Method for handling non-access stratum mobility management cause for non-terrestrial network access and apparatus therefor

Abstract

An apparatus (e.g., user equipment (UE)) for handling non-access stratum mobility management reasons for non-terrestrial network (NTN) access is described. The apparatus receives a first message from a network node of a network. The first message includes a specific cause indicating that a Public Land Mobile Network (PLMN) is not allowed to operate at a current location of the apparatus. The device starts a timer. In an event associated with the timer, the device releases a connection between the device and the PLMN.

Description

Technical Field

[0001] The present disclosure relates generally to mobile communications and, more particularly, to handling non-access stratum mobility management reasons for non-terrestrial network access. Background Art

[0002] Unless otherwise indicated in this section, the approaches described in this section are not prior art to the claims listed below and are not admitted to be prior art by inclusion in this section.

[0003] In the traditional 3rd Generation Partnership Project (3GPP) network (e.g., the 4th generation (4G) Long-Term Evolution (LTE) system or the 5th generation (5G) New Radio (NR) system), the non-access stratum (NAS) is a functional layer between the user equipment (UE) and the core network. For example, in the 5th generation system (5G system, 5GS), multiple network functions (NFs) are introduced, such as Access and Mobility Management Function (AMF), Session Management Function (SMF), Short Message Service Function (SMSF), Location Management Function (LMF) and User Plane Function (UPF), and each NF can interact with other NFs by using reference points / interfaces. In the fourth generation system (4G system, 4GS), the evolved packet core (EPC) includes multiple entities, such as a mobile management entity (MME), a serving gateway (S-GW), a public data network (PDN) gateway (P-GW), a home subscriber server (HSS), and a policy and charging rules function (PCRF). In addition, a public land mobile network (PLMN) is a network established and operated by an administration or a recognized operating agency (ROA) with the specific purpose of providing land mobile communication services in one or more frequency bands to the public. Once the UE is powered on, the UE can perform network and cell selection to select the PLMN it will register with and select a cell (and / or network node) belonging to the selected PLMN.After confirming the PLMN and its corresponding cell (and / or network node), the UE can initiate a NAS mobility management (MM) (e.g., evolved packet system (EPS) MM (EMM) or 5G MM (5G MM, 5GMM)) process to the core network and interact with the above-mentioned NF for wireless communication.

[0004] During the NAS MM process, the UE may accordingly receive a message including a specific cause indicating that the PLMN is not allowed to operate at the current location of the UE, i.e., the UE is restricted from accessing the PLMN via a satellite (cell) at the current location. However, the details of how the UE handles the specific cause have not been fully discussed, and there are still some issues that need to be resolved. For example, upon receiving a specific cause, if the connection between the UE and the PLMN is not released by the network, the UE will remain connected and will not be able to perform PLMN selection, causing the UE to be trapped in the current PLMN. Another problem involves the UE operation of determining when the same PLMN can be accessed again when a specific cause is received in certain messages (e.g., downlink (DL) NAS transmission messages). In addition, some conditions should be considered when allowing the UE to access the same PLMN for which a specific cause is received. Therefore, it is necessary to propose solutions to solve these problems. Summary of the invention

[0005] The following summary of the invention is illustrative only and is not intended to be limiting in any way. That is, the following summary of the invention is provided to introduce the concepts, key points, benefits and advantages of the novel and non-obvious technologies described herein. Selected embodiments are further described in the detailed description below. Therefore, the following summary of the invention is not intended to identify essential features of the claimed subject matter, nor is it intended to be used to determine the scope of the claimed subject matter.

[0006] The object of the present disclosure is to propose a solution or scheme to solve the above problems related to unclear UE operation when handling a specific reason for NTN access. It is believed that by implementing one or more of the proposed schemes described herein, the above problems will be avoided or otherwise alleviated.

[0007] In one aspect, a method of processing a non-access stratum mobility management cause may involve a processor of a device receiving a first message from a network node of a network. The first message includes a specific cause indicating that a public land mobile network is not allowed to operate at a current location of the device. In response, the method may involve the processor starting a timer. The method may also involve the processor releasing a connection between the device and the PLMN in an event associated with the timer.

