Node in wireless communication system and method performed by the same

Abstract

The present disclosure provides a node in a wireless communication system and methods performed by the same. A method performed by a first access and mobility management function (AMF) entity, the method comprising: determining whether to deregister a first access of a terminal, the terminal operating as a DualSteer terminal associated with the first access corresponding to the first AMF entity and a second access corresponding to a second AMF entity; and deregistering the first access, based on the determination.

Description

NODE IN WIRELESS COMMUNICATION SYSTEM AND METHOD PERFORMED BY THE SAME

[0001] The present disclosure relates to wireless communication networks, and more particularly, to handling scenarios, where the UE is not allowed to act as a DualSteer device in wireless communication networks.

[0002] 5G mobile communication technologies define broad frequency bands such that high transmission rates and new services are possible, and can be implemented not only in "Sub 6GHz" bands such as 3.5GHz, but also in "Above 6GHz" bands referred to as mmWave including 28GHz and 39GHz. In addition, it has been considered to implement 6G mobile communication technologies (referred to as Beyond 5G systems) in terahertz bands (for example, 95GHz to 3THz bands) in order to accomplish transmission rates fifty times faster than 5G mobile communication technologies and ultra-low latencies one-tenth of 5G mobile communication technologies.

[0003] At the beginning of the development of 5G mobile communication technologies, in order to support services and to satisfy performance requirements in connection with enhanced Mobile BroadBand (eMBB), Ultra Reliable Low Latency Communications (URLLC), and massive Machine-Type Communications (mMTC), there has been ongoing standardization regarding beamforming and massive MIMO for mitigating radio-wave path loss and increasing radio-wave transmission distances in mmWave, supporting numerologies (for example, operating multiple subcarrier spacings) for efficiently utilizing mmWave resources and dynamic operation of slot formats, initial access technologies for supporting multi-beam transmission and broadbands, definition and operation of BWP (BandWidth Part), new channel coding methods such as a LDPC (Low Density Parity Check) code for large amount of data transmission and a polar code for highly reliable transmission of control information, L2 pre-processing, and network slicing for providing a dedicated network specialized to a specific service.

[0004] Currently, there are ongoing discussions regarding improvement and performance enhancement of initial 5G mobile communication technologies in view of services to be supported by 5G mobile communication technologies, and there has been physical layer standardization regarding technologies such as V2X (Vehicle-to-everything) for aiding driving determination by autonomous vehicles based on information regarding positions and states of vehicles transmitted by the vehicles and for enhancing user convenience, NR-U (New Radio Unlicensed) aimed at system operations conforming to various regulation-related requirements in unlicensed bands, NR UE Power Saving, Non-Terrestrial Network (NTN) which is UE-satellite direct communication for providing coverage in an area in which communication with terrestrial networks is unavailable, and positioning.

[0005] Moreover, there has been ongoing standardization in air interface architecture / protocol regarding technologies such as Industrial Internet of Things (IIoT) for supporting new services through interworking and convergence with other industries, IAB (Integrated Access and Backhaul) for providing a node for network service area expansion by supporting a wireless backhaul link and an access link in an integrated manner, mobility enhancement including conditional handover and DAPS (Dual Active Protocol Stack) handover, and two-step random access for simplifying random access procedures (2-step RACH for NR). There also has been ongoing standardization in system architecture / service regarding a 5G baseline architecture (for example, service based architecture or service based interface) for combining Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and Mobile Edge Computing (MEC) for receiving services based on UE positions.

[0006] As 5G mobile communication systems are commercialized, connected devices that have been exponentially increasing will be connected to communication networks, and it is accordingly expected that enhanced functions and performances of 5G mobile communication systems and integrated operations of connected devices will be necessary. To this end, new research is scheduled in connection with eXtended Reality (XR) for efficiently supporting AR (Augmented Reality), VR (Virtual Reality), MR (Mixed Reality) and the like, 5G performance improvement and complexity reduction by utilizing Artificial Intelligence (AI) and Machine Learning (ML), AI service support, metaverse service support, and drone communication.

[0007] Furthermore, such development of 5G mobile communication systems will serve as a basis for developing not only new waveforms for providing coverage in terahertz bands of 6G mobile communication technologies, multi-antenna transmission technologies such as Full Dimensional MIMO (FD-MIMO), array antennas and large-scale antennas, metamaterial-based lenses and antennas for improving coverage of terahertz band signals, high-dimensional space multiplexing technology using OAM (Orbital Angular Momentum), and RIS (Reconfigurable Intelligent Surface), but also full-duplex technology for increasing frequency efficiency of 6G mobile communication technologies and improving system networks, AI-based communication technology for implementing system optimization by utilizing satellites and AI (Artificial Intelligence) from the design stage and internalizing end-to-end AI support functions, and next-generation distributed computing technology for implementing services at levels of complexity exceeding the limit of UE operation capability by utilizing ultra-high-performance communication and computing resources.

[0008] The present disclosure relates to addressing scenarios, in wireless communication systems, where DualSteer-capable User Equipment (UE) encounters registration rejections or operational restrictions in single or multiple access networks, causing inefficiencies in network resource utilization and disruption in DualSteering functionalities.

[0009] The principal object of embodiments herein is to disclose methods and systems for handling scenarios, where the UE is not allowed to act as a DualSteer device in wireless communication networks.

[0010] Another object of embodiments herein is to disclose methods and systems for handling a scenario, where the UE registering over a first access network with DualSteer capability receives a reject from the first access network which states that the UE cannot act as a DualSteer device.

[0011] Another object of embodiments herein is to disclose methods and systems for handling a scenario, where the UE with DualSteer capability already registered over a first access network, identifies and tries to register over a second access network for DualSteering, receives a reject from the second access network which states that the UE cannot as a DualSteer device over this second network.

[0012] Another object of embodiments herein is to disclose methods and systems for avoiding networks that do not support DualSteering in wireless communication networks, wherein a UE with DualSteer capability is already registered over the first access network, and attempts to register on the second access network (i.e., second PLMN or RAT), but that second access network does not support DualSteering and unnecessarily receives signalling from the UE, which can load the network.

[0013] Accordingly, the embodiments herein provide a method for managing DualSteering communication. The method comprises indicating, by a Network Function (NF) in a Public Land Mobile Network (PLMN), a combination of two or more Radio Access Technologies (RATs) that can be used by a User Equipment (UE) for registering for DualSteering, to the UE, and selecting, by the UE, the indicated RAT combinations for DualSteering communication.

[0014] Accordingly, the embodiments herein provide a method for managing DualSteering communication. The method comprises triggering, by one of a User Equipment (UE), and a Network Function (NF), a deregistration procedure on at least one of, at least one access network that the UE is currently registered on, and all access networks that the UE is currently registered on; and ceasing, by the UE, to operate as a DualSteer device.

[0015] Accordingly, the embodiments herein provide a Network Function (NF) in a Public Land Mobile Network (PLMN) comprising a processing module; a memory; and a transceiver, wherein the processing module is coupled with the memory, and the transceiver. The processing module is configured to indicate a combination of two or more Radio Access Technologies (RATs) that can be used by a User Equipment (UE) for registering for DualSteering, to the UE.

[0016] Accordingly, the embodiments herein provide a User Equipment (UE) comprising a processing module; a memory; and a transceiver, wherein the processing module is coupled with the memory, and the transceiver. The processing module is configured to trigger a deregistration procedure on at least one of, at least one access network that the UE is currently registered on, and all access networks that the UE is currently registered on, in response to determining that the UE is not allowed to perform DualSteering.

[0017] Accordingly, the embodiments herein provide a Network Function (NF) in a Public Land Mobile Network (PLMN) comprising a processing module; a memory; and a transceiver, wherein the processing module is coupled with the memory, and the transceiver. The processing module is configured to trigger a deregistration procedure on at least one of, at least one access network that the UE is currently registered on, and all access networks that the UE is currently registered on, in response to determining that the UE is not allowed to perform DualSteering.

[0018] These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating at least one embodiment and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.

[0019] The methods and systems provided by the present disclosure provide solutions that optimize the handling of DualSteer-capable UE's behavior in scenarios where access network restrictions or limitations arise.

