WO2026005382A1

WO2026005382A1 - Method and apparatus for handling storage validity of satellite information during non-access stratum procedure in a wireless communication system

Info

Publication number: WO2026005382A1
Application number: PCT/KR2025/008474
Authority: WO
Inventors: Lalith KUMAR; Utsav SINHA; Aman Agarwal; Sidhant JAIN; Dinesh Rooparam CHOUDHARY; Vishal YADAV
Original assignee: Samsung Electronics Co Ltd
Current assignee: Samsung Electronics Co Ltd
Priority date: 2024-06-25
Filing date: 2025-06-19
Publication date: 2026-01-02
Anticipated expiration: 2026-12-25

Abstract

The disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. Embodiments disclosed herein describe a method, a user equipment (UE) (200) and a network apparatus (300) for handling storage validity of satellite information during non-Access Stratum (NAS) procedure in communication network system. The method involves the UE (200) receives satellite and forward (S&F) monitoring list from the network apparatus (300) when the network apparatus (300) accepts or rejects the NAS procedure and stores the S&F monitoring list. Further, the UE (200) receives NAS message from the network apparatus (300) including an indication to delete the stored S&F monitoring list at the UE (200). Furthermore, the UE (200) deletes the stored S&F monitoring list when the indication in the NAS message indicates to delete the stored S&F monitoring list for the current PLMN and uses any satellite to access the service.

Description

METHOD AND APPARATUS FOR HANDLING STORAGE VALIDITY OF SATELLITE INFORMATION DURING NON-ACCESS STRATUM PROCEDURE IN A WIRELESS COMMUNICATION SYSTEM

The present application relates to a wireless communication network system and a satellite communication system and more specifically relates to handling storage validity of satellite information during a non-Access Stratum (NAS) procedure in a communication network system.

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 (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.

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.

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.

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.

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.

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.

The present disclosure relates to method and apparatus for handling storage validity of satellite information during non-access stratum in a wireless communication system.

According to an aspect of an exemplary embodiment, there is provided a communication method in a wireless communication system.

Aspects of the present disclosure provide efficient communication methods in a wireless communication system.

The invention is illustrated in the accompanying drawings, where like reference letters indicate corresponding parts. The embodiments will be better understood from the following description with reference to the drawings.

FIG. 1 is a schematic diagram that illustrates an example of an S&F satellite operation mode of a 5G system with satellite access according to the prior art;

FIG. 2 is a block diagram that illustrates the hardware components associated with the UE according to the embodiments as disclosed herein;

FIG. 3 is a block diagram that illustrates the hardware components associated with the network apparatus according to the embodiments as disclosed herein;

FIG. 4A is a flow diagram that illustrates a proposed method for handling storage validity of satellite information during a NAS procedure in a communication network system by a UE according to the embodiments as disclosed herein;

FIG. 4B is a flow diagram that illustrates a proposed method for receiving the S&F monitoring list from the network apparatus according to the embodiments as disclosed herein;

FIG. 5A is a flow diagram that illustrates a proposed method for handling storage validity of satellite information during a NAS procedure in a communication network system by a network apparatus according to the embodiments as disclosed herein;

FIG. 5B is a flow diagram that illustrates a proposed method for sending the S&F monitoring list to the UE by the network apparatus according to the embodiments as disclosed herein;

FIG. 6A is a sequence diagram that illustrates an existing scenario of handling storage validity of satellite parameters according to the prior art;

FIG. 6B is a sequence diagram that illustrates a proposed scenario of handling storage validity of satellite parameters according to the embodiments as disclosed herein;

FIG. 7A is a sequence diagram that illustrates an existing scenario of UE behavior when the MME on-board does not configure satellite IDs and wait timer in the DL NAS message to the UE according to the prior art;

FIG. 7B is a sequence diagram that illustrates a proposed scenario of UE behavior when the MME on-board does not configure satellite IDs and wait timer in the DL NAS message to the UE according to the embodiments as disclosed herein;

FIG. 8A is a sequence diagram that illustrates an existing scenario of handling wait timer and satellite ID upon switch off/on according to the prior art;

FIG. 8B is a sequence diagram that illustrates a proposed scenario of handling wait timer and satellite ID upon switch off/on according to the embodiments as disclosed herein;

FIG. 9 is a block diagram of a terminal or user equipment (UE) 900 according to an embodiment of the disclosure;

FIG. 10 is a block diagram of a base station (BS) 1000 according to an embodiment of the disclosure; and

FIG. 11 is a block diagram of a network entity 1100 according to an embodiment of the disclosure.

In an aspect, the objects are achieved by providing a method for handling storage validity of satellite information during a NAS procedure in a communication network system. The method includes receiving by a UE a S&F monitoring list from a network apparatus when the network apparatus accepts or rejects the NAS procedure. The S&F monitoring list includes satellite IDs belonging to the same PLMN over which the UE can attempt or re-attempt the NAS procedure. Further, the method includes storing by the UE the S&F monitoring list and receiving a NAS message from the network apparatus. The NAS message includes an indication to delete the stored S&F monitoring list at the UE. Furthermore, the method includes deleting by the UE the stored S&F monitoring list when the indication in the NAS message indicates to delete the stored S&F monitoring list for the current PLMN and using by the UE any satellite to access the service.

In another aspect, the objects are achieved by providing a method for handling storage validity of satellite information during a NAS procedure in a communication network system. The method includes determining by a network apparatus that a UE indicates an S&F capability and generating by the network apparatus an S&F monitoring list when the UE supports the S&F capability. The S&F monitoring list includes satellite IDs belonging to at least one of the same PLMN and equivalent PLMN over which the UE can attempt or re-attempt the NAS procedure. Further, the method includes sending by the network apparatus the S&F monitoring list to the UE when the network apparatus accepts or rejects the NAS procedure and sending by the network apparatus a NAS message to the UE. The NAS message includes an indication to delete the stored S&F monitoring list at the UE.

In yet another aspect, the objects are achieved by providing a UE for handling storage validity of satellite information during a NAS procedure in a communication network system. The UE includes a memory, a processor, and a satellite information controller connected to the memory and the processor. The satellite information controller receives an S&F monitoring list from the network apparatus when the network apparatus accepts or rejects the NAS procedure. The S&F monitoring list includes satellite IDs belonging to the same PLMN over which the UE can attempt or re-attempt the NAS procedure. Further, the satellite information controller stores the S&F monitoring list in the memory and receives a NAS message from the network apparatus. The NAS message includes an indication to delete the stored S&F monitoring list at the UE. Furthermore, the satellite information controller deletes the stored S&F monitoring list from the memory of the UE when the indication in the NAS message indicates to delete the stored S&F monitoring list and selecting or reselecting by the UE a cell of the same PLMN or an equivalent PLMN to attempt or re-attempt the NAS procedure after deleting the stored S&F monitoring list.

In yet another aspect, the objects are achieved by providing a network apparatus for handling storage validity of satellite information during a NAS procedure in a communication network system. The network apparatus includes a memory including information of a UE, a processor, and an S&F monitoring list controller connected to the memory and the processor. The S&F monitoring list controller determines that the UE indicates a S&F capability and generates an S&F monitoring list when the UE supports the S&F capability. The S&F monitoring list includes satellite IDs belonging to the same PLMN over which the UE can attempt or re-attempt the NAS procedure, and the satellite IDs are based on SIB information broadcasted by an eNB associated with the network apparatus. Further, the S&F monitoring list controller sends the S&F monitoring list to the UE when the network apparatus accepts or rejects the NAS procedure and sends a NAS message to the UE. The NAS message includes an indication to delete the stored S&F monitoring list at the UE, and the indication includes a value indicating to the UE to delete the stored S&F monitoring list or continue to retain the S&F monitoring list.

Hereinafter, embodiments of the disclosure will be described in detail with reference to the accompanying drawings.

In describing the embodiments, descriptions related to technical contents well-known in the art and not associated directly with the disclosure will be omitted. Such an omission of unnecessary descriptions is intended to prevent obscuring of the main idea of the disclosure and more clearly transfer the main idea.

For the same reason, in the accompanying drawings, some elements may be exaggerated, omitted, or schematically illustrated. Further, the size of each element does not completely reflect the actual size. In the drawings, identical or corresponding elements are provided with identical reference numerals or different reference numerals.

The advantages and features of the disclosure and ways to achieve them will be apparent by making reference to embodiments as described below in detail in conjunction with the accompanying drawings. However, the disclosure is not limited to the embodiments set forth below, but may be implemented in various different forms. The following embodiments are provided only to completely disclose the disclosure and inform those skilled in the art of the scope of the disclosure, and the disclosure is defined only by the scope of the appended claims. Throughout the specification, the same or like reference numerals designate the same or like elements. Furthermore, in describing the disclosure, a detailed description of known functions or constitution incorporated herein will be omitted in the case that it is determined that the description may make the subject matter of the disclosure unnecessarily unclear. The terms which will be described below are terms defined in consideration of the functions in the disclosure, and may be different according to users, intentions of the operators, or customs. Therefore, the definitions of the terms should be made based on the contents throughout the specification.

Herein, it will be understood that each block of the flowchart illustrations, and combinations of blocks in the flowchart illustrations, may be performed based on computer program instructions. These computer program instructions may be loaded collectively onto at least one processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which perform through any one of, or in any combination of, the at least one processor of the computer or other programmable data processing apparatus, create means for performing the functions specified in the flowchart block(s). These computer program instructions may also be stored in a non-transitory computer usable or computer-readable memory that may direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer usable or computer-readable memory produce an article of manufacture including instruction means that perform the function specified in the flowchart block(s). The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable data processing apparatus to produce a computer executed process such that the instructions that perform on the computer or other programmable data processing apparatus provide steps for executing the functions specified in the flowchart block(s).

Further, each block may represent a module, segment, or portion of code, which includes one or more executable instructions for executing the specified logical function(s). It should also be noted that in some alternative implementations, the functions noted in the blocks may occur out of the order. For example, two blocks(or functions) shown in succession may in fact be performed substantially concurrently or the blocks may sometimes be performed in the reverse order, depending upon the functionality involved.

As used in embodiments of the disclosure, a "~unit" may refer to a software element or a hardware element, such as a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC), which performs a predetermined function. However, the term including the word "~unit" does not always have a meaning limited to software or hardware. The "~unit" may be constructed either to be stored in an addressable storage medium or to execute one or more processors. Therefore, the "~unit" includes, for example, software elements, object-oriented software elements, components such as class elements and task elements, processes, functions, properties, procedures, sub-routines, segments of a program code, drivers, firmware, micro-codes, circuits, data, database, data structures, tables, arrays, and parameters. The components and functions provided by the "~unit" may be either combined into a smaller number of components and a "~unit," or divided into additional components and a "~unit." Moreover, the components and "~units" may be implemented to reproduce one or more central processing units (CPUs) within a device or a security multimedia card. Further, in the embodiments, the "～unit" may include one or more processors.

It should be appreciated that the blocks in each flowchart and combinations of the flowcharts may be performed by one or more computer programs which include instructions. The entirety of the one or more computer programs may be stored in a single memory device or the one or more computer programs may be divided with different portions stored in different multiple memory devices.

Any of the functions or operations described herein can be processed by one processor or a combination of processors. The one processor or the combination of processors is circuitry performing processing and includes circuitry like an application processor (AP, e.g. a CPU), a communication processor (CP, e.g., a modem), a graphics processing unit (GPU), a neural processing unit (NPU) (e.g., an artificial intelligence (AI) chip), a Wi-Fi chip, a Bluetooth® chip, a global positioning system (GPS) chip, a near field communication (NFC) chip, connectivity chips, a sensor controller, a touch controller, a finger-print sensor controller, a display driver integrated circuit (IC), an audio CODEC chip, a universal serial bus (USB) controller, a camera controller, an image processing IC, a microprocessor unit (MPU), a system on chip (SoC), an IC, or the like.

It will be appreciated that various embodiments of the disclosure according to the claims and description in the specification can be realized in the form of hardware, software or a combination of hardware and software.

Any such software may be stored in non-transitory computer readable storage media. The non-transitory computer readable storage media store one or more computer programs (software modules), the one or more computer programs include computer-executable instructions that, when executed by one or more processors of an electronic device individually or collectively, cause the electronic device to perform a method of the disclosure.

Any such software may be stored in the form of volatile or non-volatile storage such as, for example, a storage device like read only memory (ROM), whether erasable or rewritable or not, or in the form of memory such as, for example, random access memory (RAM), memory chips, device or integrated circuits or on an optically or magnetically readable medium such as, for example, a compact disk (CD), digital versatile disc (DVD), magnetic disk or magnetic tape or the like. It will be appreciated that the storage devices and storage media are various embodiments of non-transitory machine-readable storage that are suitable for storing a computer program or computer programs comprising instructions that, when executed, implement various embodiments of the disclosure. Accordingly, various embodiments of the present disclosure may provide a program comprising code for implementing apparatus or a method as claimed in any one of the claims of this specification and a non-transitory machine-readable storage storing such a program.

