B4, the DRA/SLF
10 308 is configured to send the authentication information answer to the MME 306.
Based on the authentication information answer, the MME 306 is configured to
send a ciphered options request to the user equipment 302 at step B5. In response,
at step B6, the user equipment 302 is configured to send a ciphered options response
to the MME 306.
15 [0094] Further, at step B7, the MME 306 is configured to send an update
location request to the DRA/SLF 308. In this embodiment, the DRA/SLF 308 is
configured to send the update location request to the 4G core network 312, and
specifically to the HSS 134 within the 4G core network 310 at step B7a. In an
embodiment, the existing HSS 134 is configured to retrieve and provide UUT AVP
20 value as an update location answer to the DRA/SLF 308 at step B7b. In this
particular scenario, the UUT AVP value is 4G. Furthermore, the DRA/SLF 308 is
configured to send the update location answer to the MME 306 at step B8. In an
embodiment, based on the update location answer (i.e. the UUT AVP value), the
MME 306 is configured to select the 4G core network 310 for the user equipment
25 302, and at step B9, the user equipment 302 is successfully latched on to the 4G
core network 310.
[0095] It may be appreciated that the user equipment 302, the network entity
304, the MME 306, and the DRA/SLF 308 are similar to the user equipment 102,
the network entity 106, the MME 120, and the DRA/SLF 128 of FIG. 1,
27
respectively, in their functionality. Further, the 4G core network 310 and the 4G/5G
combination core network 312 are similar to 100-2 and 100-1 of FIG. 1,
respectively.
[0096] Further, it may be appreciated that the steps shown in FIGS. 3A-3B
5 are merely illustrative. Other suitable steps may be used, if desired. Moreover, the
steps of the flow diagrams (300-1, 300-2) may be performed in any order and may
include additional steps, without departing from the scope of the current disclosure.
[0097] FIG. 4 illustrates an exemplary representation 400 of communication
between mobility management entity (MME), home subscriber server (HSS), and
10 network entry points, in accordance with an embodiment of the present disclosure.
[0098] Referring to FIG. 4, an MME 402 communicates with an HSS 404
to determine whether user equipment(s) are 4G only or migrated to 4G/5G
combination core network. The HSS 404 is configured to retrieve this information
and respond to the MME 402 with a UUT AVP value, where if the UUT AVP value
15 is 4G only, then the MME 402 establishes a connection between the user
equipment(s) and 4G core network entry point 406, and if the UUT AVP value if
4G/5G combination core, then the MME 402 establishes a connection between the
user equipment(s) and the 4G/5G combination core network entry point 408. As
depicted in FIG. 4, the 4G core network entry point 406 includes a GW-C 406-1
20 and a GW-U 406-2, and the 4G/5G combination core network 408 includes an SMF
408-1 and a UPF 408-2.
[0099] It may be appreciated that the MME 402, the HSS 404, the GW-C
406-1 and SMF 408-1, and the GW-U 406-2 and UPF 408-2 are similar to the MME
120, the HSS 116/134, the SMF/GW-C 110, and the UPF/GW-U 112 of FIG. 1,
25 respectively, in their functionality.
[00100] Although FIG. 4 shows exemplary components of the representation
400, in other embodiments, the representation 400 may include fewer components,
different components, differently arranged components, or additional functional
28
components than depicted in FIG. 4. Additionally, or alternatively, one or more
components of the representation 400 may perform functions described as being
performed by one or more other components of the representation 400.
[00101] FIG. 5 illustrates an exemplary architecture for a system 500 for
5 implementing a circle level service impact for access and mobility management
function (AMF), session management function (SMF), and user plane function
(UPF) network functions, in accordance with an embodiment of the present
disclosure. In an aspect, the circle level includes a policy control function (PCF),
and a public land mobile network (PLMN). The system is configured to detect the
10 hardware and software outages in the PLMN. It may be appreciated that the
reference numerals used in FIG. 5 correspond to those used in FIG. 1 for the sake
of clarify and ease of explanation.
[00102] Referring to FIG. 5, in an embodiment, if circle level nodes (session
management function (SMF), user plane function (UPF) and policy control function
15 (PCF)) are impacted or have an issue in the 4G/5G combination core network 100-
1, then a circle-wise global flag is configured in the HSS 116/134. In such an
embodiment, the circle-wise global flag sets a value of the UUT as 4G for all
subscribers such as the user equipment 102 latched in that particular circle. The
circle level nodes that are impacted in the 4G/5G combination core network 100-1
20 may include, but not be limited to, the PCF 114, the SMF 110, and the UPF 112, as
also depicted in FIG. 5.