[0008] On the other hand, the apparatus for handling non-access layer mobility management reasons may include a transceiver that communicates with a network node of the network during operation. The apparatus may also include a processor communicatively coupled to the transceiver. The processor may receive a first message from the network node via the transceiver. The first message includes a specific reason indicating that a public land mobile network is not allowed to operate at the current location of the apparatus. The processor may start a timer. The processor may release the connection between the apparatus and the PLMN in an event associated with the timer.

[0009] In another aspect, a method for processing a non-access stratum mobility management cause may involve a processor of a device registering with a public land mobile network. The method may also involve the processor receiving a downlink non-access stratum (DLNAS) transmission message from a network node. The DL NAS transmission message includes a specific cause indicating that a public land mobile network is not allowed to operate at a current location of the device. In response, the method may involve the processor starting a timer. The method may also involve the processor determining not to access the PLMN via satellite before the timer expires (e.g., not sending any uplink non-access stratum transmission message or registration message).

[0010] It is worth noting that although the description provided herein may be in the context of certain radio access technologies, networks and network topologies such as fifth generation systems and fourth generation evolved packet system mobile networks, the proposed concepts, schemes and any variants / derivatives thereof may be implemented, applied and performed in other types of radio access technologies, networks and network topologies, such as but not limited to: Ethernet, Universal Terrestrial Radio Access Network (UTRAN), E-UTRAN, Global System for Mobilecommunication (GSM), General Packet Radio Service (GPRS) / Enhanced Data rates for Global Evolution (EDGE) Radio Access Network (GERAN), Long-Term Evolution (LTE), LTE-Advanced, LTE-Advanced Pro, Internet of Things (IoT), Industrial Internet of Things (IIoT), Narrowband Internet of Things (NB-IoT) and any future developed network technology. Therefore, the scope of the present disclosure is not limited to the examples described herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The accompanying drawings are included to provide a further understanding of the present invention and are incorporated into and constitute a part of the present invention. The accompanying drawings illustrate embodiments of the present invention and together with the description are used to explain the principles of the present invention. It is understood that the drawings are not necessarily to scale, as some components may be shown in a manner not proportional to the size in actual implementation in order to clearly illustrate the concepts of the present invention.

[0012] Figure 1 is a schematic diagram of an exemplary network system according to an embodiment of the present disclosure.

[0013] Figure 2 An example communication system including at least an example communication device and an example network device according to an embodiment of the present disclosure is shown.

[0014] Figure 3 An example process according to an embodiment of the present disclosure is shown.

[0015] Figure 4 Another example process according to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0016] Detailed embodiments and implementations of the claimed subject matter are disclosed herein. However, it should be understood that the disclosed embodiments and implementations are merely illustrations of the claimed subject matter that may be embodied in various forms. However, the present invention may be implemented in many different forms and should not be construed as being limited to the exemplary embodiments and implementations set forth herein. On the contrary, these exemplary embodiments and implementations are provided so that the description of the present invention is comprehensive and complete, and will fully convey the scope of the present invention to those skilled in the art. In the following description, details of well-known features and technologies may be omitted to avoid unnecessarily obscuring the presented embodiments and implementations.

[0017] Overview

[0018] According to embodiments of the present disclosure, various techniques, methods, schemes and / or solutions for handling non-access layer mobility management reasons are disclosed. According to the present disclosure, many possible solutions may be implemented individually or in combination. That is, although these possible solutions may be described separately, two or more of these possible solutions may be implemented in one or another combination.

[0019] Figure 11 is a schematic diagram of an example network system 100 according to an embodiment of the present invention. In general, the network system 100 may include a UE 110, a radio access network (RAN) 120, and a core network 130. In the UE 110, a protocol stack having multiple layers is introduced, for example, a NAS layer configured to communicate with the core network 130 of the network system 100, a radio resource control (RRC) layer configured for high-level configuration and control, a packet data convergence protocol / radio link control (PDCP / RLC) layer, a media access control (MAC) layer, and a physical (PHY) layer.

