Method and system for managing 5GMM parameters of standalone non-public network at a user equipment

Abstract

A method (1900) for managing 5G Mobility Management (5GMM) parameters of a Standalone Non Public Network (SNPN) at a User Equipment (UE), the method includes selecting an SNPN identifier (SNPN ID) from among SNPN IDs in a first list, determining whether the first list includes a valid Subscriber Permanent Identifier (SUPI) for the SNPN ID, the first list including SNPN parameter values associated with the SNPN IDs, identifying a first SUPI from a first Universal Subscriber Identifier Module (USIM) of the UE in response to determining that the first list does not include the valid SUPI, generating a first SNPN registration request based on the SNPN ID and the first SUPI to attempt registration with a first SNPN associated with the SNPN ID, and updating a second list with the SNPN ID, the first SUPI, and a SNPN parameter value corresponding to the first SNPN upon successful registration.

Description

FIELD

[0001] The present disclosure relates to Standalone Non-Public Networks (SNPNs), and moreparticularly, relates to methods and systems for storing 5G Mobility Management (5GMM)parameters of an SNPN at a User Equipment (UE).BACKGROUND

[0002] An SNPN is a private network infrastructure that operates independently of publicnetworks, such as the Internet and is designed to provide secure communication and dataexchange between devices within the network. Generally, the SNPN is operated by an NPNoperator which does not rely on network functions provided by a Public Land Mobile Network(PLMN). Further, the SNPN is operated by an NPN operator, who may have subscriptions tomultiple SNPNs which are identified based on a combination of a PLMN ID and a NetworkIdentifier (NID).

[0003] Despite the various benefits provided by SNPNs, there are several challenges associatedwith the implementation and maintenance of SNPNs. For example, when storing 5G MobilityManagement (5GMM) parameters in a non-volatile memory of a user equipment (UE), theSNPN may be mapped with an invalid Subscriber Permanent Identifier (SUPI), as the SUPImay be referred from a list of subscriber data where SUPI is not configured. Such a situationmight lead to issues in subscription and SNPN selection. Furthermore, in conventional SNPNsystems, the forbidden SNPNs, which may be classified as "temporarily forbidden SNPNs" or"permanently forbidden SNPNs," are not saved across power cycles. This may lead to theselection of a forbidden SNPN in the next power cycle by the UE, which delays the overalltime to perform normal operations.

[0004] In general, a mobile equipment is configured with a list of subscriber data whichincludes information such as, a subscriber identifier, an Extensible Authentication Protocol(EAP) based primary authentication information, 5G Authentication and Key Agreement(AKA), etc. Further, the mobile equipment (referred as UE) when installed with a USIM, stores5GMM parameters when operating in SNPN access mode. The storage of 5GMM parameters(ref. 24501 Annexure C2) is based on the following conditions:if the UE does not support access to an SNPN using credentials from a credentialsholder, the 5GMM parameters shall be stored per subscribed SNPN in the non-volatile memoryin the ME along with the subscriber identifier associated with the SNPN identity of the SNPNin the "list of subscriber data" configured in the ME (ref. 3GPP TS 23. 122 [5]) andif the UE supports access to an SNPN using credentials from a credentials holder, the5GMM parameters shall be stored in a non-volatile memory in the ME per:the subscribed SNPN along with the subscriber identifier associated with theselected entry in the "list of subscriber data" configured in the ME (see 3GPP TS 23.122[5]); orthe PLMN subscription along with the SUPI from the USIM which is associatedwith the PLMN subscription.The 5GMM parameters include 5G-Globally Unique Temporary Identity (GUTI), last visitedregistered TAI, 5GS update status, 5G NAS security context parameters from a full native 5GNAS security context (see 3GPP TS 33.501

[24] ), security keys KAUSF and KSEAF (see3GPP TS 33.501

[24] ), UE parameter update counter (see subclause 9.11.3.53A), andconfigured Network Slice Selection Assistance Information (NSSAI(s)).

[0005] Further, according to the conventional art, if the 5GMM parameters are associated withthe PLMN subscription, then the 5GMM parameters may only be used if the SUPI from theUSIM which is associated with the selected PLMN subscription matches the SUPI stored inthe non-volatile memory, else the UE delete the 5GMM parameters. Also, if the 5GMMparameters are associated with the subscribed SNPN of the entry in the "list of subscriber data",then the 5GMM parameters may only be used if the subscriber identifier of the selected entryof the "list of subscriber data" matches the subscriber identifier stored in the non-volatilememory. Thus, effective and efficient storage of 5GMM parameters is always a challenge inmulti-USIM UEs when operating in SNPN access mode.

[0006] For ease the "list of subscriber data" mentioned in the above section in 23.122 3gpp TSsection 4.9.3 may be referred to as an "Operator based list of subscriber data" in the presentdisclosure. Further, the stored "5GMM parameters associated with the subscribed SNPN of theentry in the "list of subscriber data" along with the subscriber identity used" as mentioned inthe above sections in 24.501 3gpp TS Annexure C2 may be referred to as "UE based list ofSNPN subscriber data and 5GMM Parameters" in the present disclosure.SUMMARY

[0007] This summary is provided to introduce a selection of concepts in a simplified formatthat is further described in the detailed description of the inventive concepts. This summary isnot intended to identify key or essential inventive concepts, nor is it intended for determiningthe scope of the inventive concepts.

[0008] According to embodiments, a solution for the effective management of SNPNparameters and handling of forbidden SNPNs addressing the above-mentioned challenges isprovided.

[0009] According to embodiments of the present disclosure, a method for managing 5GMobility Management (5GMM) parameters of a Standalone Non Public Network (SNPN) at aUser Equipment (UE) is disclosed. The method includes selecting an SNPN identifier (SNPNID) from among a plurality of SNPN IDs in a first list, determining whether the first listincludes a valid Subscriber Permanent Identifier (SUPI) for the SNPN ID, the first list includinga plurality of SNPN parameter values associated with the plurality of SNPN IDs, identifying afirst SUPI from a first Universal Subscriber Identifier Module (USIM) of the UE in responseto determining that the first list does not include the valid SUPI for the SNPN ID, generating afirst SNPN registration request based on the SNPN ID and the first SUPI to attempt registrationwith a first SNPN associated with the SNPN ID, and updating a second list with the SNPN ID,the first SUPI, and one or more first SNPN parameter values corresponding to the first SNPNupon successful registration with the first SNPN.

[0010] According to embodiments of the present disclosure, a method for managing 5GMMparameters of an SNPN at a User Equipment (UE) is disclosed. The method includes selectingan SNPN identifier (SNPN ID) from among a plurality of SNPN IDs in a first list, determiningwhether the first list includes a valid Subscriber Permanent Identifier (SUPI) for the SNPN ID,the first list including a plurality of SNPN parameter values associated with the plurality ofSNPN IDs, identifying a first SUPI from a Universal Subscriber Identifier Module (USIM) ofthe UE in response to determining that the first list does not include the valid SUPI for theSNPN ID, generating an SNPN registration request based on the SNPN ID and the first SUPI,receiving a registration reject indication from a first SNPN associated with the SNPN ID inresponse to the SNPN registration request, and updating a second list with the SNPN ID in aforbidden SNPN category based on the registration reject indication.

[0011] According to embodiments of the present disclosure, a device for managing 5GMMparameters of an SNPN at a User Equipment (UE) is disclosed. The device includes processingcircuitry configured to select an SNPN identifier (SNPN ID) from among a plurality of SNPNIDs in a first list, determine whether the first list includes a valid Subscriber PermanentIdentifier (SUPI) for the SNPN ID, the first list including a plurality of SNPN parameter valuesassociated with the plurality of SNPN IDs, identify a first SUPI from a first UniversalSubscriber Identifier Module (USIM) of the UE in response to determining that the first listdoes not include the valid SUPI for the SNPN ID, generate a first SNPN registration requestbased on the SNPN ID and the first SUPI to attempt registration with a first SNPN associatedwith the SNPN ID, and update a second list with the SNPN ID, the first SUPI, and one or morefirst SNPN parameter values corresponding to the first SNPN upon successful registration withthe first SNPN.

[0012] According to embodiments of the present disclosure, a device for managing 5GMMparameters of an SNPN at a User Equipment (UE) is disclosed. The device includes processingcircuitry configured to select an SNPN identifier (SNPN ID) from among a plurality of SNPNIDs in a first list, determine whether the first list includes a valid Subscriber PermanentIdentifier (SUPI) for the SNPN ID, the first list including a plurality of SNPN parameter valuesassociated with the plurality of SNPN IDs, identify first SUPI from a Universal SubscriberIdentifier Module (USIM) of the UE in response to determining that the first list does notinclude the valid SUPI for the SNPN ID, generate an SNPN registration request based on theSNPN ID and the first SUPI, receive a registration reject indication from a first SNPNassociated with the SNPN ID in response to the SNPN registration request, and update a secondlist with the SNPN ID in a forbidden SNPN category based on the registration reject indication.