[0020] Embodiments herein are illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the various figures. The embodiments herein will be better understood from the following description with reference to the following illustratory drawings. Embodiments herein are illustrated by way of examples in the accompanying drawings, and in which:

[0021] FIG. 1A depicts a scenario, wherein a UE registering over the first access network with DualSteer capability receives a reject from the network which states that the UE cannot act as a DualSteer device;

[0022] FIG. 1B depicts a scenario, wherein a UE with DualSteer capability (which is already registered over the first access network), identifies and tries to register over a second access network for DualSteering, receives a reject from the second access network which states that the UE cannot as a DualSteer device over this second network;

[0023] FIG. 2 depicts a scenario, wherein a UE registering over a first access network with DualSteer capability receives a reject from the network which states that the UE cannot act as a DualSteer device;

[0024] FIG. 3 is a flowchart depicting the actions to be taken by the UE on receiving an indication that the UE is not allowed to act as a DualSteer device on this PLMN;

[0025] FIG. 4 depicts a scenario, wherein a UE with DualSteer capability already registered over the first access network, identifies, and tries to register over a second access network for DualSteering, receives a reject from the second access network which states that the UE cannot as a DualSteer device over this second network;

[0026] FIG. 5 is a flowchart depicting the actions to be taken by the UE on receiving an indication that the UE is not allowed to act as a DualSteer device on a second PLMN;

[0027] FIG. 6 depicts the process of switching DualSteer status by a UE;

[0028] FIG. 7 is a flowchart depicting the process of managing DualSteering;

[0029] FIG. 8 is a flowchart depicting the process of managing DualSteering;

[0030] FIG. 9 depicts the UE;

[0031] FIG. 10 depicts the AMF;

[0032] FIG. 11 is a flow diagram depicting the process of avoiding networks that do not support DualSteering in wireless communication networks;

[0033] FIG. 12 is a flow diagram depicting the process of avoiding networks that do not support DualSteering in wireless communication networks; and

[0034] FIG. 13 is a flow diagram depicting the process of avoiding networks that do not support DualSteering in wireless communication networks.

[0035] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.

[0036] For the purposes of interpreting this specification, the definitions (as defined herein) will apply and whenever appropriate the terms used in singular will also include the plural and vice versa. It is to be understood that the terminology used herein is for the purposes of describing particular embodiments only and is not intended to be limiting. The terms "comprising", "having" and "including" are to be construed as open-ended terms unless otherwise noted.

[0037] The words / phrases "exemplary", "example", "illustration", "in an instance", "and the like", "and so on", "etc.", "etcetera", "e.g.," , "i.e.," are merely used herein to mean "serving as an example, instance, or illustration." Any embodiment or implementation of the present subject matter described herein using the words / phrases "exemplary", "example", "illustration", "in an instance", "and the like", "and so on", "etc.", "etcetera", "e.g.", "i.e." is not necessarily to be construed as preferred or advantageous over other embodiments.

[0038] Embodiments herein may be described and illustrated in terms of blocks which carry out a described function or functions.　These blocks, which may be referred to herein as managers, units, modules, hardware components or the like, are physically implemented by analog and / or digital circuits such as logic gates, integrated circuits, microprocessors, microcontrollers, memory circuits, passive electronic components, active electronic components, optical components, hardwired circuits and the like, and may optionally be driven by a firmware. The circuits may, for example, be embodied in one or more semiconductor chips, or on substrate supports such as printed circuit boards and the like.　The circuits constituting a block may be implemented by dedicated hardware, or by a processor (example, one or more programmed microprocessors and associated circuitry), or by a combination of dedicated hardware to perform some functions of the block and a processor to perform other functions of the block.　Each block of the embodiments may be physically separated into two or more interacting and discrete blocks without departing from the scope of the disclosure.　Likewise, the blocks of the embodiments may be physically combined into more complex blocks without departing from the scope of the disclosure.

[0039] It should be noted that elements in the drawings are illustrated for the purposes of this description and ease of understanding and may not have necessarily been drawn to scale. For example, the flowcharts / sequence diagrams illustrate the method in terms of the steps required for understanding of aspects of the embodiments as disclosed herein. Furthermore, in terms of the construction of the device, one or more components of the device may have been represented in the drawings by conventional symbols, and the drawings may show only those specific details that are pertinent to understanding the present embodiments so as not to obscure the drawings with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein. Furthermore, in terms of the system, one or more components / modules which comprise the system may have been represented in the drawings by conventional symbols, and the drawings may show only those specific details that are pertinent to understanding the present embodiments so as not to obscure the drawings with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.

[0040] The accompanying drawings are used to help easily understand various technical features and it should be understood that the embodiments presented herein are not limited by the accompanying drawings. As such, the present disclosure should be construed to extend to any modifications, equivalents, and substitutes in addition to those which are particularly set out in the accompanying drawings and the corresponding description. Usage of words such as first, second, third etc., to describe components / elements / steps is for the purposes of this description and should not be construed as sequential ordering / placement / occurrence unless specified otherwise.

[0041] The embodiments herein achieve methods and systems for handling scenarios, where the UE is not allowed to act as a DualSteer device in wireless communication networks. Referring now to the drawings, and more particularly to FIGS. 2 through 13, where similar reference characters denote corresponding features consistently throughout the figures, there are shown embodiments.

[0042] The following definitions and abbreviations have been disclosed herein:

[0043] UE: User equipment or terminal

[0044] ME: Mobile equipment

[0045] PLMN: Public Land Mobile Network

[0046] HPLMN : Home Public Land Mobile Network

[0047] EHPLMN: Equivalent Home Public Land Mobile Network.

[0048] VPLMN: Visited Public Land Mobile Network.

[0049] RAT: Radio Access Technology.

[0050] SUPI: Subscription Permanent Identifier

[0051] DualSteer device: A device supporting traffic steering and switching of user data (for different services) across two 3GPP access networks; it can be a single UE, in case of non-simultaneous data transmission over the two networks, or two separate UEs in case of simultaneous data transmission over the two networks.

[0052] Traffic steering: The procedure that selects an access network and transfers traffic over the selected access network. This can apply to traffic of one or multiple services / applications across two 3GPP access networks, including scenarios where all services use the same network connection (no simultaneous data over the two networks) or different services are steered across different networks (with simultaneous data over the two networks).

[0053] Traffic switching: The procedure that moves all traffic from one access network to another access network in a way that minimizes service interruption. This can apply to traffic of one or multiple services / applications across two 3GPP access networks, including scenarios where all services use the same network connection (no simultaneous data over the two networks) or different services are moved to different networks (with simultaneous data over the two networks).

[0054] non simultaneous data transmission: Where all services use the same network connection at a time (no simultaneous data transfer over the two (access) networks) for data communication and may switch between two networks as per traffic switching procedure but does not transmit data over two networks simultaneously.

[0055] simultaneous data transmission: Where different services are steered across different networks concurrently (with simultaneous data over the two networks).

[0056] The term RAT / RAT-type as defined herein can be at least one of the following: NG-RAN, 5G, 4G, 3G, 2G, EPS, 5GS, NR, NR in unlicensed bands, NR (LEO) satellite access, NR (MEO) satellite access, NR (GEO) satellite access, NR (OTHERSAT) satellite access, NR RedCap, E-UTRA, E-UTRA in unlicensed bands, NB-IoT, WB-IoT, LTE-M, and so on.

[0057] Examples of NAS messages can be, but not limited to, REGISTRATION REQUEST message; DEREGISTRATION REQUEST message; SERVICE REQUEST message; CONTROL PLANE SERVICE REQUEST; IDENTITY REQUEST; AUTHENTICATION REQUEST; AUTHENTICATION RESULT; AUTHENTICATION REJECT; REGISTRATION REJECT; REGISTRATION ACCEPT; DEREGISTRATION ACCEPT; SERVICE REJECT; SERVICE ACCEPT; UE CONFIGURATION UPDATE command; UE PARAMETERS UPDATE command, and so on.