Hereinafter, the determination of priority between A and B in the present disclosure may refer to various actions such as selecting the one having a higher priority based on a predefined priority rule and performing an operation corresponding thereto, or omitting or dropping an operation corresponding to the one having a lower priority.

Hereinafter, "A or B" as described in the present disclosure may be understood as "A and/or B," which may include A, or B, or both A and B.

In addition, "at least one of A, B, and C" as described in the present disclosure may be understood to include A, or B, or C, or any combination of A, B, and C.

In addition, "at least one of A, B, or C" as described in the present disclosure may be understood to include A, or B, or C, or any combination of A, B, and C.

Furthermore, "A/B" as described in the present disclosure may be understood as "A and/or B," which may include A, or B, or both A and B.

Furthermore, "A, B" as described in the present disclosure may be understood as "A and/or B," which may include A, or B, or both A and B.

Furthermore, "A and B" as described in the present disclosure may be understood as "A and/or B," which may include A, or B, or both A and B.

Furthermore, “if condition A and condition B are satisfied,” as described in the present disclosure, may not be limited to a case where both condition A and condition B are satisfied, but may be understood to include a case where either condition A or condition B is individually satisfied, both condition A and condition B are satisfied, or one or more additional conditions are satisfied in combination.

Furthermore, throughout this disclosure, ordinal terms such as "first," "second," "third," etc., (and similar qualifiers) are used merely to distinguish between different instances, occurrences, configurations, messages, stages, or aspects of elements, operations, or information as described herein. Unless the context clearly dictates otherwise, the use of such ordinal terms does not itself require that the elements, operations, or information distinguished by these terms be structurally different, numerically distinct, or substantively dissimilar. For example, a "first signal" and a "second signal" may refer to instances of the same signal transmitted at different times or containing the same core information despite minor variations, or they may refer to signals with different content or characteristics, depending on the specific context. Similarly, a "first value" and a "second value" may represent the same magnitude but measured or applied in different circumstances, or they may represent different magnitudes. The interpretation should be guided by the specific technical context, function, and relationship described in the relevant portion of the specification and claims.

Furthermore, the terms “first ~”, “second ~”, etc., as described in the present disclosure with respect to various elements (e.g., information, objects, operation, sequences, or the like), should not limit those elements. These terms may only be intended to distinguish one element from another, and may not be intended to indicate a specific order. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element.

Furthermore, even if “first ~” and “second ~” are described in the present disclosure, it may be understood that element(s) referred to by “first ~” and “second ~” may be the same or different. For example, in case of element(s) being information, first information and second information may both be same information and, in some cases, are separate and different information.

In addition, the terms “if ~” and “in case that ~” as used in the disclosure or claims may be interpreted to include the meanings of “when (or upon) ~,” “in response to ~,” “based on ~,” or “according to ~,” and may be used interchangeably with these expressions. In addition, expressions other than those exemplified herein may also be used, as long as they have substantially the same meaning and do not impair the technical features of the present disclosure.

For example, the physical layer signaling may be referred to as Layer 1 (L1) signaling and may include downlink control information (DCI). In addition, the higher layer signaling may include a medium access control (MAC) control message, a radio resource control (RRC) signaling message, a non-access stratum (NAS) signaling message, or an application layer message. The RRC signaling message may be referred to as L3 (layer 3) signaling. It should be noted, however, that the higher layer signaling is not limited to the aforementioned examples.

In addition, the term "not perform" as used in the present disclosure or claims may, in context, be understood to mean that the corresponding step is omitted or skipped. Such a term may be replaced with other terms having the same or substantially equivalent meaning.

In addition, "transmitting a message including A and B" as described in the present disclosure, may be understood as encompassing both (i) transmitting A and B in a single message, and (ii) transmitting A and B separately via multiple messages (e.g., transmitting a first message including A and a second message including B). This interpretation may also apply to messages that include two or more items (e.g., A, B, C), transmitted either together or separately.

In addition, "transmitting a message including A and transmitting a message including B" may also be interpreted as transmitting a message including A and B in a single message.

In the specific embodiments of the present disclosure described below, terms or components included in the disclosure may be expressed in singular or plural form depending on the specific embodiments presented. However, such singular or plural expressions are selected appropriately for convenience of description, and the present disclosure is not limited to a singular or plural number of components. A component expressed in the plural form may be implemented as a single component, and a component expressed in the singular form may be implemented as multiple components.

The drawings or flowcharts described below illustrate exemplary methods that may be implemented according to the principles of the present disclosure, and various modifications may be made to the methods illustrated in the flowcharts of the present disclosure. For example, although illustrated as a series of steps, various steps in each drawing or flowchart may overlap, occur in parallel, occur in a different order, or be repeated. In other examples, any step may be omitted or replaced with another step.

The methods and apparatuses proposed in the embodiments of the present disclosure are not limited to each embodiment individually, but may also be applied in combination of all or some of the embodiments proposed in the disclosure. Therefore, the embodiments of the present disclosure may be modified and applied without significantly departing from the scope of the present disclosure, as would be understood by those skilled in the art.

In this case, even if certain wordings are described differently across embodiments, they may be used interchangeably or in substitution or in combination if their underlying concepts are equivalent. For example, for the same or equivalent concept, even if one embodiment uses the expression "A" and another embodiment uses the expression "B", such expressions may be understood interchangeably, in substitution, or in combination.

The terms used in the following description to refer to access nodes, network entities, messages, interfaces between network entities, various types of identification information, and the like, are provided merely for the convenience of explanation by way of example. Therefore, the present disclosure is not limited to the terms described below, and other terms having equivalent technical meanings may also be used. Such terms may also be interchangeable with terms defined in any 3rd generation partnership project (3GPP) technical specifications (TS) where appropriate.

Hereinafter, a base station is an entity that allocates resources to terminals, and may be at least one of a gNode B, an eNode B, a Node B, a base station (BS), a wireless access unit, a BS controller, or a node on a network.

Furthermore, the base station of the present disclosure may include a split architecture comprising a central unit (CU) and a distributed unit (DU). In this structure, the CU is configured to process the higher layers of the control and user planes, while the DU is configured to process lower-layer radio resource functions. The embodiments of the present disclosure may be equally applicable to 5G base station architectures in which such CU and DU functional splits are implemented.

A terminal may include a UE, a mobile station (MS), a cellular phone, a smartphone, a computer, or a multimedia system capable of performing communication functions.

In the disclosure, a downlink (DL) refers to a radio link through which a BS transmits a signal to a UE, and an uplink (UL) refers to a radio link through which a UE transmits a signal to a BS.

Furthermore, hereinafter, 5th generation (5G) mobile communication technologies (e.g., 5G new radio (NR)), 6th generation (6G) mobile communication technologies may be described by way of example, but the embodiments of the present disclosure may also be applied to other communication systems having similar technical backgrounds or channel types. For example, newly evolved mobile communication systems developed after 5G and 6G may be included. Furthermore, based on determinations by those skilled in the art, the embodiments of the present disclosure may also be applied to other communication systems (e.g., Wi-Fi systems) through some modifications without significantly departing from the scope of the present disclosure

In the following description, the terms physical channel and signal may be used interchangeably with data or control signal. For example, the term physical downlink shared channel (PDSCH) refers to a physical channel through which data is transmitted, but the term PDSCH may also be used to refer to the data itself. That is, in the present disclosure, the expression "transmit a physical channel" may be interpreted as being equivalent to the expression "transmit data or a signal via a physical channel."

Hereinafter, in the context of the present disclosure, higher layer signaling may refer to signaling corresponding to at least one or any combination of the following: master information block (MIB), system information block (SIB) or SIB M (M = 1, 2, ...), radio resource control (RRC), or medium access control (MAC) control element (CE), or a non-access stratum (NAS) signaling message, or an application layer message. The RRC signaling message may be referred to as L3 (layer 3) signaling.

In addition, L1 signaling may refer to signaling corresponding to at least one or any combination of signaling techniques using the at least one or any combination of the following physical layer channels or signaling: physical downlink control channel (PDCCH), downlink control information (DCI), user equipment (UE)-specific DCI, group-common DCI, common DCI, scheduling DCI (e.g., DCI used for scheduling downlink or uplink data), non-scheduling DCI (e.g., DCI not used for scheduling downlink or uplink data) physical uplink control channel (PUCCH), or uplink control information (UCI). The L1 signaling message may be referred to as a physical layer signaling.

Hereinafter, the expression that information is configured by the BS, as used in the present disclosure or claims, may, in context, be understood to mean that the terminal receives the corresponding information from the BS via a physical layer signaling or a higher layer signaling. Such an expression may be replaced with other terms having the same or substantially equivalent meaning.

Hereinafter, the operational principle of the present disclosure will be described in detail with reference to the accompanying drawings.

The application is based on and claims priority from Indian Provisional Applications 202441048578 filed on 25th June 2024 and 202441050696 filed on 02nd July 2024, the disclosures of which is hereby incorporated by reference herein.

The advent of 5th generation (5G) communication systems has brought significant advancements in providing enhanced mobile broadband, ultra-reliable low-latency communication, and massive machine-type communication. Among these advancements, the integration of satellite communication within the 5G framework presents a promising solution to extend coverage to remote and underserved areas. One of the operational modes in this context is the Store and Forward (S&F) satellite operation, which is particularly beneficial for delay-tolerant communication services. This mode is designed to provide intermittent or temporary connectivity for user equipment (UEs) under satellite coverage when direct, real-time connections are not feasible.

The S&F concept is well-established in the realms of delay-tolerant networking (DTN) and disruption-tolerant networking (DTN). The S&F satellite operations are particularly suited for delivering delay-tolerant or non-real-time Internet of Things (IoT) services using non-geostationary satellite orbit (NGSO) satellites.

In 5G or 4G systems with satellite access, the S&F operating mode is utilized when a feeder link is unavailable for the serving satellite at the current UE location. In such scenarios, the UE receives a wait timer and satellite IDs from the on-board Mobility Management Entity (MME) when the ground-based MME is not accessible. This mechanism ensures that UEs can still receive communication services despite intermittent satellite connectivity.

However, the S&F mode introduces several challenges. For instance, there may be multiple satellites, such as SAT-1, SAT-3, and SAT-5, which serve the UE at different times. Not all satellites may have the UE context, which is crucial for communication. If the UE attempts to access a satellite that lacks its context, the satellite may reject the request, leading to a loss of context on the UE side while the network maintains it.

Also, there is no mechanism available at the network using which network can indicate to the UE to use any satellite accessible to it. i.e. when the UE is selectively using the satellites in other words accessing only subset of satellite. How to indicate to the UE that the UE may use any satellite(s).

Moreover, existing mechanisms do not adequately address scenarios where the wait timer expires. Specifically, the UE's actions upon wait timer expiry and the duration for which the satellite IDs should be considered valid for attach or tracking area update (TAU) procedures remain unclear. Additionally, if satellite IDs are not included in the Non-Access Stratum (NAS) message, such as Partial Attach Accept or Partial TAU Accept, the UE's subsequent actions are not well-defined.

Thus, it is desired to address the above-mentioned disadvantages or other shortcomings or at least provide a useful alternative.

The principal object of the invention herein is to provide a method, a UE, and a network apparatus for handling storage validity of satellite information during a NAS procedure in a communication network system.

Another object of the invention herein is to provide a dedicated indication to the UE by the network apparatus to delete any previously provided S&F Monitoring List.

Yet another object of the invention herein is to allow the UE to select/reselect any cell of the same Public Land Mobile Network (PLMN) or equivalent PLMN, e.g., broadcasting any satellite ID or not broadcasting any satellite ID.

The embodiments and their features are detailed with reference to the non-limiting examples shown in the drawings and described below. Well-known components and techniques are omitted to avoid unnecessary detail. The described embodiments are not mutually exclusive and can be combined to form new embodiments. The term "or" is used in a non-exclusive sense unless stated otherwise. The examples provided are for illustrative purposes to aid understanding and should not be seen as limiting the scope of the embodiments.

As is existing in the field, embodiments can be described and illustrated in terms of blocks which carry out a described function or functions.　These blocks, which can 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 can optionally be driven by firmware and software. 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 can be implemented by dedicated hardware, or by a processor (e.g., 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 can 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 can be physically combined into more complex blocks without departing from the scope of the disclosure.

The accompanying drawings aid in understanding the technical features, but the embodiments are not limited to these drawings. The disclosure extends to any alterations, equivalents, and substitutes beyond those shown. Terms like first, second, etc., are used for distinction and do not limit the elements.

Throughout the specification, the definitions of the various terms used in the embodiments are as follows:

Satellite: An artificial body placed in orbit around the earth or moon or another planet in order to collect information or for communication.

Satellite Constellation: Group of satellites placed in orbit around the earth or moon or another planet in order to collect information or for communication.

