Method and apparatus for enabling user equipment to exit manual network selection mode

Abstract

The disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. The present disclosure relates to field of wireless communication that discloses method and apparatus for enabling a User Equipment (UE) to exit a manual network selection mode registered on a first Public Land Mobile Network (PLMN) selected by a user. The apparatus detects whether one or more criteria for an automatic network selection mode are complied, upon occurrence of one or more disaster conditions. The one or more criteria comprises an indication of whether disaster roaming is enabled in the UE is set to disaster roaming is enabled in the UE. Further, the apparatus automatically registers with a second PLMN when the one or more criteria are detected.

Description

METHOD AND APPARATUS FOR ENABLING USER EQUIPMENT TO EXIT MANUAL NETWORK SELECTION MODE

[0001] The present disclosure relates to field of wireless telecommunication network. Particularly, the present disclosure relates to a method and system for enabling User Equipment (UE) to exit manual network selection mode.

[0002] Fifth generation (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 6 gigahertz (GHz)” bands such as 3.5GHz, but also in “Above 6GHz” bands referred to as millimeter wave (mmWave) including 28GHz and 39GHz. In addition, it has been considered to implement sixth generation (6G) mobile communication technologies (referred to as Beyond 5G systems) in terahertz (THz) 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 multi input multi output (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 BandWidth Part (BWP), new channel coding methods such as a Low Density Parity Check (LDPC) 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 Vehicle-to-everything (V2X) 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, New Radio Unlicensed (NR-U) aimed at system operations conforming to various regulation-related requirements in unlicensed bands, new radio (NR) user equipment (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, Integrated Access and Backhaul (IAB) 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 Dual Active Protocol Stack (DAPS) handover, and two-step random access for simplifying random access procedures (2-step random access channel (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 Augmented Reality (AR), Virtual Reality (VR), Mixed Reality (MR) 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 Orbital Angular Momentum (OAM), and Reconfigurable Intelligent Surface (RIS), 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 Artificial Intelligence (AI) 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] Mobile Network Operators (MNOs) continue to enhance their networks with advancements in technology. Due to the wide usage of mobile communication networks, it has become the primary source of communication during the humanitarian efforts in a major disaster. Along with the enhancement of mobile networks, there is a need for MNOs to address Disaster Conditions. Disaster Condition is a condition that a government decides when to initiate and terminate, e.g. a natural disaster. When this condition applies, users may have the opportunity to mitigate service interruptions and failures. Disaster Roaming is a special roaming policy that applies during a disaster condition. During the disaster condition, a user may not receive service from a PLMN it would normally be served by, due to failure of service, but is able to register with other PLMNs. Such a user is termed as “Disaster Inbound Roamer”.

[0009] Minimization of Service Interruption (MINT) is a feature that aims to enable a UE to obtain service from a PLMN offering disaster roaming services when a disaster condition applies to the UE's determined PLMN with disaster condition. A UE is considered as "registered for disaster roaming services" when it has successfully completed initial registration or mobility registration for disaster roaming services. A registration is performed with 5GS registration type "disaster roaming initial registration" in the REGISTRATION REQUEST message. A registration is performed with 5GS registration type "disaster roaming mobility registration updating" in the REGISTRATION REQUEST message. MS determined PLMN with Disaster Condition is a PLMN to which a Disaster Condition applies.

[0010] The UE and the network may support MINT. UEs can obtain service in the event of a disaster, when there are PLMN operators prepared to offer service. MINT is constrained to a particular time and place. To reduce the impact to the network (Fifth Generation (5G) system or Evolved Packet System (EPS)) of supporting disaster roaming, the potential congestion resulting from an influx or outflux of Disaster Inbound Roamers is taken into account. If a UE has no coverage of Home PLMN (HPLMN), then the UE obtains information that a Disaster Condition applies to the UE's HPLMN. In such case, the UE can register with a PLMN offering Disaster Roaming service.

[0011] The information disclosed in this background of the disclosure section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

[0012] The present disclosure aims to address a problem that arises when a user equipment (UE) in manual network selection mode switches to automatic network selection mode and does not return to the manual network selection mode.

[0013] The technical problems to be solved by the embodiments of the present invention are not limited to those described above, and other technical problems not explicitly mentioned will be clearly understood by those skilled in the art from the following description.

[0014] Disclosed herein is a method of dynamically allocating inactivity timer value in a wireless communication network. The method includes detecting whether one or more criteria for an automatic network selection mode are complied, upon occurrence of one or more disaster conditions. The one or more criteria comprises an indication of whether disaster roaming is enabled in the UE is set to disaster roaming is enabled in the UE. Further, the method includes automatically registering with a second PLMN when the one or more criteria are detected.

[0015] Further, disclosed herein is an apparatus for enabling a User Equipment (UE) to exit a manual network selection mode registered on a first Public Land Mobile Network (PLMN) selected by a user. The apparatus comprises a processor and a memory communicatively coupled to the processor, where the memory stores processor executable instructions, which, on execution, may cause the apparatus to detect whether one or more criteria for an automatic network selection mode are complied, upon occurrence of one or more disaster conditions. The one or more criteria comprises an indication of whether disaster roaming is enabled in the UE is set to disaster roaming is enabled in the UE. Further, the apparatus automatically registers with a second PLMN when the one or more criteria are detected.

[0016] Further, disclosed herein is a method performed by a user equipment (UE) in a wireless communication system. The method comprises detecting, while the UE is in a manual network selection mode and registered on a first public land mobile network (PLMN), at least one case for exiting the manual network selection mode, registering on a second PLMN automatically based on the at least one case for exiting the manual network selection mode, in case that a procedure that triggered the UE to exit the manual network selection mode is ended, moving to the manual network selection mode and selecting the first PLMN.

[0017] Further, disclosed herein is a UE in a wireless communication system. The UE comprises at least one transceiver, at least one processor communicatively coupled to the at least one transceiver and at least one memory, communicatively coupled to the at least one processor, storing instructions executable by the at least one processor individually or in any combination to cause the terminal to detect, while the UE is in a manual network selection mode and registered on a first public land mobile network (PLMN), at least one case for exiting the manual network selection mode, to register on a second PLMN automatically based on the at least one case for exiting the manual network selection mode, in case that a procedure that triggered the UE to exit the manual network selection mode is ended, to move to the manual network selection mode, and to select the first PLMN.

[0018] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

[0019] According to the present disclosure, it is possible to prevent a user equipment (UE) from remaining in the automatic network selection mode when the UE originally operated in manual network selection mode, thereby ensuring that the UE can return to the manual selection mode when appropriate. This enables improved control over network selection behavior, particularly in scenarios involving emergency calls, disaster conditions, or user-initiated network selection, and prevents unintended network changes.