[0058] The term 5GMM sublayer states in this embodiment are at least one of the below:

[0059] 1) 5GMM-NULL

[0060] 2) 5GMM-DEREGISTERED

[0061] 2-1) 5GMM-DEREGISTERED.NORMAL-SERVICE

[0062] 2-2) 5GMM-DEREGISTERED.LIMITED-SERVICE

[0063] 2-3) 5GMM-DEREGISTERED.ATTEMPTING-REGISTRATION

[0064] 2-4) 5GMM-DEREGISTERED.PLMN-SEARCH

[0065] 2-5) 5GMM-DEREGISTERED.NO-SUPI

[0066] 2-6) 5GMM-DEREGISTERED.NO-CELL-AVAILABLE

[0067] 2-7) 5GMM-DEREGISTERED.eCALL-INACTIVE

[0068] 2-8) 5GMM-DEREGISTERED.INITIAL-REGISTRATION-NEEDED

[0069] 3) 5GMM-REGISTERED-INITIATED

[0070] 4) 5GMM-REGISTERED

[0071] 4-1) 5GMM-REGISTERED.NORMAL-SERVICE

[0072] 4-2) 5GMM-REGISTERED.NON-ALLOWED-SERVICE

[0073] 4-3) 5GMM-REGISTERED.ATTEMPTING-REGISTRATION-UPDATE

[0074] 4-4) 5GMM-REGISTERED.LIMITED-SERVICE

[0075] 4-5) 5GMM-REGISTERED.PLMN-SEARCH

[0076] 4-6) 5GMM-REGISTERED.NO-CELL-AVAILABLE

[0077] 4-7) 5GMM-REGISTERED.UPDATE-NEEDED

[0078] 5) 5GMM-DEREGISTERED-INITIATED

[0079] 6) 5GMM-SERVICE-REQUEST-INITIATED

[0080] The term EMM sublayer states are at least one of the below:

[0081] 1) EMM-NULL

[0082] 2) EMM-DEREGISTERED

[0083] 2-1) EMM-DEREGISTERED.NORMAL-SERVICE

[0084] 2-2) EMM-DEREGISTERED.LIMITED-SERVICE

[0085] 2-3) EMM-DEREGISTERED.ATTEMPTING-TO-ATTACH

[0086] 2-4) EMM-DEREGISTERED.PLMN-SEARCH

[0087] 2-5) EMM-DEREGISTERED.NO-IMSI

[0088] 2-6) EMM-DEREGISTERED.ATTACH-NEEDED

[0089] 2-7) EMM-DEREGISTERED.NO-CELL-AVAILABLE

[0090] 2-8) EMM-DEREGISTERED.eCALL-INACTIVE

[0091] 3) EMM-REGISTERED-INITIATED

[0092] 4) EMM-REGISTERED

[0093] 4-1) EMM-REGISTERED.NORMAL-SERVICE

[0094] 4-2) EMM-REGISTERED.ATTEMPTING-TO-UPDATE

[0095] 4-3) EMM-REGISTERED.LIMITED-SERVICE

[0096] 4-4) EMM-REGISTERED.PLMN-SEARCH

[0097] 4-5) EMM-REGISTERED.UPDATE-NEEDED

[0098] 4-6) EMM-REGISTERED.NO-CELL-AVAILABLE

[0099] 4-7) EMM-REGISTERED.ATTEMPTING-TO-UPDATE-MM

[0100] 4-8) EMM-REGISTERED.IMSI-DETACH-INITIATED

[0101] 5) EMM-DEREGISTERED-INITIATED

[0102] 6) EMM-TRACKING-AREA-UPDATING-INITIATED

[0103] 7) EMM-SERVICE-REQUEST-INITIATED

[0104] The term 'DualSteering' implies that a UE can perform at least one of traffic steering, traffic splitting and traffic switching of user data (for different or same services) across two or more 3GPP access networks.

[0105] In the context of DualSteer, the current standard does not have any provision that describe behaviour the behaviour of a User Equipment (UE) in the following scenarios:

[0106] - A UE registering over a first access network with DualSteer capability receives a reject from the network which states that the UE cannot act as a DualSteer device (as depicted in FIG. 1A).

[0107] - A UE with DualSteer capability already registered over a first access network, identifies and tries to register over a second access network for DualSteering; however, the UE receives a reject from the second access network which states that the UE cannot as a DualSteer device over this second network (as depicted in FIG. 1B).

[0108] - A UE with DualSteer capability already registered over the first access network, attempts to register on the second access network (i.e., second PLMN or RAT), but that second access network does not support DualSteering and unnecessarily receives signalling from UE which loads the network.

[0109] FIG. 1A depicts a scenario, wherein a UE registering over the first access network with DualSteer capability receives a reject from the network which states that the UE cannot act as a DualSteer device.

[0110] As depicted in FIG. 1A, in step 1, the UE triggers a registration to a Home Public Land Mobile Network / Visited Public Land Mobile Network_1　(HPLMN / VPLMN_1) network, wherein the registration request includes an identifier which informs the network that this UE is registering for DualSteering. The UE sends a 5GMM message (for example, REGISTRATION REQUEST / UL NAS TRANSPORT or any other Non Access Stratum (NAS) message), and updates its capability of "dualSteer capable" and registers to a HPLMN / VPLMN_1 network. In step 2, the Access and Mobility Management Function (AMF) of HPLMN / VPLMN_1 interacts with a Unified data management (UDM); for example, using Nudm_UECM_Registration operation or any other suitable Network Function (NF) and retrieves the subscription data or policy for this UE. The AMF determines that this UE is not allowed to act as a DualSteer device; for example, based on subscription change, location / area, time, S-NSSAI, and so on. In step 3, the AMF determines, that this UE is not allowed to act as a DualSteer device on this PLMN or across all the PLMNs. Current solutions do not define the behaviour of the network and the UE in this situation.

[0111] FIG. 1B depicts a scenario, wherein a UE with DualSteer capability (which is already registered over the first access network), identifies and tries to register over a second access network for DualSteering, receives a reject from the second access network which states that the UE cannot as a DualSteer device over this second network.

[0112] As depicted in FIG. 1B, in step 1, the UE triggers a registration to a HPLMN / VPLMN_1 network, wherein the registration request includes an identifier which informs the network that this UE is registering for DualSteering. The UE sends a 5GMM message (for example, REGISTRATION REQUEST / UL NAS TRANSPORT or any other NAS message) and updates its capability of "DualSteer capable" and registers to the HPLMN / VPLMN_1 network. In step 2, the HPLMN / VPLMN_1 sends the NAS message (for example, DL NAS TRANSPORT / REGISTRATION ACCEPT message) to the UE. In step 3, the UE identifies and tries to register over the second access network for DualSteering; for example, upon receiving the UE subscription information from the network (as in step 2). In step 4, the UE determines that it is allowed to perform DualSteering and sends a REGISTRATION REQUEST over the selected / determined / identified second access network (VPLMN_2). In step 5, the AMF of VPLM2 interacts with the UDM (for example, using Nudm_UECM_Registration operation or NF) and retrieves the subscription data for this UE. The AMF determines that this UE is not allowed to act as a DualSteer device; for example, based on subscription change, location, time, S-NSSAI, and so on, on this PLMN. In step 6, the AMF of VPLMN2 determines, that this UE is not allowed to perform a DualSteer device on this PLMN or across all the PLMNs. Current solutions do not define the behaviour of the network and the UE in this situation.

[0113] In both the above scenarios, it is required to define the behaviour of the UE in the context of DualSteer concept.

[0114] Hence, there is a need in the art for solutions which will overcome the above mentioned drawback(s), among others.

[0115] FIG. 2 depicts a scenario, wherein a UE registering over a first access network with DualSteer capability receives a reject from the network which states that the UE cannot act as a DualSteer device.

[0116] In step 201 (which can be an optional step, the UE 101 triggers a registration to a HPLMN / VPLMN_1 network 102, wherein the registration request includes an identifier which informs the HPLMN / VPLMN_1 network 102 that this UE 101 is registering for DualSteering. The UE 101 sends a 5GMM message (for example, REGISTRATION REQUEST / UL NAS TRANSPORT or any other suitable NAS message). The UE 101 further updates its capability of "dualSteer capable" and registers to the HPLMN / VPLMN_1 network 102. In step 202, an AMF 102A of HPLMN / VPLMN_1 network 102 interacts with a UDM 103 (for example, using Nudm_UECM_Registration operation or with PCF or any other suitable NF) and retrieves the subscription data or policy for this UE 101. Based on the retrieved subscription data or policy for this UE 101, in step 203, the AMF 102A determines that this UE 101 is not allowed to act as a DualSteer device (for example, based on subscription change, location, time, S-NSSAI, and so on). In step 204, the AMF 102A sends the NAS message (for example, DL NAS TRANSPORT / REGISTRATION REJECT / REGISTRATION ACCEPT / UE CONFIGURATION COMMAND message) to the UE 101 indicating that this UE is not allowed to act as a DualSteer device on this PLMN. In an embodiment herein, the AMF 102A sends the NAS message to the UE 101 with a cause / indication / IE. When the UE 101 receives such an indication from the AMF 102A in the NAS message, the UE 101 can take at least one of the actions (as disclosed in FIG. 3).

[0117] FIG. 3 is a flowchart depicting the actions to be taken by the UE on receiving an indication that the UE is not allowed to act as a DualSteer device on this PLMN.

