FORM 2
THE PATENTS ACT, 1970
(39 OF 1970)
AND
THE PATENT RULES, 2003
COMPLETE SPECIFICATION
(See section 10 and rule 13)
“A SYSTEM AND METHODS FOR AVAILING SERVICES
IN AN INTERNATIONAL ROAMING BY USING
PROACTIVE COMMANDS”
We, RELIANCE JIO INFOCOMM LIMITED, an Indian National, of, 3rd Floor, Maker
Chamber‐IV, 222, Nariman Point, Mumbai‐400021, Maharashtra, India.
The following specification particularly describes the invention and the manner in
which it is to be performed.
2
TECHNICAL FIELD
The present disclosure generally relates to mobile communications and is more
specifically, directed to systems and methods for availing services from a foreign
network while a mobile user is in international roaming.
5 BACKGROUND
A subscriber identity module (SIM) configured in a mobile device or a smart
device in the form of a chip card contains essential individual subscriber data
that is required for facilitating mobile services. A typical SIM card comprises an
integrated circuit chip that is intended to securely store the international mobile
10 subscriber identity (IMSI) number and the related key/s, which may be used to
identify and authenticate subscribers/users on the mobile devices along with
other information including, but not limiting to, its unique serial number (ICCID),
international mobile subscriber identity (IMSI) number and security
authentication and ciphering information. SIM cards are typically designed to be
15 transferable between different mobile devices. Further, the SIM circuit forms a
part of the function of a Universal Integrated Circuit Card (UICC) physical smart
card (referred to as ‘SIM’ card herein). Also, the SIM comprises a SIM file system
that further consists of the Master File (MF), Dedicated Files (DFs) and the
Elementary Files (EFs) that are mainly used for controlling the user equipment’s
20 (UE) behaviour in the network by facilitating a secured registration to desired
network, deciding which services should be restricted and allowed and
subsequently maintaining a status list of the EF and DF files.
Further, each subscriber is identified by a unique International Mobile Subscriber
Identity (IMSI) which consists of the PLMN (MCC, MNC) of a network operator
25 and the Mobile Subscription Identification Number (MSIN). There are different
network operators (either available in same country or different country) which
provide such voice and data services to subscribers not only of their own
3
subscribers but also from other networks. Therefore, in an exemplary instance,
of international roaming, when the subscriber (Roaming Subscriber (RS)) leaves
the home network and moves to a foreign location (Roamed Network (RN)), the
user equipment receives services from another network within the same country
due to unavailability 5 of the home network as per bilateral roaming agreements
between the home and the roamed network operators.
In recent years, wireless communication networks have undergone tremendous
growth and commercialization, thereby resulting in increased number of services
and features offered on such devices. Therefore, it has now become essential to
10 provide good quality roaming network for maintaining a network operator’s
brand value for roaming services, since these network operators provide a
plurality of subscribed services to the users/subscribers by facilitating
registration, authentication, location updating, handovers, call routing, etc.
Currently, the wireless networks are being configured to provide an Auto IMSI
15 Switch SIM application in case of international roaming by facilitating swapping
the IMSI (home IMSI) of the home network operator with an IMSI (Global IMSI)
of a global Network Operator. With the updated IMSI, the user equipment may
easily avail services in international roaming. However, there are two
prerequisites for successful functioning of the Auto IMSI Switch, one of which is
20 that the Auto IMSI Switch SIM application is able to detect rejection of user
equipment’s in attempting to attach to the available network followed by the
second prerequisite that the SIM application is able to affirm that the user
equipment is in the international location.
Additionally, for efficient swapping of the IMSI, the user equipment should be
25 able to communicate with the subscriber identity module using a variety of
commands such as proactive commands (as specified in the 3GPP TS 31.111
standard, including, but not limiting to, PROVIDE LOCAL INFORMATION (PLI) and
REFRESH). The PLI proactive command is typically used to request the user
4
equipment to transmit the current local information directly to the subscriber
identity module, wherein the current local information includes but not limited
to, local information relating to user equipment, IMEI, network measurement
results, current date and time zones, language settings, current access
technology, current 5 network search mode and battery status. Further, in
situations where the attach request of the user equipment cannot be accepted
by the international roaming network, the international roaming network rejects
the attach request based on appropriate cause code value specified in the 3GPP
TS 24.301, including, but not limiting to, Illegal user equipment, unavailability of
10 cells in tracking area, non‐allowable EPS service, non‐allowable tracking area and
non‐allowable PLMN. The existing technologies for Auto IMSI Switch SIM
application provide a solution by using a particular Elementary File (EF) of the
SIM card viz. EFFPLMN. When the user equipment having the home IMSI sends the
attach request to the international roaming network and receives an attach
15 reject with reject Cause such as “PLMN Not Allowed”, the user equipment
updates the Forbidden PLMN list in the USIM FPLMN elementary file (EFFPLMN)
with the PLMN value of the roamed network from which it received the reject
message resulting in triggering of the Auto IMSI Switch SIM application to
replace the home IMSI by global IMSI. Thereupon, when the user equipment
20 having the global IMSI re‐sends the attach request, the international roaming
network will be attached successfully with the user equipment. Similarly, the
Auto IMSI Switch SIM application can be triggered when the user returns back to
the home network from the international roaming. However, these existing
solutions for Auto IMSI Switch SIM application poses certain limitations, one of
25 which is inability to update the EFFPLMN values when the reject cause is not
“PLMN Not Allowed” i.e. in the event the reject cause is not “PLMN Not
Allowed”, the Auto IMSI Switch SIM application cannot be triggered. Thus, this
Auto IMSI Switch SIM application is not a robust criteria.