Service User: An individual who has received a priority level assignment from a regional/national authority (i.e., an agency authorized to issue priority assignments) and has a subscription to a mobile network operator.

Visited PLMN (VPLMN): This is a PLMN different from the HPLMN (if the Equivalent Home Public Land Mobile Network (EHPLMN) list is not present or is empty) or different from an EHPLMN (if the EHPLMN list is present).

Allowable PLMN: In the case of a mobile station (MS) operating in MS operation mode A or B, this is a PLMN which is not in the list of "forbidden PLMNs" in the MS. In the case of an MS operating in MS operation mode C or an MS not supporting A/Gb mode and not supporting Iu mode, this is a PLMN which is not in the list of "forbidden PLMNs" and not in the list of "forbidden PLMNs for General Packet Radio Service (GPRS) service" in the MS.

Available PLMN: PLMN(s) in the given area which is/are broadcasting capability to provide wireless communication services to the UE.

Camped on a cell: The MS (ME if there is no Subscriber Identity Module (SIM)) has completed the cell selection/reselection process and has chosen a cell from which it plans to receive all available services. Note that the services may be limited and that the PLMN or the Standalone Non-Public Networks (SNPN) may not be aware of the existence of the MS (ME) within the chosen cell.

EHPLMN: Any of the PLMN entries contained in the Equivalent HPLMN list.

Equivalent HPLMN list: To allow provision for multiple HPLMN codes, PLMN codes that are present within this list shall replace the HPLMN code derived from the IMSI for PLMN selection purposes. This list is stored on the Universal Subscriber Identification Module (USIM) and is known as the EHPLMN list. The EHPLMN list may also contain the HPLMN code derived from the IMSI. If the HPLMN code derived from the IMSI is not present in the EHPLMN list, then it shall be treated as a Visited PLMN for PLMN selection purposes.

Home PLMN: This is a PLMN where the Mobile Country Code (MCC) and Mobile Network Code (MNC) of the PLMN identity match the MCC and MNC of the IMSI.

Registered PLMN (RPLMN): This is the PLMN on which certain LR (location registration, which is also called a registration procedure) outcomes have occurred. In a shared network, the RPLMN is the PLMN defined by the PLMN identity of the CN operator that has accepted the LR.

Registration: This is the process of camping on a cell of the PLMN or the SNPN and doing any necessary LRs.

User controlled PLMN (UPLMN): PLMN/access technology combination in the "User Controlled PLMN Selector with Access Technology" data file in the SIM (in priority order).

Operator Controlled PLMN (OPLMN): PLMN/access technology combination in the "Operator Controlled PLMN Selector with Access Technology" data file in the SIM (in priority order) or stored in the ME (in priority order).

Serving satellite: A satellite providing the satellite access to a UE. In the case of NGSO, the serving satellite is always changing due to the nature of the constellation.

Store & Forward Satellite operation: In the context of the proposed solution, it is an operation mode of a 5G system with satellite access where the 5G system can provide some level of service (in storing and forwarding the data) when satellite connectivity is intermittently/temporarily unavailable, e.g., to provide communication service for UEs under satellite coverage without a simultaneous active feeder link connection to the ground segment.

S&F data retention period: It is the data storage validity period for the 5G system with satellite access supporting store and forward operation (e.g., after which undelivered data stored is being discarded).

UE-Satellite-UE Communication: For the 5G system with satellite access, it refers to the communication between UEs under the coverage of one or more serving satellites using satellite access without going through the ground segment.

The invention pertains to a communication network system and specifically to a set of Non-Access Stratum (NAS) messages utilized within the system. The NAS messages include but are not limited to the following: 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, and UE PARAMETERS UPDATE command.

The 5GMM sublayer states referenced in the proposed solution include the following: (1) 5GMM-NULL representing a state with no established 5GMM context, (2) 5GMM-DEREGISTERED which encompasses several sub-states including NORMAL-SERVICE, LIMITED-SERVICE, ATTEMPTING-REGISTRATION, PLMN-SEARCH, NO-SUPI, NO-CELL-AVAILABLE, eCALL-INACTIVE, and INITIAL-REGISTRATION-NEEDED, (3) 5GMM-REGISTERED-INITIATED indicating the initial stage of registration, (4) 5GMM-REGISTERED which includes NORMAL-SERVICE, NON-ALLOWED-SERVICE, ATTEMPTING-REGISTRATION-UPDATE, LIMITED-SERVICE, PLMN-SEARCH, NO-CELL-AVAILABLE, and UPDATE-NEEDED sub-states, (5) 5GMM-DEREGISTERED-INITIATED representing a state where deregistration has been initiated, and (6) 5GMM-SERVICE-REQUEST-INITIATED indicating the initiation of a service request within the 5GMM framework.

In an embodiment, the term Evolved Universal Mobile Telecommunication Access (EUTRA) Mobility Management (EMM) sublayer states are one or more of the following: (1) EMM-NULL representing the UE is not registered with the network, (2) EMM-DEREGISTERED which encompasses several sub-states including NORMAL-SERVICE, LIMITED-SERVICE, ATTEMPTING-TO-ATTACH, PLMN-SEARCH, NO-IMSI, ATTACH-NEEDED, NO-CELL-AVAILABLE, and eCALL-INACTIVE, (3) EMM-REGISTERED-INITIATED indicating the UE has initiated the registration process, (4) EMM-REGISTERED which encompasses several sub-states including NORMAL-SERVICE, ATTEMPTING-TO-UPDATE, LIMITED-SERVICE, PLMN-SEARCH, UPDATE-NEEDED, NO-CELL-AVAILABLE, ATTEMPTING-TO-UPDATE-MM, IMSI-DETACH-INITIATED, (5) EMM-DEREGISTERED-INITIATED indicating the UE has initiated a deregistration process, (6) EMM-TRACKING-AREA-UPDATING-INITIATED indicating the UE has initiated a TAU to inform the network that it has moved to a new tracking area, and (7) EMM-SERVICE-REQUEST-INITIATED indicating the UE has initiated a service request.

The term "Radio Access Technology" (RAT) as defined in this proposed solution encompasses a wide range of technologies including Next Generation Radio Access Network (NG-RAN), Fifth Generation (5G), Fourth Generation (4G), Third Generation (3G), Second Generation (2G), Evolved Packet System (EPS), 5G System (5GS), New Radio (NR), NR in unlicensed bands, NR via Low Earth Orbit satellites (NR(LEO)), NR via Medium Earth Orbit satellites (NR(MEO)), NR via Geostationary Orbit satellites (NR(GEO)), NR via other satellite types (NR(OTHERSAT)), NR Reduced Capability (NR RedCap), Evolved Universal Terrestrial Radio Access (E-UTRA), E-UTRA in unlicensed bands, Narrowband Internet of Things (NB-IoT), Wideband IoT (WB-IoT), and Long Term Evolution (LTE) for Machines (LTE-M).

The 5GS registration types include initial registration, mobility registration updating, periodic registration updating, emergency registration, and Standalone Non-Public Networks (SNPN) onboarding registration. Additionally, there are "disaster roaming initial registration" and "disaster roaming mobility registration updating" types. When the registration type is not set to "disaster roaming initial registration" or "disaster roaming mobility registration updating," it means that the 5GS registration type is set to a value other than these two. One or more of the following registration types must be set: initial registration, mobility registration updating, periodic registration updating, emergency registration, or SNPN onboarding registration.

The following discloses PLMN selection as per 23.122 without RPLMN. The MS selects and attempts registration on any PLMN/access technology combinations if available and allowable in the following order: a) either the HPLMN (if the EHPLMN list is not present or is empty) or the highest priority EHPLMN that is available (if the EHPLMN list is present), b) each PLMN/access technology combination in the "User Controlled PLMN Selector with Access Technology" data file in the SIM (in priority order), c) each PLMN/access technology combination in the "Operator Controlled PLMN Selector with Access Technology" data file in the SIM (in priority order) or stored in the ME (in priority order), d) other PLMN/access technology combinations with received high-quality signal in random order, and e) other PLMN/access technology combinations in order of decreasing signal quality.

The following discloses PLMN selection as per 23.122 with RPLMN. The MS selects and attempts registration on any PLMN/access technology combinations if available and allowable in the following order: a) either the RPLMN or the last registered PLMN, b) either the HPLMN (if the EHPLMN list is not present or is empty) or the highest priority EHPLMN that is available (if the EHPLMN list is present), c) each PLMN/access technology combination in the "User Controlled PLMN Selector with Access Technology" data file in the SIM (in priority order), d) each PLMN/access technology combination in the "Operator Controlled PLMN Selector with Access Technology" data file in the SIM (in priority order) or stored in the ME (in priority order), e) other PLMN/access technology combinations with received high-quality signal in random order, and f) other PLMN/access technology combinations in order of decreasing signal quality.

For a 5G system with satellite access, the following requirements apply: The 5G system shall support service continuity between NR terrestrial access network and NR satellite access networks owned by the same operator or owned by 2 different operators having an agreement. The Non Terrestrial Networks (NTN) and Terrestrial Networks (TN) could either operate in two different frequency bands (e.g. FR1 vs FR2), or in same frequency band (e.g. FR1 or FR2). The terms satellite 3GPP access, satellite access, satellite access network, new radio (NR) satellite access network, satellite NG-RAN access technology and NR Satellite access have been interchangeably used and have the same meaning. The methods, issues or solutions disclosed in this embodiment are explained using NR satellite access or Satellite NG-RAN Access Technology as an example and is not restricted or limited to NR Satellite access only. However, the solutions proposed in this embodiment are also applicable for Satellite E-UTRAN access Technology, Narrow Band (NB)-S1 mode or Wide Band (WB)-S1 mode via satellite E-UTRAN access and/or NB-IOT or WB-IOT Satellite Access/Architecture. The solutions which are defined for NR (5G core (5GC)) are also applicable to existing RATs like E-UTRA/LTE, the corresponding CN entities needs to be replaced by LTE entities for e.g. AMF with MME, g-nodeB with e-nodeB, Unified Data Management Function (UDM) with home subscriber server (HSS) etc. But principles of the solution remain same. In the similar way, the solutions or proposal which are defined for LTE (Evolved Packet Core (EPC)) are also applicable to other RAT(s) (for ex- 5G or 5GC and other RATs).

An example list of NAS messages can be, but not limited to, REGISTRATION REQUEST message; DEREGISTRATION REQUEST message (also called as Detach request message); SERVICE REQUEST message; CONTROL PLANE SERVICE REQUEST; IDENTITY REQUEST; AUTHENTICATION REQUEST; AUTHENTICATION RESULT; AUTHENTICATION REJECT; REGISTRATION REJECT; DEREGISTRATION/DETACH ACCEPT; SERVICE REJECT; SERVICE ACCEPT, and so on. The Network used in this embodiment is explained using any 5G Core Network Function for e.g. AMF. However, the network could be any 5G/EUTRAN Core Network Entities like Access and Mobility Management Function (AMF)/Session management function (SMF)/MME/User plane function (UPF) or the Network could be any 5G/EUTRAN RAN Entity like eNB or gNB or NG-RAN etc. The messages used or indicated in this embodiment are shown as an example. The messages could be any signaling messages between UE and the Network Functions/Entities or between different Network functions/entities. The term area/location/geographical area are used in this embodiment may refer to any of cell/cell ID, Tracking Area Code (TAC)/ Tracking Area Identity (TAI), PLMN, Mobile Country Code (MCC)/ Mobile Network Code (MNC), Latitude/longitude, Closed access group (CAG) cell or any geographical location/coordinate.

The methods, issues or solutions disclosed in this embodiment are explained using NR access or NG-RAN Access Technology as an example and is not restricted or limited to NR access only. However, the solutions proposed in this embodiment are also applicable for E-UTRAN access Technology, NB-S1 mode or WB-S1 mode via E-UTRAN access and/or NB-IOT or WB-IOT Access/Architecture. The solutions which are defined for NR (5GC) are also applicable to legacy RATs like E-UTRA/LTE, the corresponding CN entities needs to be replaced by LTE entities for e.g. AMF with MME, g-nodeB with e-nodeB, UDM with HSS etc. But principles of the solution remains same. The Network used in this embodiment is explained using any 5G Core Network Function for e.g. AMF. However, the network could be any 5G/EUTRAN Core Network Entities like AMF/SMF/MME/UPF or the Network could be any 5G/EUTRAN RAN Entity like eNodeB (eNB) or gNodeB (gNB) or NG-RAN etc. The messages used or indicated in this embodiment are shown as an example. The messages could be any signalling messages between UE and the Network Functions/Entities or between different Network functions/entities.