[0020] The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate exemplary embodiments and, together with the description, explain the disclosed principles. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the figures to reference like features and components. Some embodiments of system and / or methods in accordance with embodiments of the present subject matter are now described, by way of example only, and regarding the accompanying figures, in which:

[0021] FIG. 1A shows an exemplary architecture for exiting a manual network selection mode in a User Equipment (UE) registered on a first Public Land Mobile Network (PLMN) selected by a user, in accordance with some embodiments of the present disclosure;

[0022] FIG. 1B shows a call flow diagram illustrating exiting a manual network selection mode in a User Equipment (UE) registered on a first Public Land Mobile Network (PLMN) selected by a user, in accordance with some embodiments of the present disclosure;

[0023] FIG. 1C shows an exemplary call flow diagram illustrating entering back a manual network selection mode in a User Equipment (UE), in accordance with some embodiments of the present disclosure;

[0024] FIG. 2 shows a detailed block diagram of an apparatus for enabling a User Equipment (UE) to exit a manual network selection mode registered on a first Public Land Mobile Network (PLMN) selected by a user, in accordance with some embodiments of the present disclosure;

[0025] FIG. 3 shows a flowchart illustrating method of exiting a manual network selection mode in a User Equipment (UE) registered on a first Public Land Mobile Network (PLMN) selected by a user, in accordance with some embodiments of the present disclosure; and

[0026] FIG. 4 illustrates a block diagram of an exemplary computer system for implementing embodiments consistent with the present disclosure.

[0027] It should be appreciated by those skilled in the art that any block diagrams herein represent conceptual views of illustrative systems embodying the principles of the present subject matter. Similarly, it will be appreciated that any flow charts, flow diagrams, state transition diagrams, pseudo code, and the like represent various processes which may be substantially represented in computer readable medium and executed by a computer or processor, whether such computer or processor is explicitly shown.

[0028] In the present document, the word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any embodiment or implementation of the present subject matter described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments.

[0029] While the disclosure is susceptible to various modifications and alternative forms, specific embodiment thereof has been shown by way of example in the drawings and will be described in detail below. It should be understood, however that it is not intended to limit the disclosure to the specific forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternative falling within the scope of the disclosure.

[0030] The terms “comprises”, “comprising”, “includes”, or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a setup, device, or method that comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such setup or device or method. In other words, one or more elements in a system or apparatus proceeded by “comprises… a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or method.

[0031] In an embodiment, present disclosure defines a trigger “an indication of whether disaster roaming is enabled in a User Equipment (UE), provided by the HPLMN”. The trigger is defined to decide whether UE is provisioned to use MINT or not. The UE checks for the said trigger to exit from manual network selection mode. In the present description, the terms UE and Mobile Station (MS) are interchangeably used.

[0032] In an embodiment, a MS is pre-configured with an indication of whether disaster roaming is enabled in the UE (in USIM / ME). In an embodiment, a MS is configured by the HPLMN or the VPLMN.

[0033] In an embodiment, the present disclosure adds the trigger “an indication of whether disaster roaming is enabled in the UE, provided by the HPLMN” to the list of triggers defined in Third Generation Partnership Project (3GPP). The trigger is added to decide whether UE is provisioned to use MINT or not. The list of triggers in accordance with embodiments of the present disclosure are defined below:

[0034] Step-1: UE detects that the below conditions are met

[0035] 1) the MS supports MINT;

[0036] 2) an indication of whether disaster roaming is enabled in the UE, provided by the HPLMN; i.e. the UE determines that disaster roaming is enabled for it.

[0037] 3) there is no available PLMN which is declared as an equivalent PLMN by the RPLMN; and

[0038] 4) the RPLMN of the MS is considered as the MS determined PLMN with disaster condition based on the determination of the MS determined PLMN with disaster condition.

[0039] Step 2: UE may automatically register on a different PLMN (for example, the FPLMN which can provide the disaster roaming service) and optionally can provide an indication to the upper layers (for e.g. from NAS later to the user interface in the UE) that the MS has exited manual network selection mode.

[0040] If the MS does not have an indication of whether disaster roaming is enabled in the UE stored in the ME, or the indication of whether disaster roaming is enabled in the UE stored in the ME is set to "Disaster roaming is disabled in the UE", disaster roaming is disabled at the MS. In this case, the MS shall not select another PLMN and optionally should not exit the Manual network selection mode. In order to solve this limitation, the present disclosure adds a trigger “an indication of whether disaster roaming is enabled in the UE, provided by the HPLMN;” to decide whether to select another PLMN in Manual mode and optionally exit the Manual network selection mode.

[0041] In an embodiment, the MS is pre-configured with an indication of whether disaster roaming is enabled in the UE (in the USIM / ME). In another embodiment, the MS is configured by the HPLMN or the VPLMN using at least one of, Non-Access Stratum (NAS) message or Access Stratum (AS) message.

[0042] In an embodiment, the indication of whether disaster roaming is enabled in the UE stored in the ME is set to "disaster roaming is enabled in the UE“. This indicates to the UE / ME that disaster roaming is enabled for the UE by the network e.g. HPLMN / Equivalent HPLMN (EHPLMN) or VPLMN. This indication indicates to the UE that disaster roaming is enabled. Only if disaster roaming is enabled in the UE, the UE may automatically register on a different PLMN (for example the FPLMN which can provide the disaster roaming service) and optionally can provide an indication to the upper layers (for e.g. from NAS layer to the user interface in the UE) that the MS has exited manual network selection mode.

[0043] In an embodiment, the present disclosure proposes that “an indication of whether disaster roaming is enabled in the UE, provided by the HPLMN;” is considered as a trigger to decide whether UE is provisioned to use MINT or not.

[0044] In an embodiment, the present disclosure can also use “the “list of PLMN(s) to be used in disaster condition” is non-empty” from the manual mode exit criterion additional to criteria of disaster roaming is enabled in the UE to exit the manual mode and select another PLMN.

[0045] The present disclosure enables the UE to exit the manual network selection mode, even when the list of PLMN(s) to be used in disaster condition" is empty. Thus, the UE can connect to a another PLMN automatically which was not selected by the user by performing the manual network selection and receive network services from another PLMN and exit the Manual network selection mode.

[0046] The present disclosure focuses to add the scenarios and trigger for entering back Manual Network Selection Mode after fulfilling the procedure for which UE had exited the Manual Network Selection Mode.

[0047] For instance, the present disclosure focuses to overcome the scenario when the UE is registered on a PLMN (say PLMN-1, e.g., AMF, MME) in manual Network Selection mode and the UE detects that the manual mode exit criteria are met i.e., for instance, emergency call failed on RPLMN due to ims-EmergencySupport-r9 not broadcast in SIB1 or PLMN-1 enters disaster conditions and UE is enabled to use disaster roaming services or RLOS access initiation by the user. Then, the UE exits manual network selection mode.