[0020] In one example, if the network system 100 is a 5GS, the core network 130 may include multiple network functions (NFs), such as AMF, SMF, SMSF, LMF, UPF, and / or other NFs. Specifically, the AMF may manage access control and mobility, and support other NFs to communicate with the UE 110 and the RAN 120. The SMF may provide session management, IP address allocation and management, UP function selection and control. The SMSF may manage SMS subscription and delivery through the non-access layer. The LMF may support location measurement and determination of the UE 110, and uplink location measurement from the RAN 120. Each NF may interact with other NFs by using reference points / interfaces (e.g., N1, N2, N3, N4, N6, and N11). In another example, if the network system 100 is an EPS, the core network 130 may include multiple entities, such as an MME, an S-GW, a P-GW, an HSS, and a PCRF. Specifically, the MME may provide mobility and session management (including bearer management and connection management) to the UE. The S-GW can be responsible for exchanging traffic between the P-GW and the RAN, and the P-GW can be responsible for data traffic between the S-GW and other networks (e.g., the IP multimedia subsystem (IMS) or the Internet). The HSS can store data for customer profiles, create authentication vectors sent to the MME, and save information about the PDN to be connected and information identifying the MME. The PCRF can provide quality of service (QoS) information to the P-GW to control charging rules, traffic control rules, and traffic priorities. Each of the above entities can interact with other entities through different interfaces (e.g., S1-U, S1-MME, S11, S6a, S5, Gx, Gxc, and SGi).

[0021] In addition, the RAN 120 and the core network 130 may be part of a public land mobile network (PLMN), wherein the PLMN is a network established and operated by an administration or ROA, with the specific purpose of providing land mobile communication services in one or more frequency bands to the public. Specifically, once the UE 110 is turned on, the UE 110 may perform a network (PLMN) selection to select the PLMN to which it will register and a cell selection to select a cell (and / or network node) belonging to the selected PLMN. After confirming the PLMN and the corresponding cell, the UE 110 may initiate a non-access layer mobility management (NAS MM) process to the core network 130 via the RAN 120, wherein the RAN 120 may include at least one base station (BS) 121 (e.g., an evolved NodeB (eNB), a next generation NodeB (gNB) or a transmission and reception point (TRP)) and at least one satellite 122, and then interact with the above-mentioned NF / entities for data communication.

[0022] Based on non-terrestrial network (NTN) communication, since the satellite (cell) can be configured to provide services for several UEs with national and security concerns, the UE can receive a specific cause during the NAS MM process, which is used to indicate that the PLMN is not allowed to operate at the current location of the UE. In other words, although only this satellite is available at the current location of the UE, the UE can be restricted from accessing the current PLMN via the satellite (cell). However, it is worth noting that in the current 3GPP standard, there are some unresolved issues regarding the UE operation for handling specific causes of NTN access. For example, after receiving a specific cause, if the connection between the UE and the PLMN is not released by the network, the UE will remain connected and cannot perform PLMN selection, which will cause the UE to be trapped in the current PLMN. Another problem involves that when a specific cause is received in certain messages (e.g., DL NAS transport messages), it is unclear about how to determine when the UE operation can access the same PLMN again. In addition, some conditions (e.g., when emergency services are required, or the UE has moved to a new location) should also be considered to allow the UE to access the same PLMN for which the specific cause is received.

[0023] Under the first proposed scheme according to the present disclosure, the UE may receive a first message from a network node (or core network) of a network (e.g., network system 100), wherein the first message may include a specific reason indicating that the PLMN is not allowed to operate at the current location of the UE, and the network node may be a satellite (cell). Specifically, under the condition that the network corresponds to a fifth generation system (5GS), the first message may include a registration rejection message, a service rejection message, a deregistration request message, or a DL NAS transmission message. Alternatively, under the condition that the network corresponds to an evolved packet system (EPS), the first message may include an attachment rejection message, a detachment request message, a service rejection message, or a tracking area update rejection message. The specific cause may include EPS Mobility Management (EMM) or 5G Mobility Management (5GMM) cause #78, meaning "PLMN is not allowed to operate at the current UE location", or other cause values ​​with similar meanings of not allowing operation.

[0024] In some embodiments, when the first message is received, the UE may start a protection timer, for example, timer T3540 or timer T3440, and enter a deregistered state (for example, 5GMM or EMM-DEREGISTERED.PLMN-SEARCH state or 5GMM or EMM-REGISTERED.PLMN-SEARCH state) to search for other PLMNs, that is, the UE may perform PLMN selection instead of staying in the current PLMN. In some embodiments, the UE may release the connection between the PLMN and the UE in an event associated with the protection timer. Specifically, the event may include expiration of the protection timer. In other words, if the protection timer expires after receiving the first message, the UE locally releases the connection with the PLMN (and the core network). In addition, after locally releasing the connection between the PLMN and the UE, the UE performs PLMN selection to search for other PLMNs.