[00103] As an example but not limitation, if SMFs of location 1 are impacted,
the HSS 116/134 is configured to set the value of the UUT as 4G for all subscribers
latched in the location 1, which also includes subscribers of other circles roaming
25 in the location 1. In this scenario, the value of the UUT is returned to the impacted
circle’s MMEs 120, in this example, to the MMEs of location 1. Further, the MMEs
120 of location 1 is configured to select the existing 4G core network 100-2 to serve
5G home subscribers present in the location 1, as well as other circle’s subscribers
roaming in the location 1, for example, location 2 public land mobile network
29
(PLMN) subscriber in location 1. On restoration of the impacted circle level nodes,
in this example, the SMFs of location 1, the HSS 116/134 is configured to overwrite
the value of the UUT and return the value of the UUT as 5G to the MME 120 (i.e.
the MMEs of location 1). For all 5G subscribers in location 1, the MMEs 120
5 gradually selects the 5G core network (i.e. 100-1) for new attach requests coming
from user equipments such as 102 over 4G radio.
[00104] Although FIG. 5 shows exemplary components of the system
architecture 500, in other embodiments, the system 500 may include fewer
components, different components, differently arranged components, or additional
10 functional components than depicted in FIG. 5. Additionally, or alternatively, one
or more components of the system 500 may perform functions described as being
performed by one or more other components of the system 500.
[00105] FIGS. 6A-6B illustrate exemplary sequence flow diagrams (600-1,
600-2) of a method for implementing a circle level service impact for SMF, PCF,
15 and UPF network functions, in accordance with embodiments of the present
disclosure. It may be appreciated that the method may be explained with reference
to steps of FIGS. 6A and 6B interchangeably. In an embodiment, the user equipment
602 is communicatively coupled to the MME 614 via a network entity 606 such as
the eNodeB 606 or coupled to the AMF 622 via a network entity 604 such as the
20 gNodeB 604.
[00106] At step A1, it is determined by the system 100 that circle level nodes
are impacted, for example, PCF 608, SMF/GW-C 610, UPF/GW-U 612, have gone
down. In response, at step A1a, the impacted circle level nodes is configured to
communicate radio access network (RAN) connectivity loss to a first network entity
25 604 such as gNodeB. In another embodiment, an administrator is configured to
execute bulk network initiates de-registration operation. Thereafter, a connected
user equipment 602 lost connectivity to 5G network, at step A1b. Further, at step
A2, an administrator of the UDM/HSS 620 configures a list of impacted PLMNs in
the HSS 620 to override a value of UTT from 5G to 4G. In an embodiment, the
30
administrator of the UDM/HSS 620 is configured to check for visited PLMN
identities (IDs) in an update location request. In an embodiment, this configuration
is replicated in all affected circles.
[00107] Referring to FIG. 6A, at step A3, the user equipment 602 is
5 configured to try to latch on 5G network with ‘x’ retry attempts based on network
settings being on automatic. In case all the retry attempts are unsuccessful, the user
equipment 602 is configured to try to latch on to 4G network. Therefore, in such an
embodiment, the user equipment 602 is configured to initiate attach request with a
second network entity 606 such as the eNodeB.
10 [00108] Further, at step A4, random access procedure is initiated for the user
equipment 602. The random access procedure includes establishing RRC
connection and executing authentication call flow for the user equipment 602. In
response thereto, at step A5, MME 614 is configured to send an update location
request to DRA/SLF 616. At steps A5a and A5b, the DRA/SLF 616 is configured
15 to send the update location request to other EPC nodes 618, and other EPC nodes
618 is configured to send the update location request to UDM/HSS 620,
respectively.
[00109] Furthermore, at step A6, in response to receiving the update location
request, the HSS 620 is configured to check the visited PLMN value of AVP
20 “visited-PLMN-ID.” If the configuration for respective PLMN is present, then the
HSS 620 overrides the user’s default UUT from 5G to 4G. The HSS 620 is
configured to send this updated configuration of UUT value in an update location
answer/response to the DRA/SLF 616 via other EPC nodes 618 in steps A6a and
A6b. In an embodiment, if the configuration for the respective PLMN is not present,
25 the HSS 620 is configured to send the UUT value from user equipment’s profile.