5
Another limitation relates to a limited amount of memory and processing power
available on the SIM card. In an exemplary event, the size of EFFPLMN may vary
from subscriber identity module to subscriber identity module based on the
operator requirements and therefore, different user equipments update the
EFFPLMN differently based 5 on their implementation since there is no standard
definition to update the FPLMN list. Therefore, this approach is less efficient and
poses certain limitations, inter alia, the Auto IMSI Switch SIM application
compares the updated values with the previous values to detect the updation.
Accordingly, in order to overcome the aforementioned problems inherent in the
10 existing solutions for Auto IMSI Switch SIM application, there exists a need of an
efficient mechanism to create holistic criteria for Auto IMSI Switch SIM
application by using the PLI proactive commands independent of the cause code
sent by any user and can work regardless of the cause code received.
SUMMARY
15 This section is provided to introduce certain objects and aspects of the present
disclosure in a simplified form that are further described below in the detailed
description. This summary is not intended to identify the key features or the
scope of the claimed subject matter.
Embodiments of the present disclosure may relate to a method for availing at
20 least one service by a user equipment while in an international roaming, the
method comprising: transmitting, by the user equipment, an attach request to at
least one second network in an event the user equipment having a home IMSI is
in the international roaming by entering a second location from a first location,
wherein the first location is served by at least one first network and the second
25 location is served by the at least one second network, and the home IMSI
corresponds to the first location; receiving, by the user equipment, an attach
reject in response to the attach request, wherein the attach reject is received
6
from the at least one second network; updating, by the user equipment, at least
one location parameter of the second location at the subscriber identity module,
wherein the subscriber identity module is configured at the user equipment, and
the at least one location parameter has an associated status; analysing, by the
subscriber identity module, 5 the associated status of the at least one location
parameter of the second location; requesting, by the subscriber identity module,
to receive at least one network parameter of the at least one second network
from the user equipment in an event the associated status of the at least one
location parameter corresponds to the attach reject; communicating, by the user
10 equipment, the at least one network parameter of the at least one second
network to the subscriber identity module, wherein the at least one network
parameter comprises a mobile country code of the second location; replacing
the home IMSI of the user equipment with a global IMSI, by the subscriber
identity module, in an event the at least one network parameter corresponds to
15 the second location; re‐transmitting, by the user equipment having the global
IMSI, the attach request to the at least one second network; and availing, by the
user equipment, the at least one service while in the international roaming in an
event the at least one second network accepts the attach request with the global
IMSI.
20 Further, the embodiments of the present disclosure encompass a method for
availing at least one service by a user equipment while leaving an international
roaming, the method comprising: transmitting, by the user equipment, an attach
request to at least one first network in an event the user equipment having a
global IMSI leaves the international roaming by entering a first location from a
25 second location, wherein the first location is served by at least one first network
and the second location is served by the at least one second network; receiving,
by the user equipment, an attach reject in response to the attach request,
wherein the attach reject is received from the at least one first network;
updating, by the user equipment, at least one location parameter of the first
7
location at the subscriber identity module, wherein the subscriber identity
module is configured at the user equipment, and the at least one location
parameter has an associated status; analysing, by the subscriber identity module,
the associated status of the at least one location parameter of the first location;
requesting, by the 5 subscriber identity module, to receive at least one network
parameter of the at least one first network from the user equipment in an event
the associated status of the at least one location parameter corresponds to the
attach reject; communicating, by the user equipment, the at least one network
parameter of the at least one first network to the subscriber identity module,
10 wherein the at least one network parameter comprises a mobile country code of
the first location; replacing the global IMSI of the user equipment with a home
IMSI, by the subscriber identity module, in an event the at least one network
parameter corresponds to the first location, wherein the home IMSI corresponds
to the first location; re‐transmitting, by the user equipment having the home
15 IMSI, the attach request to the at least one first network; and availing, by the
user equipment, the at least one service while leaving the international roaming
in an event the at least one first network accepts the attach request with the
home IMSI.