[0048] In other words, when MS or the UE has registered on a PLMN selected by the user, the MS shall not automatically register on a different PLMN unless:

[0049] i) the new PLMN is declared as an equivalent PLMN by the registered PLMN. If the MS is registered for disaster roaming services, the UE shall also detect that the new PLMN offers disaster roaming services to the MS determined PLMN with disaster condition as broadcasted by the NG-RAN cell of the new PLMN and that the MS determined PLMN with disaster condition in the old PLMN is also a MS determined PLMN with disaster condition in the new PLMN.

[0050] ii) the user initiates an emergency call while the MS is in limited service state and either the network does not broadcast the indication of support of emergency calls in limited service state, the registration request for emergency services is rejected by the network or the attach request for emergency bearer services is rejected by the network; or

[0051] iii) the user initiates access to RLOS, while the MS is in limited service state and either the network does not broadcast the indication of support of RLOS in limited service state, or the EPS attach request for access to RLOS is rejected by the network, or the EPS tracking area update request for access to RLOS is rejected by the network.

[0052] If case ii) or iii) occurs, the MS can provide an indication to the upper layers that the MS has exited manual network selection mode. Once the MS has registered on a PLMN selected by the user, the MS may automatically register on a different PLMN if:

[0053] 1) the MS supports MINT;

[0054] 2) the "list of PLMN(s) to be used in disaster condition" is non-empty or the indication of whether disaster roaming is enabled in the UE is set to "Disaster roaming is enabled in the UE";;

[0055] 3) there is no available PLMN which is declared as an equivalent PLMN by the RPLMN; and

[0056] 4) the RPLMN of the MS is considered as the MS determined PLMN with disaster condition based on the determination of the MS determined PLMN with disaster condition.

[0057] If the above case occurs, the MS can provide an indication to the upper layers that the MS has exited manual network selection mode.

[0058] Further, when the procedure for which UE exited manual network selection mode is completed and / or no more applicable for instance, emergency call ended, disaster conditions ended, RLOS session is ended by the user, the UE remains in Automatic Network Selection mode even though the user preference was Manual Network Selection Mode prior to the exit criteria.

[0059] Generally, the UE and the network may support minimization of service interruption (MINT). The MINT aims to enable a UE to obtain service from a PLMN offering disaster roaming services when a disaster condition applies to the UE's determined PLMN with disaster condition. The disaster condition may be defined as scenario when the users may have the opportunity to mitigate service interruptions and failures and disaster roaming is the special roaming policy that applies during a Disaster Condition.

[0060] In general, the purpose of the MINT is to minimize interruption of service to users of the UE when a wireless network to which these users are subscribed cannot provide service due to a disaster such as e.g. a fire, by enabling the users to obtain service on other networks, while at the same time protecting those other networks from congestion.

[0061] When a disaster condition applies, all UEs of the PLMN subject to disaster (PLMN D) that are located in an area where the Disaster Condition applies will look for another PLMN (e.g., PLMN A, PLMN C) in that area and attempt to register on it to obtain service. This could cause a large number of UEs to migrate from the PLMN subject to disaster to another PLMN, and attempt registration at around the same time, leading to signaling overload in the other PLMN due to the massive influx of roamers.

[0062] In such scenarios, the UEs can obtain service in the event of a disaster, if there are PLMN operators prepared to offer service. The minimization of service interruption is constrained to a particular time and place. To reduce the impact to the 5G System and EPS of supporting Disaster Roaming, the potential congestion resulting from an influx or outflux of Disaster Inbound Roamers is taken into account. If the UE has no coverage of its HPLMN, then obtains information that a Disaster Condition applies to the UE's HPLMN, the UE can register with a PLMN offering Disaster Roaming service.

[0063] Thus, there is a need of a system that support a means for the PLMN operator to be aware of the area where Disaster Condition applies. In other words, the 3GPP may support provision of service to Disaster Inbound Roamer only within the specific region where Disaster Condition applies. Further, the 3GPP system shall be able to provide efficient means for a network to inform Disaster Inbound roamers that a Disaster Condition is no longer applicable. Furthermore, the 3GPP system shall be able to provide means to enable a UE to access PLMNs in a forbidden PLMN list if a Disaster condition applies and no other PLMN is available except for PLMNs in the forbidden PLMN list.

[0064] The present disclosure provides a mechanism which proposes to add the scenarios and trigger for entering Manual Network Selection Mode after fulfilling the procedure for which UE had exited the Manual Network Selection Mode.

[0065] For ease of understanding, the following scenario:

[0066] - Initially, the UE is registered on a PLMN (say PLMN-1, e.g., AMF, MME) in manual Network Selection mode.

[0067] - When the UE detects that the manual mode exit criteria are met (e.g., emergency call failed on RPLMN due to ims-EmergencySupport-r9 not broadcast in SIB1 or PLMN-1 enters disaster conditions and UE is enabled to use disaster roaming services or RLOS access initiation by the user)

[0068] - The UE may exit manual network selection mode and the MS shall automatically select and register on a different PLMN which is not the PLMN selected by the user .

[0069] - When the procedure for which UE exited manual network selection mode is completed and / or no more applicable (e.g., emergency call ended, disaster conditions ended, RLOS access initiation by the user ended). The procedure in this embodiment is at least one of the below and not limited to:

[0070] -> the new PLMN is declared as an equivalent PLMN by the registered PLMN. If the MS is registered for disaster roaming services, the UE may also detect that the new PLMN offers disaster roaming services to the MS determined PLMN with disaster condition as broadcasted by the NG-RAN cell of the new PLMN and that the MS determined PLMN with disaster condition in the old PLMN is also a MS determined PLMN with disaster condition in the new PLMN;

[0071] -> the user may select automatic mode;

[0072] -> the user may further initiate an emergency call while the MS is in limited service state and either the network does not broadcast the indication of support of emergency calls in limited service state, the registration request for emergency services is rejected by the network or the attach request for emergency bearer services is rejected by the network; or

[0073] -> the user may initiate access to Restricted Local Operator Services RLOS, while the MS is in limited service state and either the network does not broadcast the indication of support of RLOS in limited service state, or the EPS attach request for access to RLOS is rejected by the network, or the EPS tracking area update request for access to RLOS is rejected by the network.

[0074] - Once the MS has registered on a PLMN selected by the user, the MS may automatically register on a different PLMN if:

[0075] -> the MS supports MINT;

[0076] -> the "list of PLMN(s) to be used in disaster condition" is non-empty or the indication of whether disaster roaming is enabled in the UE is set to "Disaster roaming is enabled in the UE";;

[0077] -> when there is no available PLMN which is declared as an equivalent PLMN by the RPLMN; and

[0078] -> when the RPLMN of the MS is considered as the MS determined PLMN with disaster condition based on the determination of the MS determined PLMN with disaster condition as specified in clause 4.4.3.1.1 of 3GPP TS 23.122.