At step A6c, the DRA/SLF 616 is configured to send the update location response
to the MME 614.
[00110] Referring to FIG. 6B, at step A7, in response to receiving the update
location response (i.e., UUT value as 4G), the MME 614 selects the 4G network
31
instead of 5G network. Specifically, the MME 614 selects SGW/PGW from EPC
core network. Therefore, a default bearer is created and the user equipment 602 is
successfully connected to 4G core network for services.
[00111] It may be appreciated that the steps shown in FIGS. 6A-6B are
5 merely illustrative. Other suitable steps may be used, if desired. Moreover, the steps
of the flow diagrams (600-1, 600-2) may be performed in any order and may include
additional steps, without departing from the scope of the current disclosure.
[00112] FIG. 7 illustrates an exemplary architecture of a system 700 for
implementing a super core level service impact for policy control function (PCF),
10 in accordance with an embodiment of the present disclosure. It may be appreciated
that the reference numerals used in FIG. 7 correspond to those used in FIG. 1 for
the sake of clarify and ease of explanation.
[00113] Referring to FIG. 7, in an embodiment, if super core level nodes are
impacted or have an issue in the 4G/5G combination core network 100-1, then a
15 global flag may be configured in the HSS 116/134. In such an embodiment, the
global flag is set a value of the UUT as 4G for all subscribers such as the user
equipment 102 with home PLMN belonging to that node. The super core level node
that may be impacted in the 4G/5G combination core network 100-1 may include,
but not be limited to, the PCF 114, as also depicted in FIG. 7.
20 [00114] As an example but not limitation, if the PCF 114 of location 1 is
impacted or is unavailable, the HSS 116/134 may set the value of the UUT as 4G
for all subscribers with home PLMN belonging to the location 1 as well as circles
parented to the location 1. In this scenario, the value of the UUT may be returned
to all affected MMEs 120. This will overwrite the original UUT value in the
25 subscriber profile for subscribers belonging to the home PLMNs which is served
by the super core impacted, i.e. the PCF 114.
32
[00115] In this manner, the affected MMEs 120 of those 5G subscribers are
configured to select the existing 4G core network, whereas other 5G subscribers of
the non-impacted circles continue to be served in the 5G core network.
[00116] On restoration of the impacted super core level nodes, i.e. the PCF
5 114, global settings of the HSS 116/134 again overwrites the value of the UUT and
return the value of the UUT as 5G to the affected MME 120. For all impacted 5G
subscribers, the affected MMEs 120 gradually selectsthe 5G core network (i.e. 100-
1) for new attach requests coming from user equipments such as 102 over 4G radio.
[00117] Although FIG. 7 shows exemplary components of the system 700,
10 in other embodiments, the system 700 may include fewer components, different
components, differently arranged components, or additional functional components
than depicted in FIG. 7. Additionally, or alternatively, one or more components of
the system 700 may perform functions described as being performed by one or more
other components of the system 700.
15 [00118] FIGS. 8A-BB illustrate exemplary sequence flow diagrams (800-1,
800-2) of a method for implementing a super core level service impact for PCF, in
accordance with embodiments of the present disclosure. It may be appreciated that
the method may be explained with reference to steps of FIGS. 8A and 8B
interchangeably. In an embodiment, the user equipment 802 is communicatively
20 coupled to the MME 812 via a network entity 806 such as the eNodeB 806 or
coupled to the AMF 820 via a network entity 804 such as the gNodeB 804.
[00119] At step A1, the system 100 determines that the outage is occurred at
super core level and super core level nodes are impacted, for example, the PCF 810,
and/or other 5G NFs 808 have gone down. In response, at step A1a, the impacted
25 super core level nodes communicates RAN connectivity loss to a first network
entity 804 such as gNodeB. In another embodiment, an administrator may execute
bulk network initiates de-registration operation. Thereafter, a connected user
equipment 802 lost connectivity to 5G network, at step A1b. Further, at step A2, an
administrator of the UDM/HSS 818 configures a list of impacted PLMNs in the
33
HSS 818 to override a value of UTT from 5G to 4G. In an embodiment, the
administrator of the UDM/HSS 818 checks for home PLMN from international
mobile subscriber identity (IMSI) prefix. In an embodiment, this configuration may
be required only on the UDM/HSS 818 service the respective core.