Moreover, the embodiments of the present disclosure encompass a system for
20 availing at least one service by a user equipment while one of in an international
roaming and leaving the international roaming, the system comprising: a user
equipment configured to: transmit an attach request to at least one second
network in an event the user equipment having a home IMSI is in the
international roaming by entering a second location from a first location, and
25 transmit an attach request to at least one first network in an event the user
equipment having a global IMSI leaves the international roaming by entering the
first location from the second location, wherein the first location is served by at
least one first network and the second location is served by the at least one
second network, and the home IMSI corresponds to the first location; receive an
8
attach reject event in response to the attach request from one of the at least one
first network and the at least one second network; update at least one location
parameter of one of the first location and the second location at a subscriber
identity module, wherein the subscriber identity module is configured at the user
equipment, and the at 5 least one location parameter has an associated status;
communicate at least one network parameter of one of the at least one second
network and the at least one first network to the subscriber identity module,
wherein the at least one network parameter of the at least one first network and
the at least one second network comprises a mobile country code of the first
10 location and the second location, respectively; the subscriber identity module
configured to: analyse the associated status of the at least one location
parameter of one of the first location and the second location; request to receive
the at least one network parameter of one of the at least one second network
and the at least one first network from the user equipment in an event the
15 associated status of the at least one location parameter corresponds to the
attach reject; replace the home IMSI of the user equipment with the global IMSI
in an event the at least one network parameter corresponds to the second
location; replace the global IMSI of the user equipment with the home IMSI in an
event the at least one network parameter corresponds to the first location;
20 wherein, the user equipment having one of the home IMSI and the global IMSI is
configured to re‐transmit the attach request to one of the at least one first
network and the at least one second network to avail the at least one service
while one of in the international roaming and leaving the international roaming
in an event the at least one first network and the at least one second network
25 accepts the home IMSI and the global IMSI, respectively.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated herein, and constitute a
part of this disclosure, illustrate exemplary embodiments of the disclosed
9
methods and systems in which like reference numerals refer to the same parts
throughout the different drawings. Components in the drawings are not
necessarily to scale, emphasis instead being placed upon clearly illustrating the
principles of the present disclosure. Some drawings may indicate the
components using block 5 diagrams and may not represent the internal circuitry of
each component. It will be appreciated by those skilled in the art that disclosure
of such drawings includes disclosure of electrical components or circuitry
commonly used to implement such components.
FIG.1 illustrates a system architecture [100] for availing at least one service by a
10 user equipment while one of in an international roaming and leaving the
international roaming in accordance with an embodiment of the present
disclosure.
FIG.2 illustrates an exemplary method flow diagram [200] comprising the
method for availing at least one service by a user equipment while in an
15 international roaming in accordance with an embodiment of the present
disclosure.
FIG.3 illustrates an exemplary method flow diagram [300] comprising the
method for availing at least one service by a user equipment while leaving an
international roaming in accordance with an embodiment of the present
20 disclosure.
DETAILED DESCRIPTION
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
25 embodiments of the present disclosure may be practiced without these specific
details. Several features described hereafter can each be used independently of
one another or with any combination of other features. An individual feature
10
may not address any of the problems discussed above or might address only one
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 which like 5 reference numerals refer to the same parts
throughout the different drawings.
Embodiments of the present disclosure may relate to a system and methods for
availing a service by a user equipment when user is either in an international
roaming or is leaving the international roaming. The system comprises a user
10 equipment and a subscriber identity module configured inside the user
equipment for providing functionalities in accordance with the present
invention. Further, the user equipment, present within a first network,
communicates with a second network for availing services when the user
equipment is in international roaming, provided the second network may have
15 the bilateral agreement with the service provider of the subscriber identity
module. Similarly, the user equipment, present within the second network,
communicates with the first network for availing services when the user
equipment leaves international roaming. Furthermore, the user equipment may
have more than one or two subscriber identity modules configured to operate
20 either one at a time or all at the same.
The at least one service as used herein may comprise at least one of a voice call,
multimedia broadcast multicast message, a voice message, a short message
service, a VoIP data, a video data and internet data.
The user equipment as used herein may refer to any computing device operable
25 with a subscriber identity module (SIM), wherein the subscriber identity module
comprises an IMSI, a unique key shared with the network operator. The user
equipment present in a home location may have a home IMSI, while the user
equipment present in an international location (second location) may have a
11
global IMSI. Further, the user equipment includes, but not limited to, a smart
phone, a mobile phone, a tablet, a phablet and any such device as obvious to a
person skilled in the art. Furthermore, the user equipment may comprise an
input means such as a keyboard, an operating system, a memory unit, a display
interface, 5 etc. which functions/communicates with other entities such as base
station or any such network equipment with the help of the subscriber identity
module.
The first location as used herein may refer to the home location of the subscriber
identity module, wherein the first location is served by at least one first network
10 i.e. the at least one first network provide the at least one service to the user
equipment located in the home location.
The second location as used herein may refer to any international location other
than the home location of the subscriber identity module, wherein the second
location is served by at least one second network i.e. the at least one second
15 network i.e. the at least one second network provide the at least one service to
the user equipment located in the second location.
The international roaming as used herein may refer to any event when the user
equipment avails services while travelling outside the geographical coverage
area of the home location.
20 FIG.1 illustrates a preferred embodiment of the present disclosure which
encompasses a system architecture for availing at least one service by a user
equipment when a user is either in an international roaming or is leaving the
international roaming. The system [100] comprises a user equipment [110] and a
subscriber identity module [120] configured inside the user equipment for
25 providing various functionalities in accordance with the present invention. The
user equipment [110] further comprises a plurality of sub systems [102, 102A,
120B, 102C, 103, 104, 105 and 106]. Further, the subsystems [102, 102A, 120B,
12
102C, 103, 104, 105 and 106] comprised within the user equipment [110] may
include, but not limiting to, a modem subsystem [102] with a Baseband DSP
processor [102C] and a plurality of radio interfaces [102A]. The user equipment
[110] may further include a cellular radio [102B] transmission/reception radio
frequency (RF) connected 5 to the antenna [107] for receiving and transmitting
wireless services such as VoIP and Internet/Intranet services. Also, the user
equipment [110] may comprise an application processor [104], a memory
subsystem [105], a power subsystem [106] and an external I/O interfaces
subsystem [103].