The terms camp and register are used interchangeably and have the same meaning. The terms wait timer, DisCo wait timer, Discontinuous Coverage wait (DCW) timer, Random timer, Random wait timer, DCW Timer are all used interchangeably and have the same meaning. The terms wait range, Disco Wait Range, Discontinuous Coverage Wait Range, DCW Range are all used interchangeably and have the same meaning. The term area as used in this embodiment may refer to any of cell/cell ID, TAC/TAI, PLMN, MCC/MNC, Latitude/longitude, any CAG/CAG identifier or any geographical location/coordinate. For the list of possible NAS messages please refer to 3GPP TS 24.501 or 3GPP TS 24.301, for list of AS messages please refer to 3GPP TS 38.331 or 3GPP TS 36.331. The cause names in this embodiment are for illustration purpose and it can have any name. The NAS messages and access stratum (AS) messages described in this embodiment is only for illustration purpose it can be any NAS or AS messages as per defined protocol between UE and AMF/MME or UE and gNB (NG-RAN/any RAN node)/ eNB.

In an embodiment, the term satellite is used interchangeably with 5G or 4G system with satellite access and is used to represent any Satellite(s) or constellation of Satellites(s) or any aerial body/satellite in any of the Satellite orbits (for ex- LEO/MEO/GEO/HEO etc) or any 5G system with Satellite Access or 4G System with Satellite Access or any RAN Entity or Core Network Entity or any Network Function(s) associated with the Satellite Access/RAT/PLMN/Network.

Referring now to the drawings, and more particularly to FIGS. 1 through 8, there are shown preferred embodiments.

FIG. 1 is a schematic diagram illustrating an example of an S&F Satellite operation according to the prior art. This example contrasts with the current assumption for the normal/default Satellite operation of a 5G system with satellite access. Under the normal/default Satellite operation mode, signaling and data traffic exchange between a UE with satellite access and the remote ground network requires the service and feeder links to be active simultaneously. This ensures that when the UE interacts over the service link with the satellite, there is a continuous end-to-end connectivity path between the UE, the satellite, and the ground network.

In contrast, the S&F Satellite operation mode handles the end-to-end exchange of signaling/data traffic as a combination of two steps that are not concurrent in time (steps A and B in FIG. 1). At step A, a signaling/data exchange occurs between the UE and the satellite without the satellite being simultaneously connected to the ground network (i.e., the satellite operates the service link without an active feeder link connection). At step B, connectivity between the satellite and the ground network is established, allowing communication between the satellite and the ground network. Thus, the satellite transitions from being connected to the UE in step A to being connected to the ground network in step B.

The support of S&F satellite operation is particularly suited for the delivery of delay-tolerant/non-real-time IoT satellite services with NGSO satellites.

In one embodiment, an MME functionality is split into two parts: an MME-onboard (the MME part onboard the satellite) and an MME-ground. When a UE initiates an Attach or TAU procedure, it indicates support for S&F mode to the MME following existing NAS capability. If these procedures cannot be completed due to S&F operation, the MME sends an Attach or TAU Reject message to the UE. The Attach or TAU Reject message includes:

a) A new information element indicating to the UE that the attach or TAU procedure cannot be completed because of the S&F operation and that the UE can re-attempt the attach or TAU in this PLMN during the next satellite pass. This informs the UE that the information contained in the Attach or TAU Request message is stored by the MME and that the network will be available to the UE after interaction with the ground network.

b) A wait timer indicating to the UE the time it should wait before re-attempting the Attach/TAU procedure in the current or another satellite of the same PLMN or any other NAS or AS signaling message.

c) Optionally, a list of Satellite IDs over which the UE may re-attempt the Attach/TAU procedure after the wait timer expires. The Satellite IDs are based on the SIB information broadcasted by eNB.

The manner in which the UE processes this information is up to UE implementation. During the wait timer, the UE can search for another terrestrial or satellite PLMN to obtain normal service.

FIG. 2 is a block diagram that illustrates the hardware components associated with the UE (200) according to the embodiments as disclosed herein. As illustrated, the UE (200) includes a processor (201), a memory (202), a communicator (203), and a satellite information controller (204).

Examples of the UE (200) can include, but are not limited to, Consumer Electronics (such as Mobile Phones and Smartphones), Tablets, Wearable Devices, Computing Devices (such as Laptops, Notebooks, Desktops, Workstations, etc.), IoT Devices, Automotive Systems (such as connected cars, Autonomous Vehicles, Vehicle-to-Everything (V2X) communication devices, etc.), Enterprise Devices such as robotics, Specialized Equipment (such as Medical Devices, Public Safety Devices, etc.), Media Devices (such as Gaming Consoles, Streaming Devices, etc.).

The processor (201) is responsible for handling storage validity of satellite information during a NAS procedure in a communication network system. The processor (201) communicates with the memory (202), the communicator (203), and the satellite information controller (204). The processor (201) is configured to execute instructions stored in the memory (202) and to handle storage validity of satellite information during a NAS procedure. The processor (201) may include one or a plurality of processors, maybe a general-purpose processor such as a Central Processing Unit (CPU), an Application Processor (AP), or the like, a graphics-only processing unit such as 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).

The memory (202) stores the operating system, application software, and temporary data used by the processor (201). The memory (202) is not limited to a volatile memory and/or a non-volatile memory. Further, the memory (202) may include a plurality of computer-readable storage media. The memory (202) may include non-volatile storage elements. For example, non-volatile storage elements may include magnetic hard disks, optical disks, floppy disks, flash memories, or forms of electrically programmable memories (EPROM) or electrically erasable and programmable (EEPROM) memories.

The memory (202) stores the operating system, application software, and temporary data used by the processor (201). The memory (202) stores instructions to be executed by the processor (201). The memory (202) may include non-volatile storage elements. Examples of such non-volatile storage elements may include magnetic hard disks, optical disks, floppy disks, flash memories, or forms of EPROM or EEPROM memories. In addition, the memory (202) 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 that the memory (202) is non-movable. The memory (202) stores the S&F monitoring list received from the network apparatus (300). The S&F monitoring list includes satellite IDs belonging to same PLMN over which the UE (200) can attempt or re-attempt the NAS procedure.

The communicator (203) facilitates satellite communication between the network apparatus (300) and the UE (200), supporting various communication protocols such as Transmission Control Protocol/ Internet Protocol (TCP/IP), User Datagram Protocol (UDP) and second generation Digital Video Broadcasting by Satellite (DVB-S2). Further, the communicator (203) is configured for communicating internally between internal hardware components and with the network apparatus (300) via one or more networks. The communicator (203) includes an electronic circuit specific to a standard that enables wired or wireless communication. The communicator (203) facilitates receiving of a S&F monitoring list from the network apparatus (300) when the network apparatus (300) accepts or rejects the NAS procedure and receiving of a NAS message from the network apparatus (300) including an indication to delete the stored S&F monitoring list for the current PLMN at the UE (200). Further, the communicator (203) uses any satellite to access the service which further includes selects or reselects a cell of the same PLMN or an equivalent PLMN to attempt or re-attempt the NAS procedure, after deleting the stored S&F monitoring list.

In an embodiment, the satellite information controller (204) is a specialized hardware component engineered to manage the storage validity of satellite information during a NAS procedure in a communication network system. This hardware implementation ensures efficient and reliable execution of processes integral to maintaining seamless communication in satellite-based systems.

The satellite information controller (204) features an innovative integrated circuit structure with a multi-core architecture tailored to optimize the handling of storage validity. Each core within the architecture is specifically designed to execute distinct functions. For instance, one core is responsible for receiving the Store and Forward (S&F) monitoring list from the network apparatus (300). Another core handles the secure storage of the S&F monitoring list in the memory (202). Additional cores manage tasks such as receiving NAS messages from the network apparatus and processing satellite-specific protocols. This hardware-centric approach not only ensures the technical robustness of the system but also highlights the structural and functional innovation embedded within the satellite information controller (204). The multi-core design and task-specific optimizations demonstrate a technical contribution to the field of satellite communication, meeting the requirements of Section 3(k) of the Patents Act by showcasing a tangible and inventive technical advancement.

In an embodiment, the satellite information controller (204) receives a S&F monitoring list from the network apparatus (300) when the network apparatus accepts or rejects the NAS procedure. The S&F monitoring list includes satellite IDs belonging to same PLMN over which the UE (200) can attempt or re-attempt the NAS procedure. The satellite information controller (204) stores the S&F monitoring list in the memory (202) and a NAS message is received from the network apparatus (300). The NAS message includes an indication to delete the stored S&F monitoring list at the UE (200).

In an embodiment, the satellite information controller (204) deletes the stored S&F monitoring list from the memory (202) of the UE (200) when the indication in the NAS message indicates to delete the stored S&F monitoring list for the current PLMN. Further, the satellite information controller (204) uses any satellite to access the service which further includes selecting or reselecting a cell of the same PLMN or an equivalent PLMN to attempt or re-attempt the NAS procedure, after deleting the stored S&F monitoring list.

The comprehensive management capabilities of the satellite information controller (204) ensure seamless handling of storage validity of satellite information during a NAS procedure in a communication network. In cases where the stored S&F monitoring list becomes outdated or invalid, the satellite information controller (204) proactively initiates a refresh process to obtain the latest satellite IDs from the network apparatus (300). This proactive approach minimizes the chances of communication failures and ensures that the UE (200) can always attempt or re-attempt the NAS procedure with the most accurate and up-to-date satellite information. By doing so, the satellite information controller (204) significantly contributes to the overall robustness and efficiency of the communication network.

FIG. 3 is a block diagram that illustrates the hardware components associated with the network apparatus (300) according to the embodiments as disclosed herein. As illustrated, the network apparatus (300) includes a processor (301), a memory (302), a communicator (303), and a S&F monitoring list controller (304).

Examples of the network apparatus (300) can include, but is not limited to Base Stations (such as macro cells, small cells, femtocells, picocells) for wireless communication, Antennas and RF Units (e.g., multiple input multiple output (MIMO), beamforming) to enhance signal coverage and data throughput, Core Network Equipment (e.g., MMEs, S-GWs, P-GWs in 4G; AMFs, UPFs in 5G) for data routing, mobility, and session control, Network function Virtualization (NFV) and Software-Defined Networking (SDN) for dynamic resource allocation and scalability, Edge Computing Nodes (e.g., MEC servers) for low-latency processing, Backhaul and Transport Equipment (e.g., fiber-optic links, microwave relays, Ethernet switches) to connect base stations to the core network, Network Management Systems (NMS) and Operation Support Systems (OSS) for network configuration, fault management, and optimization, Radio Network Controllers (RNCs) in 3G, Distributed Units (DUs), and Centralized Units (CUs) in 5G, Network Slicing Components for virtualized resource allocation, Security elements (e.g., Firewalls, IDS, AAA Servers) for secure communication.

The satellite communication system refers to a network of artificial satellites that facilitate communication by transmitting signals from one point on Earth to another. These systems can include various types of satellites such as, but are not limited to, GSO satellites, NGSO satellites, Geostationary Earth Orbit (GEO) satellites, Medium Earth orbit (MEO) satellites, Low Earth orbit (LEO) satellites, Sun-synchronous orbit (SSO) satellites and Geostationary Transfer Orbit (GTO) satellites.

In an embodiment, the network apparatus (300) includes a processor (301), a memory (302), a communicator (303), and an S&F monitoring list controller (304). The processor (201) is coupled with the memory (302) which includes an information of the UE (200), the communicator (303), and the S&F monitoring list controller (304).

The processor (301) is responsible for handling storage validity of satellite information during a NAS procedure in a communication network system. The processor (301) communicates with the memory (302), the communicator (303), and the S&F IOC controller (304). The processor (301) is configured to execute instructions stored in the memory (302) and to handle storage validity of satellite information during a NAS procedure. The processor (301) may include one or a plurality of processors, maybe a general-purpose processor such as a CPU, an AP, or the like, a graphics-only processing unit such as a GPU, a VPU, and/or an AI dedicated processor such as an NPU.

The memory (302) stores the operating system, application software, and temporary data used by the processor (301). The memory (302) stores instructions to be executed by the processor (301). The memory (302) may include non-volatile storage elements. Examples of such non-volatile storage elements may include magnetic hard disks, optical disks, floppy disks, flash memories, or forms of EPROM or EEPROM memories. In addition, the memory (302) 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 that the memory (302) is non-movable. The memory (302) includes the information of the UE (200), a S&F monitoring list when the UE (200) supports the S&F capability. The S&F monitoring list includes satellite IDs belonging to at least one of the same PLMN and equivalent PLMN over which the UE (200) can attempt or re-attempt the NAS procedure, and the satellite IDs are based on SIB information broadcasted by an eNB associated with the network apparatus (300).

The communicator (303) facilitates satellite communication between the network apparatus (300) and the UE (200), supporting various communication protocols such as Transmission Control Protocol/ Internet Protocol (TCP/IP), User Datagram Protocol (UDP) and second generation Digital Video Broadcasting by Satellite (DVB-S2). Further, the communicator (303) is configured for communicating internally between internal hardware components and with the UE (200) via one or more networks. The communicator (303) includes an electronic circuit specific to a standard that enables wired or wireless communication. The communicator (303) facilitates the transmission of the S&F monitoring list to the UE (200) when the network apparatus (300) accepts or rejects the NAS procedure and sends a NAS message to the UE (200). The NAS message includes an indication to delete the stored S&F monitoring list at the UE (200). The indication includes a value indicating to the UE (200) to delete the stored S&F monitoring list or continue to retain the S&F monitoring list.