5 [00120] Referring to FIG. 8A, at step A3, the user equipment 802 is
configured to try to latch on 5G network with ‘x’ retry attempts based on network
settings being on automatic. In case all the retry attempts are unsuccessful, the user
equipment 802 is configured to try to latch on to 4G network. Therefore, in such an
embodiment, the user equipment 802 is configured to initiate attach request with a
10 second network entity 806 such as the eNodeB.
[00121] Further, at step A4, a random access procedure is initiated for the
user equipment 802. The random access procedure includes establishing RRC
connection and executing authentication call flow for the user equipment 802. In
response thereto, at step A5, MME 812 may send an update location request to
15 DRA/SLF 814. At steps A5a and A5b, the DRA/SLF 814 sends the update location
request to other EPC nodes 816, and other EPC nodes 816 sends the update location
request to UDM/HSS 818, respectively.
[00122] Furthermore, at step A6, in response to receiving the update location
request, for the respective PLMN, the HSS 818 checks the home PLMN value of
20 AVP “subscription-ID” that includes the IMSI value. If the configuration for
respective PLMN is present, then the HSS 818 overrides the user’s default UUT
from 5G to 4G. The HSS 818 is configured to send this updated configuration of
UUT value in an update location answer/response to the DRA/SLF 814 via other
EPC nodes 816 in steps A6a and A6b. At step A6c, the DRA/SLF 814 is configured
25 to send the update location response to the MME 812.
[00123] Referring to FIG. 8B, at step A7, in response to receiving the update
location response (i.e., UUT value as 4G), the MME 812 is configured to select the
4G network instead of 5G network. Specifically, the MME 812 selects SGW/PGW
34
from EPC core network. Therefore, a default bearer is created and the user
equipment 802 is successfully connected to 4G core network for services.
[00124] It may be appreciated that the steps shown in FIGS. 8A-8B are
merely illustrative. Other suitable steps may be used, if desired. Moreover, the steps
5 of the flow diagrams (800-1, 800-2) may be performed in any order and may include
additional steps, without departing from the scope of the current disclosure.
[00125] FIG. 9 illustrates an exemplary architecture of a system 900 for
implementing a circle level service impact as well as a super core level service
impact, in accordance with an embodiment of the present disclosure. It may be
10 appreciated that the reference numerals used in FIG. 9 correspond to those used in
FIG. 1 for the sake of clarify and ease of explanation.
[00126] Referring to FIG. 9, in an embodiment, if circle level nodes as well
as super core level nodes are impacted or have an issue in the 4G/5G combination
core network 100-1, then a global flag may be configured in the HSS 116/134. In
15 such an embodiment, the global flag may set a value of the UUT as 4G for all
subscribers such as the user equipment 102 latched in that particular circle as well
as for subscribers belonging to circles parented by the impacted super core location.
The circle level nodes that are impacted in the 4G/5G combination core network
100-1 may include, but not be limited to, the SMF 110, and the UPF 112, and the
20 super core level nodes that are impacted may include, but not be limited to, the PCF
114, as also depicted in FIG. 9.
[00127] As an example but not limitation, if UPF 112 of location 1 is not
serviceable and PCF 114 of location 2 is also unavailable, the HSS 116/134 is
configured to set the value of the UUT as 4G for all subscribers latched in the
25 location 1, which is configured to also include subscribers of other circles roaming
in the location 1, and for all subscribers with home PLMN belonging to the location
2 as well as circles parented to the location 2. In this scenario, the value of the UUT
is returned to the impacted circle’s MMEs 120, in this example, to the MMEs of
location 1. Hence, subscribers latched in location 1 are served in 4G core network.
35
Further, the HSS 116/134 returns the value of the UUT to the MMEs 120 affected
because of PCF at location 2 not being serviceable.
[00128] In an embodiment, on restoration of the impacted super core level
nodes, i.e. the PCF 114, global flag (settings) of the HSS 116/134 again overwrite
5 the value of the UUT and return the value of the UUT as 5G to the affected MMEs
120. For all impacted 5G subscribers, the affected MMEs 120 gradually selects the
5G core network (i.e. 100-1) for new attach requests coming from user equipments
such as 102 over 4G radio.