10 The present invention further encompasses that the subscriber identity module
[120] comprises a processor [120B], an I/O interface [120A], a RAM temporary
storage [120C], an EEPROM/Non‐ volatile Memory (NVM) [120D] and a SIM file
system [120E]. Further, the EEPROM/Non‐ Volatile Memory (NVM) [120D]
consists of an operating system code, a code of other SIM applications and the
15 Auto IMSI Switch SIM application. The SIM file system [120E] and USIM
application contains elementary files and location parameters such as EFLOCI
(Location Information), EFPSLOCI (PS Location Information), EFEPSLOCI (PS Location
Information) and various application specific files used by SIM applications
running on the subscriber identity module [120] along with a plurality of context
20 and configuration files of the Auto IMSI Switch SIM application. The present
invention also encompasses storage of information related to the home IMSI and
the global IMSI in the Auto IMSI Switch SIM application.
In an event, the user having the user equipment [110] enters into the
international roaming when travels from the first location to the second location,
25 the user equipment [110] may not be able to avail any services since the IMSI of
the subscriber identity module [120] remains home IMSI and the user [110]
having the home IMSI may not be permitted to avail services from the second
location.
13
The user equipment [110] having the home IMSI may, therefore, further be
configured to scan the at least one second network available in the second
location to transmit an attach request to the at least one second network,
wherein the attach request comprises either the home IMSI or the global IMSI.
The attach request comprises 5 the home IMSI in an event the user equipment
[110] travels from the first location to the second location. The user equipment
[110] may further receive an attach reject in response to the attach request from
the at least one second network in an event the home network operator may not
have the bilateral roaming agreement with the network operator in the
10 international location into which the subscriber is roaming. The attach reject
comprises at least one EMM cause of the network rejection, wherein the at least
one EMM cause of the network rejection includes, but not included to, Illegal UE,
Illegal ME, EPS services not allowed, EPS services and non‐EPS services not
allowed, PLMN not allowed, Tracking area not allowed, Roaming not allowed in
15 this tracking area, EPS services not allowed in this PLMN, No suitable cells in
tracking area, Congestion, Not authorized for this CSG, Requested service option
not authorized in this PLMN, Severe network failure.
On receiving the attach reject, the user equipment [110] may be configured to
update the at least one location parameter (EFLOCI (Location Information), EFPSLOCI
20 (PS Location Information), EFEPSLOCI (PS Location Information)) of the second
location at the subscriber identity module [120], wherein each of the at least one
location parameter of the second location has an associated status. The
associated status of the at least one location parameter of the second location
indicates one of a attach reject and an attach acceptance by the at least one
25 second network. In a preferred embodiment, the updation of the at least one
location parameter of the second location is based on the radio access
technology of the at least one second network from which the user equipment
[110] has received the attach reject. This updation of the at least one location
parameter of the second location further triggers the auto IMSI Switch SIM
14
application. In a preferred embodiment, the user equipment [110] may notify an
event data to the subscriber identity module [120], wherein the event data
comprises an update of at least one elementary file present in the subscriber
identity module [120].
The subscriber identity module 5 [120] may further be configured to analyse the
associated status of each of the at least one location parameter of the second
location, wherein the process of analysis further includes checking whether or
not the associated status of the at least one location parameter is updated. In an
event, the associated status of the at least one location parameter indicates the
10 attach reject, the subscriber identity module [120] requests the user equipment
[110] to receive at least one network parameter of the at least one second
network by transmitting the proactive command such as PROVIDE LOCAL
INFORMATION (PLI) command.
On receiving the PROVIDE LOCAL INFORMATION (PLI) command from the
15 subscriber identity module [120], the user equipment [110] may be configured to
communicate at least one network parameter of the at least second network,
wherein the at least one network parameter includes a mobile country code of
the second location, but not limited to, a mobile network code of the second
location. In a preferred embodiment, the user equipment [110] may determine
20 the at least one network parameter of the at least second network based on the
Auto IMSI switch SIM application residing in the subscriber identity module [120]
and subsequently communicate the same to the subscriber identity module
[120].
The user equipment [110] further communicates a terminal response containing,
25 but not including, the at least one network parameter of the at least one second
network to the subscriber identity module [120], pursuant to which the
subscriber identity module [120] may be configured to replace the home IMSI
with the global IMSI based on at least one of the information related to
15
elementary files, the home IMSI and the global IMSI in the Auto IMSI Switch SIM
application, the at least one second network and the at least one first network in
an event the at least one network parameter corresponds to the second
location. The present invention therefore, encompasses replacing of the home
IMSI with the global IMSI, irrespective 5 of the cause code sent by the user by
using the proactive commands.
Further, the user equipment [110] having the global IMSI may now be configured
to re‐scan the at least one second network available in the second location to
transmit the attach request to the at least one second network, wherein the
10 attach request will now comprise the global IMSI of the user equipment [110]. In
an event any one of the at least one second network operator has the bilateral
roaming agreement with the network operator in the international location into
which the subscriber is roaming, the at least one second network accepts the
new attach attempt of the user equipment [110], the user equipment [110] may
15 be enabled to avail the at least one service while in the international roaming. In
another embodiment, when the user having the user equipment [110] travels
further to a new location other than the home location, the user equipment
[110] having the global IMSI may be served by a set of new networks (other than
the at least one first network) subject to the bilateral agreement between the
20 home and the roamed network operators.