The S&F monitoring list controller (304) is a specialized hardware designed to ensure handling storage validity of satellite information during a NAS procedure in a communication network system

In an embodiment, the structure of such innovative integrated circuit of the S&F monitoring list controller (304) can include a multi-core architecture that enables the handling of the storage validity of satellite information during a NAS procedure in a communication network system. Each core is optimized for specific tasks, such as determining the S&F capability of the UE (200), generating the S&F monitoring list, sending the S&F monitoring list to the UE (200), and sending a NAS message to the UE (200) including an indication to delete the stored S&F monitoring list.

The S&F monitoring list controller (304) determines that the UE (200) indicates a S&F capability. The S&F satellite operation in a 5G system with satellite access provides some level of communication service for the UEs (200) under satellite coverage with intermittent/temporary satellite connectivity for delay-tolerant communication service.

The S&F monitoring list controller (304) generates a S&F monitoring list, when the UE (200) supports the S&F capability. The S&F monitoring list includes satellite IDs belonging to at least one of the same PLMN and equivalent PLMN over which the UE (200) can attempt or re-attempt the NAS procedure. Further, the satellite IDs are based on SIB information broadcasted by an eNB associated with the network apparatus (300).

The S&F monitoring list controller (304) sends the S&F monitoring list to the UE (200) when the network apparatus (300) accepts or rejects the NAS procedure and sends a NAS message to the UE (200). The NAS message includes an indication to delete the stored S&F monitoring list at the UE and the indication includes a value indicating to the UE (200) to delete the stored S&F monitoring list or continue to retain the S&F monitoring list.

The comprehensive management capabilities of the S&F monitoring list controller (304) ensure seamless handling of storage validity of satellite information during a NAS procedure in a communication network.

FIG. 4A is a flow diagram that illustrates a proposed method for handling storage validity of satellite information during a NAS procedure in a communication network system by a UE (200) according to embodiments as disclosed herein. At step 401, the method includes the UE (200) receiving an S&F monitoring list from a network apparatus (300) when the network apparatus (300) accepts or rejects the NAS procedure. The S&F monitoring list includes satellite IDs belonging to the same PLMN over which the UE (200) can attempt or re-attempt the NAS procedure and UE (200) storing the S&F monitoring list. The satellite IDs are based on SIB information broadcasted by an eNB associated with the network apparatus (300). At step 402, the method includes the UE (200) receiving a NAS message from the network apparatus (300). The NAS message includes an indication to delete the stored S&F monitoring list at the UE (200). The indication includes a value indicating to the UE (200) to delete the stored S&F monitoring list or continue to retain the S&F monitoring list. At step 403, the method includes the UE (200) deleting the stored S&F monitoring list when the indication in the NAS message indicates to delete the stored S&F monitoring list for the current PLMN. At step 404, the method includes the UE (200) using any satellite to access the service which further includes selecting or reselecting by the UE (200), a cell of the same PLMN or an equivalent PLMN to attempt or re-attempt the NAS procedure, after deleting the stored S&F monitoring list. The UE (200) selects or reselects the cell of the same PLMN or the equivalent PLMN irrespective of whether the cell is broadcasting or not broadcasting any satellite ID of the satellite IDs available in the S&F monitoring list after the stored S&F monitoring list for the current PLMN is deleted by the UE (200).

FIG. 4B is a flow diagram that illustrates the proposed method for receiving the S&F monitoring list from the network apparatus (300) according to the embodiments as disclosed herein. In an embodiment, at step 401a, the method 401 initiates the NAS procedure with the network apparatus (300) and indicates to the network apparatus (300) the UE's (200) support for an S&F capability. Then the UE (200) performs one of steps 401b or 401c. At step 401b, the method 401 receives a NAS reject message from the network apparatus (300) when the NAS procedure is not completed due to an S&F operation. The NAS reject message includes the S&F monitoring list including the satellite IDs belonging to the same PLMN (the same PLMN implies the PLMN over which the UE attempted the NAS procedure or the PLMN from which the UE received the NAS message) over which the UE (200) can attempt or re-attempt the NAS procedure. At step 401c, the method 401 receives a NAS accept message from the network apparatus (300) when the NAS procedure is completed. The NAS accept message includes the S&F monitoring list including the satellite IDs belonging to the same PLMN over which the UE (200) can attempt or re-attempt the NAS procedure. The UE (200) supporting the S&F satellite operation receives a NAS message without including the information element with the S&F monitoring list, the UE (200) erases any stored value for the S&F monitoring list of the current PLMN. Further, the UE (200) stores S&F monitoring list when it receives from the current PLMN.

The term same PLMN in this embodiment implies the PLMN/the equivalent PLMN over which the UE (200) attempted the NAS procedure or the PLMN/the equivalent PLMN from which the UE (200) received the NAS message.

FIG. 5A is a flow diagram that illustrates a proposed method for handling storage validity of satellite information during a NAS procedure in a communication network system by the network apparatus (300) according to the embodiments as disclosed herein. At step 501, the method includes the network apparatus (300) determining that a UE (200) indicates an S&F capability. At step 502, the method includes the network apparatus (300) generating an S&F monitoring list when the UE (200) supports the S&F capability. The S&F monitoring list includes satellite IDs belonging to at least one of the same PLMN and equivalent PLMN over which the UE (200) can attempt or re-attempt the NAS procedure. The satellite IDs are based on SIB information broadcasted by an eNB. At step 503, the method includes the network apparatus (300) sending the S&F monitoring list to the UE (200) when the network apparatus (300) accepts or rejects the NAS procedure. At step 504, the method includes the network apparatus (300) sending a NAS message to the UE (200). The NAS message includes an indication to delete the stored S&F monitoring list at the UE (200). The indication includes a value indicating to the UE (200) to delete the stored S&F monitoring list or continue to retain the S&F monitoring list.

FIG. 5B is a flow diagram that illustrates a proposed method for sending the S&F monitoring list to the UE (200) by the network apparatus (300) according to the embodiments as disclosed herein.

In an embodiment at step 503a, the method 503 detects an initiation of the NAS procedure with the network apparatus (300) and performs one of the steps 503b or 503c. At step 503b, the method 503 sends an NAS reject message to the UE (200), when the NAS procedure is not completed due to an S&F operation. The NAS reject message includes the S&F monitoring list including the satellite IDs belonging to the same PLMN over which the UE (200) can attempt or re-attempt the NAS procedure. At step 503c, the method 503 sends an NAS accept message to the UE (200), when the NAS procedure is completed. The NAS reject accept includes the S&F monitoring list including the satellite IDs belonging to the same PLMN over which the UE (200) can attempt or re-attempt the NAS procedure.

FIG. 6A is a sequence diagram that illustrates an existing scenario of handling storage validity of satellite parameters, according to the prior art.

The 5G or 4G system with satellite access may support store and forward mechanism (i.e. S/F operating mode or mechanism) when feeder link is not available for the serving satellite at the current UE location. According to the existing mechanisms, the UE (200) receives a wait timer and satellite IDs from MME on-board (602) when MME ground (603) is not available. In case when the wait timer gets expired, what should be the UE (200) action and for how long the UE (200) should consider the satellite IDs as valid for Attach or TAU procedures after wait timer expiry. When the satellite IDs are not included in the NAS message (Attach Accept/ TAU accept or any other NAS message) what should be the UE (200) action is not defined.

At step 1, the UE (200) starts an initial attach procedure/TAU procedure and sends an Attach request/TAU request to the MME on-board satellite via available service link. At step 2, in the absence of feeder link, the MME on-board (602) cannot forward a UE NAS signalling message to the MME on-ground (603). The MME on-board (602) sends a Downlink (DL) NAS message for e.g. NAS message (e.g. Attach Accept / Reject, Tracking Area update Accept / Reject or any other NAS message) to the UE (200). The MME on-board (602) includes the wait timer and satellite IDs in the DL NAS message. At step 3, the UE (200) receives the DL NAS signalling message with wait timer and satellite IDs from the step 2 and starts the wait timer. The UE (200) starts the wait timer and waits till the expiry of the wait timer before reattempting the attach/TAU procedure on the satellite with these satellite IDs, optionally on per PLMN basis.

On wait timer expiry, when the UE (200) does not find any satellite with these satellite IDs then what action should UE (200) perform and for how long the UE (200) should consider the satellite IDs as valid for Attach or TAU procedures after wait timer expiry is not defined in the existing methods.

FIG. 7 is a sequence diagram that illustrates a proposed scenario of handling storage validity of satellite parameters according to the embodiments as disclosed herein.

In an embodiment, at step 1, the UE (200) starts an initial Attach procedure/TAU procedure and sends an Attach request/TAU request to an MME on-board (602) satellite via an available service link. At step 2, in the absence of feeder link, the MME on-board (602) cannot forward a UE NAS signaling message to an MME on-ground (603). The MME on-board (602) sends a DL NAS message for e.g. NAS message (e.g. Attach Accept / Reject, Tracking Area update Accept / Reject or any other NAS message) to the UE (200). The MME on-board (602) includes wait timer and satellite IDs in the DL NAS message. At step 3, the UE (200) receives the DL NAS signaling message with the wait timer and the satellite IDs from the step 2 and starts the wait timer. The UE (200) starts the wait timer and waits till the expiry of the wait timer before reattempting the Attach/TAU procedure on the satellite with these Satellite IDs, optionally on per PLMN basis. At step 4, on wait timer expiry, then UE (200) can perform any of below action in any order or combination:

A) The UE (200) can start a Satellite ID Validity timer for which these satellite IDs (also called as list of satellite IDs or stored Satellite IDs in this embodiment) will be valid. On the expiry of a Satellite ID Validity timer the UE (200) shall delete theses satellite IDs. The satellite ID validity timer value can be obtained in any of below combinations:

▶ The network can provide in any AS or NAS message (e.g. in the Attach/TAU accept or any other AS or NAS message)

▶ The timer value can be obtained/adjusted based on the UE location change from the time when the Attach/TAU Accept is received to the time when the wait timer got expired.

▶ It can be a predefined timer stored in UE (200)/ME/SIM, optionally on per PLMN basis. The PLMN can be the serving PLMN which has configured in the UE (200) or the HPLMN or EHPLMN.

B) In an embodiment, the UE (200) can discard the satellite IDs on wait timer expiry.

In an embodiment, a satellite ID validity timer calculates the time for which the UE (200) shall consider the stored satellite IDs as valid, the timer is started after the wait timer has expired or optionally when the wait timer has started (i.e. when the NAS message is received along with the wait timer or the satellite ID Validity timer) or when the coverage of at least one cell belonging to this satellite IDs is lost. This time determines when coverage of at least one cell of this satellite IDs is lost and how long UE can wait before it can find the cells of the same satellite IDs.

In an embodiment, the satellite ID validity timer is at least equal to or greater than wait timer.

In an embodiment, the satellite ID validity timer is restarted (i.e. stopped and started again each time UE (200) finds a cell belonging to this satellite IDs) or when the UE (200) performs a NAS signaling with the network(e.g. establishes a NAS signaling or AS signaling connection with the network) i.e. when the UE (200) enters into connected state/mode optionally on at least one of the cells belonging to this satellite IDs or when the UE (200) enters into the IDLE state/mode optionally on at least one of the cells belonging to these satellite IDs.

In an embodiment, when the list of satellite IDs are deleted by the UE (200), the UE (200) is allowed to select or reselect any cell of the same PLMN or equivalent PLMN e.g. broadcasting any satellite ID or not broadcast any satellite ID. i.e. When the S&F Monitoring List is deleted then the UE (200) may use any satellite(s).

FIG. 7A is sequence diagram that illustrates an existing scenario of UE (200) behavior when the MME on-board does not configure satellite IDs and wait timer in the DL NAS message to the UE (200) according to the prior art.

At step 1, the UE (200) starts an initial Attach procedure/TAU procedure and sends an Attach request/TAU request to an MME on-board satellite (702) via available service link. At step 2a, in the absence of feeder link, the MME on-board (702) cannot forward a UE NAS signaling message to the MME on-ground (703). The MME on-board (702) sends a DL NAS message for e.g. Attach Accept / Reject, Tracking Area update Accept / Reject or any other NAS message) to the UE (200). The MME on-board (702) does not configure satellite IDs in the DL NAS message. At step 2b, in the absence of feeder link, the MME on-board (702) cannot forward a UE NAS signaling message to the MME on-ground (703). The MME on-board (702) sends a DL NAS message for e.g. Attach Accept / Reject, Tracking Area update Accept / Reject or any other NAS message) to the UE (200). The MME on-board (702) does not configure wait timer in the DL NAS message.