[00129] In an embodiment, on restoration of the impacted circle level nodes,
10 in this example, the UPF of location 1, the HSS 116/134 is configured to again
overwrite the value of the UUT and return the value of the UUT as 5G to the MME
120 (i.e. the MMEs of location 1). For all 5G subscribers in location 1, the MMEs
120 gradually selects the 5G core network (i.e. 100-1) for new attach requests
coming from user equipments such as 102 over 4G radio.
15 [00130] Although FIG. 9 shows exemplary components of the system 900,
in other embodiments, the system 900 may include fewer components, different
components, differently arranged components, or additional functional components
than depicted in FIG. 9. Additionally, or alternatively, one or more components of
the system 900 may perform functions described as being performed by one or more
20 other components of the system 900.
[00131] FIGS. 10A-10B illustrate exemplary sequence flow diagrams (1000-
1, 1000-2) of a method for implementing a circle level service impact as well as a
super core level service impact, in accordance with embodiments of the present
disclosure. It may be appreciated that the method may be explained with reference
25 to steps of FIGS. 10A and 10B interchangeably. In an embodiment, the user
equipment 1002 is communicatively coupled to the MME 1016 via a network entity
1006 such as the eNodeB 1006 or coupled to the AMF 1026 via a network entity
1004 such as the gNodeB 1004.
36
[00132] At step A1, the system 100 determines that the circle level nodes are
impacted, for example, SMF/GW-C 1010, UPF/GW-U 1012 have gone down, as
well as super core level nodes are impacted, for example PCF 1014 has gone down.
In response, at step A1a, the impacted circle level nodes and super core level nodes
5 communicate RAN connectivity loss to a first network entity 1004 such as gNodeB.
In another embodiment, an administrator is configured to execute bulk network
initiates de-registration operation. Thereafter, a connected user equipment 1002 lost
connectivity to 5G network, at step A1b. Further, at step A2, an administrator of
the UDM/HSS 1022 configures a list of impacted PLMNs in the HSS 1022 to
10 override a value of UTT from 5G to 4G. In an embodiment, the administrator of the
UDM/HSS 1022 is configured to check for visited PLMN IDs in an update location
request and for home PLMN from the IMSI prefix as well as PLMNs for all circles
served by the respective super core, i.e. PCF 1014. In an embodiment, this
configuration is replicated in all affected circles.
15 [00133] Referring to FIG. 10A, at step A3, the user equipment 1002 is
configured to try to latch on 5G network with ‘x’ retry attempts based on network
settings being on automatic. In case all the retry attempts are unsuccessful, the user
equipment 1002 is configured to try to latch on to 4G network. Therefore, in such
an embodiment, the user equipment 1002 is configured to initiate attach request
20 with a second network entity 1006 such as the eNodeB.
[00134] Further, at step A4, random access procedure may be initiated for the
user equipment 1002. The random access procedure includes establishing RRC
connection and executing authentication call flow for the user equipment 1002. In
response thereto, at step A5, MME 1016 is configured to send an update location
25 request to DRA/SLF 1018. At steps A5a and A5b, the DRA/SLF 1018 is configured
to send the update location request to other EPC nodes 1020, and other EPC nodes
1020 is configured to send the update location request to UDM/HSS 1022,
respectively.
37
[00135] Furthermore, at step A6, in response to receiving the update location
request, the HSS 1022 is configured to check the visited PLMN value of AVP
“visited-PLMN-ID,” and for the respective PLMN, the HSS 1022 is configured to
check the home PLMN value of AVP “subscription-ID.” If the configuration for
5 respective PLMN is present, then the HSS 1022 is configured to override the user’s
default UUT from 5G to 4G. The HSS 1022 is configured to send this updated
configuration of UUT value in an update location answer/response to the DRA/SLF
1018 via other EPC nodes 1020 in steps A6a and A6b. At step A6c, the DRA/SLF
1018 is configured to send the update location response to the MME 1016.
10 [00136] Referring to FIG. 10B, at step A7, in response to receiving the update
location response (i.e., UUT value as 4G), the MME 1016 is configured to select
the 4G network instead of 5G network. Specifically, the MME 1016 is configured
to select SGW/PGW from EPC core network. Therefore, a default bearer is created
and the user equipment 1002 is successfully connected to 4G core network for
15 services.
[00137] It may be appreciated that the steps shown in FIGS. 10A-10B are
merely illustrative. Other suitable steps may be used, if desired. Moreover, the steps
of the flow diagrams (1000-1, 1000-2) may be performed in any order and may
include additional steps, without departing from the scope of the current disclosure.