[0079] If the above case occurs, the MS can provide an indication to the upper layers that the MS has exited manual network selection mode.

[0080] The UE may enter Manual Network Selection Mode and select RPLMN (on which it was registered prior to exiting the Manual mode). The UE may optionally indicate to upper layers (for e.g. from NAS layer to the user interface in the UE) that it’s moving back to Manual mode again.

[0081] For e.g., after an emergency call is released, the MS may re-start operating in manual network selection mode and optionally, select the RPLMN (on which it was registered prior to emergency call initiation). In another case, the MS may determine that a disaster condition may be ended and may be exited Manual Network Selection Mode for availing disaster roaming services, the MS may re-start operating in manual network selection mode and optionally select the RPLMN (on which it was registered prior to emergency call initiation). Further, the MS may determine that Restricted Local Operator Services (RLOS) session is completed or user ended the RLOS session, and it had exited Manual Network Selection Mode for availing RLOS services, the MS may re-start operating in manual network selection mode and optionally select the RPLMN (on which it was registered prior to starting the RLOS services). The MS may optionally indicate to upper layers (for e.g. from NAS layer to the user interface in the UE) that it’s moving back to Manual mode again in all of the above scenarios.

[0082] In yet another embodiment, in the Fig2, Step 0b: when the UE detects that the manual mode exit criteria are met, UE memorize / remember that that the UE selection mode is manual mode and the PLMN it was registered to in the manual mode, optionally MS / UE MS does not provide an indication to the upper layers that the MS has exited manual network selection mode. When UE in the Step 0d found that: Procedure for which UE exited manual network selection mode is completed and / or no more applicable (e.g., emergency call ended or disaster conditions ended) then UE move to the UE selection mode and the PLMN memorized / remembered in step: 0b. Optionally, if the UE / MS has MS / UE MS provided an indication to the upper layers that the MS has exited manual network selection mode in the step 0b then UE / MS additionally in the step:od provide an indication to the upper layers that the MS has exited automatic network selection mode or entering manual selection mode.

[0083] In yet another embodiment, the UE can determine emergency call is ended when upper layer indicated (e.g to the NAS) that emergency call is ended or emergency PDU session is released, emergency PDN connection is released or emergency callback timer is expired.

[0084] Consider a pre-condition that a User Equipment (UE) is registered on a Public Land Mobile Network-1 (PLMN-1). When the PLMN-1 enters disaster condition, the UE detects that the manual mode exit criteria are met and the UE provides an indication to the upper layers that the UE has exited manual network selection mode, in such a scenario. The steps of exiting Manual Network Selection Mode is provided below:

[0085] Consider a pre-condition that a User Equipment (UE) is registered on a Public Land Mobile Network-1 (PLMN-1). When the PLMN-1 enters disaster condition, the UE detects that the manual mode exit criteria are met and the UE provides an indication to the upper layers that the UE has exited manual network selection mode, in such a scenario. The steps of exiting Manual Network Selection Mode is provided below:

[0086] - Step 0 (Pre-Conditions): UE is registered on a PLMN (say PLMN-1, e.g., AMF) selected by the user, in Manual Network Selection Mode. Registered PLMN (RPLMN) encounters and enters disaster condition.

[0087] - Step 1: UE detects that the manual mode exit criteria are met based on below condition:

[0088] 1. the UE supports MINT;

[0089] 2. the “list of PLMN(s) to be used in disaster condition” is non-empty;

[0090] 3. there is no available PLMN which is declared as an equivalent PLMN by the RPLMN; and

[0091] 4. the RPLMN of the UE is considered as the UE determined PLMN with disaster condition based on the determination of the UE determined PLMN with disaster condition as specified in clause 4.4.3.1.1 of 3GPP TS 23.122 >

[0092] - Step 2: UE may automatically register on a different PLMN and optionally can provide an indication to the upper layers that the MS has exited manual network selection mode.

[0093] The “list of PLMN(s) to be used in disaster condition” can be empty. When the Home PLMN (HPLMN) wants the UE to connect to any Forbidden PLMN (FPLMN) without any priority among them during disaster condition. But as the list is empty, the UE will not be able to select the FPLMN (since the UE is still in the manual network selection mode) and register for disaster roaming service. At the same time, the UE will be unable to receive normal services as the allowable PLMN i.e., the RPLMN is not in service due to disaster situation. Thus, the UE will remain in “No service”. To prevent the scenario in which the UE remains in “No Service” during disaster conditions, the present disclosure overcomes this existing problem.

[0094] FIG. 1A shows an exemplary architecture for exiting a manual network selection mode in a User Equipment (UE) registered on a first Public Land Mobile Network (PLMN) selected by a user, in accordance with some embodiments of the present disclosure.

[0095] Exemplary architecture 100 illustrates a User Equipment (UE) 101, a first Public Land Mobile Network (PLMN) 103 selected by a user and a second PLMN 105. The UE 101 and the UE are alternatively used in the present disclosure. The UE 101 may be associated with the first PLMN 103 through a communication network (not shown in figure). As an example, the UE 101 may include, without limitation, any device used by a user to communicate and / or access content such as, but not limited to, mobile phones, smartphones, laptops, wearables, Internet of Things (IoTs), and the like with LTE / 5G / 6G capabilities. As an example, the communication network may be a wireless telecommunication network such as Long-Term Evolution (LTE) network, 5thGeneration (5G) network, 6thGeneration (6G) network and the like.

[0096] In an embodiment, the UE 101 may be registered to the first PLMN 103 selected by the user. During one or more disaster conditions, the UE 101 may determine the occurrence of the one or more disaster conditions when a notification indicating the occurrence of the one or more disaster conditions is received from a second PLMN 105. The second PLMN 105 is a Forbidden PLMN (FPLMN). The FPLMN may be a list of PLMN to which the UE 101 should not attempt to connect. The one or more disaster conditions may include, without limitation, the user initiates an emergency call while the UE 101 is in limited service state, the user initiates access to Restricted Local Operator Services (RLOS) while the UE 101 is in limited service state, the first PLMN 103 selected by the user is affected due to disaster and the UE 101 is enabled to use disaster roaming services.

[0097] In an embodiment, upon occurrence of the one or more disaster conditions, the UE 101 may detect whether one or more criteria for an automatic network selection mode are complied. The one or more criteria may include an indication of whether disaster roaming is enabled in the UE 101 is set to disaster roaming is enabled in the UE 101. The one or more criteria further includes, without limitation, UE 101 supports Minimization of Service Interruption (MINT), unavailability of a PLMN which is an equivalent PLMN determined by the PLMN registered by the UE 101, and Registered (RPLMN) of the UE 101 is considered as the UE 101 determined PLMN with the one or more disaster conditions based on determining that the UE 101 determined PLMN is affected with the one or more disaster conditions. In an embodiment, when the one or more criteria for the automatic network selection mode are complied, the UE 101 may store the first PLMN 103 selected by the user in the manual network selection mode before exiting the manual network selection mode. This is performed to register the UE 101 with the same PLMN when the when the one or more disaster conditions are ended.