When the UE (200) receives such a configuration as in the steps 2a or/and 2b, what should be the UE (200) behavior is not defined in the existing methods.

FIG. 7B is sequence diagram that illustrates a proposed scenario of UE (200) behavior when the MME on-board (702) does not configure satellite IDs and wait timer in the DL NAS message to the UE (200) according to the embodiments as disclosed herein.

At step 1, the UE (200) starts an initial Attach procedure/TAU procedure and sends an attach request/TAU request to an MME on-board satellite (702) via an available service link. At step 2a, in the absence of feeder link, the MME on-board (702) cannot forward a UE NAS signaling message to an MME on-ground (703). The MME on-board (702) sends a DL NAS message (for e.g. Attach Accept / Reject, Tracking Area update Accept / Reject or any other NAS message) to the UE (200). The MME on-board (702) does not configure satellite IDs in the DL NAS message. At step 2b, in the absence of feeder link, the MME on-board (702) cannot forward a UE NAS signaling message to the MME on-ground (703). The MME on-board (702) sends a DL NAS message for e.g. Attach Accept / Reject, Tracking Area update Accept / Reject or any other NAS message) to the UE (200). The MME on-board (702) does not configure wait timer in the DL NAS message. At step 3a, in case when the satellite IDs are not present in the NAS message (for e.g. Attach Accept / Reject, Tracking Area update Accept / Reject or any other NAS message), optionally the wait timer is included, the UE (200) can perform any of the below actions in any order or combinations:

a) The UE (200) shall delete any stored satellite IDs. i.e. If the UE (200) supports S&F satellite operation and the ATTACH ACCEPT message or TAU accept message or any of the NAS message does not include the S&F satellite operation parameters IE i.e. does not configure the list of satellite ID, the UE shall erase any stored value for the S&F monitoring list of the current PLMN.

b) The UE (200) shall stop the satellite IDs validity timer.

c) The UE (200) should wait for the expiry of the wait timer and after expiry the UE (200) can start the Attach/TAU procedure or in general a NAS procedure in the current or another satellite of the same PLMN. Upon the wait timer expiry, the UE (200) should start PLMN selection procedure(optionally) and consider camping/selecting on any cell of the PLMN from which ATTACH REJECT/ Tracking Area Reject Msg is received and start ATTACH/TAU procedure or any NAS signalling procedure on the same PLMN or other PLMN.

d) In an embodiment, a dedicated indication is provided to the UE (200) in the NAS message, based on this dedicated indication as part of the NAS or the AS message the UE (200) deletes the stored list of satellite IDs. This dedicated indication can be a new information element (IE) or existing IE with the value indicating to the UE (200) to delete the stored list of satellite IDs or continue to retain the list of satellite IDs (i.e. not delete it) for e.g. list of satellite IDs Information element is provided to the UE (200) but without including any satellite IDs or indicating the size of the IE as zero. This indicates to the UE that list of satellite IDs, if any stored in the UE (200) should be deleted.

i.e. If the UE (200) supports S&F satellite operation and the MME is operating in S&F mode, the MME may include the S&F satellite operation parameters IE in the TRACKING AREA UPDATE ACCEPT message, in normal tracking area updating procedure and in periodic tracking area updating procedure, to provide:

for S&F monitoring list:

i) a S&F monitoring list; or

ii) an indication to delete any previously received S&F monitoring list;

If the UE (200) supporting S&F satellite operation receives the S&F satellite operation parameters IE in the TRACKING AREA UPDATE ACCEPT message and indicates:

c) "S&F monitoring list present", the UE (200) shall delete any previously stored value for the S&F monitoring list of the current PLMN and the UE (200) may store the S&F monitoring list value, for the current PLMN, provided in the S&F satellite operation parameters IE

d)"S&F monitoring list not present and delete any previously received S&F monitoring list", the UE (200) shall delete any previously received S&F monitoring list value stored for the current PLMN.

At step 3b, in case when wait timer is not present in the NAS message (for e.g. Attach Accept / Reject, Tracking Area update Accept/ Reject or any other NAS message) e.g. wait timer IE is not included or IE is included but indicated with value e.g. zero second or 0 value which indicates to the UE (200) that wait timer is not applicable/not allowed/not assigned, optionally list of satellite IDs is present (or included) the UE (200) can perform any of the below actions in any order or combinations:

a) The UE (200) shall delete any stored wait timer value or stop the running wait timer.

b) The UE (200) should start a UE (200) implementation random timer. The UE (200) should wait before re-attempting the Attach/TAU procedure in the current or another satellite of the same PLMN for the duration of this random timer. Upon the UE (200) implemented random timer expiry, the UE (200) should consider the list of Satellite IDs over which the UE (200) may re-attempt the Attach/TAU procedure.

c) In an embodiment, a dedicated indication is provided to the UE (200) in the NAS message or AS message, based on this dedicated indication as part of the NAS or the AS message the UE (200) delete the stored wait timer value or stop any running wait timer. This dedicated indication can be a new information element or existing information element with the value indicating to the UE (200) to delete the stored wait timer value or stop any running wait timer or continue to run the wait timer (i.e. not delete it) for e.g. wait timer Information element is provided to the UE (200) but without including any time value or indicating the value of the information element as zero or with the value which indicates to the UE (200) that it has to stop the wait timer or should delete the wait timer value and not apply the wait timer.

In an embodiment, when the wait timer is not present in the NAS message (for e.g. Attach Accept / Reject, Tracking Area update Accept / Reject or any other NAS message), UE would consider the wait timer as already expired and UE could immediately re-attempt the Attach/TAU procedure considering the list of Satellite IDs received in Attach Reject/ Tracking Area Reject message.

The terms MME-onboard represent the MME part which is onboard the satellite and MME-ground represent the MME part which is in the ground network. These can also be called as MME.

In an embodiment, the message TAU reject, attach reject are used only for illustration purpose those can be any of the NAS or AS messages for e.g. service reject, service accept, TAU accept, Attach accept, etc.

In an embodiment, when a UE (200) triggers a NAS signaling e.g. Attach request, TAU request, service request procedure towards the network e.g. MME, in the response NAS message the network should include the wait timer information element, the UE (200) should stop the ongoing timer and start with the new value received (i.e. restart the timer) in the latest response message like TAU accept, service accept or attach accept message. If the wait timer IE is not included in the response NAS message, then the UE (200) should continue to run the ongoing wait timer.

In an embodiment, when a UE (200) triggers a NAS signaling e.g. by starting the Attach request, TAU request, service request procedure towards the network e.g. MME the UE (200) should stop the wait timer.

In an embodiment, when a UE (200) triggers a NAS signaling e.g. by starting the Attach request, TAU request, service request procedure towards the network e.g. MME, the UE (200) will stop the wait timer before the UE (200) initiates a NAS signaling towards the network.

FIG. 8A is a sequence diagram that illustrates an existing scenario of handling wait timer and satellite ID upon switch off/on according to the prior art.

The 5G or 4G system with satellite access may support Store and Forward mechanism (i.e. S/F operating mode or mechanism) when feeder link is not available for the serving satellite at the current UE location. As specified in the existing mechanisms, the UE (200) receives a wait timer and satellite IDs from MME on-board (802) when MME ground (803) is not available. In case when UE (200) receives wait timer and satellite IDs in Attach/TAU reject and then UE (200) is switched OFF-> ON, what should happen to wait timer and satellite IDs received during initial Attach or TAU procedure is not defined. If wait timer is given and satellite IDs is not configured in Attach / TAU reject message, what should be the UE (200) action is not defined. If wait timer is not included and Optionally satellite IDs is given, the UE (200) action is not defined.

At step 1, the UE (200) starts an initial Attach procedure/TAU procedure and sends an attach request/TAU request to the MME on-board satellite (802) via available service link.

At step 2, in the absence of feeder link, MME on-board (802) cannot forward UE NAS signaling message to the MME on-ground (803). The MME on-board (802) sends a DL NAS message for e.g. ATTACH REJECT/ Tracking Area Reject Msg to the UE (200). The MME on-board (802) includes the wait timer and satellite IDs in the DL NAS message.

At step 3, the UE (200) receives DL NAS signaling message and wait timer and satellite IDs from step 2. At a later time period before the wait timer expiry, the UE (200) is switched OFF.

When the UE (200) is switched ON, what should be the behavior of the UE (200) with respect to wait timer and satellite IDs received at step 2 is not defined. This may lead to unknown UE (200) side behavior.

FIG. 8B is a sequence diagram that illustrates a proposed scenario of handling wait timer and satellite ID upon switch off/on according to the embodiments as disclosed herein.

At step 2, in the absence of feeder link, the MME on-board (802) cannot forward UE NAS signaling message to the MME on-ground (803). The MME on-board (802) sends a DL NAS message for e.g. ATTACH REJECT/ Tracking Area Reject Msg to the UE (200). The MME on-board (802) includes the wait timer and satellite IDs in the DL NAS message.

At step 3, the UE (200) receives DL NAS signaling message and wait timer and satellite IDs from step 2. As per the wait timer received, UE (200) should wait before re-attempting the Attach/TAU procedure in the current or another satellite of the same PLMN. At a time period before the wait timer expiry, UE (200) is switched OFF.

At step 4, when the UE (200) is switched OFF -or- after switch off and switch ON again or USIM is removed, optionally when the UE (200) moves to EMM-DEREGISTERED STATE the UE (200) shall stop/invalidate the wait timer and delete/invalidate the stored satellite IDs received at step 2. Upon switch ON, UE (200) performs a PLMN selection and could retry Attach procedure on the same PLMN on which UE (200) tried Attach/TAU procedure at step 1 or on a different PLMN.

FIG. 9 is a block diagram of a terminal or user equipment (UE) 900 according to an embodiment of the disclosure. FIG. 9 corresponds to the example of the terminal or UE of FIG. 2.

The terminal is an electronic device capable of wireless communication, may include a User Equipment (UE), a portable phone, a smartphone, a tablet, an Internet of things (IoT) device, etc., having various form factors, and may perform wireless communication with a base station (BS) through a wireless channel.

Referring to FIG. 9, the UE 900 may include at least one transceiver (hereinafter, referred to as simply "transceiver") 901, at least one processor (hereinafter, referred to as simply "processor") 902, and at least one memory (hereinafter, referred to as simply "memory") 903. According to at least one or a combination of methods corresponding to the embodiments described in the present disclosure, the transceiver 901, the processor 902, and the memory 903 of the UE 900 may operate. However, components of the UE 900 are not limited to the exemplary components illustrated in FIG. 9. In another embodiment, the UE 900 may further include additional components in addition to the above-mentioned components, or some components may be omitted. Further, in some embodiments, any combination of the transceiver 901, the processor 902, or the memory 903 may be integrated in the form of one component.

The transceiver 901 may be a communication circuit or communication circuitry that enables the UE 900 to perform wireless communication with a node or an entity of a network. For example, the transceiver 901 may enable the UE 900 to transmit or receive a signal to or from a BS through cellular communication, or to transmit or receive a signal to or from another UE through cellular communication. For example, the transceiver 901 may support at least one of various cellular communication technologies including 3rd generation (3G), 4th generation (4G), long term evolution (LTE), 5th generation (5G) NR, 6th generation (6G), and various cellular wireless communication technologies supported by the transceiver (901) may include all subsequent generations of evolved wireless communications.

According to an embodiment, the UE 900 may include a plurality of transceivers. For example, in the case of supporting evolved-universal terrestrial radio access-new radio (E-UTRA-NR) sual connectivity (EN-DC), the UE 900 may include a first transceiver supporting the 4G LTE wireless communication and a second transceiver supporting the 5G NR wireless communication. According to another embodiment, in the case of supporting NR-dual connectivity (NR-DC), the UE 900 may include a plurality of transceivers supporting the 5G NR wireless communication. According to still another embodiment, in the case of supporting near field wireless communication, the UE 900 may separately include a transceiver supporting at least one standard in the group of wireless communication protocol standards as defined in the protocol standards for Bluetooth®, wireless local area network (WLAN) network (including institute of electrical and electronics engineers (IEEE) 802.11-2016 standard or its amendments, e.g., 802.11ah, 802.11ad, 802.11ay, 802.11ax, 802.11az, 802.11ba, and 802.11be, without being limited thereto).

According to an embodiment, the transceiver 901 may include various circuit structures used to transmit or receive signals to or from a BS through a wireless channel. The signals may include control information and data. For example, the transceiver 901 may include a radio frequency (RF) transmitter for up-converting and amplifying the frequency of a transmitted signal and an RF receiver for low-noise-amplifying a received signal and down-converting the frequency thereof. The transceiver 901 may output a signal received through a wireless channel to the processor 902 and may transmit, through a wireless channel, a signal output from the processor 902.