20 [00138] A person of ordinary skill in the art will readily ascertain that the
illustrated steps are set out to explain the exemplary embodiments shown, and it
should be anticipated that ongoing technological development will change the
manner in which particular functions are performed. These examples are presented
herein for purposes of illustration, and not limitation. Further, the boundaries of the
25 functional building blocks have been arbitrarily defined herein for the convenience
of the description. Alternative boundaries can be defined so long as the specified
functions and relationships thereof are appropriately performed. Alternatives
(including equivalents, extensions, variations, deviations, etc., of those described
herein) will be apparent to persons skilled in the relevant art(s) based on the
38
teachings contained herein. Such alternatives fall within the scope and spirit of the
disclosed embodiments.
[00139] FIG. 11 illustrates an exemplary computer system 1100 in which or
with which embodiments of the present disclosure may be implemented. As shown
5 in FIG. 11, the computer system 1100 may include an external storage device 1110,
a bus 1120, a main memory 1130, a read-only memory 1140, a mass storage device
1150, communication port(s) 1160, and a processor 1170. A person skilled in the
art will appreciate that the computer system 1100 may include more than one
processor and communication port(s). The processor 1170 may include various
10 modules associated with embodiments of the present disclosure. The
communication port(s) 1160 may be any of an RS-232 port for use with a modembased dialup connection, a 10/100 Ethernet port, a Gigabit or 10 Gigabit port using
copper or fibre, a serial port, a parallel port, or other existing or future ports. The
communication port(s) 1160 may be chosen depending on a network, such a Local
15 Area Network (LAN), Wide Area Network (WAN), or any network to which the
computer system 1100 connects. The main memory 1130 may be random-access
memory (RAM), or any other dynamic storage device commonly known in the art.
The read-only memory 1140 may be any static storage device(s). The mass storage
device 1150 may be any current or future mass storage solution, which can be used
20 to store information and/or instructions.
[00140] The bus 1120 communicatively couples the processor 1170 with the
other memory, storage, and communication blocks. Optionally, operator and
administrative interfaces, e.g., a display, keyboard, and a cursor control device, may
also be coupled to the bus 1120 to support direct operator interaction with the
25 computer system 1100. Other operator and administrative interfaces may be
provided through network connections connected through the communication
port(s) 1160. Components described above are meant only to exemplify various
possibilities. In no way should the aforementioned exemplary computer system
1100 limit the scope of the present disclosure.
39
[00141] Therefore, the present disclosure provides overriding the UUT value
based on 5G core network unavailability flag at different levels like circle level,
super core level, etc. The disclosed solution is applicable to multiple cores of
different types, for example, between 4G and 5G cores. The disclosed solution is
5 also applicable to multiple cores of different types, for example, between 5G and
6G cores. The solution is applicable to multiple cores of same type, for example,
multiple 5G cores identified as core IDs. The same is for multiple 4G cores. The
switchover between 5G and 6G may be subject to possibility that 6G may be
utilizing existing infrastructure of 4G / 5G.
10 [00142] In an embodiment of the present invention, the first network is a 5G
network or a combination of 4G and 5G cellular networks. Furthermore, the second
network is a 4G network.
[00143] In an alternate embodiment, the first network may be a 6G network
or a combination of 5G and 6G cellular networks. Furthermore, the second network
15 is a 5G network. In this, the associated infrastructure parameters and Intelligent
reflecting surfaces (IRS), capable for 6G network in addition to the 5G network
structure may get auto aligned to serve the network.
[00144] Further, the disclosed solution does not require any change in any of
the network function modules or nodes. In particular, there is no change required in
20 the provisioning architecture of the HSS or the UDM. Subscriber or customer
profiles are not duplicated because of the switchover, thereby there is no added
complexity.
[00145] The method and system of the present disclosure may be
implemented in a number of ways. For example, the methods and systems of the
25 present disclosure may be implemented by software, hardware, firmware, or any
combination of software, hardware, and firmware. The above-described order for
the steps of the method is for illustration only, and the steps of the method of the
present disclosure are not limited to the order specifically described above unless
specifically stated otherwise. Further, in some embodiments, the present disclosure
40
may also be embodied as programs recorded in a recording medium, the programs
including machine-readable instructions for implementing the methods according
to the present disclosure. Thus, the present disclosure also covers a recording
medium storing a program for executing the method according to the present
5 disclosure.