Similarly, in another instance, the user having the user equipment [110] with the
global IMSI leaves the international roaming, when travels back to the first
location from the second location, the user equipment [110] having the global
IMSI may further be configured to scan at least one first network available in the
25 first location to transmit an attach request to the at least one first network,
wherein the attach request comprises the global IMSI. The user equipment [110]
may further receive an attach reject in response to the attach request from the
at least one first network in an event the global IMSI is not switched back to the
16
home IMSI. The attach reject comprises at least one EMM cause of the network
rejection, wherein the at least one EMM cause of the network rejection includes,
but not included to, Illegal UE, Illegal ME, EPS services not allowed, EPS services
and non‐EPS services not allowed, PLMN not allowed, Tracking area not allowed,
Roaming not allowed in this 5 tracking area, EPS services not allowed in this PLMN,
No suitable cells in tracking area, Congestion, Not authorized for this CSG,
Requested service option not authorized in this PLMN, Severe network failure.
Further, on receiving the attach reject, the user equipment [110] may be
configured to update the at least one location parameter (EFLOCI (Location
10 Information), EFPSLOCI (PS Location Information), EFEPSLOCI (PS Location
Information)) of the first location at the subscriber identity module [120],
wherein each of the at least one location parameter of the first location has an
associated status. The associated status of the at least one location parameter of
the first location indicates one of an attach reject and an attach acceptance by
15 the at least one first network. In a preferred embodiment, the updation of the at
least one location parameter of the first location is based on the radio access
technology of the at least one first network from which the user equipment
[110] has received the attach reject. This updation of the at least one location
parameter of the first location further triggers the auto IMSI Switch SIM
20 application. In a preferred embodiment, the user equipment [110] may notify an
event data to the subscriber identity module [120], wherein the event data
comprises update of at least one elementary file present in the subscriber
identity module [120].
The subscriber identity module [120] may further be configured to analyse the
25 associated status of each of the at least one location parameter of the first
location, wherein the process of analysis further includes checking whether or
not the associated status of the at least one location parameter is updated. In an
event, the associated status of the at least one location parameter indicates the
17
attach reject, the subscriber identity module [120] requests the user equipment
[110] to receive at least one network parameter of the at least one first network
by transmitting the proactive command such as PROVIDE LOCAL INFORMATION
(PLI) command.
On receiving 5 the PROVIDE LOCAL INFORMATION (PLI) command from the
subscriber identity module [120], the user equipment [110] may be configured to
communicate at least one network parameter of the at least first network,
wherein the at least one network parameter includes a mobile country code of
the second location, but not limited to, a mobile network code of the first
10 location. In a preferred embodiment, the user equipment [110] may determine
the at least one network parameter of the at least first network based on the
Auto IMSI switch SIM application residing in the subscriber identity module [120]
and further communicate the same to the subscriber identity module [120].
The user equipment [110] further communicates a terminal response containing,
15 but not including, the at least one network parameter of the at least first
network to the subscriber identity module [120], pursuant to which the
subscriber identity module [120] may be configured to replace the global IMSI
with the home IMSI based on at least one of the information related to the
elementary files, the home IMSI and the global IMSI in the Auto IMSI Switch SIM
20 application, the at least one second network and the at least one first network in
an event the at least one network parameter corresponds to the first location.
Further, the user equipment [110] having the home IMSI may now be configured
to re‐scan the at least one first network available in the first location to transmit
the attach request to the at least one first network, wherein the attach request
25 will now comprise the home IMSI of the user equipment [110]. Consequently,
the user equipment [110] may be enabled to avail the at least one service while
leaving the international roaming.
18
As illustrated in FIG.2, the present disclosure encompasses an exemplary method
[200] for availing at least one service by a user equipment while in an
international roaming in accordance with an embodiment of the present
disclosure, wherein the method may be performed by the user equipment [110]
and the subscriber 5 identity module [120] by using the proactive commands. The
following includes detailed steps involved in availing at least one service by a
user equipment in an international roaming. The method step may initiate at
step 202 where the user having the user equipment [110] with the home IMSI
travels from the first location to the second location while entering the
10 international roaming. The user having the user equipment [110] enters into the
international roaming when travels from the first location to the second location,
and may not be able to avail any services since the IMSI of the subscriber identity
module remains home IMSI.
At step 204, the user equipment [110] having the home IMSI may be configured
15 to scan the at least one second network available in the second location.
At step 206 and after the accomplishment of the step 204, the user equipment
[110] may transmit the attach request to the at least one second network,
wherein the attach request comprises the home IMSI.
At step 208, the user equipment [110] may further receive an attach reject in
20 response to the attach request from the at least one second network in an event
the home network operator may not have the bilateral roaming agreement with
the network operator in the international location into which the subscriber is
roaming.