[0025] In some embodiments, the UE may receive a second message from a network node (or core network) of the network (e.g., network system 100), wherein the second message may indicate the release of the connection between the UE and the PLMN. In other words, the network (and / or PLMN) may decide whether to release the connection with the UE and / or reject / ignore the UE's request to register / connect to the core network (and / or PLMN). If the core network (and / or PLMN) determines that the PLMN is not allowed to operate at the current location of the UE, the network may send a second message to the UE indicating the release of the connection between the PLMN and the UE. After receiving the second message, the UE may stop the protection timer and release the connection with the network (and / or PLMN). In other words, the network may request the UE to release the connection before the protection timer expires. Therefore, the UE may perform PLMN selection in the deregistered state after releasing the connection.

[0026] Therefore, by configuring a protection timer (e.g., timer T3540 or timer T3440) after receiving a specific reason indicating that the PLMN is not allowed to operate in the UE's current location, the UE may be able to release the connection with the current PLMN (and / or core network) to search for other PLMNs in a deregistered state.

[0027] Under the second proposed scheme according to the present disclosure, the UE may first register with the PLMN (and / or core network) and select a network node corresponding to the PLMN, e.g., a satellite. Then, if it is determined that the PLMN is not allowed to operate at the current location of the UE, the UE may receive a DL NAS transmission message including a specific cause from the network node, wherein the specific cause may indicate that the PLMN is not allowed to operate at the current location of the UE. Specifically, the specific cause may include EMM or 5GMM cause #78, meaning "PLMN is not allowed to operate at the current UE location".

[0028] In some embodiments, the UE may start a prohibit timer after receiving a DL NAS transmission message from a satellite. Then, in some embodiments, the UE decides not to access the PLMN via the satellite (e.g., not to send any UL NAS transmission message or registration message) before the prohibit timer expires.

[0029] In some implementations, after starting the prohibition timer, the UE may store the identity (ID) of the PLMN into a list, where the list may indicate a list of “PLMNs that are not allowed to operate at the current UE location”.

[0030] In some embodiments, after the prohibit timer is turned on, the UE may locally enter the deregistered state to perform PLMN selection. Specifically, the UE enters / switches to the 5GMM or EMM-DEREGISTERED.PLMN-SEARCH state or the 5GMM or EMM-REGISTERED.PLMN-SEARCH state to search for other PLMNs. Alternatively, in some embodiments, after the prohibit timer is turned on, the core network (and / or PLMN) may send an indication to the UE so that the UE enters / switches to the 5GMM or EMM-DEREGISTERED.PLMN-SEARCH state or the 5GMM or EMM-REGISTERED.PLMN-SEARCH state to search for other PLMNs.

[0031] In some embodiments, when the UE receives a DL NAS transmission message from a network node, even if the core network (and / or PLMN) initially determines that the UE should not be allowed to operate at the current location via a satellite (cell), the UE may access the same PLMN again under certain specific scenarios / conditions. These specific scenarios / conditions may be that the distance between the geographical location where the UE receives the DL NAS transmission message and the UE's current location is greater than a specific value (e.g., a specific value of the UE implementation). Alternatively, the specific scenario / condition may be that a prohibition timer expires or that the access is for emergency services. Once the specific scenario / condition is met (e.g., the UE's request for access at the current location is urgent, or the UE has moved to a new location), the UE may send at least one indication to the PLMN (and / or core network) to request emergency services. Upon receiving the indication indicating emergency services, the core network (and / or PLMN) may allow the UE to operate at the current location by configuring available resources for the current satellite.

[0032] Therefore, based on the above mechanism / solution, by adaptively configuring at least one timer (e.g., a protection timer and / or a prohibition timer) upon receiving a specific reason indicating that the PLMN is not allowed to operate at the current location of the UE, the connection between the PLMN and the UE can be released in time (which can be triggered by the UE or indicated by the core network / PLMN), and / or the UE can clearly determine how long it is restricted from accessing the same PLMN (i.e., determine when it can access the same PLMN again), which can solve the dilemma of the UE failing to disconnect / reconnect with the current PLMN after receiving the specific reason. In addition, if the UE requests emergency services after receiving the same specific reason, some specific scenarios / conditions are proposed so that the UE re-accesses the current PLMN through the satellite corresponding to the current PLMN, which can add more flexibility to the UE and / or the PLMN.