[0098] In an embodiment, upon detecting whether the one or more criteria for an automatic network selection mode are complied, the UE 101 may be configured to automatically register with the second PLMN 105. In an embodiment, the UE 101 exits the manual network selection mode. Further, the UE 101 may indicate one or more upper layers in the UE 101 that the UE 101 exited the manual network selection mode.

[0099] In an embodiment, the UE 101 is configured to determine whether the one or more disaster conditions to remain in the automatic network selection mode ceases to exist. The UE 101 may receive a notification from the second PLMN 105 i.e., the FPLMN that the one or more disaster conditions to remain in the automatic network selection mode ceases to exist. Upon determining that the one or more disaster conditions to remain in the automatic network selection mode ceases to exist, the UE 101 may re-enter the manual network selection mode by exiting the automatic network selection mode when the one or more disaster conditions are ended. This is performed as the UE 101 was in the manual network selection mode prior to the disaster condition. Thereafter, the UE 101 may select the first PLMN 103 stored in the UE 101 before exiting the manual network selection mode. In other words, the first PLMN 103 stored in the UE 101 before exiting the manual network selection mode is selected and the UE 101 registers with the same PLMN. This ensures that the UE 101 registers with the same PLMN selected by the UE 101 ensuring better user experience.

[0100] Call flow diagram 120 illustrated in FIG. 1B shows exiting the manual network selection mode in the UE 101 registered on the PLMN selected by the user. At step 0, the UE 101 is registered with the first PLMN 103. As an example, the UE 101 may be registered with an Access and Mobility Function (AMF) of the first PLMN 103. The PLMN with which the UE 101 is registered is also known as Registered PLMN (RPLMN). Upon an occurrence of the one or more disaster condition, the UE 101 may receive the notification indicating the occurrence of the one or more disaster conditions (not shown in figure). At step 1, the UE 101 detects whether one or more criteria for an automatic network selection mode are complied. The one or more criteria may include an indication of whether disaster roaming is enabled in the UE 101 is set to disaster roaming is enabled in the UE 101. The one or more criteria further includes, without limitation, UE 101 supports Minimization of Service Interruption (MINT), there is no available PLMN which is declared as an equivalent PLMN by the RPLMN 101, and Registered (RPLMN) of the UE 101 is considered as the UE 101 determined PLMN with disaster conditions based on determination of the UE determined PLMN with disaster condition At step 2, the UE 101 may automatically register with the second PLMN 105 when the one or more criteria are detected. As shown in the figure, the UE 101 may register with an AMF of the second PLMN 105. The UE 101 may optionally indicate to upper layers, for example, from Non-Access Stratum (NAS) layer to the user interface in the UE 101 that the UE 101 is moving back to the manual network selection mode.

[0101] Call flow diagram 130 illustrated in FIG. 1C shows the UE 101 entering back the manual network selection mode. At step 0.a, the UE 101 is registered with the first PLMN 103. As an example, the UE 101 may be registered with an Access and Mobility Function (AMF) of the first PLMN 103. The PLMN with which the UE 101 is registered is also known as Registered PLMN (RPLMN). At step 0.b, the UE 101 detects that the one or more conditions to enter the automatic network selection mode are met. The one or more conditions may include, without limitation, the user initiates an emergency call while the UE 101 is in limited service state, the user initiates access to Restricted Local Operator Services (RLOS) while the UE 101 is in limited service state, the first PLMN 103 selected by the user is affected due to disaster and the UE 101 is enabled to use disaster roaming services. At step 0.c, the UE 101 exits manual network selection mode and avails services from the second PLMN 105. As shown in the figure, the UE 101 may register with an AMF of the second PLMN 105. At step 0.d, the UE 101 determines whether the one or more conditions to remain in the automatic network selection mode ceases to exist. The UE 101 determines whether the one or more disaster conditions are ended. As an example, the UE 101 may also determine whether emergency call ended and the RLOS access initiation by the user is ended. At step 1, the UE 101 enters the manual network selection mode and selects RPLMN i.e., the first PLMN 103. In an embodiment, the UE 101 stores the first PLMN 103 selected by the user in the manual network selection mode before exiting the manual network selection mode (not shown in figure). This help the UE 101 in registering with the first PLMN 103, i.e., the PLMN selected by the user.

[0102] FIG. 2 shows a detailed block diagram of the apparatus 200 for enabling a User Equipment (UE) 101 to exit a manual network selection mode registered on a first Public Land Mobile Network (PLMN), in accordance with some embodiments of the present disclosure.

[0103] In some implementations, the apparatus 200 may include an I / O interface 201, a processor 203 and a memory 205. In an embodiment, the memory 205 may be communicatively coupled to the processor 203. The processor 203 may be configured to perform one or more functions of the apparatus 200 for enabling a User Equipment (UE) 101 to exit a manual network selection mode registered on a first Public Land Mobile Network (PLMN) 103, using the data 207 and the one or more modules 209 of the apparatus 200. In an embodiment, the memory 205 may store the data 207. In an embodiment, the apparatus 200 may be a functional element within the UE 101 which may be configured to perform the aspects of the present disclosure. In another embodiment, the apparatus 200 may be the UE 101 configured to perform the method discussed in present disclosure.

[0104] In an embodiment, the data 207 stored in the memory 205 may include, without limitation, criteria data 211, PLMN data 213 and other data 215. In some implementations, the data 207 may be stored within the memory 205 in the form of various data structures. Additionally, the data 207 may be organized using data models, such as relational or hierarchical data models. The other data 215 may include various temporary data and files generated by the one or more modules 209.

[0105] In an embodiment, the criteria data 211 may include one or more one or more criteria for an automatic network selection mode in the UE 101. The one or more criteria includes an indication of whether disaster roaming is enabled in the UE 101 is set to disaster roaming is enabled in the UE 101. In other words, an indication of whether disaster roaming is enabled in the UE 101, provided by the first PLMN 103, should be considered as a trigger to decide whether the UE 101 is provisioned to use Minimization of Service Interruption (MINT). The one or more criteria further includes, without limitation, the UE 101 supports MINT, unavailability of a PLMN which is an equivalent PLMN determined by the PLMN registered by the UE 101, and Registered (RPLMN) of the UE 101 is considered as the UE 101 determined PLMN with the one or more disaster conditions based on determining that the UE 101 determined PLMN is affected with the one or more disaster conditions. The UE 101 detects whether the MINT is supported by the UE 101. The UE 101 detects whether the first PLMN 103 i.e., the PLMN registered by the UE 101 is unavailable. The UE 101 detects whether the first PLMN 103 i.e., the PLMN registered by the UE 101 (RPLMN) is affected with one or more disaster conditions.