[0118] In step 301, the UE 101 checks the cause / reject cause / indication / IE (as received in the indication) and evaluates if it is a permanent cause or a temporary cause. If the reject cause is a permanent cause (i.e., the cause / indication / IE indicates that the UE 101 is not allowed to act as DualSteer device across all the PLMNs; for example, the UE's subscription does not allow the UE 101 to act as a DualSteer device), in step 302, the UE 101 stops acting as a DualSteer device and continues with its current registration on the HPLMN / VPMLN1 network 102 (if the UE is already registered on the HPLMN / VPMLN1 network 102). The UE 101 further does not initiate any action for selecting a second access network to get registered for DualSteer purpose, till the UE 101 is switched off and switched on again (i.e. till the UE 101 performs a power cycle) or till the UE 101 registers again due to a trigger where the UE 101 can again indicate that it wants to register for DualSteering (capability indicate DualSteer). If the reject cause is temporary (i.e., the cause / indication / IE indicates that the UE 101 is not allowed to act as a DualSteer device in this PLMN (for example, due to network policy / subscription, and so on), in step 303, the UE 101 performs a PLMN search / selection to register on a different network which can provide dual registration capability to the UE 101.

[0119] The UE 101 can further perform at least one of the below actions:

[0120] - The UE 101 can enter 5GMM sublayer states or EMM sublayer states.

[0121] - The UE 101 can perform PLMN selection, cell selection or cell reselection.

[0122] - The UE 101 can stop acting as a DualSteer device.

[0123] - If indication indicates that the UE 101 should not perform DualSteering acting as a single UE, and in case of non-simultaneous data transmission over the two networks, then the UE 101 should not perform DualSteering as a single UE for non-simultaneous data transmission.

[0124] - If the indication indicates that the UE 101 should not perform DualSteering acting as two separate UEs, and in case of simultaneous data transmission over the two networks, then the UE 101 should not perform DualSteering as a two separate UEs in case of simultaneous data transmission over the two networks.

[0125] The UE 101 can perform at least one of the above steps till the UE 101 is switched off / on (i.e., power cycle) or the new SUPI is inserted; i.e., SUPI has changed.

[0126] When the indication / or new IE / cause is received in the NAS message, the UE 101 can start a timer (which can be one of a UE implementation timer, or a timer configured by the network, or a timer pre-configured in the UE). While the timer is running, the UE 101 shall act as described above; i.e., the UE 101 will not act as a DualSteer device for a determined time based on the timer value. It may not act as a single UE, or it may not act as two separate UEs to perform multiple registrations for the purpose of DualSteering. The various actions in method 300 may be performed in the order presented, in a different order or simultaneously. Further, in some embodiments, some actions listed in FIG. 3 may be omitted.

[0127] FIG. 4 depicts a scenario, wherein a UE with DualSteer capability already registered over the first access network, identifies, and tries to register over a second access network for DualSteering, receives a reject from the second access network which states that the UE cannot as a DualSteer device over this second network.

[0128] In step 401, the UE 101 may trigger a registration to the HPLMN / VPLMN_1 network 102, wherein the registration request includes an identifier which informs the HPLMN / VPLMN_1 network 102 that this UE 101 is registering for DualSteering. The UE 101 may send a 5GMM message (for example, REGISTRATION REQUEST / UL NAS TRANSPORT or any other NAS message). The UE 101 may further update its capability of "dualSteer capable" and register to the HPLMN / VPLMN_1 network 102. In step 402, the HPLMN / VPLMN_1 network 102 may send the NAS message (for example, DL NAS TRANSPORT / REGISTRATION ACCEPT message) to the UE 101. In step 403, the UE 101 may identify and try to register over a second access network 104 for DualSteering; for example, upon receiving the UE subscription information from the HPLMN / VPLMN_1 network 102 in step 2. In step 404, the UE 101 may determine that it is allowed to perform DualSteering and send a REGISTRATION REQUEST over the selected / determined / identified second access network (VPLMN_2) 104. In step 405, the AMF 104A of VPLMN_2 104 may interact with the UDM 103 (for example, using Nudm_UECM_Registration operation or any other suitable NF) and retrieve the subscription data for this UE 101. Based on the received subscription data for the UE 101, in step 406, the AMF 104A may determine that this UE 101 is not allowed to act as a DualSteer device (for example, based on subscription change, location, time, S-NSSAI on this PLMN, and so on). In other words, the AMF 104A may determine whether to deregister the second access. Wherein, the deregistering of the access may be interpreted as deregistering of the registration for DualSteering of UE 101. On the AMF 104A determining that this UE 101 is not allowed to act as a DualSteer device, in step 407, the AMF 102A may send a DL NAS message (for example, REGISTRATION REJECT / REGISTRATION ACCEPT / UE CONFIGURATION COMMAND with cause / indication / IE) to the UE 101, which states that the UE 101 cannot as a DualSteer device over the second network 104. In other words, the AMF 104A may deregister the second access, based on the determination according to the step 406. When the UE 101 receives such an indication from the second network 104 in the NAS message (cause / reject cause), the UE 101 could take at least one of the actions (as disclosed in FIG. 5).

[0129] FIG. 5 is a flowchart depicting the actions to be taken by the UE on receiving an indication that the UE is not allowed to act as a DualSteer device on a second PLMN.

[0130] In step 501, the UE 101 may check the reject cause and evaluates if the reject cause is a permanent cause or a temporary cause. If the reject cause is a permanent cause, in step 502, the UE 101 may stop acting as a DualSteer device and continue with its current registration on HPLMN / VPMLN_1 102. The UE 101 may further do not initiate any action for selecting a second network and stop acting as a DualSteer device on any network. If the reject cause is a temporary cause, in step 503, the UE 101 may perform a PLMN search / selection to register on a second access network which can provide dual registration capability to the UE 101.

[0131] The UE 101 may further perform at least one of the below actions:

[0132] - The UE 101 may enter 5GMM sublayer states or EMM sublayer states.

[0133] - The UE 101 may perform PLMN selection, cell selection or cell reselection.

[0134] - The UE 101 may stop acting as a DualSteer device.

[0135] - If indication indicates that the UE 101 should not perform DualSteering acting as a single UE, and in case of non-simultaneous data transmission over the two networks, then the UE 101 may not perform DualSteering as a single UE for non-simultaneous data transmission.

[0136] - If the indication indicates that the UE 101 should not perform DualSteering acting as two separate UEs, and in case of simultaneous data transmission over the two networks, then the UE 101 may not perform DualSteering as a two separate UEs in case of simultaneous data transmission over the two networks.

[0137] The UE 101 may perform at least one of the above steps till the UE 101 is switched off / on (i.e., power cycle) or the new SUPI is inserted; i.e., SUPI has changed.

[0138] When the indication / or new IE / cause is received in the NAS message, the UE 101 may start a timer (which can be one of a UE implementation timer, or a timer configured by the network, or a timer pre-configured in the UE). While the timer is running, the UE 101 may act as described above; i.e., the UE 101 will not act as a DualSteer device for a determined time based on the timer value. It may not act as a single UE, or it may not act as two separate UEs to perform multiple registrations for the purpose of DualSteering. The various actions in method 500 may be performed in the order presented, in a different order or simultaneously. Further, in some embodiments, some actions listed in FIG. 5 may be omitted.

[0139] FIG. 6 depicts the process of switching DualSteer status by a UE.