[0033] Exemplary Embodiments

[0034] Figure 2 An example communication system 200 having at least an example communication device 210 and an example network device 220 according to an embodiment of the present disclosure is shown. Each of the communication device 210 and the network device 220 can perform various functions to implement the schemes, techniques, processes and methods described herein related to handling NAS MM causes in NTN access, including the above descriptions of various proposed designs, concepts, schemes, systems and methods, including the network system 100, and the processes described below.

[0035] Each of the devices 210 and 220 may be part of an electronic device, which may be a network device or UE (e.g., UE 110), such as a portable or mobile device, a wearable device, an in-vehicle device or vehicle, a wireless communication device, or a computing device. For example, each of the devices 210 and 220 may be implemented in a smartphone, a smart watch, a personal digital assistant, an electronic control unit (ECU) in a vehicle, a digital camera, or a computing device such as a tablet, a laptop, or a notebook computer. Each of the devices 210 and 220 may also be part of a machine-type device, which may be an IoT device, such as a fixed or static device, a home device, a roadside unit (RSU), a wired communication device, or a computing device. For example, each of the devices 210 and 220 may be implemented in a smart thermostat, a smart refrigerator, a smart door lock, a wireless speaker, or a home control center. When implemented as or in a network device, each of device 210 and device 220 may be implemented in an eNB in ​​an LTE, LTE-Advanced, or LTE-Advanced Pro network or in a gNB, satellite, repeater, or TRP in a 5G network, NR network, or IoT network.

[0036] In some embodiments, each of the apparatus 210 and the apparatus 220 may be implemented in the form of one or more integrated circuit (IC) chips, for example, one or more single-core processors, one or more multi-core processors, one or more complex instruction set computing (CISC) processors, or one or more reduced instruction set computing (RISC) processors. In the above various schemes, each of the apparatus 210 and the apparatus 220 may be implemented as a network device or a UE. Each of the apparatus 210 and the apparatus 220 may include Figure 2 At least some of the components shown in the apparatus 210 and the apparatus 220 are shown in the figure, for example, the processor 212 and the processor 222, respectively. Each of the apparatus 210 and the apparatus 220 may also include one or more other components that are not related to the solution proposed in the present disclosure (for example, an internal power supply, a display device and / or a user interface device). Therefore, for the sake of brevity, these components of the apparatus 210 and the apparatus 220 are shown in the figure. Figure 2 It is not shown in the figure and is not described below.

[0037] In one aspect, each of the processors 212 and 222 may be implemented in the form of one or more single-core processors, one or more multi-core processors, one or more RISC processors, or one or more CISC processors. That is, although the singular term "processor" is used herein to refer to the processors 212 and 222, according to the present disclosure, the processors 212 and 222 may include multiple processors in some embodiments and may include a single processor in other embodiments. On the other hand, each of the processors 212 and 222 may be implemented in the form of hardware (and optionally firmware) having electronic components, including, for example but not limited to, one or more transistors, one or more diodes, one or more capacitors, one or more resistors, one or more inductors, one or more memristors, and / or one or more varactors, which are configured and arranged to implement a specific purpose according to the present invention. In other words, in at least some embodiments, each of the processors 212 and 222 is a dedicated machine specifically designed, configured, and configured to perform specific tasks, including those tasks related to processing NAS MM causes in NTN access according to embodiments of the present disclosure.

[0038] In some embodiments, the device 210 may further include a transceiver 216 coupled to the processor 212. The transceiver 216 is capable of wirelessly transmitting and receiving data. In some embodiments, the transceiver 216 is capable of wirelessly communicating with networks of different types of different radio access technologies (RAT). In some embodiments, the transceiver 216 may be equipped with multiple antenna ports (not shown), for example, four antenna ports. That is, the transceiver 216 may be equipped with multiple transmit antennas and multiple receive antennas for multiple input multiple output (MIMO) wireless communication. In some embodiments, the device 220 may further include a transceiver 226 coupled to the processor 222. The transceiver 226 may include a transceiver capable of wirelessly transmitting and receiving data. In some embodiments, the transceiver 226 may be capable of wirelessly communicating with UEs / networks of different types of different RATs. In some embodiments, the transceiver 226 may be equipped with multiple antenna ports (not shown), for example, four antenna ports. That is, the transceiver 226 may be equipped with multiple transmit antennas and multiple receive antennas for MIMO wireless communication.