[00146] While the foregoing describes various embodiments of the present
disclosure, other and further embodiments of the present disclosure may be devised
without departing from the basic scope thereof. The scope of the present disclosure
is determined by the claims that follow. The present disclosure is not limited to the
10 described embodiments, versions, or examples, which are included to enable a
person having ordinary skill in the art to make and use the present disclosure when
combined with information and knowledge available to the person having ordinary
skill in the art.
ADVANTAGES OF THE INVENTION
15 [00147] The present disclosure provides an efficient approach towards
switchover of a user equipment between networks.
[00148] The present disclosure does not require any change in the
architecture of any network function module or node, and specifically, does not
require a change in the provisioning architecture of a home subscriber server (HSS).
20 [00149] The present disclosure avoids duplication of subscriber profiles
because of the switchover between networks.
[00150] The disclosed solution is applicable to multiple cores of different
types, for example, between 4G and 5G cores, and between 5G and 6G cores.
[00151] The disclosed solution is applicable to multiple cores of same type,
25 for example, multiple 5G cores identified as core identities. The same is for multiple
4G cores.

We Claim:
1. A system (900) for switching at least one user equipment (UE) connected
with a first network to a second network on detection of an outage in said
first network, said system (100) comprising:
5 a home UE server (HSS) (116/134) configured to enable a global
flag when circle-level nodes and super core-level nodes are impacted
responsive to an outage in the first network, wherein said global flag sets a
UE-usage-type (UUT) attribute-value-pair (AVP) to indicate the second
network for user equipments latched in the impacted circle-level nodes and
10 for user equipments belonging to circles parented by the impacted super
core-level nodes; and
a mobility management entity (MME) (120) configured to receive
said value of the UUT from said HSS (116/134) and to switch at least one
user equipment (102) of the user equipments in the impacted circle-level
15 nodes or impacted super core-level nodes, to said second network when said
UUT AVP value indicates the second network, wherein UEs latched in the
impacted circle-level nodes and the impacted super core-level nodes are
served in said second network.
2. The system (900) as claimed in claim 1, wherein the circle-level nodes that
20 are impacted in the first network comprise a session management function
(SMF) (110) and the user plane function (UPF) (112), wherein the said super
core level nodes that are impacted comprise a policy control function (PCF)
(114).
25 3. The system (900) as claimed in claim 2, wherein when the UPF (112) of a
first location is not serviceable and the policy control function (PCF) (114)
of a second location is also unavailable, the HSS (116/134) is configured to
set the value of the UUT as the second network for all UEs latched in said
first location, including UEs of other circles roaming in said first location,
42
and for all UEs with home public land mobile network (PLMN) belonging
to said second location as well as circles parented to said second location.
4. The system (900) as claimed in claim 1, wherein said HSS (116/134) is
5 configured to return said value of said UUT to the impacted circle’s MMEs
(120), and said UEs latched in said impacted circle-level nodes and the
impacted super core-level nodes are served in second network core.
5. The system (900) as claimed in claim 1, wherein said HSS (116/134) is
10 configured to update or set flags for a table having said UUT as an attribute
and a value as a network type selected from said second network, said first
network, or 6G for operations including adjusting server parameters,
adjusting options, and configuring and tuning an instance for outage
detection.
15
6. The system (900) as claimed in claim 4, wherein when said HSS (116/134)
is configured to set, remove, or modify the global flag for the outage
detection, said table is restarted, and said global flag value is persisted for
an instance until said HSS removes it.
20
7. The system (900) as claimed in claim 1, wherein upon restoration of the
impacted super core level nodes, said global flag settings of said HSS
(116/134) overwrite said value of said UUT and return said value of said
UUT as said first network to affected MMEs (120), and for all impacted said
25 UEs of first network of said affected MMEs (120) select said first network
(100-1) for new attach requests coming from said user equipments (102)
over second network radio.
8. The system (900) as claimed in claim 1, wherein upon restoration of the
30 impacted circle level nodes, said HSS (116/134) overwrites said value of
said UUT and returns said value of said UUT as said first network to MMEs
(120) of impacted location, and for all said first network UEs in said
location, said MMEs (120) gradually select said first network (100-1) for
43
new attach requests coming from said user equipments (102) over second
network radio.