[0013] To further clarify the advantages and features of the inventive concepts, a moreparticular description of the inventive concepts will be rendered by reference to specificexamples thereof, which are illustrated in the appended drawings. It is appreciated that thesedrawings depict only embodiments of the inventive concepts and are therefore not to beconsidered limiting its scope. The inventive concepts will be described and explained withadditional specificity and detail with the accompanying drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0014] These and other features, aspects, and advantages of the inventive concepts will becomebetter understood when the following detailed description is read with reference to theaccompanying drawings in which like characters represent like parts throughout the drawings,wherein:

[0015] Figure 1 illustrates a sequence of operations depicting a challenge with AKA-basedSNPN with a single USIM, according to state of the art;

[0016] Figure 2 illustrates an example process flow depicting a method for addressing thechallenge illustrated in figure 1, according to embodiments of the present disclosure;

[0017] Figure 3 illustrates a sequence of operations depicting a challenge associated withAKA-based SNPN in a multi-SIM scenario, according to state of the art;

[0018] Figure 4 illustrates an example process flow depicting a method for addressing thechallenge illustrated in figure 3, according to embodiments of the present disclosure;

[0019] Figure 5 illustrates a sequence of operations depicting a challenge associated withAKA-based SNPN in a multi-SIM scenario, according to state of the art;

[0020] Figure 6 illustrates a sequence of operations of a method for addressing the challengeillustrated in figure 5, according to embodiments of the present disclosure;

[0021] Figures 7A-7C illustrate a sequence of operations depicting a challenge associated withAKA-based SNPN in a multi-SIM scenario, according to state of the art;

[0022] Figures 8A-8C illustrate a sequence of operations of a method for addressing thechallenge illustrated in figures 7A-7C, according to embodiments of the present disclosure;

[0023] Figure 9 illustrates a sequence of operations depicting a challenge associated withAKA-based SNPN in a multi-SIM scenario, according to state of the art;

[0024] Figure 10 illustrates a sequence of operations of a method for addressing the challengeillustrated in figure 9, according to embodiments of the present disclosure;

[0025] Figure 11 illustrates a sequence of operations depicting a challenge associated withAKA-based SNPN in a multi-SIM scenario, according to state of the art;

[0026] Figure 12 illustrates a sequence of operations of a method for addressing the challengeillustrated in figure 11, according to embodiments of the present disclosure;

[0027] Figure 13 illustrates an example process flow depicting a method of storing 5GMMparameters of an SNPN at a User Equipment (UE), according to embodiments of the presentdisclosure;

[0028] Figure 14 illustrates an example process flow depicting a method of storing 5GMMparameters of an SNPN at the UE, according to embodiments of the present disclosure;

[0029] Figure 15 illustrates an example process flow depicting a method of storing 5GMMparameters of an SNPN at the UE, according to embodiments of the present disclosure;

[0030] Figure 16 illustrates an example process flow depicting a method of storing 5GMMparameters of an SNPN at the UE, according to embodiments of the present disclosure;

[0031] Figure 17 illustrates a process flow depicting a method for managing 5GMMparameters of an SNPN at the UE, according to embodiments of the present disclosure;

[0032] Figure 18 illustrates a process flow depicting a method for managing 5GMMparameters of an SNPN at the UE, according to embodiments of the present disclosure;

[0033] Figure 19 illustrates a process flow depicting a method for managing 5GMMparameters of an SNPN at the UE, according to embodiments of the present disclosure;

[0034] Figure 20 illustrates a process flow depicting a method for managing 5GMMparameters of an SNPN at the UE, according to embodiments of the present disclosure; and

[0035] Figure 21 is a diagram illustrating the configuration of the UE in a wirelesscommunication system, according to embodiments of the present disclosure.

[0036] Further, skilled artisans will appreciate that elements in the drawings are illustrated forsimplicity and may not have been necessarily drawn to scale. For example, the flow chartsillustrate the method in terms of prominent operations involved to help to improveunderstanding of aspects of the inventive concepts. Furthermore, in terms of the constructionof the device, one or more components of the device may have been represented in the drawingsby conventional symbols, and the drawings may show only those specific details that arepertinent to understanding embodiments of the inventive concepts so as not to obscure thedrawings with details that will be readily apparent to those of ordinary skill in the art havingthe benefit of the description herein.DETAILED DESCRIPTION

[0037] It should be understood at the outset that although illustrative implementations ofembodiments of the present disclosure are illustrated below, the inventive concepts may beimplemented using any number of techniques, whether currently known or in existence. Thepresent disclosure should in no way be limited to the illustrative implementations, drawings,and techniques illustrated below, including the exemplary design and implementationillustrated and described herein, but may be modified within the scope of the appended claimsalong with their full scope of equivalents.

[0038] The term "some" as used herein is defined as "none, or one, or more than one, or all."Accordingly, the terms "none," "one," "more than one," "more than one, but not all" or "all"would all fall under the definition of "some." The term "embodiments" may refer to noembodiments, to one embodiment, to several embodiments, or to all embodiments.Accordingly, the term "embodiments" is defined as meaning "no embodiment, or oneembodiment, or more than one embodiment, or all embodiments."

[0039] The terminology and structure employed herein are for describing, teaching, andilluminating embodiments and their specific features and elements and do not limit, restrict, orreduce the spirit and scope of the claims or their equivalents.

[0040] More specifically, any terms used herein such as but not limited to "includes,""comprises," "has," "consists," and grammatical variants thereof do NOT specify an exactlimitation or restriction and certainly do NOT exclude the possible addition of one or morefeatures or elements, unless otherwise stated, and furthermore must NOT be taken to excludethe possible removal of one or more of the listed features and elements, unless otherwise statedwith the limiting language "MUST comprise" or "NEEDS TO include."

[0041] Whether or not a certain feature or element was limited to being used only once, eitherway, it may still be referred to as "one or more features" or "one or more elements" or "at leastone feature" or "at least one element." Furthermore, the use of the terms "one or more" or "atleast one" feature or element does NOT preclude there being none of that feature or element,unless otherwise specified by limiting language such as "there NEEDS to be one or more . . ."or "one or more element is REQUIRED."

[0042] Unless otherwise defined, all terms, and especially any technical and / or scientific terms,used herein may be taken to have the same meaning as, or a similar meaning to, that commonlyunderstood by one having ordinary skill in the art.

[0043] The terms "user", "user device", "user equipment", or "UE" may be usedinterchangeably throughout the description.

[0044] Embodiments of the inventive concepts will be described below in detail with referenceto the accompanying drawings.

[0045] Figure 1 illustrates a sequence of operations depicting a challenge with Authenticationand Key Agreement. (AKA) based Stand-alone Non-Public Network (SNPN) with a singleUniversal Subscriber Identity Module (USIM), according to state of the art. In this scenario,the sequence of operations corresponds to communication between user device 101 (alsoreferred to as "the user 101" or application processor (AP)), New Radio (NR) at Non-AccessStratum (NAS) layer 103 (referred to as "NR NAS 103"), and the network 105. According toembodiments, references herein to the NR NAS 103 and / or the network 105 may correspondto respective devices (e.g., base stations) configured to implement operations performed by theNR NAS 103 and / or the network 105. The term base station may generally refer to a fixedstation that communicates with user equipment and / or other base stations, and may exchangedata and control information by communicating with user equipment and / or other base stations.For example, the base station may also be referred to as a Node B, an evolved-Node B (eNB),a next generation Node B (gNB), a sector, a site, a base transceiver system (BTS), an accesspoint (AP), a relay node, a remote radio head (RRH), a radio unit (RU), a small cell, or the like.In the present specification, a base station or a cell may be interpreted in a comprehensive senseto indicate some area or function covered by a base station controller (BSC) in CDMA, a Node-B in WCDMA, an eNB in LTE, a gNB or sector (site) in 5G, and the like, and may cover allthe various coverage areas such as megacell, macrocell, microcell, picocell, femtocell and relaynode, RRH, RU, and small cell communication range. The user device 101 may be a multiUniversal Subscriber Identity Module (MUSIM) device. Examples of the user device 101 mayinclude, a smartphone, a tablet, a laptop, a personal computing device, and so forth. Further,the network 105 may correspond to 5th Generation (5G) SNPN. Moreover, NR NAS 103 is aprotocol layer that may be configured to provide control and management services for the end-to-end communication between the user device 101 and the network 105. The NR NAS 103may be responsible for various operations such as, but not limited to, authentication, mobilitymanagement, and security.

[0046] The NR NAS 103 may be configured to handle the communication between the userdevice 101 and the network 105. The NR NAS 103 may also be configured to provide acommon interface between the user device 101 and the various network domains, such as theradio access network (RAN) and the core network (CN). Specifically, the NR NAS 103 maybe configured to provide secure, reliable, and efficient communication between the user device101 and the network 105, and to support the various services and applications offered by the5G NR networks 105.

[0047] The user device (also referred to as the user equipment (UE) 101) may include a singleUSIM. Further, SNPN may be based on AKA-based authentication. At operation 102, the UE101 may be powered ON and initialized to operate in SNPN access mode. Further, at operation104, the user device 101 (may also be referred to as "Mobile Equipment (ME)), prior toinstallation of the USIM, may be configured with a list of subscriber data which may includeinformation such as, but not limited to, Subscriber Permanent Identity (SUPI), credentials,SNPN, as so forth. The list of subscriber data may also be referred to as an operator-based listof subscriber data (also referred to herein as the "first list"). Further, the UE-based list (and / orthe operator-based list) of subscriber data may include information such as, but not limited to,SNPN Identifier (SNPN ID), SUPI, 5G Globally Unique Temporary Identifier (5G-GUTI),allowed slices, authentication keys, temporary forbidden SNPNs, and / or permanentlyforbidden SNPNs. Operation 106 may correspond to the initialization of registration of USIMincluded in UE 101 with an SNPN to perform communication with the network 105.Specifically, the UE 101 may generate a "registration request" message to subscribe the USIMwith an SNPN with ID1 (also referred to as SNPN1) using AKA-based authentication. Uponacceptance of the "registration request" message, the network 105 may transmit the"registration accept" message along the 5G-GUTI information, as shown in operation 108. The5G-GUTI may be a temporary identifier assigned to the UE 101 by the network 105. The 5G-GUTI may be used to identify the UE 101 within the network 105. The 5G-GUTI may be usedin combination with other identifiers, such as, but not limited to, the SUPI, to manage the UE'smobility within the network 105. Further, operations 110-112 may correspond to thederegistration process. Specifically, at operation 110, the UE 101 may generate a"deregistration request" message. The "deregistration request" message may be transmitted tothe network 105 via the NR NAS 103, as shown in operation 112.