[0039] In some embodiments, the device 210 may further include a memory 214 coupled to the processor 212 and accessible to the processor 212 and storing data therein. In some embodiments, the device 220 may further include a memory 224 coupled to the processor 222 and accessible to the processor 222 and storing data therein. Each of the memory 214 and the memory 224 may include a random access memory (RAM) of a type such as a dynamic random access memory (DRAM), a static random access memory (SRAM), a thyristor random access memory (T-RAM), and / or a zero capacitance random access memory (Z-RAM). Alternatively, or in addition, each of the memory 214 and the memory 224 may include a read-only memory (ROM) of a type such as a mask ROM, a programmable ROM (PROM), an erasable programmable ROM (EPROM), and / or an electrically erasable programmable ROM (EEPROM). Alternatively, or in addition, each of the memory 214 and the memory 224 may include a non-volatile random access memory (NVRAM) of the type of flash memory, solid-state memory, ferroelectric random access memory (FeRAM), magnetoresistive random access memory (MRAM) and / or phase change memory, etc. Alternatively, or in addition, each of the memory 214 and the memory 224 may include a UICC.

[0040] Each of the apparatus 210 and the apparatus 220 may be a communication entity capable of communicating with each other using various schemes proposed according to the present disclosure. For illustrative purposes and not limiting, a description of the capabilities of the apparatus 210 as a user equipment (e.g., UE 110) and / or a network node (e.g., base station 121 and / or satellite 122) of a network is provided below.

[0041] Under certain proposed schemes according to the present disclosure regarding handling NAS MM causes for NTN access from the perspective of the UE, the processor 212 of the device 210 as or implemented in the UE 110 may receive a first message from a network node of the network via the transceiver 216, wherein the first message may include a specific reason indicating that the PLMN is not allowed to operate at the current location of the device (e.g., UE 110). In addition, the processor 212 may start a timer (or referred to as a protection timer). In addition, the processor 212 may release the connection between the device and the PLMN in an event associated with the timer.

[0042] In some implementations, the event may include the expiration of a timer.

[0043] In some implementations, processor 212 may stop the timer in response to receiving a second message, where the second message may indicate a release of a connection between the device (eg, UE 110) and the PLMN.

[0044] In some embodiments, under the condition that the network corresponds to 5GS, the first message may include at least one of the following: a registration rejection message, a service rejection message, a deregistration request message, and a DL NAS transmission message.

[0045] In some implementations, the first message may include at least one of the following items under the condition that the network corresponds to EPS: an attach reject message, a detach request message, a service reject message, and a tracking area update reject message.

[0046] In some embodiments, the specific cause may include EMM or 5GMM cause #78, and the network node may include a satellite.

[0047] In some embodiments, the timer may include timer T3540 or timer T3440.

[0048] In some implementations, processor 212 may perform PLMN selection in response to releasing a connection between a device (eg, UE 110) and the PLMN.

[0049] Under certain proposed schemes according to the present disclosure regarding handling NAS MM causes for NTN access from the perspective of a UE, a processor 212 in a device 210 as or implemented in a UE 110 may register with a PLMN. In addition, the processor 212 may receive a DL NAS transmission message from a network node via a transceiver 216, wherein the DL NAS transmission message may include a specific cause indicating that the PLMN is not allowed to operate at the current location of the device (e.g., UE 110). In addition, the processor 212 may start a timer (or referred to as a prohibition timer). In addition, the processor 212 may determine not to access the PLMN via a satellite before the timer expires (e.g., not to send any uplink (UL) NAS transmission message or registration message).

[0050] In some implementations, the processor 212 may store an identification (ID) of the PLMN. In addition, the processor 212 may enter a deregistered state to perform PLMN selection.

[0051] In some embodiments, processor 212 may determine that a device (e.g., UE 110) is allowed to access the PLMN under the following conditions: the distance between the geographic location where the DL NAS transmission message is received and the current location of the device (e.g., UE 110) is greater than a specific value; or a timer expires; or the access is for emergency services.

[0052] In some embodiments, the specific cause may include EMM or 5GMM cause #78, and the network node may include a satellite.