The processor 902 may control general operations of the UE 900 according to embodiments of the disclosure. The processor 902 may be implemented by one or more integrated circuit (or circuitry) (IC) chips and may execute various data processings. The processor 902 may include at least one electric circuit, and may execute instructions (or a program, codes, data, etc.) stored in the memory 903, individually, collectively or in any combination thereof. Further, the processor 902 may include a single-core processor or multi-core processor, and may include a processor assembly including a plurality of processing circuits (circuitry) according to a specific implementation scheme.

The processor 902 may be electrically, operatively, or communicatively coupled to the transceiver 901 to control the transceiver 901.

The processor 902 may include at least one processor (or processing circuitry), and the at least one processor may perform the following operations individually, collectively or in any combination thereof. For example, the processor 902 may include a communication processor (CP) configured to control communication operations and an application processor (AP) configured to control execution of an upper layer (for example, an application layer) . In a specific embodiment, at least a part of the processor 902 may be included in one chip and the other part of the processor 902 may be included in another chip. Otherwise, at least one processor may be included in another component, for example, the transceiver 901 or the memory 903.

The processor 902 may perform or control or cause an operation of the UE 900 for executing at least one or a combination of methods according to embodiments of the disclosure. For example, the processor 902 may control operations of the UE 900 for processing a downlink signal received from a BS or generating and transmitting an uplink signal to a BS. To this end, the processor 902 may execute a computer program, codes, or instructions stored in the memory 903, so as to control other components of the UE 900 to enable execution of various operations.

The memory 903 corresponds to a hardware storage device capable of temporarily or permanently storing information and may include one or more storage media. For example, the memory 903 may include a memory assembly including one or more storage media. For example, the one or more storage media may include permanent memory, such as a hard drive, flash memory, or read-only memory (ROM), semipermanent memory, such as random access memory (RAM), cache memory, or a combination thereof.

The memory 903 may be electrically, operatively, or communicatively coupled to the processor 902 and may be accessed by the processor 902.

The memory 903 may store a computer program, codes, or instructions executable by the processor 902. According to an embodiment, a computer program, codes, or instructions executable by the processor 902 may be either stored in a single memory device or separated and distributedly stored in two or more memory devices. By executing the instructions stored in the memory 903, the processor 902 may perform various functions according to an embodiment of the disclosure.

According to an embodiment of the disclosure, operations of the UE 900 may be caused to be performed based on execution of instructions (or a computer program or codes) stored in the memory 903 by at least one processor (or processing circuitry) configured to execute the same individually, collectively, or in any combination thereof, based on processing circuitry that is not configured to execute instructions, and/or based on components of processing circuitry that is not configured to execute instructions.

FIG. 10 is a block diagram of a base station (BS) 1000 according to an embodiment of the disclosure.

The BS 1000 may perform wireless communication with at least one user equipment (UE) located within the area of the BS 1000 through a wireless channel.

Referring to FIG. 10, the BS 1000 may include at least one transceiver (hereinafter, referred to as simply "transceiver") 1001, at least one processor (hereinafter, referred to as simply "processor") 1002, and at least one memory (hereinafter, referred to as simply "memory") 1003. According to at least one or a combination of methods corresponding to the embodiments described in the present disclosure, the transceiver 1001, the processor 1002, and the memory 1003 of the BS 1000 may operate. However, components of the BS 1000 are not limited to the exemplary components illustrated in FIG. 10. In another embodiment, the BS 1000 may further include additional components in addition to the above-mentioned components, or some components may be omitted. Further, in some embodiments, any combination of the transceiver 1001, the processor 1002, or the memory 1003 may be integrated in the form of one component.

The transceiver 1001 may be a communication circuit or communication circuitry that enables the BS 1000 to perform wireless communication with a node or an entity of a network. For example, the transceiver 1001 may enable the BS 1000 to transmit or receive a signal to or from the UE X00 through cellular communication, or to transmit or receive a signal to or from another network entity through wireless communication. For example, the transceiver 1001 may support various cellular communication technologies including 3rd generation (3G), 4th generation (4G), long term evolution (LTE), 5th generation (5G) NR, 6th generation (6G), and various cellular wireless communication technologies supported by the transceiver (1001) may include all subsequent generations of evolved wireless communications. According to an embodiment, the transceiver 1001 may include various circuit structures used to transmit or receive signals to or from a UE through a wireless channel. The signals may include control information and data. For example, the transceiver 1001 may include a radio frequency (RF) transmitter for up-converting and amplifying the frequency of a transmitted signal and an RF receiver for low-noise-amplifying a received signal and down-converting the frequency thereof. The transceiver 1001 may output a signal received through a wireless channel to the processor 1002 and may transmit, through a wireless channel, a signal output from the processor 1002.

Meanwhile, according to an embodiment of the present disclosure, the BS 1000 may perform communication with a node or an entity of a network through wired or wireless communication. For example, the BS 1000 may perform wired or wireless communication with an adjacent BS, or a node or an entity of a core network through a backhaul network. Although not illustrated in FIG. 10, when the BS 1000 performs wired communication, the BS 1000 may further include a separate network interface for wired communication in addition to the transceiver 1001. The network interface may be referred to as network interface circuitry or communication interface circuitry.

The processor 1002 may control general operations of the BS 1000 according to embodiments of the disclosure. The processor 1002 may be implemented by one or more integrated circuit (or circuitry) (IC) chips and may execute various data processings. The processor 1002 may include at least one electric circuit, and may execute instructions (or a program, codes, data, etc.) stored in the memory 1003, individually, collectively or in any combination thereof. Further, the processor 1002 may include a single-core processor or multi-core processor, and may include a processor assembly including a plurality of processing circuits (circuitry) according to a specific implementation scheme.

The processor 1002 may be electrically, operatively, or communicatively coupled to the transceiver 1001 to control the transceiver 1001.

The processor 1002 may include at least one processor (or processing circuitry), and the at least one processor may perform the following operations individually, collectively or in any combination thereof. In a specific embodiment, at least a part of the processor 1002 may be included in one chip and the other part of the processor 1002 may be included in another chip. Otherwise, at least one processor may be included in another component, for example, the transceiver 1001 or the memory 1003.

The processor 1002 may perform or control or cause an operation of the BS 1000 for executing at least one or a combination of methods according to embodiments of the disclosure. For example, the processor 1002 may control operations of the BS 1000 for generating and transmitting a downlink signal to a UE or processing an uplink signal received from a UE. Otherwise, the BS 1000 may transmit or receive a signal to or from a neighboring BS, transfer a signal received from a UE to an upper node of the network, or transmit a signal transferred from an upper node of the network to a UE. To this end, the processor 1002 may execute a computer program, codes, or instructions stored in the memory 1003, so as to control other components of the BS 1000 to enable execution of various operations.

The memory 1003 corresponds to a hardware storage device capable of temporarily or permanently storing information and may include one or more storage media. For example, the memory 1003 may include a memory assembly including one or more storage media. For example, the one or more storage media may include permanent memory, such as a hard drive, flash memory, or read-only memory (ROM), semipermanent memory, such as random access memory (RAM), cache memory, or a combination thereof.

The memory 1003 may be electrically, operatively, or communicatively coupled to the processor 1002 and may be accessed by the processor 1002.

The memory 1003 may store a computer program, codes, or instructions executable by the processor 1002. According to an embodiment, a computer program, codes, or instructions executable by the processor 1002 may be either stored in a single memory device or separated and distributedly stored in two or more memory devices. By executing the instructions stored in the memory 1003, the processor 1002 may perform various functions according to an embodiment of the disclosure.

According to an embodiment of the disclosure, operations of the BS 1000 may be caused to be performed based on execution of instructions (or a computer program or codes) stored in the memory 1003 by at least one processor (or processing circuitry) configured to execute the same individually, collectively, or in any combination thereof, based on processing circuitry that is not configured to execute instructions, and/or based on components of processing circuitry that is not configured to execute instructions.

The UE or the base station may perform various communication procedures related to the control plane or the user plane by cooperating with one or more network entities based on wireless communication. For example, the UE may communicate with network entity such as an Access and Mobility Management Function (AMF) or a Session Management Function (SMF) via the base station, or the base station may perform at least one communication procedure by directly transmitting and receiving signals to/from, or relaying signals between, the network entities.

The structure of the above-described network entity will be described in more detail with reference to the drawings.

FIG. 11 is a block diagram of a network entity 1100 according to an embodiment of the disclosure. FIG. 11 corresponds to the example of the network apparatus of FIG. 3.

The network entity 1100 may include an entity (apparatus, device, or server, etc.) that performs one or more network functions (NFs) or a part of a network function constituting a core network (e.g., a 5th generation (5G) core (5GC)) in a communication system. In this case, multiple NFs may be implemented within a single network entity, or a single NF may be distributed and implemented across a plurality of network entities. In addition, when an NF is implemented within the network entity, the NF may be implemented in the form of software, and in such a case, a program for operating the NF may be stored in memory of the network entity 1100.

A single NF may be implemented by one or more instances, which may be deployed on the same network entity or distributed across multiple network entities to operate. The instance may be a software unit that logically executes a specific network function, and may be implemented in a form that is decoupled from physical hardware resources. Further, one or more NFs may be implemented in the form of one network slice to operate to satisfy specifications required by a particular service.

The NF may include at least one of an access and mobility management function (AMF), a session management function (SMF), a local session management function (L-SMF), a user plane function (UPF), a local user plane function (L-UPF), a policy control function (PCF), a unified data management (UDM), a unified data repository (UDR), a network exposure function (NEF), a network repository function (NRF), an application function (AF), a network slice selection function (NSSF), a network data analytics function (NWDAF), a network slice admission control function (NSACF), an authentication server function (AUSF), or a data network (DN).

Referring to FIG. 11, the network entity 1100 may include at least one network interface 1101, at least one processor 1102 (hereinafter, "processor"), and at least one memory 1103 (hereinafter, "memory"). As described above, a NF may be implemented in the form of a physical device such as the network entity 1100, or may be virtualized and executed in the form of an instance. When implemented as an instance, the NF need not necessarily include physical components as illustrated in FIG. 11. In such a case, the instance may be logically represented as comprising one or more logical functional elements.

According to at least one or a combination of methods corresponding to the embodiments described in the present disclosure, the network interface 1101, the processor 1102, and the memory 1103 of the network entity 1100 may operate. However, components of the network entity 1100 are not limited to the exemplary components illustrated in FIG. 11. In another embodiment, the network entity 1100 may further include additional components in addition to the above-mentioned components, or some components may be omitted. Further, in an embodiment, the network interface 1101, the processor 1102, or the memory 1103 may be integrated in the form of one component.

The network interface 1101 is a collective term for a transmitter part of the network entity 1100 and a receiver part of the network entity 1100, and may be a communication circuit for transmitting or receiving a signal to or from a user equipment (UE), a base station (BS), or another network entity. Here, the communication circuit may include both a communication circuit for wireless communication and a communication circuit for a wired communication. For example, the network interface 1101 may include a circuit, logic, hardware, etc., configured to exchange a control plane message or a user plane message with a UE, a BS, or other core network entities through wireless communication or wired communication. The network interface 1101 may operate using various protocols (e.g., non-access stratum (NAS) protocol). The network interface 1101 may also be referred to, for convenience of description or depending on implementation, as communication circuitry, network interface circuitry, or a communication interface circuitry.

The processor 1102 may control general operations of the network entity 1100 according to embodiments of the disclosure. The processor 1102 may be implemented by one or more integrated circuit (or circuitry) (IC) chips and may execute various data processings. The processor 1102 may include at least one electric circuit, and may execute instructions (or a program, codes, data, etc.) stored in the memory 1103, individually, collectively or in any combination thereof. Further, the processor 1102 may include a single-core processor or multi-core processor, and may include a processor assembly including a plurality of processing circuits (circuitry) according to a specific implementation scheme. Further, it should be noted that, according to another embodiment, in a case where NF is implemented in the form of an instance, the network function may be not necessarily configured by physical hardware.

According to an embodiment, the processor 1102 may be electrically, operatively, or communicatively coupled to the network interface 1101 to control the network interface 1101.

The processor 1102 may include at least one processor (or processing circuitry), and the at least one processor may perform the following operations individually, collectively or in any combination thereof. In a specific embodiment, at least a part of the processor 1102 may be included in one chip and the other part of the processor 1102 may be included in another chip. Otherwise, at least one processor may be included in another component, for example, the network interface 1101 or the memory 1103.

The processor 1102 may perform or control or cause an operation of the network entity 1100 for executing at least one or a combination of methods according to embodiments of the disclosure. For example, the processor 1102 may control operations of the network entity 1100 for exchanging a control plane message or a user plane message with a UE, a BS, or other core network entities through wireless or wired communication, using various protocols (e.g., NAS protocol). To this end, the processor 1102 may execute a computer program, codes, or instructions stored in the memory 1103, so as to control other components of the network entity 1100 to enable execution of various operations.