[0140] In step 601, the UE 101 may be registered on the first access network (i.e., for example, AMF 102A of HPLMN / VPLMN_1 102) over NF. In step 602, the UE 101 may determine that it is allowed to perform DualSteering and register itself over the selected / determined / identified second access network (VPLMN_2) 104. In steps 603A, and 603B, the AMF 102A of the first access network (HPLMN / VPLMN_1) 102, or the AMF 104A of the second access network (VPLMN_1 / VPLMN_2) 104 may interact with the UDM / PCF 103 for retrieving the changed subscription data / UE policy for this UE 101. In step 604A, with the UE 101 being registered for DualSteering over both the network accesses, the AMF 102A of the first access network (HPLMN / VPLMN_1) 102 may determine that this UE 101 is not allowed to act as a DualSteer device on this PLMN or across all the PLMNs (for example, based on subscription change, location, time, S-NSSAI on this PLMN, and so on). In other words, the AMF 102A may determine whether to deregister the first access. Wherein, the deregistering of the access may be interpreted as deregistering of the registration for DualSteering of UE 101. In step 604B, with the UE 101 being registered for DualSteering over both the network accesses, the AMF 104A of the second access network (VPLMN_1 / VPLMN_2) 104 may determine that this UE 101 is not allowed to act as a DualSteer device on this PLMN or across all the PLMNs (for example, based on subscription change, location, time, S-NSSAI on this PLMN, and so on). In other words, the AMF 102A may determine whether to deregister the second access. Wherein, the deregistering of the access may be interpreted as deregistering of the registration for DualSteering of UE 101. In step 605A, the NF (for example, AMF 102A of the first access network (HPLMN / VPLMN_1) 102) may send a DL NAS message (for example, REGISTRATION REJECT / REGISTRATION ACCEPT / UE CONFIGURATION COMMAND) with cause / indication / IE to the UE 101, wherein the DL NAS message states that the UE 101 cannot act as a SualSteer device optionally over this network. In summary, the indication indicates to the UE 101 that it can stop acting as a DualSteer device and can start acting as a normal UE. In step 605B, the NF (for example, the AMF 104A of the second access network (VPLMN_1 / VPLMN_2) 104) may send a DL NAS message (for example, REGISTRATION REJECT / REGISTRATION ACCEPT / UE CONFIGURATION COMMAND) with cause / indication / IE to the UE 101 which states that the UE 101 cannot act as a DualSteer device optionally over this network. In summary, the indication indicates to the UE 101 that it can stop acting as a Dualsteer device and can start acting as a normal UE. In other words, the AMF 102A (or 104A) may deregister the first access (or the second access), based on the determination according to the step 604A and 604B.

[0141] On determining that the UE 101 is not allowed to act as a DualSteer UE or DualSteer device, the UE 101 may perform at least one of the below actions in any order or combinations:

[0142] - The UE 101 may release the current active PDU session(s).

[0143] - The UE 101 may deregister (i.e., the UE 101 triggers a deregistration procedure by sending a deregistration request message to the network) on the first access network, or the second access network, or both the access networks.

[0144] - The UE 101 may trigger PDU session HO from one access network to another access network; i.e., when the UE 101 will not act as a DualSteer device, the UE 101 may act as a normal UE 101 with a single access network registered, and the UE 101 may move the PDU sessions of the second access network to the first access network. The first access network may be the primary access network where the UE 101 determines or has been indicated by the network that it can remain in registered state as a normal UE.

[0145] - The UE 101 may stop acting as a DualSteer device on the current registered network; i.e., on at least one of the VPLMN_1 102 or / and VPLMN_2 104.

[0146] - The UE 101 may start PLMN selection / cell selection / cell reselection and search for another network / cell over which it could act as a DualSteer device. Optionally, if the cause indicates to the UE 101 that it is not allowed to act as a DualSteer device on the current network / area / TAI / cell / in this time, and so on, the UE 101 may start PLMN selection / cell selection / cell reselection and search for another network / cell over which it could act as a DualSteer device.

[0147] - When the indication / or new IE / cause is received in the NAS message, the UE 101 may start a timer (this can be a UE implementation timer, or a timer configured by the network, or a timer pre-configured in the UE 101). While the timer is running the UE 101 shall act as described above; i.e., the UE 101 may not act as a DualSteer device for the determined time based on the timer value configured by the network or based on determination of the UE 101. It may not act as a single UE 101 or it may not act as two separate UEs to perform multiple registrations for the purpose of DualSteering.

[0148] If the indication indicates that UE 101 should not perform DualSteering (when the UE 101 is acting as a single UE), in case of non-simultaneous data transmission over the two networks, the UE 101 may not perform DualSteering as a single UE 101 for non-simultaneous data transmission.

[0149] If the indication indicates that UE 101 should not perform DualSteering and the UE 101 is acting as two separate UEs, then in case of simultaneous data transmission over the two networks, the UE 101 may not perform DualSteering as a two separate UEs in case of simultaneous data transmission over the two networks.

[0150] The UE 101 may perform at least one of the above steps till the UE 101 is switched off / on (i.e. power cycle) or the new SUPI is inserted; i.e., SUPI has changed.

[0151] In an embodiment herein, the network 102 / 104 may trigger a deregistration procedure on the second access network 104, and indicate to the UE 101 that the UE 101 is allowed to remain registered as a normal UE 101 and not act a DualSteer UE.

[0152] In summary, the indication indicates to the UE 101 that it can stop acting as a Dualsteer UE and can start acting as a normal UE. Optionally, after a certain time, the network 102 / 104 can trigger a deregistration procedure over the second access network 104 and indicate to the UE 101 that it is not allowed to act as DualSteer UE. Optionally, the UDM 103 can decide which access has to be released and on that access, the UDM 103 triggers a deregistration notification to the AMF 102A / 104A. The AMF 102A / 104A sends a deregistration message to the UE 101. Optionally, the deregistration message sent to the UE 101 can be after a pre-defined interval of time. so that the UE 101 gets sufficient time to move the PDU sessions from one access to another access before it gets a deregistration message from the network.

[0153] Consider that the UE 101 is registered as a normal UE 101 in steps 601 to 604B and the UE 101 is not acting as a DualSteer UE or a DualSteer device. In steps 605A / 605B, the AMF 102A can indicate to the UE 101 that the UE 101 can start acting as a DualSteer device / UE.

[0154] In an embodiment herein, if the UE 101 is not registered as a DualSteer device, the UE 101 can start behaving as a DualSteer UE, by attempting to select and register on the second access network 104 for DualSteering; i.e. the UDM / PCF 103 can notify the NF (for example, AMF 104A), on there being a change in subscription or policy. The AMF 104A determines that the UE 101 can now start acting as Dualsteer UE, thus the AMF 104A notifies the UE 101 using a NAS message that the UE 101 can start acting as Dualsteer UE.

[0155] In an embodiment herein, the UDM / PCF 103 can indicate to the UE 101 that the UE 101 can act as a Dualsteer UE, and this information is sent transparently to the UE 101 without the AMF 104A determining this; for example, as part of SOR information or using UE parameter update procedure as described in TS 23.501 and TS 23.502.

[0156] In an embodiment herein, the UDM / PCF 103 can indicate to the UE 101 that the UE 101 cannot act as a Dualsteer UE, and this information is sent transparently to the UE 101 without the AMF 104A determining this; for example, as part of SOR information or using UE parameter update procedure as described in TS 23.501 and TS 23.502.

[0157] The UE 101 can be informed or indicated with the time period(s) (for example, in a NAS message or pre-configured in the ME or in the SIM) in which a UE 101 is allowed to act as a DualSteer device or the area(s) in which the UE 101 is not allowed to act as a DualSteer device.

[0158] The UE 101 shall act or attempt to behave as a DualSteer device only within the time period(s) that the UE 101 is allowed to act as a DualSteer device. The UE 101 shall not act or attempt to behave as a DualSteer device only within the time period(s) that the UE 101 is not allowed to act as a DualSteer device. The time can be at least one of and not limited to the time-slot (for example, determined by start time and end time), the time at which message is received indicating allowed to act as a DualSteer device or not allowed to act as a DualSteer device optionally including the duration till which the respective status is applicable.

[0159] The UE 101 shall act or attempt to behave as a DualSteer device only in the area(s) that the UE 101 is allowed to act as a DualSteer device. The UE 101 shall not act or attempt to behave as a DualSteer device in the area(s) where the UE 101 is not allowed to act as a DualSteer device. The term area / location / geographical area as referred to herein, may refer to any of cell / cell ID, TAC / TAI, PLMN, MCC / MNC, latitude / longitude, CAG cell or any geographical location / coordinate.

[0160] The DualSteering allowed or not allowed indication can be further granular. The indication can indicate as to when the UE 101 should attempt, or the UE 101 should not attempt in the following possibilities:

[0161] - Two NR / 5GC accesses (first or second access) in a single PLMN (HPLMN or VPLMN) with each access being NR TN or NR NTN (first or second access); the configuration / indication / IE given to the UE 101 can indicate to the UE 101 whether this combination is possible or not.

[0162] - Two NR / 5GC accesses in two different PLMNs (including two VPLMNs or a VPLMN and the HPLMN) with each access being NR TN or NR NTN (first or second access). The configuration / indication / IE given to the UE 101 can indicate to the UE 101 whether this combination is possible or not.

[0163] - NR / 5GC access (first or second access) and E-UTRA / EPC access (first or second access) in two different PLMNs (including two VPLMNs or a VPLMN and the HPLMN). The configuration / indication / IE given to the UE 101 can indicate to the UE 101 whether this combination is possible or not.