At step 210, the user equipment [110], on receiving the attach reject, may be
25 configured to update the at least one location parameter (EFLOCI (Location
Information), EFPSLOCI (PS Location Information), EFEPSLOCI (PS Location
Information)) of the second location at the subscriber identity module [120],
19
wherein each of the at least one location parameter of the second location has
the associated status. The associated status of the at least one location
parameter of the second location indicates one of a attach reject and an attach
acceptance by the at least one second network. In a preferred embodiment, the
updation of the at least 5 one location parameter of the second location is based
on the radio access technology of the at least one second network from which
the user equipment [110] has received the attach reject. This updation of the at
least one location parameter of the second location further triggers the auto
IMSI Switch SIM application. In a preferred embodiment, the user equipment
10 [110] may notify an event data to the subscriber identity module [120], wherein
the event data comprises update of at least one elementary file present in the
subscriber identity module [120].
At step 212, the subscriber identity module [120] may analyse the associated
status of each of the at least one location parameter of the second location.
15 At step 214, the process of analysis further includes checking whether or not the
associated status of the at least one location parameter is updated. In an event,
the associated status of the at least one location parameter indicates the attach
reject, the method [200] leads to step 216, else the method [200] may terminate
at step 230.
20 At step 216, the subscriber identity module [120] may request the user
equipment [110] to receive at least one network parameter of the at least one
second network by transmitting the proactive command such as PROVIDE LOCAL
INFORMATION (PLI) command.
At step 218, the user equipment [110] may determine the at least one network
25 parameter of the at least second network, wherein the at least one network
parameter includes a mobile country code of the second location, but not limited
to, a mobile network code of the second location. In a preferred embodiment,
20
the user equipment [110] may determine the at least one network parameter of
the at least second network based on the Auto IMSI switch SIM application
residing in the subscriber identity module [120].
At step 220, the user equipment [110] may communicate the terminal response
containing, but not including, the 5 at least one network parameter of the at least
one second network to the subscriber identity module [120].
At step 222, the subscriber identity module [120] may check whether or not the
at least one network parameter of the at least second network corresponds to
the second location. In an event the at least one network parameter corresponds
10 to the second location, the method [200] may lead to step 224. Alternately, the
method [200] may terminate at step 230.
At step 224, the subscriber identity module [120] may be configured to replace
the home IMSI with the global IMSI based on at least one of the information
related to the elementary files, the home IMSI and the global IMSI in the Auto
15 IMSI Switch SIM application, the at least one second network and the at least
one first network by using the proactive commands.
At step 226, the user equipment [110] having the global IMSI may re‐scan the at
least one second network available in the second location to re‐transmit the
attach request to the at least one second network, wherein the attach request
20 will now comprise the global IMSI of the user equipment [110].
At step 228, the at least one second network accepts the new attach attempt of
the user equipment [110] and the user equipment [110] may be enabled to avail
the at least one service while in the international roaming in an event any one of
the at least one second network operator has the bilateral roaming agreement
25 with the network operator in the international location into which the subscriber
is roaming. The method [200] terminates at the step 230.
21
As illustrated in FIG.3, the present disclosure encompasses an exemplary method
[300] for availing at least one service by the user equipment while leaving an
international roaming in accordance with an embodiment of the present
disclosure, wherein the method may be performed by the user equipment [110]
and the subscriber 5 identity module [120] by using the proactive commands. The
following includes detailed steps involved in availing at least one service by the
user equipment while leaving the international roaming. The method step may
initiate at step 302 where the user having the user equipment [110] with the
global IMSI travels back to the first location from the second location while
10 leaving the international roaming. The user having the user equipment [110]
leaves the international roaming when travels from the second location to the
first location, and may not be able to avail any services since the IMSI of the
subscriber identity module remains global IMSI.
At step 304, the user equipment [110] having the global IMSI may be configured
15 to scan the at least one first network available in the first location.
At step 306 and after the accomplishment of the step 304, the user equipment
[110] may transmit the attach request to the at least one first network, wherein
the attach request comprises the global IMSI.
At step 308, the user equipment [110] may further receive an attach reject in
20 response to the attach request from the at least one first network in an event
the global IMSI is not switched back to the home IMSI.
At step 310, the user equipment [110], on receiving the attach reject, may be
configured to update the at least one location parameter (EFLOCI (Location
Information), EFPSLOCI (PS Location Information), EFEPSLOCI (PS Location
25 Information)) of the first location at the subscriber identity module [120],
wherein each of the at least one location parameter of the first location has an
associated status. The associated status of the at least one location parameter of
22
the first location indicates one of a attach reject and an attach acceptance by the
at least one first network. In a preferred embodiment, the updation of the at
least one location parameter of the first location is based on the radio access
technology of the at least one first network from which the user equipment
[110] has received the attach reject. 5 This updation of the at least one location
parameter of the first location further triggers the auto IMSI Switch SIM
application. In a preferred embodiment, the user equipment [110] may notify an
event data to the subscriber identity module [120], wherein the event data
comprises update of at least one elementary file present in the subscriber
10 identity module [120].
At step 312, the subscriber identity module [120] may analyse the associated
status of each of the at least one location parameter of the first location.
At step 314, the process of analysis further includes checking whether or not the
associated status of the at least one location parameter is updated. In an event,
15 the associated status of the at least one location parameter indicates the attach
reject, the method [300] leads to step 316, else the method [300] may terminate
at the step 330.