[0053] Under certain proposed schemes according to the present disclosure regarding handling of NAS MM causes for NTN access from a network (NW) perspective, a processor 222 of a device 220 implemented as or in a network node of a network (e.g., a base station (BS) 121 and / or a satellite 122) may send a first message to a UE (e.g., UE 110) via a transceiver 226, wherein the first message may include a specific cause indicating that the PLMN is not allowed to operate at the current location of the device (e.g., UE 110). In addition, the processor 222 may release the connection between the device (e.g., UE 110) and the PLMN in an event associated with a timer (or referred to as a protection timer) of the device (e.g., UE), wherein the event may include expiration of a timer. The timer may include a timer T3540, a timer T3440, or other types of timers.

[0054] In some implementations, processor 222 may send a second message to the device (eg, UE 110) via transceiver 226, where the second message may indicate releasing a connection between the device (eg, UE 110) and the PLMN.

[0055] In some embodiments, under the condition that the network corresponds to 5GS, the first message may include at least one of the following: a registration rejection message, a service rejection message, a deregistration request message, and a DL NAS transmission message.

[0056] In some implementations, the first message may include at least one of the following items under the condition that the network corresponds to EPS: an attach reject message, a detach request message, a service reject message, and a tracking area update reject message.

[0057] In some embodiments, the specific cause may include EMM or 5GMM cause #78, and the network node may include a satellite.

[0058] Under certain proposed schemes according to the present disclosure regarding processing of NAS MM causes for NTN access from a network (NW) perspective, a processor 222 of a device 220 implemented as or in a network node of a network (e.g., a base station (BS) 121 and / or a satellite 122) may receive a registration of a PLMN from a device (e.g., a UE 110) via a transceiver 226. In addition, the processor 222 may send a DL NAS transmission message to the UE (e.g., the UE 110) via the transceiver 226, wherein the DL NAS transmission message may include a specific cause indicating that the PLMN is not allowed to operate at the current location of the device (e.g., the UE 110). In addition, the processor 222 may not receive any access attempt (e.g., a UL NAS transmission message or a registration message) from the device (e.g., the UE 110) via the satellite access before a timer (or referred to as a prohibition timer) of the device (e.g., the UE 110) expires via the transceiver 226.

[0059] In some embodiments, processor 222 may determine that a device (e.g., UE 110) is allowed to access the PLMN under the following conditions: the distance between the geographic location where the DL NAS transmission message is received and the current location of the device (e.g., UE 110) is greater than a certain value; or a timer expires; or the access is for emergency services.

[0060] In some embodiments, the specific cause may include EMM or 5GMM cause #78, and the network node may include a satellite.

[0061] Example process

[0062] Figure 3 An example process 300 is shown for implementing an embodiment according to the present disclosure. The process 300 may represent an aspect of implementing the various designs, concepts, schemes, systems and methods proposed above, whether in part or in whole, including the above. More specifically, the process 300 may represent an aspect of the proposed concepts and schemes related to handling non-access layer mobility management reasons for non-terrestrial network access. The process 300 may include one or more operations, actions or functions as shown in one or more blocks 310 to 330. Although shown as discrete blocks, various blocks of the process 300 may be divided into additional blocks, combined into fewer blocks, or deleted, depending on the desired implementation. In addition, the blocks / sub-blocks of the process 300 may be arranged in a manner such that: Figure 3300 may be performed in the order shown, or may be performed in a different order. In addition, one or more blocks / sub-blocks of process 300 may be performed iteratively. Process 300 may be implemented by apparatus 210 and apparatus 220 and any variants thereof. For illustrative purposes only and without limiting the scope, process 300 is described below in the context of apparatus 210 as a user equipment (e.g., UE 110) and apparatus 220 as a communication entity such as a network node (e.g., base station 121 and / or satellite 122) of a network. Process 300 may start from block 310.

[0063] At block 310, the process 300 may involve the processor 212 of the device 210 as or implemented in the UE 110, receiving a first message from a network node of a network, wherein the first message may include a specific reason indicating that the PLMN is not allowed to operate at the current location of the device (e.g., the UE 110). The process 300 may continue from block 310 to block 320.

[0064] At block 320 , the process 300 may involve the processor 212 starting a (guard) timer. From block 320 , the process 300 may continue to block 330 .