[0048] Further, for every registration process, the UE 101 may store and / or update 5G-GUTIand 5GMM parameters, as received from the network 105. Thus, the UE 101 may maintain arecord of each of the SNPN and corresponding 5G-GUTI and 5GMM parameters. The storedrecord of SNPNs and corresponding 5G-GUTI and 5GMM parameters may be utilized by theUE 101 to establish future communication connection. The network 105 may utilize the 5G-GUTI to uniquely identify the UE 101 within the network 105. Further, the 5GMM parametersmay be used by the UE 101 to manage the mobility of the UE 101. However, when storing the5G-GUTI and 5GMM parameters, the UE 101 may map the selected SNPN with an invalidsubscriber ID (SUPI), as the SUPI value may be referred from the list of subscriber data whereSUPI may not be configured as the SNPN is AKA based SNPN (SNPN1), as shown inoperation 114. Particularly, such a list of subscriber data may be defined by an operator and / orvendor of the network 105 and the SUPI value may not be defined as the SNPN subscriptionmay be performed using the AKA-based authentication. Thus, the UE 101 may store the invalidSUPI corresponding to the selected SNPN which may lead to issues in connecting andestablishing a connection with the SNPN for future communication.

[0049] Figure 2 illustrates an example process flow depicting a method 200 for addressing thechallenge illustrated in figure 1, according to embodiments of the present disclosure. Theoperations of the method 200 may be performed by the UE 101 and / or the network 105, whichmay be communicably coupled via the NR NAS 103 protocol layer. Some of the operationsillustrated in figure 2 are similar to operations illustrated in figure 1, and accordingly, similarreference numerals have been assigned to corresponding operations. Specifically, operations202-212 are similar to operations 102-112, and therefore a description of these operations hasbeen omitted for the sake of brevity.

[0050] Specifically at operation 214, while maintaining the record of the selected SNPN andcorresponding 5G-GUTI and 5GMM parameters, instead of selecting the SUPI value from thelist of subscriber data as may be defined by the operator and / or vendor, the method 200 mayinclude retrieving a valid SUPI value from the selected USIM which is used for the registrationprocess. The UE 101 may associate the retrieved SUPI value with the selected entry of "list ofsubscriber data". Thus, the UE 101 may store 5G Mobility Management (5GMM) parameterswhich may include a valid SUPI e.g., SUPI from USIM 1, credential information (for exampleEAP / 5G AKA), SNPN value (for example SNPN1), and 5G-GUTI (e.g., 5G-GUTI_1corresponding to SNPN1), as shown in operation 216. In embodiments, the UE 101 may utilizethe stored information of the 5GMM parameters for future communication with the selectedSNPN.

[0051] Thus, the method 200 may prevent the UE 101 from associating the selected SNPNwith an invalid SUPI, and / or reduce the occurrence thereof, and thereby resolving and / orreducing the issues in a subscription that may arise due to an invalid SUPI.

[0052] Figure 3 illustrates a sequence of operations depicting a challenge associated withAKA-based SNPN in a multi-USIM scenario, according to the state of the art. In this scenario,the sequence of operations corresponds to a communication between the UE 101, the NR NAS103, and the network 105. The user device 101 may be a MUSIM device. In examples, the UE101 may be a dual USIM device that includes a USIM1 and a USIM2.

[0053] At operation 302, the UE 101 may be powered ON and initialized to operate in SNPNaccess mode. Further, at operation 304, the user device 101 (may also be referred to as "MobileEquipment (ME)), prior to installation of USIM, may be configured with a list of subscriberdata which may include information such as, but not limited to, Subscriber Permanent Identity(SUPI), credentials, SNPN, as so forth. At operation 306, the USIM1 may be selected for AKA-based authentication for an SNPN. Operations 308-310 may correspond to the registrationprocess of USIM1 with the SNPN to perform communication with the network 105.Specifically, the UE 101 may generate a "registration request" message to subscribe the USIM1with an SNPN with ID1 (also referred as SNPN1) using AKA-based authentication, as shownin operation 308. Upon acceptance of the "registration request" message, the network 105 maytransmit the "registration accept" message along with the 5G-GUTI information, as shown inoperation 310.

[0054] Further, if USIM1 is removed, the UE may initiate a deregistration process to offloadthe network 105. Operations 312-314 may correspond to the deregistration process.Specifically, at operation 312, the UE 101 may generate a "deregistration request" message.The "deregistration request" message may be transmitted to the network 105 via the NR NAS103, as shown in operation 314. Further, the USIM1 may be removed in operation 312.

[0055] However, as a process of maintaining a record of each subscribed SNPN, when storingthe 5G-GUTI and / or other 5GMM parameters, the UE 101 may map the selected SNPN withan invalid subscriber ID (SUPI), as the SUPI value may be referred from the list of subscriberdata where SUPI may not be configured as the SNPN is AKA based SNPN (SNPN1), as shownin operations 316-318. Thus, the UE 101 may store invalid SUPI corresponding to the selectedSNPN which may lead to issues in connecting and establishing a connection with the SNPNfor future communication.

[0056] Next at operation 320, the USIM2 may be inserted and / or activated. Therefore, the UE101 may initiate the registration and / or subscription process for the USIM2 to initialize thecommunication of USIM2 with the network 105. Specifically, at operation 322, the UE 101may retrieve the 5GMM parameters corresponding to the USIM1 and the SNPN1 subscriptioncombination from the network 105. Further, the UE 101 may use the received 5GMMparameters corresponding to the USIM1 and the SNPN1 subscription for the subscription ofthe USIM2 and the SNPN1, as shown in operation 322. However, the use of 5GMM parameterscorresponding to USIM1 and SNPN1 for the USIM2 and SNPN1 may lead to subscription andSNPN selection issues, as the 5GMM parameters are related to another subscriber identity (e.g.,USIM1), as shown in operation 324. Thus, the invalid selection of 5GMM parameters may leadto wastage of resources and time while subscribing to an SNPN.

[0057] Figure 4 illustrates an example process flow depicting a method 400 for addressing thechallenge illustrated in figure 3, according to embodiments of the present disclosure. Theoperations of the method 400 may be performed by the UE 101 and / or the network 105, whichmay be communicably coupled via the NR NAS 103. The operations of the method 400 whichare similar to the operations illustrated in figure 3, are provided with similar referencenumerals. Specifically, operations 402-414 are similar to operations 302-314, therefore adescription of these operations has been omitted for the sake of brevity.

[0058] Specifically, at operation 416, while maintaining the record of the selected SNPN andcorresponding 5G-GUTI and 5GMM parameters, instead of selecting the SUPI value from thelist of subscriber data which includes invalid SUPI for AKA based SNPN, the method 400 mayinclude retrieving a valid SUPI value from the selected USIM which is used for the registrationprocess. Further, the UE 101 may associate the retrieved SUPI value with the selected entry of"list of subscriber data". Thus, the UE 101 may store 5G Mobility Management (5GMM)parameters which may include a valid SUPI e.g., SUPI from USIM 1, credential information(for example EAP / 5G AKA), SNPN value (for example SNPN1), and 5G-GUTI, as shown inoperation 418. Further, at operation 420, the USIM2 may be inserted and / or activated. Here, atoperation 422, when performing registration using USIM2, instead of selecting 5GMMparameters corresponding to USIM1 and SNPN1 combination for USIM2 and SNPN1, themethod 400 may include performing the complete registration operations as performed forUSIM1. Thus, the method 400 may avoid or reduce subscription and SNPN selection issues as5GMM parameters related to other subscriber identity are not selected. Thus, the method 400helps in saving resource and time for the UE 101 and / or the network 105.

[0059] Figure 5 illustrates a sequence of operations depicting a challenge associated withAKA-based SNPN in a multi-SIM scenario, according to the state of the art. In this scenario,the sequence of operation corresponds to a communication between the UE 101, the NR NAS103, and the network 105. In examples, the UE 101 may be a dual USIM device that includesthe USIM1 and the USIM2, as also shown in figure 3.

[0060] Further, operations 502-524 are similar to the operations 302-324, as explained inreference to figure 3, thus a description of these operations has been omitted for the sake ofbrevity. Specifically, after receiving 5GMM parameters corresponding to USIM1 andSNSPN1, the UE 101 may initiate the registration process for USIM2 with SNPN1 using thereceived parameters, as shown in operation 526. As the 5GMM parameters used for theregistration process relate to another subscriber identity, the registration request may berejected by the network 105, as shown in operation 528. At operation 530, the 5G-GUTI, lastregistered Tracking Area Identity (TAI), and next generation Key Set Identifier (ngKSI) valuemay be deleted, in response to the registration reject indication. At operations 532-534, the UE101 may initiate a deregistration request and USIM2 may be removed from the UE 101. Atoperation 536, while maintaining the record of the selected SNPN and the deleted 5G-GUTIand other 5GMM parameters, the UE 101 may map the selected SNPN with an invalid SUPI,as the SUPI may be referred from the list of subscriber data where the SUPI is not configuredfor SNPN1. Further, the previously stored valid 5GMM parameters for USIM1 and SNPN1combination may be overwritten, as shown in operation 536. Thus, the UE 101 mayunnecessarily overwrite the invalidated information over the valid information of an SNPN.This may lead to subscription and connection issues with the selected SNPN in futurecommunication. Particularly, the UE 101 may re-perform the complete registration for theselected SNPN with new 5G-GUTI and 5GMM parameters as a result of the overwrite.

[0061] Figure 6 illustrates a sequence of operation of a method 600 for addressing thechallenge illustrated in figure 5, according to embodiments of the present disclosure. Theoperations of the method 600 may be performed by the UE 101 and the network 105, whichmay be communicably coupled via the NR NAS 103. The operations of the method 600 whichare similar to operations illustrated in figure 5 are provided with similar reference numerals.Specifically, operations 602-614 are similar to operations 502-514, therefore the description ofthese operations has been omitted for the sake of brevity.