[0164] - NR / 5GC access (first or second access) and E-UTRA / EPC access (first or second access) in a single PLMN (HPLMN or VPLMN). The configuration / indication / IE given to the UE 101 can indicate to the UE 101 whether this combination is possible or not.

[0165] - Public Network Integrated NPN (PNI-NPN) (integrated with the HPLMN or integrated with the VPLMN) (first or second access) and PLMN access (TN / NTN plus TN or NTN) (first or second access). This scenario assumes only non-simultaneous transmission. The configuration / indication / IE given to the UE 101 can indicate to the UE 101 whether this combination is possible or not.

[0166] The configuration / indication / IE can be given to the UE 101 in AS or NAS message or it can be pre-configured in the UE 101 (ME or Universal Subscriber Identity Module (USIM) or both), given in the data path as part of PDU sessions etc. The UE 101 gets this information on which combination the UE 101 can register / select for DualSteering. Additionally, the UE 101 can be informed on what is the first access allowed and for a given first access, what is the second access allowed.

[0167] In an embodiment herein, the UE 101 is assumed to support DualSteering feature. The network 102 / 104 can indicate to the UE 101 that the UE 101 has to re-register with a DualSteer indication, or based on this indication, the UE 101 can send / trigger the registration procedure.

[0168] FIG. 7 is a flowchart depicting the process of managing DualSteering.

[0169] In step 701, the NF 102A, 104A determines a combination of two or more RATs that can be used by the UE 101 for registering for DualSteering. In an embodiment herein, the combination of two or more RATs is one of a first USIM on NR, and a second USIM on NR; the first USIM on LTE, and the second USIM on NR; the first USIM on a PNI-NPN, and the second USIM on a PLMN access at-least one of a Terrestrial network, and a Non Terrestrial network; and the first USIM on the Terrestrial network, and the second USIM on the Non Terrestrial network. The first USIM as referred to herein represents a UE or part of a DualSteer device which is dependent on the first USIM. Similarly, the DualSteer device will have at least one more second USIM representing a second UE. On determining the combination of two or more RATs that can be used by the UE 101 for registering for DualSteering, in step 702, the NF 102A, 104A indicates the determined combination of two or more RATs that can be used by the UE 101 for registering for DualSteering, to the UE 101. In an embodiment herein, the NF 102A, 104A further indicates a priority among the combination of two or more RATs that can be used by the UE 101 for registering for DualSteering. In step 703, the UE 101 receives the indication from the NF 102, 104, and if the UE 101 is registered on two or more RATs (as provided in the received indication), the UE 101 performs DualSteering. The various actions in method 700 may be performed in the order presented, in a different order or simultaneously. Further, in some embodiments, some actions listed in FIG. 7 may be omitted.

[0170] FIG. 8 is a flowchart depicting the process of managing DualSteering.

[0171] In step 801, one of the UE 101, and the NF 102A / 104A determines that the UE 101 is not allowed to perform DualSteering. On determining that the UE 101 is not allowed to perform DualSteering, in step 802, one of the UE 101, and the NF 102A / 104A triggers the deregistration procedure on at least one access network that the UE 101 is currently registered on, and / or all access networks that the UE 101 is currently registered on. In step 803, the UE 101 successfully completes the deregistration procedure on at least one access network that the UE 101 is currently registered on, and / or all access networks that the UE 101 is currently registered on. If the UE 101 is still registered on at least one access network (step 804), in step 805, the UE 101 continues to operate as a normal UE 101 on at least one access network on which the deregistration procedure has not been triggered. If the UE 101 is still registered on at least one access network (step 804), in step 806, the UE 101 suspends operations. The various actions in method 800 may be performed in the order presented, in a different order or simultaneously. Further, in some embodiments, some actions listed in FIG. 8 may be omitted.

[0172] FIG. 9 depicts the UE.

[0173] The UE 101, as depicted, comprises a processing module 901, at least one memory 902, and at least one transceiver 903. The processing module 901 can be at least one of a single processor, a plurality of processors, multiple homogeneous or heterogeneous cores, multiple Central Processing Units (CPUs) of different kinds, microcontrollers, special media, and other accelerators. The processing module 901 may be an Application Processor (AP), a graphics-only processing unit such as a Graphics Processing Unit (GPU), a Visual Processing Unit (VPU), and / or an Artificial Intelligence (AI)-dedicated processor such as a Neural Processing Unit (NPU).

[0174] In an embodiment herein, the at least one transceiver 903 is configured to enable communication between the UE, and at least one external entity (such as, but not limited to, the HPLMN / VPLMN_1 102, the VPLMN_1 / VPLMN_2 104, and so on) through a network or cloud. The transceiver 903 through which the UE 101 and the at least one external entity communicate may include wired and / or wireless communication medium compatible with one or more different communication protocols. The transceiver 903 may be configured for communication through a network. The network may comprise, but are not limited to, Global Positioning System (GPS), Global System for Mobile Communications (GSM), Local Area Network (LAN), Wireless Fidelity (Wi-Fi) compatibility, Bluetooth Low Energy (BLE), Near-field Communication (NFC), and so on. The wireless communication may further comprise one or more of Bluetooth, Zonal Intercommunication Global Standard (ZigBee), short-range wireless communication such as Ultra-wideband (UWB), medium-range wireless communication such as Wi-Fi, or long-range wireless communication such as Third Generation (3G), Fourth Generation (4G), or Worldwide Interoperability for Microwave Access (WiMAX), according to the usage environment.

[0175] In the embodiment shown herein, the at least one memory 902 may comprise one or more volatile and non-volatile memory components that are capable of storing data and instructions to be executed. Examples of the at least one memory 902 can be, but are not limited to, NAND, embedded Multimedia Card (eMMC), Secure Digital (SD) cards, Universal Serial Bus (USB), Serial Advanced Technology Attachment (SATA), solid-state drive (SSD), and so on. The at least one memory 902 may also include one or more computer-readable storage media. Examples of non-volatile storage elements may include magnetic hard discs, optical discs, floppy discs, flash memories, or forms of electrically programmable memories (EPROM) or electrically erasable and programmable (EEPROM) memories. In addition, the at least one memory 902 may, in some examples, be considered a non-transitory storage medium. The term "non-transitory" may indicate that the storage medium is not embodied in a carrier wave or a propagated signal. However, the term "non-transitory" should not be interpreted to mean that the at least one memory 902 is non-movable. In certain examples, a non-transitory storage medium may store data that can, over time, change (for example, in Random Access Memory (RAM) or cache).

[0176] The processing module 901 can receive the indication from the NF 102, 104, wherein the indication comprises a combination of two or more RATs that can be used by the UE 101 for registering for DualSteering. In an embodiment herein, the combination of two or more RATs is one of a first USIM on NR, and a second USIM on NR; the first USIM on LTE, and the second USIM on NR; the first USIM on a PNI-NPN, and the second USIM on a PLMN access at-least one of a Terrestrial network, and a Non Terrestrial network; and the first USIM on the Terrestrial network, and the second USIM on the Non Terrestrial network, via the transceiver 903. The processing module 901 can perform DualSteering, if the UE 101 is registered on two or more RATs (as provided in the received indication).

[0177] The processing module 901 can determine that the UE 101 is not allowed to perform DualSteering. On determining that the UE 101 is not allowed to perform DualSteering, the processing module 901 can trigger the deregistration procedure on at least one access network that the UE 101 is currently registered on, and / or all access networks that the UE 101 is currently registered on. The processing module 901 can successfully complete the deregistration procedure on at least one access network that the UE 101 is currently registered on, and / or all access networks that the UE 101 is currently registered on. If the UE 101 is still registered on at least one access network, the processing module 901 can continue to enable the UE 101 to operate as a normal UE 101 on at least one access network on which the deregistration procedure has not been triggered.

[0178] FIG. 10 depicts the AMF.

[0179] In an embodiment herein, the network function (NF) 1000 can be an AMF 102A / 104A, or any Network function at the core network 102 / 104. The NF 1000, as depicted, comprises a processing module 1001, at least one memory 1002, and at least one transceiver 1003.

[0180] The processing module 1001 can be at least one of a single processor, a plurality of processors, multiple homogeneous or heterogeneous cores, multiple Central Processing Units (CPUs) of different kinds, microcontrollers, special media, and other accelerators. The processing module 1001 may be an Application Processor (AP), a graphics-only processing unit such as a Graphics Processing Unit (GPU), a Visual Processing Unit (VPU), and / or an Artificial Intelligence (AI)-dedicated processor such as a Neural Processing Unit (NPU).