At step 316, the subscriber identity module [120] may request the user
equipment [110] to receive at least one network parameter of the at least one
20 first network by transmitting the proactive command such as PROVIDE LOCAL
INFORMATION (PLI) command.
At step 318, the user equipment [110] may determine the at least one network
parameter of the at least first network, wherein the at least one network
parameter includes a mobile country code of the first location, but not limited to,
25 a mobile network code of the first location. In a preferred embodiment, the user
equipment [110] may determine the at least one network parameter of the at
23
least first network based on the Auto IMSI switch SIM application residing in the
subscriber identity module [120].
At step 320, the user equipment [110] may communicate the terminal response
containing, but not including, the at least one network parameter of the at least
5 one first network to the subscriber identity module [120].
At step 322, the subscriber identity module [120] may check whether or not the
at least one network parameter of the at least first network corresponds to the
first location. In an event the at least one network parameter corresponds to the
first location, the method [300] may lead to step 324. Alternately, the method
10 [300] may terminate at the step 330.
At step 324, the subscriber identity module [120] may be configured to replace
the global IMSI with the home IMSI based on at least one of the information
related to the elementary files, the home IMSI and the global IMSI in the Auto
IMSI Switch SIM application, the at least one second network and the at least
15 one first network by using the proactive commands.
At step 326, user equipment [110] having the home IMSI may re‐scan the at least
one first network available in the first location to transmit the attach request to
the at least one first network, wherein the attach request will now comprise the
home IMSI of the user equipment [110].
20 At step 328, the user equipment [110] may now be enabled to avail the at least
one service while leaving the international roaming by using the proactive
commands in an event the at least one first network accepts the new attach
attempt of the user equipment [110]. The method [300] terminates at step 330.
Therefore, the present invention encompasses a system and methods for
25 availing the services by the user equipment when the user is either in the
international roaming or is leaving the international roaming. The present
24
invention further encompasses triggering the Auto IMSI Switch SIM application
by using proactive commands and further replacing of the home IMSI with the
global IMSI and vice versa, irrespective of the cause code sent by the user,
thereby providing a robust solution in any international roaming scenario
covering all the rejection 5 cause codes of the user equipment’s attach attempt.
This in turn helps in reducing the probability of the failure of providing service to
the users in the international locations and consequently provide seamless user
experience in international roaming scenarios without any deterrence in
international location.
10 Though a limited number of the user equipment [110], the subscriber identity
module [120] and the components/sub systems therein, have been shown in the
figures; however, it will be appreciated by those skilled in the art that the system
[100] of the present disclosure encompasses any number and varied types of the
entities/elements user equipment [110], the subscriber identity module [120]
15 and the components/sub systems therein.
While considerable emphasis has been placed herein on the disclosed
embodiments, it will be appreciated that many embodiments can be made and
that many changes can be made to the embodiments without departing from the
principles of the present disclosure. These and other changes in the
20 embodiments of the present disclosure will be apparent to those skilled in the
art, whereby it is to be understood that the foregoing descriptive matter to be
implemented is illustrative and non‐limiting.
25
We claim:
1. A method [200] for availing at least one service by a user equipment [110]
while in an international roaming, the method [200] comprising:
 transmitting, by the user equipment [110], an attach request to at
least one second 5 network in an event the user equipment [110]
having a home IMSI is in the international roaming by entering a
second location from a first location, wherein
the first location is served by at least one first network and the
second location is served by the at least one second network, and
10 the home IMSI corresponds to the first location;
 receiving, by the user equipment [110], an attach reject in response
to the attach request, wherein the attach reject is received from the
at least one second network;
 updating, by the user equipment [110], at least one location
15 parameter of the second location at the subscriber identity module
[120], wherein
the subscriber identity module [120] is configured at the user
equipment [110], and
the at least one location parameter has an associated status;
20  analysing, by the subscriber identity module [120], the associated
status of the at least one location parameter of the second location;
 requesting, by the subscriber identity module [120], to receive at
least one network parameter of the at least one second network from
26
the user equipment [110] in an event the associated status of the at
least one location parameter corresponds to the attach reject;
 communicating, by the user equipment [110], the at least one
network parameter of the at least one second network to the
subscriber identity 5 module [120], wherein the at least one network
parameter comprises a mobile country code of the second location;
 replacing the home IMSI of the user equipment [110] with a global
IMSI, by the subscriber identity module [120], in an event the at least
one network parameter corresponds to the second location;
10  re‐transmitting, by the user equipment [110] having the global IMSI,
the attach request to the at least one second network; and
 availing, by the user equipment [110], the at least one service while in
the international roaming in an event the at least one second network
accepts the attach request with the global IMSI.
15 2. The method [200] as claimed in claim 1, further comprising notifying an
event data to the subscriber identity module [120], wherein the event data
comprises update of at least one elementary file present in the subscriber
identity module [120].
3. The method [200] as claimed in claim 1, wherein the at least one service
20 comprises at least one of a voice call, a multimedia broadcast multicast
message, a voice message, a short message service, a VoIP data, a video data
and an internet data.
4. The method [200] as claimed in claim 1, wherein the attach request
comprises one of the home IMSI and the global IMSI.
27
5. The method as claimed in claim 1, wherein the first location corresponds to a
home location of the subscriber identity module [120].