[0106] In an embodiment, the PLMN data 213 may include PLMN selected by the user in the manual network selection mode before exiting the manual network selection mode. The PLMN data 213 may be used to register the UE 101 with the first PLMN 103 when the UE 101 re-enters the manual network selection mode by exiting the automatic network selection mode when the one or more disaster conditions are ended.

[0107] In an embodiment, the data 207 may be processed by one or more modules 209 of the apparatus 200. In some implementations, the one or more modules 209 may be communicatively coupled to the processor 203 for performing one or more functions of the apparatus 200. In an implementation, the one or more modules 209 may include, without limiting to, a detection module 217, a registration module 219 and other modules 221.

[0108] As used herein, the term module may refer to an Application Specific Integrated Circuit (ASIC), an electronic circuit, a hardware processor 203 (shared, dedicated, or group) and memory that execute one or more software or firmware programs, a combinational logic circuit, and / or other suitable components that provide the described functionality. In an implementation, each of the one or more modules 209 may be configured as stand-alone hardware computing units. In an embodiment, the other modules 221 may be used to perform various miscellaneous functionalities on the apparatus 200. It will be appreciated that such one or more modules 209 may be represented as a single module or a combination of different modules.

[0109] In an embodiment, one of the one or more modules corresponding to a determination module may be configured to determine an occurrence of one or more disaster conditions. The occurrence of the one or more disaster conditions are determined when a notification indicating the occurrence of the one or more disaster conditions is received from a second PLMN 105. In an embodiment, the second PLMN 105 is a Forbidden PLMN (FPLMN). The one or more conditions may include, but is not limited to, the user initiating an emergency call while the UE 101 is in limited service state, the user initiating an access to Restricted Local Operator Services (RLOS) while the UE 101 is in limited service state, the first PLMN 103 selected by the user is affected due to disaster and the UE 101 is enabled to use disaster roaming services. On occurrence of the one or more conditions, the detection module 217, detects whether one or more criteria for an automatic network selection mode are complied. The one or more criteria, may include, but is not limited to, an indication of whether disaster roaming is enabled in the UE 101 is set to disaster roaming is enabled in the UE 101, UE 101 supports Minimization of Service Interruption (MINT), unavailability of a PLMN which is an equivalent PLMN determined by the PLMN registered by the UE 101, and Registered (RPLMN) of the UE 101 is considered as the UE 101 determined PLMN with the one or more disaster conditions based on determining that the UE 101 determined PLMN is affected with the one or more disaster conditions. Further, when the one or more criteria for the automatic network selection mode are complied, the first PLMN 103 selected by the user is stored in the manual network selection mode, before exiting the manual network selection mode.

[0110] In an embodiment, the registration module 219 automatically registers the UE 101 with a second PLMN 105 when the one or more criteria are detected by the detection module 217.

[0111] In an embodiment, the other modules 221, may indicate that the UE 101 exited the manual network selection mode, to one or more upper layers in the UE 101. Further, the determination module determines whether the one or more disaster conditions to remain in the automatic network selection mode ceases to exist. The other modules 221 may enable re-entering of the UE 101, to the manual network selection mode by exiting the automatic network selection mode, when the one or more conditions are ended. Further, other modules 221 may enable selecting of the first PLMN 103 stored in the UE 101 before exiting the manual network selection mode.

[0112] FIG. 3 is a flowchart illustrating a method of exiting a manual network selection mode in a User Equipment (UE) 101 registered on a first Public Land Mobile Network (PLMN) selected by a user in accordance with some embodiments of the present disclosure.

[0113] As illustrated in FIG. 3, the method 300 may include one or more blocks illustrating a method of exiting a manual network selection mode in a User Equipment (UE) 101 registered on a first Public Land Mobile Network (PLMN) 103 selected by a user, using the apparatus 200 illustrated in FIG. 2. The method 300 may be described in the general context of computer executable instructions. Generally, computer executable instructions can include routines, programs, objects, components, data structures, procedures, modules, and functions, which perform specific functions or implement specific abstract data types.

[0114] The order in which the method 300 is described is not intended to be construed as a limitation, and any number of the described method blocks can be combined in any order to implement the method. Additionally, individual blocks may be deleted from the methods without departing from the scope of the subject matter described herein. Furthermore, the method can be implemented in any suitable hardware, software, firmware, or combination thereof.

[0115] At block 301, the method 300 includes detecting, by a processor 203 of the apparatus 200, whether one or more criteria for an automatic network selection mode are complied, upon occurrence of one or more disaster conditions. The one or more criteria comprises an indication of whether disaster roaming is enabled in the UE 101 is set to disaster roaming is enabled in the UE 101. The processor 203 determines occurrence of the one or more disaster conditions when a notification indicating the occurrence of the one or more disaster conditions is received from a second PLMN 105. The second PLMN 105 is a Forbidden PLMN (FPLMN). The one or more criteria further includes, without limitation, UE 101 supports Minimization of Service Interruption (MINT), unavailability of a PLMN which is an equivalent PLMN determined by the PLMN registered by the UE 101, and Registered (RPLMN) of the UE 101 is considered as the UE 101 determined PLMN with the one or more disaster conditions based on determining that the UE 101 determined PLMN is affected with the one or more disaster conditions. The one or more disaster conditions to enter the automatic network selection mode may include, without limitation, the user initiates an emergency call while the UE 101 is in limited service state, the user initiates access to Restricted Local Operator Services (RLOS) while the UE 101 is in limited service state, the first PLMN 103 selected by the user is affected due to disaster and the UE 101 is enabled to use disaster roaming services. In an embodiment, when the one or more criteria for the automatic network selection mode are complied, the processor 203 may store the first PLMN 103 selected by the user in the manual network selection mode before exiting the manual network selection mode.

[0116] At block 303, the method 300 includes automatically registering, by the processor 203, with a second PLMN 105 when the one or more criteria are detected. The processor 203 may indicate one or more upper layers in the UE 101 that the UE 101 exited the manual network selection mode. In an embodiment, the processor 203 may determine whether the one or more disaster conditions to remain in the automatic network selection mode ceases to exist. Further, the processor 203 may re-enter the manual network selection mode by exiting the automatic network selection mode when the one or more disaster conditions are ended. Thereafter, the processor 203 may select the first PLMN 103 stored in the UE 101 before exiting the manual network selection mode.

[0117] Computer System

[0118] FIG. 4 illustrates a block diagram of an exemplary computer system 400 for implementing embodiments consistent with the present disclosure. In an embodiment, the computer system 400 may be apparatus 200 illustrated in FIG. 1A. The computer system 400 may include a central processing unit (“CPU” or “processor” or “memory controller”) 402. The processor 402 may comprise at least one data processor for executing program components for executing user- or system-generated business processes. A user may include a network manager, an application developer, a programmer, an organization, or any system / sub-system being operated parallelly to the computer system 400. The processor 402 may include specialized processing units such as integrated system (bus) controllers, memory controllers / memory management control units, floating point units, graphics processing units, digital signal processing units, etc.