[0062] Specifically, at operation 616, while maintaining the record of the selected SNPN andcorresponding 5G-GUTI and 5GMM parameter, instead of selecting the SUPI value from thelist of subscriber data which includes invalid SUPI for AKA-based SNPN, the method 600 mayinclude retrieving a valid SUPI value from the selected USIM which is used for the registrationprocess (e.g., USIM1). Further, the method 600 may include associating the retrieved SUPIvalue with the selected entry of "list of subscriber data". Thus, the UE 101 may store 5GMobility Management (5GMM) parameters which may include a valid SUPI, e.g., SUPI fromUSIM1, credential information (for example EAP / 5G AKA), SNPN value (for exampleSNPN1), and 5G-GUTI, as shown in operation 618. Further, at operation 620, the USIM2 maybe inserted and / or activated. Here, at operation 622, when performing registration usingUSIM2, instead of selecting 5GMM parameters corresponding to USIM1 and SNPN1combination for USIM2 and SNPN1, the method 600 may include performing the completeregistration operations as performed for USIM1. Thus, the method 600 may avoid or reducesubscription and SNPN selection issues as 5GMM parameters related to another subscriberidentity are not selected. At operation 624, the method 600 includes performing a registrationprocess for USIM2 with the SNPN1. At operation 626, the network 105 may reject theregistration request. At operation 628, the 5G-GUTI, last registered Tracking Area Identity(TAI), and Key Set Identifier (ngKSI) value may be deleted, in response to the registrationreject indication. At operations 630-632, the UE 101 may initiate a deregistration request andUSIM2 may be removed from the UE 101. At operation 634, when storing the deleted 5G-GUTI and other 5GMM parameters, the UE 101 may select the SUPI value from USIM e.g.,USIM2, and associate the selected SUPI with the selected entry of the "list of subscriber data".Further, the UE 101 may create a separate entry to store the corresponding 5GMM parameters.This prevents overwriting of any valid entry in the UE-based list of subscriber data stored atthe UE 101, or reduces the occurrence thereof.

[0063] Thus, the method 600 may avoid or reduce subscription and SNPN selection issues, asinvalid 5GMM parameters may not be selected and / or stored at UE 101.

[0064] Figures 7A-7C illustrate a sequence of operations depicting a challenge associated withAKA-based SNPN in a multi-SIM scenario, according to state of art. In this scenario, thesequence of operation corresponds to a communication between the UE 101, the NR NAS 103,and the network 105. In an example, the UE 101 may be a dual SIM device that includes theUSIM1 and the USIM2.

[0065] At operation 702, the UE 101 may be powered ON and initialized to operate in SNPNaccess mode. Further, at operations 704-708, the user device 101 (may also be referred to as"Mobile Equipment (ME)), prior to installation of a SIM, may be configured with a list ofsubscriber data for multiple SNPNs (for example data1 corresponding to SNPN1, data2 forSNPN2, and data3 for SNPN3).

[0066] At operation 710, the USIM1 may be selected for AKA-based authentication for SNPN.Next, at operation 712, the network 105 may reject the registration request. The network 105may reject registration requests based on criteria such as, but not limited to, invalid SUPI,invalid authentication, resource unavailability, unauthorized access to selected SNPN, and soforth. At operations 716-718, the UE 101 may perform the deregistration request and USIM1may be removed. However, while maintaining the record of the selected SNPN andcorresponding 5G-GUTI and 5GMM parameters, the UE 101 may map the selected SNPN withan invalid subscriber ID (SUPI), as the SUPI value may be referred from the list of subscriberdata where SUPI may not be configured as the SNPN is AKA based SNPN (SNPN1), as shownin operation 720-722. Thus, the UE 101 may store invalid SUPI corresponding to the selectedSNPN which may lead to issues in connecting and establishing a connection with the SNPNfor future communication.

[0067] Next at operation 724, the USIM2 may be inserted and / or activated. At operation 726,the UE 101 may retrieve the 5GMM parameters corresponding to the USIM1 and the SNPN1subscription combination from the network 105. Further, the UE 101 may use the same (orsimilar) received 5GMM parameters corresponding to the USIM1 and the SNPN1 subscriptionfor the USIM2 and SNPN1 combination. However, the use of 5GMM parameterscorresponding to USIM1 and SNPN1 for the USIM2 and SNPN1 may lead to subscription andSNPN selection issues, as the 5GMM parameters are related to another subscriber identity (e.g.,USIM1) is selected, as shown in operation 728. At operation 730, the UE 101 may initiate aregistration process for USIM2 with SNPN1 using AKA. As the previous registration requestby USIM1 was rejected by the network 105, the network 105 may accept the registrationrequest from USIM2 and transmit 5G GUTI, as shown in operation 732.

[0068] Next at operations 734-736, the UE 101 may perform the deregistration request andUSIM2 may be removed. However, while maintaining the record of the selected SNPN andcorresponding 5G-GUTI and 5GMM parameters, the UE 101 may map the selected SNPN withan invalid subscriber ID (SUPI), as the SUPI value may be referred from the list of subscriberdata where SUPI may not be configured as the SNPN is AKA based SNPN (SNPN1), as shownin operations 738-740. Thus, the UE 101 may store invalid SUPI corresponding to the selectedSNPN which may lead to issues in connecting and establishing a connection with the SNPNfor future communication.

[0069] At operation 742, the USIM1 may be inserted and / or activated. At operation 744, theUE 101 may initiate the registration process for SNPN2 using AKA from USIM1. At operation746, the network 105 may accept the registration request and transmit 5G-GUTI information.Thereafter, at operation 748-750, the UE 101 may perform the deregistration request andUSIM1 may be removed. However, while maintaining the record of the selected SNPN andcorresponding 5G-GUTI and 5GMM parameters, the UE 101 may map the selected SNPN withan invalid subscriber ID (SUPI), as the SUPI value may be referred from the list of subscriberdata where SUPI may not be configured as the SNPN is AKA based SNPN (SNPN2), as shownin operation 752-754. Thus, the UE 101 may store invalid SUPI corresponding to an SNPNwhich may lead to issues in connecting and establishing a connection with the SNPN for futurecommunication.

[0070] Next at operation 756, the USIM2 may be activated and / or inserted in the UE 101. Atoperation 758, the UE 101 may initiate a registration process for SNPN2 using AKA fromUSIM2. At operation 760, the network 105 may reject the registration request, as an invalidSUPI configured for SNPN2 may be used for the registration process. However, whilemaintaining the record of the selected SNPN and corresponding 5G-GUTI and 5GMMparameters, the UE 101 may map the selected SNPN with an invalid subscriber ID (SUPI), asthe SUPI value may be referred from the list of subscriber data where SUPI may not beconfigured as the SNPN is AKA based SNPN (SNPN2), as shown in operations 762-764. Thus,the UE 101 may overwrite the previous valid entry for USIM1.

[0071] At operation 766, the USIM1 may be activated and / or inserted. At operation 764, theUE 101 may determine whether there is any valid information stored for SNPN2 and USIM1combination. Since, no valid information is found for SNPN2 and USIM1 combination, a newregistration process is initiated, as illustrated in operations 770-772. However, whilemaintaining the record of the selected SNPN and corresponding 5G-GUTI and 5GMMparameters, the UE 101 may map the selected SNPN with the invalid subscriber ID (SUPI), asthe SUPI value may be referred from the list of subscriber data where SUPI may not beconfigured as the SNPN is AKA based SNPN (SNPN2), as shown in operations 774-776. Thus,the UE 101 may overwrite the previous invalid entry for USIM2.

[0072] Thus, the state of the art fails to effectively manage 5GMM information correspondingto multi-USIM configuration for SNPN.

[0073] Figures 8A-8C illustrate a sequence of operations of a method 800 for addressing thechallenge illustrated in figures 7A-7C, according to embodiments of the present disclosure.The operations of the method 800 may be performed by the UE 101 and the network 105, whichmay be communicably coupled with each other via the NR NAS 103. The operations 802-818of the method 800 are similar to the operations discussed in figures 7A-7C, therefore onlydistinct operations have been explained in detail in reference to figures 8A-8C for the sake ofbrevity.

[0074] Specifically, at operation 820, while maintaining the record of the selected SNPN andcorresponding 5G-GUTI and 5GMM parameters, the UE 101 may retrieve a valid SUPI valuefrom the USIM1. Further, the UE 101 may associate the retrieved SUPI value with the selectedentry of the "list of subscriber data", as shown in operation 822.

[0075] Further, at operation 824, when USIM2 is activated and / or inserted, instead of selecting5GMM parameters stored of USIM1 and SNPN1 for performing registration of USIM2 withthe SNPN1, the UE 101 may perform the complete registration and / or deregistration processas previously done for USIM1, shown in operations 826-834. Specifically, the UE 101 mayretrieve 5GMM parameters for the registration of USIM with the selected SNPN e.g., SNPN1.Moreover, at operation 836, while maintaining the record of the selected SNPN andcorresponding 5G-GUTI and 5GMM parameters for USIM2, the UE 101 may retrieve a validSUPI from the USIM2. Further, the UE 101 may associate the retrieved SUPI value with theselected entry of the "list of subscriber data", as shown in operation 838.

[0076] Moreover, similar operations may be performed each time UE 101 tries to register usingany of USIM1 and / or USIM2 with any of the SNPNs (e.g., SNPN1, SNPN2, or SNPN3).Specifically, the UE 101 may effectively store 5GMM parameters for each registration andderegistration process for each USIM installed / included in the UE 101, as shown in operations840-874. According to embodiments, a list of subscriber data may include SNPN parameters(e.g., 5GMM parameters) for each combination of SNPN ID, SUPI, and USIM. Therefore, themethod 800 may prevent or reduce conflict of entries in the list of subscriber data stored at theUE 101. Thus, the method 800 may provide an effective way to subscribe and select SNPNswhile the UE 101 is operating in SNPN access mode.

[0077] Figure 9 illustrates a sequence of operations depicting challenge associated with AKAbased SNPN in a multi-SIM scenario, according to state of art. In this scenario, the sequenceof operation corresponds to a communication between the UE 101, the NR NAS 103, and thenetwork 105. The user device 101 may be a MUSIM device. In examples, the UE 101 may bea dual SIM device that includes the USIM1 and the USIM2.