[0181] In an embodiment herein, the at least one transceiver 1003 is configured to enable communication between the NF 1000, and at least one external entity (such as, but not limited to, the UE 101, the UDM / PCF 103, the VPLMN_1 / VPLMN_2 104, the HPLMN / VPLMN_1 102, and so on) through a network or cloud. The transceiver 1003 through which the NF 1000 and the at least one external entity communicate may include wired and / or wireless communication medium compatible with one or more different communication protocols. The transceiver 1003 may be configured for communication through a network. The network may comprise, but are not limited to, Global Positioning System (GPS), Global System for Mobile Communications (GSM), Local Area Network (LAN), Wireless Fidelity (Wi-Fi) compatibility, Bluetooth Low Energy (BLE), Near-field Communication (NFC), and so on. The wireless communication may further comprise one or more of Bluetooth, Zonal Intercommunication Global Standard (ZigBee), short-range wireless communication such as Ultra-wideband (UWB), medium-range wireless communication such as Wi-Fi, or long-range wireless communication such as Third Generation (3G), Fourth Generation (4G), or Worldwide Interoperability for Microwave Access (WiMAX), according to the usage environment.

[0182] In the embodiment shown herein, the at least one memory 1002 may comprise one or more volatile and non-volatile memory components that are capable of storing data and instructions to be executed. Examples of the at least one memory 1002 can be, but are not limited to, NAND, embedded Multimedia Card (eMMC), Secure Digital (SD) cards, Universal Serial Bus (USB), Serial Advanced Technology Attachment (SATA), solid-state drive (SSD), and so on. The at least one memory 1002 may also include one or more computer-readable storage media. Examples of non-volatile storage elements may include magnetic hard discs, optical discs, floppy discs, flash memories, or forms of electrically programmable memories (EPROM) or electrically erasable and programmable (EEPROM) memories. In addition, the at least one memory 1002 may, in some examples, be considered a non-transitory storage medium. The term "non-transitory" may indicate that the storage medium is not embodied in a carrier wave or a propagated signal. However, the term "non-transitory" should not be interpreted to mean that the at least one memory 1002 is non-movable. In certain examples, a non-transitory storage medium may store data that can, over time, change (for example, in Random Access Memory (RAM) or cache).

[0183] The processing module 1001 can determine a combination of two or more RATs that can be used by the UE 101 for registering for DualSteering. In an embodiment herein, the combination of two or more RATs is one of a first USIM on NR, and a second USIM on NR; the first USIM on LTE, and the second USIM on NR; the first USIM on a PNI-NPN, and the second USIM on a PLMN access at-least one of a Terrestrial network, and a Non Terrestrial network; and the first USIM on the Terrestrial network, and the second USIM on the Non Terrestrial network. On determining the combination of two or more RATs that can be used by the UE 101 for registering for DualSteering, the processing module 1001 can indicate the determined combination of two or more RATs that can be used by the UE 101 for registering for DualSteering, to the UE 101, via the transceiver 1003. In an embodiment herein, the processing module 1001 can further indicate a priority among the combination of two or more RATs that can be used by the UE 101 for registering for DualSteering.

[0184] The processing module 1001 can determine that the UE 101 is not allowed to perform DualSteering. On determining that the UE 101 is not allowed to perform DualSteering, the processing module 1001 can trigger the deregistration procedure on at least one access network that the UE 101 is currently registered on, and / or all access networks that the UE 101 is currently registered on.

[0185] FIG. 11 is a flow diagram depicting the process of avoiding networks that do not support DualSteering in wireless communication networks.

[0186] In step 1101, the UE 101 may trigger a registration to the HPLMN / VPLMN_1 network 102, wherein the registration request includes an identifier which indicates to the network 102 that this UE 101 is registering for DualSteering. The UE 101 may send a 5GMM message (for example, REGISTRATION REQUEST / UL NAS TRANSPORT or any other NAS message) and update its capability of "DualSteer capable" and register to the HPLMN / VPLMN_1 network 102. In step 1102, the HPLMN / VPLMN_1 102 may send the NAS message (for example, DL NAS TRANSPORT / REGISTRATION ACCEPT message) to the UE 101. In step 1103, the UE 101 may receive a list of PLMNs in priority order, which the UE 101 can use to register over an other access network 105 for DualSteering. The UE 101 may identify and try to register over the other access network 105 for DualSteering; for example, on receiving the UE subscription information from the network 102 in step 1102. In step 1104, the UE 101 may camp on an access network upon evaluating the PLMN list received and send a SystemInformation Request message to the other access network 105. In step 1105, the other access network 105 may send a SystemInformation message (for example, SystemInformation 1 message, SIB1, and so on) to the UE 101, wherein the SystemInformation message comprises an indication as to whether the camped network supports DualSteering capability. On decoding the SystemInformation message, in step 1106, the UE 101 may determine that the other access network 105 does not support DualSteering functionality. In other words, the UE 101 may determine whether to deregister the other access. In step 1107, the UE 101 may skip / ignore the selected other access network 105, and may not initiate any registration over this network 105. In other words, the UE 101 may deregister the other access based on the determination. The UE 101 then may camp on the next available PLMN / RAT / PLMn+RAT, as per the priority list received at step 1103.

[0187] Based on the SystemInformation message, the UE 101 may take one or more of the following actions:

[0188] - If the SystemInformation message indicates that the UE 101 should not perform DualSteering, and the UE 101 is acting as a single UE, then in case of non-simultaneous data transmission over the two networks, the UE 101 should not perform DualSteering as a single UE for non-simultaneous data transmission; and

[0189] - If the SystemInformation message indicates that the UE 101 should not perform DualSteering, and the UE 101 is acting as two separate UEs, then in case of simultaneous data transmission over the two networks, the UE 101 should not perform DualSteering as two separate UEs in case of simultaneous data transmissions over the two networks.

[0190] The UE 101 can perform at least one of the above steps on the current PLMN and would try camping on the next available PLMN, if the UE 101 finds a better PLMN which can support DualSteering for both simultaneous and non-simultaneous data transmissions.

[0191] If the complete priority list is exhausted and there is no access network found by the UE 101 that can support DualSteer functionality or for a particular access network that is not allowed to support DualSteering, the UE 101 can start a timer (wherein the timer can be a UE implementation timer, or a timer configured by the network, or a timer pre-configured in the UE). While the timer is running, the UE 101 shall not act as a DualSteering device for the determined time, wherein the determined time is based on the timer value. Once the timer has expired, the UE 101 can start from step 1104; i.e., the UE 101 will camp on an access network based on the PLMN list received and send a SystemInformation Request message to the network 104 to determine if it could act as a DualSteering device on any network from the priority list.

[0192] In an embodiment herein, the UE 101 can also receive a new PLMN list in between from the network 102.

[0193] FIG. 12 is a flow diagram depicting the process of avoiding networks that do not support DualSteering in wireless communication networks.

[0194] In step 1201, the UE 101 triggers a registration to a HPLMN / VPLMN_1 network 102, wherein the registration request comprises an identifier that informs the network 102 that this UE 101 is registering for DualSteering. The UE 101 sends a 5GMM message (for example, REGISTRATION REQUEST / UL NAS TRANSPORT or any other NAS message) and updates its capability of "dualSteer capable" and registers to the HPLMN / VPLMN_1 network 102. In step 1202, the HPLMN / VPLMN_1 102 sends the NAS message (for example, DL NAS TRANSPORT / REGISTRATION ACCEPT message) to the UE 101. In step 1203, the UE 101 receives a list of PLMNs in priority order, which the UE 101 can use to register over an other access network 105 for DualSteering. The UE 101 identifies and tries to register over the other access network 105 for DualSteering; for example, upon receiving the UE subscription information from the network 102 in step 1202. In step 1204, the UE 101 determines that the available other access network 105 is not configured in the list. Thus, the UE 101 skips / ignores the selected other access network 105 and does not initiate any registration over this network 105. The UE 101 camps on the next available PLMN / RAT / PLMn+RAT in the priority list received at step 1203.

[0195] FIG. 13 is a flow diagram depicting the process of avoiding networks that do not support DualSteering in wireless communication networks.