6. The method [200] as claimed in claim 1, wherein the second location
corresponds to a location other than the home location of the subscriber
5 identity module [120].
7. The method [200] as claimed in claim 1, wherein the attach reject comprises
at least one EMM cause of the network rejection.
8. The method [200] as claimed in claim 1, wherein the at least one location
parameter of the second location comprises at least one of a location
10 information (EFLOCI), a packet switched location information (EFPSLOCI) and an
EPS location information (EFEPSLOCI).
9. The method [200] as claimed in claim 1, wherein updating the at least one
location parameter is based on type of the at least one second network
comprising one of 2G, 3G and 4G.
15 10. The method [200] as claimed in claim 1, wherein the associated status of the
at least one location parameter of the second location indicates one of a
attach reject and an attach acceptance by the at least one second network.
11. The method [200] as claimed in claim 1, wherein the at least one network
parameter of the at least second network further comprises a mobile
20 network code of the second location.
12. A method [300] for availing at least one service by a user equipment [110]
while leaving an international roaming, the method [300] comprising:
 transmitting, by the user equipment [110] , an attach request to at
least one first network in an event the user equipment [110] having a
28
global IMSI leaves the international roaming by entering a first
location from a second location, wherein
the first location is served by at least one first network and the
second location is served by the at least one second network;
 receiving, by the 5 user equipment [110], an attach reject in response
to the attach request, wherein the attach reject is received from the
at least one first network;
 updating, by the user equipment [110], at least one location
parameter of the first location at the subscriber identity module
10 [120], wherein
the subscriber identity module [120] is configured at the user
equipment [110], and
the at least one location parameter has an associated status;
 analysing, by the subscriber identity module [120], the associated
15 status of the at least one location parameter of the first location;
 requesting, by the subscriber identity module [120], to receive at
least one network parameter of the at least one first network from
the user equipment [110] in an event the associated status of the at
least one location parameter corresponds to the attach reject;
20  communicating, by the user equipment [110], the at least one
network parameter of the at least one first network to the
subscriber identity module [120], wherein the at least one network
parameter comprises a mobile country code of the first location;
 replacing the global IMSI of the user equipment [110] with a home
25 IMSI, by the subscriber identity module [120], in an event the at
29
least one network parameter corresponds to the first location,
wherein the home IMSI corresponds to the first location;
 re‐transmitting, by the user equipment [110] having the home IMSI,
the attach request to the at least one first network; and
 availing, by the 5 user equipment [110], the at least one service while
leaving the international roaming in an event the at least one first
network accepts the attach request with the home IMSI.
13. The method [300] as claimed in claim 12, further comprising notifying an
event data to the subscriber identity module [120] , wherein the event data
10 comprises update of at least one elementary file present in the subscriber
identity module [120].
14. The method [300] as claimed in claim 12, wherein the at least one location
parameter of the first location comprises at least one of a location
information (EFLOCI), a packet switched location information (EFPSLOCI) and an
15 EPS location information (EFEPSLOCI).
15. The method [300] as claimed in claim 12, wherein the at least one network
parameter of the at least first network further comprises a mobile network
code of the first location.
16. A system [100] for availing at least one service by a user equipment
20 [110]while one of in an international roaming and leaving the international
roaming, the system [100] comprising:
 a user equipment [110] configured to:
transmit an attach request to at least one second network in an
event the user equipment [110] having a home IMSI is in the
30
international roaming by entering a second location from a first
location, and
transmit an attach request to at least one first network in an
event the user equipment [110] having a global IMSI leaves the
international 5 roaming by entering the first location from the
second location, wherein
the first location is served by at least one first network and
the second location is served by the at least one second
network, and
10 the home IMSI corresponds to the first location;
receive an attach reject event in response to the attach request
from one of the at least one first network and the at least one
second network;
update at least one location parameter of one of the first
15 location and the second location at a subscriber identity module
[120], wherein
the subscriber identity module [120] is configured at the
user equipment [110], and
the at least one location parameter has an associated
20 status;
communicate at least one network parameter of one of the at
least one second network and the at least one first network to
the subscriber identity module [120], wherein the at least one
network parameter of the at least one first network and the at
31
least one second network comprises a mobile country code of
the first location and the second location, respectively;
 the subscriber identity module [120] configured to:
analyse the associated status of the at least one location
parameter of 5 one of the first location and the second location;
request to receive the at least one network parameter of one of
the at least one second network and the at least one first
network from the user equipment [110] in an event the
associated status of the at least one location parameter
10 corresponds to the attach reject;
replace the home IMSI of the user equipment [110] with the
global IMSI in an event the at least one network parameter
corresponds to the second location;
replace the global IMSI of the user equipment [110] with the
15 home IMSI in an event the at least one network parameter
corresponds to the first location;
wherein, the user equipment [110] having one of the home IMSI and the
global IMSI is configured to re‐transmit the attach request to one of the
at least one first network and the at least one second network to avail the
20 at least one service while one of in the international roaming and leaving
the international roaming in an event the at least one first network and
the at least one second network accepts the home IMSI and the global
IMSI, respectively.
17. The system [100] as claimed in claim 16, wherein the user equipment [110] is
25 further configured to notify an event data to the subscriber identity module
32
[120], wherein the event data comprises update of at least one elementary
file present in the subscriber identity module [120].