[0078] At operation 902, the UE 101 may be powered ON and initialized to operate in SNPNaccess mode. Further, at operation 904, the user device 902 (may also be referred as "MobileEquipment (ME)), prior to installation of a SIM, may be configured with a list of subscriberdata which may include information such as, but not limited to, Subscriber Permanent Identity(SUPI), credentials, SNPN, as so forth. At operation 906, the USIM1 may be selected for AKA-based authentication. At operation 908, the registration request may be initiated to registerUSIM1 with SNPN1 using AKA. At operation 910, the network 105 may permanently rejectthe registration request for USIM1 for not being authorized to access SNPN1. At operation912, the UE 101 may store the SNPN identity (e.g., SNPN1) in a "permanently forbiddenSNPNs" list and start a timer. In examples, the timer may be a T3245 timer. At operation 914,the UE 101 may initiate the deregistration process and may switch off the power. At operation916, the deregistration request may be transmitted to the network 105 via the NR NAS 103.However, the UE 101 may only store time remaining for the T3245 timer across power cyclesand fails to store a list of "permanently forbidden SNPNs", as indicated by operation 918. Thus,when the UE 101 is powered on, the UE 101 starts the timer T3245 with the remaining valueof time, as shown by operation 920. However, as shown in operation 922, the "permanentlyforbidden SNPNs" list may not include any entry, and therefore the UE 101 may re-select thepreviously selected SNPN (for example SNPN1) for registration, as illustrated in operations922-924. Thus, the network 105 may again reject the request as USIM1 is not authorized tosubscribe to SNPN1. This may lead to wastage of time and resources during the subscriptionof a USIM with an SNPN.

[0079] Figure 10 illustrates a sequence of operation of a method 1000 for addressing thechallenge illustrated in figure 9, according to embodiments of the present disclosure. Theoperations of the method 1000 may be performed by the UE 101 and the network 105, whichmay be communicably coupled with each other via the NR NAS 103. Operations 1002-1016of the method 1000 are similar to the operations 902-916 discussed in figure 9, therefore onlydistinct operations have been explained in detail in reference to figure 10 for the sake of brevity.

[0080] Specifically, at operation 1018, instead of only storing the remaining value of the timerT3245 across power cycles, as previously done at operation 918, the UE 101 may also storethe list of "permanently forbidden SNPNs" across power cycles. In embodiments, the UE 101may store the remaining value of the timer and the list of "permanently forbidden SNPNs" ina non-volatile memory of the UE 101. Therefore, at operation 1022, the UE 101 may not selectSNPN1 for subscription as SNPN1 may be stored in the list of "permanently forbiddenSNPNs". Specifically, before generating any registration request, the UE 101 may check thelist of "permanently forbidden SNPNs" and make the selection of SNPN, accordingly. As theUE 101 may correctly select the SNPN, the USIM1 may successfully register with SNPN2, asshown in operations 1024-1026.

[0081] Therefore, the method 1000 may prevent or reduce the lack of access to normal services,and the wastage of resources and time, while subscribing to an SNPN.

[0082] Figure 11 illustrates a sequence of operations depicting a challenge associated withAKA-based SNPN in a multi-SIM scenario, according to state of art. In this scenario, thesequence of operations corresponds to a communication between the UE 101, the NR NAS103, and the network 105. The user device 101 may be a MUSIM device. In examples, the UE101 may be a dual SIM device that includes the USIM1 and the USIM2.

[0083] The operations illustrated in figure 11 are similar to the operations in figure 9, however,the operations in figure 11 relate to temporarily forbidden SNPNs. Specifically, at operation1110, the network 105 may reject the registration request based on the condition that theUSIM1 is temporarily not authorized to subscribe to the selected SNPN. However, in thescenario illustrated in figure 11, the UE 101 may only store the timer T3245 access to the powercycle and may not store the list of "temporarily forbidden SNPNs", as done for (e.g., similar tothe approach for "permanently forbidden SNPNs" discussed above). Thus, the UE 101 mayagain initiate a registration process with the forbidden SNPNs in the next power cycle, in casethe timer T3245 is yet to lapse. This may lead to wastage of time, user from not availing normalservices, and resources during the subscription of a USIM with an SNPN.

[0084] Figure 12 illustrates a sequence of operation of a method 1200 for addressing thechallenge illustrated in figure 11, according to embodiments of the present disclosure. Theoperations of the method 1200 may be performed by the UE 101 and the network 105, whichmay be communicably coupled with each other via the NR NAS 103. Operations 1202-1216of the method 1200 are similar to the operations 1102-1116 discussed in figure 11, thereforeonly distinct operations have been explained in detail in reference to figure 12 for the sake ofbrevity.

[0085] Specifically, at operation 1218, instead of only storing the remaining value of the timerT3245 across power cycles, as previously done at operation 1118, the UE 101 may also storethe list of "temporarily forbidden SNPNs" across power cycles. Therefore, at operation 1222,the UE 101 may not select SNPN1 for subscription as SNPN1 may be stored in the list of"temporarily forbidden SNPNs". Accordingly, at operations 1224-1226, the USIM1 maysuccessfully register with SNPN2.

[0086] Therefore, the method 1200 may prevent or reduce lack of access to normal services,and the wastage of resources time, while subscribing to an SNPN.

[0087] Figure 13 illustrates an example process flow of a method 1300 of storing 5GMMparameters of an SNPN at a User Equipment (UE), according to embodiments of the presentdisclosure.

[0088] The method 1300 may be based on the assumption that a SUPI value is associated witha USIM (e.g., USIM1) as 123456, and the selected SNPN is SNPN1. At operation 1302, themethod 1300 may include checking whether the "list of subscriber data" as defined by thevendor / operator (may also be referred to as "operator-based list of subscriber data") includes avalid SUPI value for the selected SNPN. In case, the operator-based list of subscriber dataincludes a valid SUPI value corresponding to the selected SNPN (e.g., SNPN1), the method1300 may perform operation 1304. Specifically, at operation 1304, the method 1300 maydetermine whether a UE-based list of subscriber data which is stored at the UE 101, includes5GMM parameters corresponding to selected SNPN and the identified SUPI value. In case, theUE-based list of subscriber data includes 5GMM parameters corresponding to the selectedSNPN and the identified SUPI, the UE 101 may use the stored 5GMM parameters to establishthe connection of the USIM (e.g., USIM1) and the selected SNPN (e.g., SNPN1), as indicatedin operation 1308. However, in case the UE-based list of subscriber data does not include5GMM parameters corresponding to the selected SNPN and the identified SUPI, the method1300 may include using SUPI entry details from the operator-based list of subscriber data (e.g.,default 5GMM parameters) to establish a connection of the USIM (e.g., USIM1) and theselected SNPN (e.g., SNPN1), as indicated in operation 1310.

[0089] Moreover, in case the operator-based list of subscriber data does not include a validSUPI value, the method 1300 may include deriving a SUPI value from the USIM, as shown inoperation 1306. In embodiments, the International Mobile Subscriber Identity (IMSI) value ofthe USIM may correspond to the SUPI of the USIM. At operation 1314, the method 1300 mayinclude determining whether the memory includes 5GMM parameters corresponding to theIMSI value / SUPI value of USIM and the selected SNPN. In case, the 5GMM parameterscorresponding to the IMSI / SUPI value of USIM and the selected SNPN are available, themethod 1300 may use AKA-based authentication with IMSI / SUPI value and other 5GMMparameters, as shown in operation 1316. However, in case the 5GMM parameterscorresponding to the IMSI / SUPI value of USIM and the selected SNPN are not available, themethod 1300 may include using the AKA-based authentication using the IMSI / SUPI valueonly, as shown in operation 1318.

[0090] At operation 1312, the method 1300 may include triggering the registration of theUSIM with the selected SNPN. Upon successful registration, the UE 101 may receive 5G-GUTI and 5GMM parameters including information such as, but not limited to, ngKSI valueas 1, GUTI-1, allowed slice as 1, UE Route Selection Policy (URSP) rules as 1, 2, and so forth,as shown in operation 1320. Further, the UE 101 may effectively store the received 5G-GUTIand the 5GMM parameters along with the associated SNPN and SUPI / IMSI values of USIM.

[0091] According to embodiments, the UE-based list of subscriber data may includeinformation as highlighted in Table 1, below:

[0092] Further, an operator-based list of subscriber data may include information ashighlighted in Table 2, below: TABLE 2

[0093] However, these are merely embodiments, and Table 1 and Table 2 may include and / oromit any information.

[0094] Example of information updated at the UE 101 as a result of the method 1300 is asfollows:

[0095] Figure 14 illustrates an example process flow of a method 1400 of storing 5GMMparameters of an SNPN at the UE, according to embodiments of the present disclosure. Theoperations of the method 1400 are similar to operations of the method 1300, therefore similarreference numerals have been provided for corresponding operations and a description of theoperations has been omitted for the sake of brevity.

[0096] However, the operations of the method 1400 correspond to USIM2 having a SUPI valueof 222222. Thus, as a result of the method 1400, the information which may be updated at theUE 101 may be as follow:

[0097] Figure 15 illustrates an example process flow depicting a method 1500 of storing5GMM parameters of an SNPN at the UE 101, according to embodiments of the presentdisclosure. While most of the operations of the method 1500 are similar to operations discussedin figures 13 and 14, only distinct operations have been explained in view of figure 15.Specifically, the operations 1508-1520 have already been discussed at least in figures 13 and14.

[0098] Specifically, figures 13 and 14 relate to scenarios where the registration is completed.However, figure 15 corresponds to a scenario where the network 105 may reject the registrationreject as shown in operation 1522.

[0099] In particular, at operation 1502, a SIM2 with IMSI: 222222 may be inserted at the UE101. At operation 1504, the UE 101 may read SNPN subscriber data from the operator-basedlist. At step 1506, the UE may select SNPN1 as the selected SNPN for the connection.Thereafter, the UE 101 may perform operations 1508-1520 which are similar to operations asdiscussed in figures 13-14. Further, at step 1522, the registration request may be rejected. Insuch a scenario, the UE-based list may also include two separate columns to store informationon forbidden SNPNs, where one column corresponds to temporarily forbidden SNPNs andanother column correspond to permanently forbidden SNPNs, as also shown in the table below:

[0100] Figure 16 illustrates an example process flow depicting a method 1600 of storing5GMM parameters of an SNPN at the UE, according to embodiments of the present disclosure.While most of the operations of the method 1600 are similar to operations discussed in figures13-15, only distinct operations have been explained in view of figure 16. Specifically, theoperations 1602-1620 have already been in discussed at least in figures 13-15. At operation1622, the method 1600 includes storing 5GMM parameters upon successful registration ofUSIM with the SNPN. A further operation 1624 may indicate that the method 1600 may alsoinclude storing the 5GMM parameters and list of forbidden SNPNs across different powercycles. For example, even for the registration of USIM2 with the SNPN1, the UE 101 mayinclude information stored for USIM1 and SNPN1, as shown below:

[0101] Thus, according to the present disclosure, the UE 101 may maintain the list of forbiddenSNPNs along with other 5GMM parameters across different power cycles.