9. The system (900) as claimed in claim 1, wherein said HSS (116/134) is
5 configured to configure a list of impacted PLMNs in said HSS (116/134) to
override a value of said UUT from said first network to said second network
and is configured to check for visited PLMN IDs in an update location
request and for home PLMN from an IMSI prefix as well as PLMNs for all
circles served by said respective super core (PCF).
10
10. A method of switching at least one user equipment (UE) connected with a
first network to a second network on detection of an outage in said first
network, the method comprising:
enabling, by a home UE server (HSS) (116/134), a global flag when
15 circle-level nodes and super core-level nodes are impacted responsive to an
outage in the first network;
setting, by said HSS (116/134), a UE-usage-type (UUT) attributevalue-pair (AVP) to indicate the second network for user equipments
latched in the impacted circle-level nodes and for user equipments
20 belonging to circles parented by the impacted super core-level nodes;
receiving, by a mobility management entity (MME) (120), said
value of the UUT from said HSS (116/134); and
switching, by said MME (120), at least one user equipment (102) of
said at least one user equipments of the user equipments in the impacted
25 circle-level nodes or impacted super core-level nodes, to said second
network when said UUT AVP value indicates the second network, wherein
UEs latched in the impacted circle-level nodes and the impacted super corelevel nodes are served in said second network.
44
11. The method as claimed in claim 10, wherein the circle-level nodes that are
impacted in the first network comprise a session management function
(SMF) (110) and a user plane function (UPF) (112), and the super core-level
nodes that are impacted comprise a policy control function (PCF) (114).
5
12. The method as claimed in claim 10, further comprising setting, by said HSS
(116/134), the value of the UUT as the second network for all UEs latched
in a first location when the UPF (112) of said first location is not serviceable
and the policy control function (PCF) (114) of a second location is
10 unavailable, including UEs of other circles roaming in said first location and
UEs with home PLMN belonging to said second location and circles
parented to said second location.
13. The method as claimed in claim 10, further comprising returning, by said
15 HSS (116/134), said value of said UUT to MMEs (120) of an impacted
circle such that UEs latched in said impacted circle are served in second
network core.
14. The method as claimed in claim 10, further comprising updating or setting,
20 by said HSS (116/134), flags for a table having said UUT as an attribute and
a value as a network type selected from said second network, said first
network, or 6G for operations including adjusting server parameters,
adjusting options, and configuring and tuning an instance for outage
detection.
25
15. The method as claimed in claim 14, further comprising restarting, by said
HSS (116/134), said table when said HSS sets, removes, or modifies the
global flag for outage detection, and persisting said global flag value for the
instance until said HSS removes it.
30
16. The method as claimed in claim 10, further comprising overwriting, by said
HSS (116/134), said value of said UUT as said first network upon
45
restoration of the impacted super core-level nodes and returning said value
of said UUT to affected MMEs (120), wherein said affected MMEs (120)
select said first network for new attach requests coming from said user
equipments (102) over second network radio.
5
17. The method as claimed in claim 10, further comprising overwriting, by said
HSS (116/134), said value of said UUT as said first network upon
restoration of the impacted circle-level nodes and returning said value of
said UUT to said MMEs (120) of impacted location, wherein said MMEs
10 (120) gradually select said first network for new attach requests coming
from said user equipments (102) over second network radio.
18. The method as claimed in claim 10, further comprising maintaining, by said
HSS (116/134), a list of impacted PLMNs to override a value of said UUT
15 from said first network to said second network and checking, by said HSS,
for visited PLMN IDs in an update location request and for home PLMN
from an IMSI prefix as well as PLMNs for all circles served by said
respective super core (PCF).
20 19. A user equipment (UE) (102) configured to switch from a first network to a
second network on detection of an outage in said first network, the user
equipment comprising:
a processor; and
a computer-readable storage medium storing programming for
25 execution by said processor, the programming including instructions to:
receive, from a home UE server (HSS) (116/134), a UEusage-type (UUT) attribute-value-pair (AVP) indicating the second
network, wherein said HSS (116/134) is configured to enable a
global flag when circle-level nodes and super core-level nodes are
30 impacted responsive to an outage in the first network and to set the
UUT AVP to indicate the second network for user equipments
46
latched in impacted circle-level nodes and for user equipments
belonging to circles parented by impacted super core-level nodes;
and initiate, responsive to said received UUT AVP value
indicating the second network, attachment or reattachment to said
5 second network, wherein said user equipment (102) is served in said
second network until restoration of the first network.