The memory 1103 corresponds to a hardware storage device capable of temporarily or permanently storing information and may include one or more storage media. For example, the memory 1103 may include a memory assembly including one or more storage media. For example, the one or more storage media may include permanent memory, such as a hard drive, flash memory, or read-only memory (ROM), semipermanent memory, such as random access memory (RAM), cache memory, or a combination thereof.

The memory 1103 may be electrically, operatively, or communicatively coupled to the processor 1102 and may be accessed by the processor 1102.

The memory 1103 may store a computer program, codes, or instructions executable by the processor 1102. According to an embodiment, a computer program, codes, or instructions executable by the processor 1102 may be either stored in a single memory device or separated and distributedly stored in two or more memory devices. By executing the instructions stored in the memory 1103, the processor 1102 may perform various functions according to an embodiment of the disclosure.

According to an embodiment of the disclosure, operations of the network entity 1100 may be caused to be performed based on execution of instructions (or a computer program or codes) stored in the memory 1103 by at least one processor (or processing circuitry) configured to execute the same individually, collectively, or in any combination thereof, based on processing circuitry that is not configured to execute instructions, and/or based on components of processing circuitry that is not configured to execute instructions.

In an embodiment, when the UE (200) is switched off when the wait timer is running, the UE (200) shall behave as follows when the UE (200) is switched on and Optionally the USIM in the UE (200) remains the same (i.e. the USIM has not changed), let t1 be the time remaining for wait timer timeout at switch off and let t be the time elapsed between switch off and switch on. If t1 is greater than t, then the timer shall be restarted with the value t1　-　t. If t1 is equal to or less than t, then the timer need not be restarted (and considered as expired). If the UE (200) is not capable of determining t, then the UE (200) shall restart the timer with the value t1. If the UE (200) is not capable of determining t1, then the UE (200) shall restart the timer with the value t. If the UE (200) is not capable of determining t and t1, then the UE (200) shall restart the timer with the assigned value from network.

In an embodiment, when the UE (200) is switched off and switched on again, the UE (200) continue to store the list of satellite IDs in the NV memory of the UE (200) or in the USIM.

In an embodiment, when the UE (200) is switched off and switched on again, the UE (200) stops and start the wait timer i.e. the UE (200) restart the wait timer with the assigned value again.

In an embodiment, when the UE (200) is switched off, all the wait timer and satellite IDs per PLMN should be deleted by the UE (200) and considered invalid henceforth and UE (200) should behave as per step 4 or the timer is managed and restarted per PLMN ID as described in step-4.

In an embodiment, the UE (200) shall re-initiate the Attach or Tracking area Update procedure after expiry of the Wait timer, when the Wait timer is restarted/started after switch on and If the Wait timer was not restarted/started after switch on, the UE shall re-initiate the Attach or Tracking area Update procedure immediately after switch on.

In an embodiment, upon receiving the wait timer and satellite IDs at step 2, UE (200) does not re-attempt the Attach/TAU procedure in the current or another satellite of the same PLMN and performs a PLMN search procedure. During PLMN search, UE (200) finds another suitable PLMN for e.g. PLMN_2 to register, and sends the Attach REQUEST message in step 1. In the un-availability of feeder link, UE (200) receives another set of wait timer and satellite IDs from on-board MME for PLMN_2. In such a case, UE (200) should store wait timer and satellite IDs received for PLMN_2 separately. Similarly, any subsequent wait timer and satellite IDs received in such a way should be stored separately along with PLMN ID which send that information to the UE (200).

i.e. the UE (200) should store the list of satellite IDs and wait timer along with the PLMN ID which has given it to the UE (200). The UE (200) will use the respective information to determine which cells can be selected by the UE (200) per PLMN.

Example:

The UE (200) receives from PLMN-X, the Wait timer-X, Satellite IDs: Sat-ID-X-1, Sat-ID-X-2, Sat-ID-X-3. The UE (200) starts the wait timer when it receives from the network optionally after the NAS signaling connection is released or optionally when the UE (200) enters the IDLE state. The UE (200) will not attempt to send Attach REQUEST or TAU message on the PLMN-X until the Wait timer-X is running. Meanwhile the UE (200) selects PLMN-Y, and attempts Attach procedure, the UE (200) receives from PLMN-Y, the Wait timer-Y, Satellite IDs: Sat-ID-Y-1, Sat-ID-Y-2, Sat-ID-Y-3. The UE (200) starts the wait timer when it receives from the network optionally after the NAS signaling connection is released or optionally when the UE enters the IDLE state. The UE (200) will not attempt to send Attach REQUEST or TAU message on the PLMN-Y until the Wait timer-Y is running. At the expiry of Wait timer-X the UE (200) is allowed to attempt Attach request or TAU request message or any other NAS signaling message on PLMN-X optionally on the satellite IDs Sat-ID-X-1, Sat-ID-X-2, Sat-ID-X-3. Similarly on expiry of Wait timer-Y the UE (200) is allowed to attempt Attach request or TAU request message or any other NAS signaling message on PLMN-Y optionally on the satellite IDs Sat-ID-X-1, Sat-ID-X-2, Sat-ID-X-3. Both the wait timers Wait timer-X and Wait timer-Y are managed and run independently.

When the UE (200) activates the unavailability period (optionally, when the UE enter the state 5GMM-REGISTERED.NO-CELL-AVAILABLE or 5GMM-DEREGISTERED.NO-CELL-AVAILABLE and may deactivate AS layer) or enters unavailability period when the Wait timer for store and forward operation is running, the UE shall behave as follows:

-The UE (200) shall continue to run the Wait timer throughout the discontinuous coverage time period.

i.e. When the unavailability period is activated, all NAS timers are stopped and associated procedures aborted except for Wait timer i.e. wait timer continuous to run.

In yet another embodiment, when the unavailability period is activated, the UE (200) should stop the wait timer.

The terms wait timer or the S&F wait timer or the timer in this embodiment are used interchangeably and have same meaning. This can also be called as timer T3451.

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. While the preferred embodiments have been described, those skilled in the art will recognize that modifications can be made within the scope of the described embodiments.

Meanwhile, although specific embodiments of the present disclosure have been described in detail, various modifications may be made without departing from the scope of the present disclosure. Therefore, the scope of the present disclosure should not be limited to the described embodiments, but should be defined by the claims and equivalents thereof.

Claims

A method for handling storage validity of satellite information during a non-Access Stratum (NAS) procedure in a communication network system, comprising:

receiving, by a User Equipment (UE), a satellite and forward (S&F) monitoring list from a network apparatus, when the network apparatus accepts or rejects the NAS procedure, wherein the S&F monitoring list comprises satellite IDs belonging to same Public Land Mobile Network (PLMN) over which the UE can attempt or re-attempt the NAS procedure;

storing, by the UE, the S&F monitoring list;

receiving, by the UE, a NAS message from the network apparatus, wherein the NAS message comprises an indication to delete the stored S&F monitoring list at the UE;

deleting, by the UE, the stored S&F monitoring list when the indication in the NAS message indicates to delete the stored S&F monitoring list for the current PLMN; and

using, by the UE, any satellite to access the service.
The method as claimed in claim 1, using, by the UE, any satellite to access the service comprises:

selecting or reselecting, by the UE, a cell of the same PLMN or an equivalent PLMN to attempt or re-attempt the NAS procedure, after deleting the stored S&F monitoring list.
The method as claimed in claim 1, wherein the UE selects or reselects of the cell of the same PLMN or the equivalent PLMN, irrespective of whether the cell is broadcasting or not broadcasting any satellite ID of the satellite IDs available in the S&F monitoring list, after the stored S&F monitoring list is deleted by the UE.
The method as claimed in claim 1, wherein the satellite IDs are based on System Information Block (SIB) information broadcasted by an eNodeB (eNB) associated with the network apparatus.
The method as claimed in claim 1, receiving, by the UE, the S&F monitoring list from the network apparatus comprises:

initiating, by the UE, the NAS procedure with the network apparatus and indicating to the network apparatus, a UE support for a Store and Forward (S&F) capability; and

performing, by the UE, one of:

receiving an NAS reject message from the network apparatus, when the NAS procedure is not completed due to an S&F operation, wherein the NAS reject message includes the S&F monitoring list comprising the satellite IDs belonging to the same PLMN over which the UE can attempt or re-attempt the NAS procedure, and

receiving an NAS accept message from the network apparatus, when the NAS procedure is completed, wherein the NAS reject accept includes the S&F monitoring list comprising the satellite IDs belonging to the same PLMN over which the UE can attempt or re-attempt the NAS procedure.
The method as claimed in claim 1, wherein the indication comprises a value indicating to the UE to delete the stored S&F monitoring list or continue to retain the S&F monitoring list.
The method as claimed in claim 1, wherein the UE supporting S&F satellite operation receives a NAS message without including the information element with the S&F monitoring list, the UE erases any stored value for the S&F monitoring list of the current PLMN.
The method as claimed in claim 1, wherein the UE stores the S&F monitoring list when it receives from the current PLMN.
A method for handling storage validity of satellite information during a non-Access Stratum (NAS) procedure in a communication network system, comprising:

determining, by a network apparatus, that a User Equipment (UE) indicates a satellite and forward (S&F) capability;

generating, by the network apparatus, a S&F monitoring list, when the UE supports the S&F capability, wherein the S&F monitoring list comprises satellite IDs belonging to at least one of the same Public Land Mobile Network (PLMN) and equivalent PLMN over which the UE can attempt or re-attempt the NAS procedure;

sending, by the network apparatus, the S&F monitoring list to the UE, when the network apparatus accepts or rejects the NAS procedure; and

sending, by the network apparatus, a NAS message to the UE, wherein the NAS message comprises an indication to delete the stored S&F monitoring list at the UE.
The method as claimed in claim 9, wherein the satellite IDs are based on System Information Block (SIB) information broadcasted by an eNodeB (eNB).
The method as claimed in claim 9, wherein the indication comprises a value indicating to the UE to delete the stored S&F monitoring list or continue to retain the S&F monitoring list.
The method as claimed in claim 9, sending, by the network apparatus, the S&F monitoring list to the UE comprises:

detecting, by the network apparatus, an initiation of the NAS procedure with the network apparatus; and

performing, by the network apparatus, one of:

sending an NAS reject message to the UE, when the NAS procedure is not completed due to an S&F operation, wherein the NAS reject message includes the S&F monitoring list comprising the satellite IDs belonging to the same PLMN over which the UE can attempt or re-attempt the NAS procedure, and

sending an NAS accept message to the UE, when the NAS procedure is completed, wherein the NAS reject accept includes the S&F monitoring list comprising the satellite IDs belonging to the same PLMN over which the UE can attempt or re-attempt the NAS procedure.
A User Equipment (UE) for handling storage validity of satellite information during a non-Access Stratum (NAS) procedure in a communication network system, comprising:

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 UE to:

receive a satellite and forward (S&F) monitoring list from a network apparatus, when the network apparatus accepts or rejects the NAS procedure, wherein the S&F monitoring list comprises satellite IDs belonging to same Public Land Mobile Network (PLMN) over which the UE can attempt or re-attempt the NAS procedure;

store the S&F monitoring list in the at least one memory;

receive a NAS message from the network apparatus, wherein the NAS message comprises an indication to delete the stored S&F monitoring list at the UE;

delete the stored S&F monitoring list from the at least one memory of the UE when the indication in the NAS message indicates to delete the stored S&F monitoring list for the current PLMN, and

use any satellite to access the service.
The UE of claim 13, wherein the instructions further cause the UE to:

initiate the NAS procedure with the network apparatus and indicate to the network apparatus, a UE support for a Store and Forward (S&F) capability; and

perform one of:

receive an NAS reject message from the network apparatus, when the NAS procedure is not completed due to an S&F operation, wherein the NAS reject message includes the S&F monitoring list comprising the satellite IDs belonging to the same PLMN over which the UE can attempt or re-attempt the NAS procedure, and

receive an NAS accept message from the network apparatus, when the NAS procedure is completed, wherein the NAS reject accept includes the S&F monitoring list comprising the satellite IDs belonging to the same PLMN over which the UE can attempt or re-attempt the NAS procedure.
A network apparatus for handling storage validity of satellite information during a non-Access Stratum (NAS) procedure in a communication network system, comprising:

at least one processor; 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 network apparatus to:

determine that an UE indicates a satellite and forward (S&F) capability;

generate a S&F monitoring list, when the UE supports the S&F capability, wherein the S&F monitoring list comprises satellite IDs belonging to at least one of the same Public Land Mobile Network (PLMN) and equivalent PLMN over which the UE can attempt or re-attempt the NAS procedure, and wherein the satellite IDs are based on System Information Block (SIB) information broadcasted by an eNodeB (eNB) associated with the network apparatus;

send the S&F monitoring list to the UE, when the network apparatus accepts or rejects the NAS procedure; and

send a NAS message to the UE, wherein the NAS message comprises an indication to delete the stored S&F monitoring list at the UE, wherein the indication comprises a value indicating to the UE to delete the stored S&F monitoring list or continue to retain the S&F monitoring list.