[0102] Figure 17 illustrates a process flow depicting a method 1700 for managing 5GMMparameters of an SNPN at the UE 101, in accordance with embodiments of the presentdisclosure. The method 1700 may be performed by the UE 101 and / or the network 105. TheUE 101 and its associated functions along with architecture are explained in conjunction withfigure 21. The UE 101 may include, but not limited to, a mobile phone, a smartwatch, a tablet,and any other electronic device which is capable of connecting to a 4G and / or 5G network.Further, the network 105 may represent any suitable network device and / or system configuredto establish connection with the UE 101. The UE 101 may be in communication with thenetwork 105 via NR NAS 103. In embodiments, the network 105 may correspond to a 5Gnetwork.

[0103] At operation 1702, an SNPN identifier (SNPN ID) for a first SNPN registration requestmay be selected for registration of the UE with the SNPN. According to embodiments, theSNPN ID may be selected from among a plurality of SNPN IDs provided as entries in anoperator-based list of subscriber data (also referred to herein as a "first list"). In an embodiment,the SNPN ID may be selected based on input(s) provided by the user. For instance, the usermay manually select an SNPN entry with the SNPN ID from the list of subscriber dataincluding all available SNPN IDs. Further, manual selection of the SNPN may correspond toSpec - 3GPP TS 23.122-section 4.9.3.1.2. In another embodiment, the UE may select the SNPNID based on a predefined criteria and / or a predefined selection procedure. In a non-limitingexample, the predefined criteria may correspond to a scenario wherein during a power ON stateor recovery from loss of coverage state, the UE may select an entry corresponding to an SNPNwhich may be stored as registered SNPN prior to the power ON state or the loss of coveragestate. Further, in a non-limiting example, the predefined selection procedure may correspondto sequentially selecting an SNPN from the list of subscriber data. In some embodiments, theselection of SNPN may be based on Spec - 3GPP TS 23.122- Section 4.9.3.1.1.

[0104] At operation 1704, search of the SNPN ID in the operator-based list of subscriber datamay be performed. The search of the SNPN ID may be performed to identify (e.g., determine)whether the operator-based list of subscriber data includes a valid Subscriber PermanentIdentifier (SUPI) for the SNPN ID. The operator-based list of subscriber data may include aplurality of predefined or alternatively, given SNPN parameter values and associated SNPNIDs (e.g., respective SNPN parameter values associated with each of the SNPN IDs, orrespective SNPN parameter values associated with a subset of the SNPN IDs). In embodiments,the operator-based list of subscriber data may be prestored (or stored) in the UE 101 prior toinstallation of the USIM.

[0105] At operation 1706, the value of SUPI from a Universal Subscriber Identifier Module(USIM) located at the UE may be identified upon determining that for the SNPN ID from aselected entry of the operator-based list of subscriber data does not include a valid subscriberidentifier for the SNPN ID and the UE 101 has a valid USIM. Further, the UE 101 may fetch5GMM parameters associated with the SUPI and the SNPN ID from the second list if the SUPImatches the subscriber identifier stored in the second list.

[0106] At operation 1708, the first SNPN registration request may be generated based on theSNPN ID from the selected entry of an operator-based list of subscriber data and the identifiedvalue of SUPI from the USIM. In an embodiment, the first SNPN registration request may begenerated based on the SNPN ID and the 5GMM parameters associated with the SUPI.

[0107] At operation 1710, a UE-based list of subscriber data (also referred to herein as the"second list") may be updated with the selected SNPN ID, the SUPI of the USIM, and one ormore SNPN parameter values corresponding to the registered SNPN upon completion of SNPNregistration of the UE. According to embodiments, the one or more SNPN parameter valuesmay be received from the SNPN during, or upon successful completion of, registration withthe UE. According to embodiments, the UE may generate a communication signal, and transmitthe communication signal via the SNPN using the USIM and the one or more SNPN parametervalues after the UE-based list is updated in operation 1710. According to embodiments, the UEmay receive a communication signal via the SNPN using the USIM and the one or more SNPNparameter values after the UE-based list is updated in operation 1710. In embodiments, themethod 1700 may further comprise operations 1712-1722 post the operation 1710. At operation1712, installation of a new USIM at the UE may be identified. At operation 1714, a SNPN IDfor a second SNPN registration request may be selected for registration of the UE with theSNPN. In embodiments, the SNPN ID may be same as, or similar to, that used in the first SNPNregistration request.

[0108] At operation 1716, a new SUPI may be identified, the new SUPI being associated withthe new USIM located at the UE. At operation 1718, a determination is made as to whether theUE-based list of subscriber data includes the one or more SNPN parameter valuescorresponding to the identified new SUPI and the SNPN ID.

[0109] At operation 1720, the second SNPN registration request based on the selected SNPNID and the new SUPI may be generated upon determining that the UE based list of subscriberdata does not include the one or more SNPN parameter values corresponding to a pair of thenew SUPI and the SNPN ID. At operation 1722, the UE-based list of subscriber data may beupdated with the selected SNPN ID, the new SUPI, and one or more SNPN parameter valuescorresponding to the registered SNPN upon completion of SNPN registration of the UE. Inembodiments, the one or more SNPN parameter values of the registered SNPN correspond to5G Mobility Management (5GMM) parameters.

[0110] Figure 18 illustrates a process flow depicting a method 1800 for managing 5GMMparameters of an SNPN at the UE 101, in accordance with embodiments of the presentdisclosure. The method 1800 may be performed by the UE 101 and the network 105. The UE101 and its associated functions along with architecture is explained in conjunction with at leastfigure 21. The UE 101 may include, but is not limited to, a mobile phone, a smart watch, atablet, and any other electronic device which is capable of connecting to a 4G and / or 5Gnetwork. Further, the network 105 may represent any suitable network device and / or systemconfigured to establish connection with the UE 101. The UE 101 may be in communicationwith the network 105 via NR NAS 103. In embodiments, the network 105 may correspond toa 5G network. At operation 1802, an SNPN identifier (SNPN ID) for a SNPN registrationrequest may be selected for registration of the UE with the SNPN. According to embodiments,the SNPN ID may be selected from among a plurality of SNPN IDs provided as entries in anoperator-based list of subscriber data (also referred to herein as a "first list").

[0111] At operation 1804, a search for the SNPN ID in the operator-based list of subscriberdata may be performed. The search of the SNPN ID may be performed to identify whether theoperator-based list of subscriber data includes a valid Subscriber Permanent Identifier (SUPI)for the SNPN ID. The operator-based list of subscriber data may include a plurality ofpredefined or alternatively, given SNPN parameter values and associated SNPN IDs (e.g.,respective SNPN parameter values associated with each of the SNPN IDs, or respective SNPNparameter values associated with a subset of the SNPN IDs).

[0112] At operation 1806, a value of a SUPI from a Universal Subscriber Identifier Module(USIM) located at the UE may be identified upon determining that for the SNPN ID from aselected entry of the operator-based list of subscriber data does not include a valid SUPI. In anembodiment, the UE 101 may determine that the selected entry of the operator-based list ofsubscriber data does not include a valid SUPI, upon identifying that a value of SUPIcorresponds to one of "0", "0XF", or "invalid". Further, an entry including an invalid SUPImay also include a status field indicating the validity of SUPI, which may be used by the UE101 to determine whether the selected entry includes a valid SUPI or not. In anotherembodiment, the entry having the invalid SUPI may also correspond to a value of credentialsas invalid or empty, which may also be used by the UE 101 to determine whether the selectedentry includes a valid SUPI. Embodiments are exemplary in nature and the present disclosureeither covers or intend to cover any suitable technique for determining an invalid SUPI for theselected entry from the operator-based list.

[0113] At operation 1808, the SNPN registration request may be generated based on the SNPNID from the selected entry of an operator-based list of subscriber data and the identified valueof SUPI from the USIM. At operation 1810, a registration reject indication from the selectedSNPN may be received in response to the SNPN registration request.

[0114] At operation 1812, a UE-based list of subscriber data (also referred to herein as the"second list") may be updated with the selected SNPN ID in a forbidden SNPN category basedon the registration reject indication. In embodiments, the forbidden SNPN category may beclassified as a temporary forbidden SNPN category or a permanent forbidden SNPN category.The temporary forbidden SNPN category may include SNPNs that the UE 101 may be able toaccess after a lapse of predefined or alternatively, given timer or the SNPNs which aretemporarily unavailable for the selected USIM. In an embodiment, the temporary forbiddenSNPN may correspond to SNPN IDs which may not be globally unique and rejected by thenetwork with 5GMM cause #74. In some embodiments, the determination whether the SNPNID is globally unique or not is made in reference to 3GPP T 23.003 section 12.7.1. Further, theUE 101 may use said information corresponding to SNPN ID and rejection cause to determinewhether the rejection corresponds to the temporary forbidden SNPN category. The permanentforbidden SNPN category may include SNPNs for which the selected USIM is unauthorized toaccess for predefined or alternatively, given timer. In an embodiment, the permanent forbiddenSNPN may correspond to SNPN IDs which may be globally unique and rejected by the networkwith 5GMM cause #75. Further, the UE 101 may use said information corresponding to SNPNID and rejection cause to determine whether the rejection corresponds to the permanentforbidden SNPN category. According to embodiments, an attempt by the UE to register withthe SNPN associated with SNPN ID in the forbidden SNPN category before expiry of thepredefined or alternatively, given timer may be blocked (e.g., skipped, avoided, etc.).According to embodiments, the UE may register with the SNPN associated with SNPN ID inthe forbidden SNPN category after expiry of the predefined or alternatively, given timer, obtainone or more SNPN parameter values from the SNPN during, or upon successful completion of,registration with the UE, and update the UE-based list (e.g., according to operations similar tothose discussed above in connection with FIG. 17). According to embodiments, the UE maygenerate a communication signal, and transmit the communication signal via the SNPN usingthe obtained one or more SNPN parameter values after the UE-based list is updated. Accordingto embodiments, the UE may receive communication signal via the SNPN using the obtainedone or more SNPN parameter values after the UE-based list is updated.