[0119] The processor 402 may be disposed in communication with one or more Input / Output (I / O) devices (411 and 412) via I / O interface 401. The I / O interface 401 may employ communication protocols / methods such as, without limitation, audio, analog, digital, stereo, IEEE®-1394, serial bus, Universal Serial Bus (USB), infrared, PS / 2, BNC, coaxial, component, composite, Digital Visual Interface (DVI), high-definition multimedia interface (HDMI), Radio Frequency (RF) antennas, S-Video, Video Graphics Array (VGA), IEEE® 802.n / b / g / n / x, Bluetooth, cellular (e.g., Code-Division Multiple Access (CDMA), High-Speed Packet Access (HSPA+), Global System For Mobile Communications (GSM), Long-Term Evolution (LTE) or the like), etc. Using the I / O interface 401, the computer system 400 may communicate with one or more I / O devices 411 and 412.

[0120] In some embodiments, the processor 402 may be disposed in communication with a network 409 via a network interface 403. The network interface 403 may communicate with the network 409. The network interface 403 may employ connection protocols including, without limitation, direct connect, Ethernet (e.g., twisted pair 10 / 100 / 1000 Base T), Transmission Control Protocol / Internet Protocol (TCP / IP), token ring, IEEE® 802.11a / b / g / n / x, etc.

[0121] In an implementation, the preferred network 409 may be implemented as one of the several types of networks, such as intranet or Local Area Network (LAN) and such within the organization. The preferred network 409 may either be a dedicated network or a shared network, which represents an association of several types of networks that use a variety of protocols, for example, Hypertext Transfer Protocol (HTTP), Transmission Control Protocol / Internet Protocol (TCP / IP), Wireless Application Protocol (WAP) etc., to communicate with each other. Further, the network 409 may include a variety of network devices, including routers, bridges, RAN nodes, computing devices, storage devices, etc. Using the network interface 403 and the network 409, the computer system 400 may communicate with first Public Land Mobile Network (PLMN) 103 selected by a user and a second PLMN.

[0122] In some embodiments, the processor 402 may be disposed in communication with a memory 405 (e.g., RAM 413, ROM 414, etc. as shown in FIG. 6) via a storage interface 404. The storage interface 404 may connect to memory 405 including, without limitation, memory drives, removable disc drives, etc., employing connection protocols such as Serial Advanced Technology Attachment (SATA), Integrated Drive Electronics (IDE), IEEE-1394, Universal Serial Bus (USB), fiber channel, Small Computer Systems Interface (SCSI), etc. The memory drives may further include a drum, magnetic disc drive, magneto-optical drive, optical drive, Redundant Array of Independent Discs (RAID), solid-state memory devices, solid-state drives, etc.

[0123] The memory 405 may store a collection of program or database components, including, without limitation, user / application interface 406, an operating system 407, a web browser 408, and the like. In some embodiments, computer system 400 may store user / application data 406, such as the data, variables, records, etc. as described in this invention. Such databases may be implemented as fault-tolerant, relational, scalable, secure databases such as Oracle® or Sybase®.

[0124] The operating system 407 may facilitate resource management and operation of the computer system 400. Examples of operating systems include, without limitation, APPLE® MACINTOSH® OS X®, UNIX®, UNIX-like system distributions (E.G., BERKELEY SOFTWARE DISTRIBUTION® (BSD), FREEBSD®, NETBSD®, OPENBSD, etc.), LINUX® DISTRIBUTIONS (E.G., RED HAT®, UBUNTU®, KUBUNTU®, etc.), IBM® OS / 2®, MICROSOFT® WINDOWS® (XP®, VISTA® / 7 / 8, 10 etc.), APPLE® IOS®, GOOGLE TM ANDROID TM, BLACKBERRY® OS, or the like.

[0125] The user interface 406 may facilitate display, execution, interaction, manipulation, or operation of program components through textual or graphical facilities. For example, the user interface 406 may provide computer interaction interface elements on a display system operatively connected to the computer system 400, such as cursors, icons, check boxes, menus, scrollers, windows, widgets, and the like. Further, Graphical User Interfaces (GUIs) may be employed, including, without limitation, APPLE® MACINTOSH® operating systems’ Aqua®, IBM® OS / 2®, MICROSOFT® WINDOWS® (e.g., Aero, Metro, etc.), web interface libraries (e.g., ActiveX®, JAVA®, JAVASCRIPT®, AJAX, HTML, ADOBE® FLASH®, etc.), or the like.

[0126] The web browser 408 may be a hypertext viewing application. Secure web browsing may be provided using Secure Hypertext Transport Protocol (HTTPS), Secure Sockets Layer (SSL), Transport Layer Security (TLS), and the like. The web browsers 408 may utilize facilities such as AJAX, DHTML, ADOBE® FLASH®, JAVASCRIPT®, JAVA®, Application Programming Interfaces (APIs), and the like. Further, the computer system 400 may implement a mail RAN node stored program component. The mail RAN node may utilize facilities such as ASP, ACTIVEX®, ANSI® C++ / C#, MICROSOFT®, .NET, CGI SCRIPTS, JAVA®, JAVASCRIPT®, PERL®, PHP, PYTHON®, WEBOBJECTS®, etc. The mail RAN node may utilize communication protocols such as Internet Message Access Protocol (IMAP), Messaging Application Programming Interface (MAPI), MICROSOFT® exchange, Post Office Protocol (POP), Simple Mail Transfer Protocol (SMTP), or the like. In some embodiments, the computer system 400 may implement a mail client stored program component. The mail client may be a mail viewing application, such as APPLE® MAIL, MICROSOFT® ENTOURAGE®, MICROSOFT® OUTLOOK®, MOZILLA® THUNDERBIRD®, and the like.

[0127] Furthermore, one or more computer-readable storage media may be utilized in implementing embodiments consistent with the present invention. A computer-readable storage medium refers to any type of physical memory on which information or data readable by a processor may be stored. Thus, a computer-readable storage medium may store instructions for execution by one or more processors, including instructions for causing the processor(s) to perform steps or stages consistent with the embodiments described herein. The term “computer-readable medium” should be understood to include tangible items and exclude carrier waves and transient signals, i.e., non-transitory. Examples include Random Access Memory (RAM), Read-Only Memory (ROM), volatile memory, nonvolatile memory, hard drives, Compact Disc (CD) ROMs, Digital Video Disc (DVDs), flash drives, disks, and any other known physical storage media.