[0196] In step 1301, the UE 101 triggers a registration to the HPLMN / VPLMN_1 network 102, wherein the registration request comprises an identifier that informs the network 102 that this UE 101 is registering for DualSteering. The UE 101 sends a 5GMM message (for example, REGISTRATION REQUEST / UL NAS TRANSPORT or any other NAS message) and updates its capability of "DualSteer capable" and registers to the HPLMN / VPLMN_1 network 102. In step 1302, the HPLMN / VPLMN_1 102 sends the NAS message (for example, DL NAS TRANSPORT / REGISTRATION ACCEPT message) to the UE 101. In step 1303, the UE 101 sends a SystemInformation Request message to a other access network 105. In step 1304, the other access network 105 sends a SystemInformation message (for example, SystemInformation 1 message, SIB1 message, and so on) to the UE 101, which comprises an indication of whether the camped network supports DualSteering capability. In an embodiment herein, the SIB information received from the network 105 can be on-demand SIB or it can be direct broadcast SIB information. The UE 101 can read the SIB information based on the prior art mechanism and determines whether the currently selected network (or access network) supports the DualSteering. On decoding the information from the SystemInformation message, in step 1305A, the UE 101 determines that this network 105 does not support DualSteering functionality. In step 1306A, the UE 101 skips / ignores the selected other access network 105, and does not initiate any registration over this network 105. The UE 101 camps on the next available PLMN / RAT / PLMn+RAT. On decoding the information from the SystemInformation message, in step 1305B, the UE 101 determines that this network 105 supports DualSteering functionality. In step 1306B, the UE 101 selects the other access network 105 and initiates the registration procedure over this network 105.

[0197] The DualSteering allowed or not allowed indication can be further granular. The indication can indicate as to when the UE 101 should attempt, or the UE 101 should not attempt in the following possibilities, per PLMN location or time:

[0198] - Two NR / 5GC accesses in a single PLMN (HPLMN or VPLMN) with each access being NR TN or NR NTN.

[0199] - Two NR / 5GC accesses in two different PLMNs (including two VPLMNs or a VPLMN and the HPLMN) with each access being NR TN or NR NTN.

[0200] - NR / 5GC access and E-UTRA / EPC access in two different PLMNs (including two VPLMNs or a VPLMN and the HPLMN).

[0201] - NR / 5GC access and E-UTRA / EPC access in a single PLMN (HPLMN or VPLMN).

[0202] - PNI-NPN (integrated with the HPLMN or integrated with the VPLMN) and PLMN access (TN / NTN plus TN or NTN). This scenario assumes only non-simultaneous transmissions.

[0203] The above allowed or not allowed indication for different combinations can be based on per PLMN, location or time information.

[0204] The terms 'other access', 'other access network', 'first access', and 'first access network' represent the UE registration on the first and the other networks respectively to achieve DualSteering.

[0205] In an embodiment herein, the UE 101 accesses the other access network 105 for dualsteering purposes only if the respective other access network 105 is configured in the UE 101 to do so.

[0206] In an embodiment herein, the UE 101 accesses the other network 105 for dualsteering purposes only if the respective other access network 105 broadcasts / indicates in AS / NAS signalling that it supports DualSteering.

[0207] In an embodiment herein, when the UE 101 selects the other access network 105 and wants to use DualSteering, then the UE 101 will indicate that the UE 101 wants to use DualSteering (for example, as a capability / intimation) to perform DualSteering in at least one of the 5GMM message (for example, registration request) or 5GSM message (PDU session establishment / PDU session modification etc).

[0208] The first access network 102 and the other access network 105 is at least one of the:

[0209] - Two NR / 5GC accesses in a single PLMN (HPLMN or VPLMN) with each access being NR TN or NR NTN;

[0210] - Two NR / 5GC accesses in two different PLMNs (including two VPLMNs or a VPLMN and the HPLMN) with each access being NR TN or NR NTN;

[0211] - NR / 5GC access and E-UTRA / EPC access in two different PLMNs (including two VPLMNs or a VPLMN and the HPLMN);

[0212] - NR / 5GC access and E-UTRA / EPC access in a single PLMN (HPLMN or VPLMN); and

[0213] - PNI-NPN (integrated with the HPLMN or integrated with the VPLMN) and PLMN access (TN / NTN plus TN or NTN). This scenario assumes only non-simultaneous transmission.

[0214] The terms 'first access', and 'first access network' are used interchangeably herein and have the same meaning. Similarly, the terms 'second access' and 'second access network' are used interchangeably herein and have the same meaning.

[0215] The terms 'second access', 'second access network', 'first access', 'first access network' and so on, represent the UE 101 registration on the first network and the second network to achieve DualSteering.

[0216] The embodiments disclosed herein can be implemented through at least one software program running on at least one hardware device and performing network management functions to control the network elements. The elements include blocks which can be at least one of a hardware device, or a combination of hardware device and software module.

[0217] The embodiments disclosed herein describe methods and systems for handling scenarios, where the UE is not allowed to act as a DualSteer device in wireless communication networks. Therefore, it is understood that the scope of the protection is extended to such a program and in addition to a computer readable means having a message therein, such computer readable storage means contain program code means for implementation of one or more steps of the method, when the program runs on a server or mobile deviceor any suitable programmable device. The method is implemented in at least one embodiment through or together with a software program written in e.g., Very high speed integrated circuit Hardware Description Language (VHDL) another programming language, or implemented by one or more VHDL or several software modules being executed on at least one hardware device. The hardware device can be any kind of portable device that can be programmed. The device may also include means which could be e.g., hardware means like e.g., an ASIC, or a combination of hardware and software means, e.g., an ASIC and an FPGA, or at least one microprocessor and at least one memory with software modules located therein. The method embodiments described herein could be implemented partly in hardware and partly in software. Alternatively, the invention may be implemented on different hardware devices, e.g., using a plurality of CPUs.

[0218] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and / or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of embodiments and examples, those skilled in the art will recognize that the embodiments and examples disclosed herein can be practised with modification within the scope of the embodiments as described herein.

Claims

1.A method performed by a first access and mobility management function (AMF) entity, the method comprising:determining whether to deregister a first access of a terminal, the terminal operating as a DualSteer terminal associated with the first access corresponding to the first AMF entity and a second access corresponding to a second AMF entity; andderegistering the first access of the terminal, based on the determination.2.The method of claim 1, further comprising:transmitting, to the terminal, a message indicating deregistration of the first access.3.The method of claim 2, wherein the message indicating deregistration comprised an information on a cause of deregistration.4.The method of claim 1, wherein, in a case that the first access is deregistered, the second AMF entity transmits a message indicating deregistration of the first access to the terminal.5.The method of claim 1, wherein determining whether to deregister the first access is comprised:receiving, from an unified data management (UDM) entity, a subscription information of the terminal;determining, based on the subscription information, whether to deregister the first access .6.The method of claim 1, wherein determining whether to deregister the first access is comprised:receiving, from a point coordination function (PCF) entity, a policy for the terminal;determining, based on the policy, whether to deregister the first access.7.A method performed by a terminal operating as a DualSteer terminal associated with a first access corresponding to a first access and mobility management function (AMF) entity and a second access corresponding to a second AMF entity, the method comprising:determining whether to deregister at least one of the first access or the second access;deregistering, based on the determination, the at least one of the first access or the second access.8.The method of claim 7, wherein, determining whether to deregister at least one of the first access or the second access is comprised:decoding a system information block (SIB) information of the at least one of the first access and the second access;determining, based on the SIB information, whether to deregister at least one of the first access or the second access.9.The first access and mobility management function (AMF) entity comprising:a memory;a transceiver; anda processing module configured to:determine whether to deregister a first access of a terminal, the terminal operating as a DualSteer terminal associated with the first access corresponding to the first AMF entity and a second access corresponding to a second AMF entity, andderegister the first access of the terminal, based on the determination.10.The AMF entity of claim 9, wherein the processing module is further configured to:transmit, to the terminal via the transceiver, a message indicating deregistration of the first access.11.The AMF entity of claim 10, wherein the message indicating deregistration comprised an information on a cause of deregistration.12.The AMF entity of claim 9, wherein, in a case that the first access is deregistered, the second AMF entity transmits a message indicating deregistration of the first access to the terminal.13.The AMF entity of claim 9, wherein the processing module is further configured to:receive, from an unified data management (UDM) entity via the transceiver, a subscription information of the terminal;determine, based on the subscription information, whether to deregister the first access..14.The AMF entity of claim 9, wherein the processing module is further configured to:receive, from a point coordination function (PCF) entity via the transceiver, a policy for the terminal;determine, based on the policy, whether to deregister the first access.15.A terminal operating as a DualSteer terminal associated with a first access corresponding to a first access and mobility management function (AMF) entity and a second access corresponding to a second AMF entity, the terminal comprising:a memory;a transceiver; anda processing module configured to:determine whether to deregister at least one of the first access or the second access;deregister, based on the determination, the at least one of the first access or the second access.

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