[0115] In embodiments, the method 1800 may further comprise operations 1814-1820 post theoperation 1812. At operation 1814, a type of rejection received from the SNPN may bedetermined. Further, at operation 1816, the SNPN ID may be categorized in at least one of thetemporary forbidden SNPN category or the permanently forbidden SNPN category based onthe type of rejection.

[0116] Moreover, at operation 1818, in case the SNPN belongs the temporary or permanentforbidden SNPN category, the UE-based list of subscriber data may be updated to remove theselected SNPN ID from the forbidden category after a complete lapse of a predefined oralternatively, given timer. Also, at operation 1820, a lapse of (e.g., a time duration elapsed by)the predefined or alternatively, given timer may be calculated during an OFF state of the UE101. Thus, the UE 101 may be able to effectively access the temporary or permanent forbiddenSNPNs after a restricted time period.

[0117] For example, the UE 101 may initially camp on the SNPN1 which is globally uniqueand may attempt registration. Further, the network may reject the registration with 5GMMcause #75. Accordingly, the SNPN1 may be added to the permanent forbidden SNPN list. ForExample, the UE 101 may configure a timer T3245 timer with a duration of 12 hours. After alapse of 5 hours, the UE 101 is powered off. In such a scenario, the UE 101 may save a valueof time lapsed for the timer T3245 and a power off time. Thereafter, when the UE 101 ispowered ON after a lapse of 1 hour, the UE 101 may determine the remaining time of the timerT3245 using the previously saved power off time, and stored value of time lapsed for the timerT3245 and the current time during the power off condition.

[0118] Further, in embodiments, the UE-based list of subscriber data is stored in a non-volatilememory of the UE 101, and the UE-based list includes a list of SNPN IDs in the forbiddencategory (e.g., the UE-based list may include a plurality of SNPN IDs and those SNPN IDs inthe forbidden category may be associated with a corresponding indication reflecting this fact).

[0119] Figure 19 illustrates a process flow depicting a method 1900 for managing 5GMMparameters of an SNPN at the UE 101, in accordance with embodiments of the presentdisclosure. At operation 1902, the method 1900 may comprise selecting an SNPN identifier(SNPN ID) from among a plurality of SNPN IDs in a first list. At operation 1904, the method1900 may comprise determining whether the first list includes a valid Subscriber PermanentIdentifier (SUPI) for the SNPN ID, the first list including a plurality of SNPN parameter valuesassociated with the plurality of SNPN IDs.

[0120] Further, at operation 1906, the method 1900 may comprise identifying a first SUPI froma first Universal Subscriber Identifier Module (USIM) of the UE in response to determiningthat the first list does not include the valid SUPI for the SNPN ID. Moreover, at operation 1908,the method 1900 may comprise generating a first SNPN registration request based on the SNPNID and the first SUPI to attempt registration with a first SNPN associated with the SNPN ID.Thereafter, at operation 1910, the method 1900 may comprise updating a second list with theSNPN ID, the first SUPI, and one or more first SNPN parameter values corresponding to thefirst SNPN upon successful registration with the first SNPN.

[0121] Figure 20 illustrates a process flow depicting a method 2000 for managing 5GMMparameters of an SNPN at the UE 101, in accordance with embodiments of the presentdisclosure. At operation 2002, the method 2000 may comprise selecting an SNPN identifier(SNPN ID) from among a plurality of SNPN IDs in a first list. At operation 2004, the method2000 may comprise determining whether the first list includes a valid Subscriber PermanentIdentifier (SUPI) for the SNPN ID, the first list including a plurality of SNPN parameter valuesassociated with the plurality of SNPN IDs.

[0122] Further, at operation 2006, the method 2000 may comprise identifying a first SUPI froma Universal Subscriber Identifier Module (USIM) of the UE in response to determining that thefirst list does not include the valid SUPI for the SNPN ID. Moreover, at operation 2008, themethod 2000 may comprise generating an SNPN registration request based on the SNPN IDand the first SUPI. Thereafter, at operation 2010, the method 2000 may comprise receiving aregistration reject indication from a first SNPN associated with the SNPN ID in response to theSNPN registration request. At operation 2012, the method 200 may comprise updating a secondlist with the SNPN ID in a forbidden SNPN category based on the registration reject indication.

[0123] Conventional devices and methods for managing 5GMM parameters of an SNPN at aUE result in excessive failures in registering with the SNPN. For example, the conventionaldevices and methods map the SNPN with a SUPI from a list of subscriber data regardless ofwhether the SUPI from the list is valid. Also, the conventional devices and methods attempt toconnect with an SNPN via a first USIM using parameters (e.g., SNPN parameters and / or5GMM parameters) associated with a second (e.g., different) USIM. These approaches by theconventional devices and methods result in attempts to connect with SNPNs using invalidSUPIs and / or invalid parameters, causing an excessive amount of connection failures.Additionally, the conventional devices and methods do not track failed registration attemptresponses, indicating that registration to a corresponding SNPN is forbidden, through a powercycle. Accordingly, the conventional devices and methods attempt re-registration to SNPNsfor which registration is forbidden, resulting an excessive amount of registration failures. Theexcessive connection and registration failures of the conventional devices and methods, andcorresponding re-attempts, result in excessive resource consumption (e.g., power, processor,memory, bandwidth, delay, etc.).

[0124] However, according to embodiments, improved devices and methods are provided formanaging 5GMM parameters of an SNPN at a UE. For example, the improved devices andmethods may determine whether the list of subscriber data includes a valid SUPI for an SNPNand, if not, use a SUPI from a USIM of the UE. Also, the improved devices and methods maymanage a list of SNPN IDs in association with respective SUPIs of USIMs and correspondingSNPN parameters (e.g., 5GMM parameters), enabling use of SNPN parameters and / or SUPIsassociated with the proper USIM and / or SNPN. Additionally, the managed list may alsoinclude an indication of a forbidden SNPN in instances in which failed registration attemptresponses are received indicating that registration to the SNPN is forbidden, thereby enablingtracking of this forbidden state through power cycles, as well as avoidance or reduction in re-registration attempts to the forbidden SNPN while the forbidden status remains (e.g., untilexpiry of a corresponding timer). Accordingly, the improved devices and methods overcomethe deficiencies of the conventional devices and methods to at least reduce connection andregistration failures, and thus, reduce resource consumption (e.g., power, processor, memory,bandwidth, delay, etc.).

[0125] Figure 21 is a diagram illustrating the configuration of a user equipment (UE) 2100 ina wireless communication system, according to embodiments of the present disclosure. Theconfiguration of Figure 19 may be understood as a part of the configuration of the UE 2100.Further, the methods disclosed above may be implemented by the UE 2100 according to aembodiment. In embodiments, the UE 2100 corresponds to the UE 101. Hereinafter, it isunderstood that terms including "unit" or "module" at the end may refer to the unit forprocessing at least one function or operation and may be implemented in hardware, software,or a combination of hardware and software.

[0126] Referring to Figure 21, the UE 2100 may include at least one processor 2102 (may alsobe referred to herein in the singular "the processor 2102"), a communication unit 2106 (e.g.,communicator or communication interface), and / or a memory unit 2104 (e.g., storage). By wayof example, the UE 2100 may be a User Equipment, such as a cellular phone or other devicesthat communicate over a plurality of cellular networks (such as a 3G, 4G, a 5G or pre-5G, 6Gnetwork or any future wireless communication network). The communication unit 2104 mayperform functions for transmitting and / or receiving signals via a wireless channel.

[0127] As an example, the processor 2102 may be a single processing unit or a number of units,all of which could include multiple computing units. The processor 2102 may be implementedas one or more microprocessors, microcomputers, microcontrollers, digital signal processors,central processing units, state machines, logic circuitries, and / or any devices that manipulatesignals based on operational instructions. Among other capabilities, the processor 2102 isconfigured to fetch and execute computer-readable instructions and data stored in the memory.The processor 2102 may include one or a plurality of processors. At this time, one or a pluralityof processors 2102 may be a general-purpose processor, such as a central processing unit(CPU), an application processor (AP), or the like, a graphics-only processing unit such as agraphics processing unit (GPU), a visual processing unit (VPU), and / or an AI-dedicatedprocessor such as a neural processing unit (NPU). The one or a plurality of processors 2102may control the processing of the input data in accordance with a predefined or alternatively,given operating rule or artificial intelligence (AI) model stored in the non-volatile memory andthe volatile memory, e.g., the memory unit 2104. The predefined or alternatively, givenoperating rule or artificial intelligence model is provided through training or learning.

[0128] The memory unit 2104 may include any non-transitory computer-readable mediumknown in the art including, for example, volatile memory, such as Static Random AccessMemory (SRAM) and Dynamic Random Access Memory (DRAM), and / or non-volatilememory, such as Read-Only Memory (ROM), erasable programmable ROM, flash memories,hard disks, optical disks, and magnetic tapes. According to embodiments, the memory unit2104 may store the first list and the second list.