[0128] In light of the technical advancements provided by the disclosed method, the claimed steps, as discussed above, are not routine, conventional, or not well-known aspects in the art, as the claimed steps provide the aforesaid solutions to the technical problems existing in the conventional technologies. Further, the claimed steps clearly bring an improvement in the functioning of the system itself, as the claimed steps provide a technical solution to a technical problem.

[0129] The terms "an embodiment", "embodiment", "embodiments", "the embodiment", "the embodiments", "one or more embodiments", "some embodiments", and "one embodiment" mean "one or more (but not all) embodiments of the invention(s)" unless expressly specified otherwise.

[0130] The terms "including", "comprising", “having” and variations thereof mean "including but not limited to", unless expressly specified otherwise.

[0131] The enumerated listing of items does not imply that any or all the items are mutually exclusive, unless expressly specified otherwise. The terms "a", "an" and "the" mean "one or more", unless expressly specified otherwise.

[0132] A description of an embodiment with several components in communication with each other does not imply that all such components are required. On the contrary, a variety of optional components are described to illustrate the wide variety of possible embodiments of the invention.

[0133] When a single device or article is described herein, it will be clear that more than one device / article (whether they cooperate) may be used in place of a single device / article. Similarly, where more than one device / article is described herein (whether they cooperate), it will be clear that a single device / article may be used in place of the more than one device / article or a different number of devices / articles may be used instead of the shown number of devices or programs. The functionality and / or features of a device may be alternatively embodied by one or more other devices which are not explicitly described as having such functionality / features. Thus, other embodiments of invention need not include the device itself.

[0134] Finally, the language used in the specification has been principally selected for readability and instructional purposes, and it may not have been selected to delineate or circumscribe the inventive subject matter. It is therefore intended that the scope of the invention be limited not by this detailed description, but rather by any claims that issue on an application based here on. Accordingly, the embodiments of the present invention are intended to be illustrative, but not limiting, of the scope of the invention, which is set forth in the following claims.

[0135] While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

[0136] 103 First Public Land Mobile Network (PLMN)

[0137] 105 Second Public Land Mobile Network (PLMN)

[0138] 200 Apparatus

[0139] 201 I / O Interface

[0140] 203 Processor

[0141] 205 Memory

[0142] 207 Data

[0143] 209 Modules

[0144] 211 Criteria data

[0145] 213 Public Land Mobile Network (PLMN) data

[0146] 215 Other data

[0147] 217 Detection module

[0148] 219 Registration module

[0149] 221 Other modules

[0150] 400 Computer system

[0151] 401 I / O Interface of the exemplary computer system

[0152] 402 Processor of the exemplary computer system

[0153] 403 Network interface

[0154] 404 Storage interface

[0155] 405 Memory of the exemplary computer system

[0156] 406 User / Application

[0157] 407 Operating system

[0158] 408 Web browser

[0159] 411 Input devices

[0160] 412 Output devices

[0161] 413 RAM

[0162] 414 ROM

Claims

1.A method performed by a user equipment (UE) in a wireless communication system, the method comprising:detecting, while the UE is in a manual network selection mode and registered on a first public land mobile network (PLMN), at least one case for exiting the manual network selection mode;registering on a second PLMN automatically based on the at least one case for exiting the manual network selection mode;in case that a procedure that triggered the UE to exit the manual network selection mode is ended, moving to the manual network selection mode; andselecting the first PLMN.2.The method of claim 1, further comprising:memorizing the first PLMN selected by a user before exiting the manual network selection mode, based on occurrence of the at least one case for exiting the manual network selection mode.3.The method of claim 1, wherein the at least one case includes:a user initiates an emergency call while the UE is in limited service state and either a network does not broadcast the indication of support of emergency calls in limited service state, a registration request for emergency services is rejected by the network or the attach request for emergency bearer services is rejected by the network, andthe user initiates access to restricted local operator services (RLOS), while the UE is in limited service state and either the network does not broadcast the indication of support of RLOS in limited service state, or an evolved packet system (EPS) attach request for access to RLOS is rejected by the network, or an EPS tracking area update request for access to RLOS is rejected by the network.4.The method of claim 1, wherein the at least one case includes,a registered PLMN (RPLMN) of the UE is considered as a UE determined PLMN with disaster condition based on a determination of the UE determined PLMN with disaster condition.5.The method of claim 1,wherein, in case that the at least one case for exiting the manual network selection mode occurs, the UE provides an indication to an upper layer of the UE that the UE has exited the manual network selection mode, andwherein the first PLMN is selected by a user based on the manual network selection mode.6.The method of claim 3,wherein an end of the procedure that triggered the UE to exit the manual network selection mode includes the emergency call is ended or a user initiated access to RLOS is ended.7.The method of claim 4,wherein an end of the procedure that triggered the UE to exit the manual network selection mode includes the UE determines that the disaster condition has ended.8.A user equipment (UE) in a wireless communication system, the UE comprising:at least one transceiver;at least one processor communicatively coupled to the at least one transceiver; andat least one memory, communicatively coupled to the at least one processor, storing instructions executable by the at least one processor individually or in any combination to cause the terminal to:detect, while the UE is in a manual network selection mode and registered on a first public land mobile network (PLMN), at least one case for exiting the manual network selection mode,register on a second PLMN automatically based on the at least one case for exiting the manual network selection mode,in case that a procedure that triggered the UE to exit the manual network selection mode is ended, move to the manual network selection mode, andselect the first PLMN.9.The UE of claim 8,wherein the instructions further cause the terminal to memorize the first PLMN selected by a user before exiting the manual network selection mode, based on occurrence of the at least one case for exiting the manual network selection mode.10.The UE of claim 8, wherein the at least one case includes:a user initiates an emergency call while the UE is in limited service state and either a network does not broadcast the indication of support of emergency calls in limited service state, a registration request for emergency services is rejected by the network or the attach request for emergency bearer services is rejected by the network, andthe user initiates access to restricted local operator services (RLOS), while the UE is in limited service state and either the network does not broadcast the indication of support of RLOS in limited service state, or an evolved packet system (EPS) attach request for access to RLOS is rejected by the network, or an EPS tracking area update request for access to RLOS is rejected by the network.11.The UE of claim 8, wherein the at least one case includes,a registered PLMN (RPLMN) of the UE is considered as a UE determined PLMN with disaster condition based on a determination of the UE determined PLMN with disaster condition.12.The UE of claim 8,wherein, in case that the at least one case for exiting the manual network selection mode occurs, the UE provides an indication to an upper layer of the UE that the UE has exited the manual network selection mode, andwherein the first PLMN is selected by a user based on the manual network selection mode.13.The UE of claim 10,wherein an end of the procedure that triggered the UE to exit the manual network selection mode includes the emergency call is ended or a user initiated access to RLOS is ended.14.The UE of claim 11,wherein an end of the procedure that triggered the UE to exit the manual network selection mode includes the UE determines that the disaster condition has ended.

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