[0129] Embodiments disclosed herein may be implemented using processing circuitry. Forexample, according to embodiments, operations described herein as being performed by theUE 101, the NR NAS 103, the network 105, the UE 2100, the at least one processor 2102and / or the communication unit 2106 may be performed by processing circuitry. The term'processing circuitry,' as used in the present disclosure, may refer to, for example, hardwareincluding logic circuits; a hardware / software combination such as a processor executingsoftware; or a combination thereof. For example, the processing circuitry more specificallymay include, but is not limited to, a central processing unit (CPU), an arithmetic logic unit(ALU), a digital signal processor, a microcomputer, a field programmable gate array (FPGA),a System-on-Chip (SoC), a programmable logic unit, a microprocessor, application-specificintegrated circuit (ASIC), etc. For instance, embodiments disclosed herein may beimplemented using at least one software program running on at least one hardware device andperforming network management functions to control the elements.

[0130] The various operations of methods described above may be performed by any suitabledevice capable of performing the operations, such as the processing circuitry discussed above.For example, as discussed above, the operations of methods described above may be performedby various hardware and / or software implemented in some form of hardware (e.g., processor,ASIC, etc.).

[0131] The software may comprise an ordered listing of executable instructions forimplementing logical functions, and may be embodied in any "processor-readable medium" foruse by or in connection with an instruction execution system, apparatus, or device, such as asingle or multiple-core processor or processor-containing system.

[0132] The blocks or operations of a method or algorithm and functions described inconnection with embodiments disclosed herein may be embodied directly in hardware, in asoftware module executed by a processor, or in a combination of the two. If implemented insoftware, the functions may be stored on or transmitted over as one or more instructions orcode on a tangible, non-transitory computer-readable medium. A software module may residein Random Access Memory (RAM), flash memory, Read Only Memory (ROM), ElectricallyProgrammable ROM (EPROM), Electrically Erasable Programmable ROM (EEPROM),registers, hard disk, a removable disk, a CD ROM, or any other form of storage medium knownin the art.

[0133] In embodiments, the configuration illustrated in figure 19 and discussed above may alsocorrespond to a configuration of one or more network devices of the network 105, which maybe used to implement the present disclosure.

[0134] While specific language has been used to describe the disclosure, any limitations arisingon account of the same are not intended. As would be apparent to a person in the art, variousworking modifications may be made to the method in order to implement the inventiveconcepts as taught herein.

[0135] The drawings and the forgoing description give examples of embodiments. Thoseskilled in the art will appreciate that one or more of the described elements may well becombined into a single functional element. Alternatively, certain elements may be split intomultiple functional elements. Elements from one example may be added to another example.For example, orders of processes described herein may be changed and are not limited to themanner described herein.

[0136] Moreover, the actions (e.g., operations) of any flow diagram need not be implementedin the order shown; nor do all of the acts necessarily need to be performed. For example, actionsor operations illustrated as being performed serially in two consecutive blocks may actually beperformed concurrently, simultaneously, contemporaneously, or in some cases be performedin reverse order. Also, those acts that are not dependent on other acts may be performed inparallel with the other acts. The scope of embodiments is by no means limited by these specificexamples. Numerous variations, whether explicitly given in the specification or not, such asdifferences in structure, dimension, and use of material, are possible. The scope ofembodiments is at least as broad as given by the following claims.

[0137] Benefits, other advantages, and solutions to challenges have been described above withregard to specific examples. However, the benefits, advantages, solutions to challenges, andany component(s) that may cause any benefit, advantage, or solution to occur or become morepronounced are not to be construed as a critical, required, or essential feature or component ofany or all the claims.

Claims

1. A method (1900) for managing 5G Mobility Management (5GMM) parameters of a Standalone Non Public Network (SNPN) at a User Equipment (UE), the method comprising: selecting (1902) an SNPN identifier (SNPN ID) from among a plurality of SNPN IDs in a first list; determining (1904) whether the first list includes a valid Subscriber Permanent Identifier (SUPI) for the SNPN ID, the first list including a plurality of SNPN parameter values associated with the plurality of SNPN IDs; identifying (1906) a first SUPI from a first Universal Subscriber Identifier Module (USIM) of the UE in response to determining that the first list does not include the valid SUPI for the SNPN ID; generating (1908) a first SNPN registration request based on the SNPN ID and the first SUPI to attempt registration with a first SNPN associated with the SNPN ID; and updating (1910) a second list with the SNPN ID, the first SUPI, and one or more first SNPN parameter values corresponding to the first SNPN upon successful registration with the first SNPN.

2. The method (1900) as claimed in claim 1, wherein the first list is stored on the UE prior to installation of the first USIM at the UE.

3. The method (1900) as claimed in claim 1, wherein the one or more first SNPN parameter values of the first SNPN correspond to 5G Mobility Management (5GMM) parameters.

4. The method (1900) as claimed in claim 1, comprising: identifying a new installation of a second USIM at the UE; identifying a second SUPI associated with the second USIM; determining whether the second list includes one or more second SNPN parameter values corresponding to the second SUPI and the SNPN ID; generating a second SNPN registration request based on the SNPN ID and the second SUPI to attempt registration with the first SNPN in response to determining that the second list does not include the one or more second SNPN parameter values; and updating the second list with the SNPN ID, the second SUPI, and the one or more second SNPN parameter values corresponding to the first SNPN upon successful registration with the first SNPN.

5. A method (2000) for managing 5GMM parameters of an SNPN at a User Equipment (UE), the method comprising: selecting (2002) an SNPN identifier (SNPN ID) from among a plurality of SNPN IDs in a first list; determining (2004) whether the first list includes a valid Subscriber Permanent Identifier (SUPI) for the SNPN ID, the first list including a plurality of SNPN parameter values associated with the plurality of SNPN IDs; identifying (2006) a first SUPI from a Universal Subscriber Identifier Module (USIM) of the UE in response to determining that the first list does not include the valid SUPI for the SNPN ID; generating (2008) an SNPN registration request based on the SNPN ID and the first SUPI; receiving (2010) a registration reject indication from a first SNPN associated with the SNPN ID in response to the SNPN registration request; and updating (2012) a second list with the SNPN ID in a forbidden SNPN category based on the registration reject indication.

6. The method (2000) as claimed in claim 5, wherein the forbidden SNPN category is classified as a temporary forbidden SNPN category or a permanent forbidden SNPN category.

7. The method (2000) as claimed in claim 6, comprising: determining a type of rejection received from the first SNPN; and categorizing the SNPN ID in at least one of the temporary forbidden SNPN category or the permanently forbidden SNPN category based on the type of rejection.

8. The method (2000) as claimed in claim 7, comprising: updating the second list to remove the SNPN ID from the forbidden SNPN category after expiry of a timer.

9. The method (2000) as claimed in claim 8, comprising: calculating a time duration elapsed by the timer during an OFF state of the UE.

10. The method (2000) as claimed in claim 5, wherein the second list is stored in a nonvolatile memory of the UE, the second list including a list of SNPN IDs in the forbidden SNPN category.

11. A device (2100) for managing 5GMM parameters of an SNPN at a User Equipment (UE), the device (2100) comprising: a processing circuitry (2102) configured to: select an SNPN identifier (SNPN ID) from among a plurality of SNPN IDs in a first list, determine whether the first list includes a valid Subscriber Permanent Identifier (SUPI) for the SNPN ID, the first list including a plurality of SNPN parameter values associated with the plurality of SNPN IDs, identify a first SUPI from a first Universal Subscriber Identifier Module (USIM) of the UE in response to determining that the first list does not include the valid SUPI for the SNPN ID, generate a first SNPN registration request based on the SNPN ID and the first SUPI to attempt registration with a first SNPN associated with the SNPN ID, and update a second list with the SNPN ID, the first SUPI, and one or more first SNPN parameter values corresponding to the first SNPN upon successful registration with the first SNPN.

12. The device (2100) as claimed in claim 11, wherein the first list is stored on the UE prior to installation of the first USIM at the UE.

13. The device (2100) as claimed in claim 11, wherein the one or more first SNPN parameter values of the first SNPN correspond to 5G Mobility Management (5GMM) parameters.

14. The device (2100) as claimed in claim 11, wherein the processing circuitry (2102) is configured to: identify a new installation of a second USIM at the UE; identify a second SUPI associated with the second USIM; determine whether the second list includes one or more second SNPN parameter values corresponding to the second SUPI and the SNPN ID; generate a second SNPN registration request based on the SNPN ID and the second SUPI to attempt registration with the first SNPN in response to determining that the second list does not include the one or more second SNPN parameter values; and update the second list with the SNPN ID, the second SUPI, and the one or more second SNPN parameter values corresponding to the first SNPN upon successful registration with the first SNPN.

15. A device (2100) for managing 5GMM parameters of an SNPN at a User Equipment (UE), the device (2100) comprising: a processing circuitry (2102) configured to: select an SNPN identifier (SNPN ID) from among a plurality of SNPN IDs in a first list, determine whether the first list includes a valid Subscriber Permanent Identifier (SUPI) for the SNPN ID, the first list including a plurality of SNPN parameter values associated with the plurality of SNPN IDs, identify first SUPI from a Universal Subscriber Identifier Module (USIM) of the UE in response to determining that the first list does not include the valid SUPI for the SNPN ID, generate an SNPN registration request based on the SNPN ID and the first SUPI, receive a registration reject indication from a first SNPN associated with the SNPN ID in response to the SNPN registration request, and update a second list with the SNPN ID in a forbidden SNPN category based on the registration reject indication.

16. The device (2100) as claimed in claim 15, wherein the forbidden SNPN category is classified as a temporary forbidden SNPN category or a permanent forbidden SNPN category.

17. The device (2100) as claimed in claim 16, wherein the processing circuitry (2102) is configured to: determine a type of rejection received from the first SNPN; and categorize the SNPN ID in at least one of the temporary forbidden SNPN category or the permanently forbidden SNPN category based on the type of rejection.

18. The device (2100) as claimed in claim 17, wherein the processing circuitry (2102) is configured to: update the second list of subscriber data to remove the SNPN ID from the forbidden SNPN category after expiry of a timer.

19. The device (2100) as claimed in claim 18, wherein the processing circuitry (2102) is configured to: calculate a time duration elapsed by the timer during an OFF state of the UE.

20. The device (2100) as claimed in claim 15, wherein the second list is stored in a nonvolatile memory of the UE, the second list including a list of SNPN IDs in the forbidden SNPN category.