[0065] At block 320 , process 300 may involve processor 212 releasing the connection between the device and the PLMN in an event associated with the timer.

[0066] In some implementations, the event may include the expiration of a timer.

[0067] In some implementations, process 300 may involve processor 212 stopping the timer in response to receiving a second message, where the second message may indicate a release of a connection between the device (eg, UE 110) and the PLMN.

[0068] In some embodiments, under the condition that the network corresponds to 5GS, the first message may include at least one of the following: a registration rejection message, a service rejection message, a deregistration request message, and a DL NAS transmission message.

[0069] In some implementations, the first message may include at least one of the following items under the condition that the network corresponds to EPS: an attach reject message, a detach request message, a service reject message, and a tracking area update reject message.

[0070] In some embodiments, the specific cause may include EMM or 5GMM cause #78, and the network node may include a satellite.

[0071] In some embodiments, the timer may include timer T3540 or timer T3440.

[0072] In some implementations, process 300 may involve processor 212 performing PLMN selection in response to releasing a connection between a device (eg, UE 110) and the PLMN.

[0073] Figure 4 Another example process 400 is shown for implementing an embodiment according to the present disclosure. Process 400 may represent an aspect of implementing the various designs, concepts, schemes, systems and methods proposed above, whether in part or in whole, including the above. More specifically, process 400 may represent an aspect of the proposed concepts and schemes related to handling non-access layer mobility management reasons for non-terrestrial network access. Process 400 may include one or more operations, actions or functions as shown in one or more blocks 410 to 440. Although shown as discrete blocks, various blocks of process 400 may be divided into additional blocks, combined into fewer blocks, or deleted, depending on the desired implementation. In addition, the blocks / sub-blocks of process 400 may be arranged in a manner such that: Figure 4 4. The process 400 may be performed in the order shown, or may be performed in a different order. In addition, one or more blocks / sub-blocks of the process 400 may be performed iteratively. The process 400 may be implemented by the apparatus 210 and the apparatus 220 and any variants thereof. For illustrative purposes only and without limiting the scope, the process 400 is described below in the context of the apparatus 210 as a user equipment (e.g., UE 110) and the apparatus 220 as a communication entity such as a network node (e.g., base station 121 and / or satellite 122) of a network. The process 400 may start from block 410.

[0074] At block 410, the process 400 may involve the processor 212 of the apparatus 210 as or implemented in the UE 110, registering with the PLMN. From block 410, the process 400 may continue to block 420.

[0075] At block 420, flow 400 may involve processor 212 receiving a DL NAS transport message, wherein the DL NAS transport message may include a specific reason indicating that the PLMN is not allowed to operate at the current location of the device (eg, UE 110). Flow 400 may continue from block 420 to block 430.

[0076] At block 430 , the process 400 may involve the processor 212 enabling (disabling) the timer. From block 430 , the process 400 may continue to block 440 .

[0077] At block 440, process 400 may involve processor 212 determining not to access the PLMN via satellite (eg, not sending any UL NAS transmission messages or registration messages) before a timer expires.

[0078] In some implementations, process 400 may involve processor 212 storing an identification (ID) of the PLMN. In addition, a deregistered state may be entered to perform PLMN selection.

[0079] In some embodiments, processor 212 may determine that a device (e.g., UE 110) is allowed to access the PLMN under the following conditions: the distance between the geographic location where the DL NAS transmission message is received and the current location of the device (e.g., UE 110) is greater than a specific value; or a timer expires; or the access is for emergency services.

[0080] In some embodiments, the specific cause may include EMM or 5GMM cause #78, and the network node may include a satellite.

[0081] Additional Notes

[0082] The subject matter described herein sometimes shows different components contained in or connected to different other components.It should be understood that the described architecture is only an example, and many other architectures with the same function can actually be implemented.In the sense of conception, any setting of the components that implement the same function is effectively "associated" so that the desired function is realized.Therefore, any two components combined to realize a specific function herein can be regarded as "associated" with each other so that the desired function is realized, regardless of the architecture or intermediate components.Similarly, any two components so associated can also be regarded as "connected at work" or "connected at work" to realize the desired functionality, and any two components that can be so associated can also be regarded as "connected at work" to realize the desired functionality.Specific examples of operable connections include, but are not limited to, physically matchable and / or physically interactive components and / or wirelessly interactive and / or wirelessly interactive components and / or logically interactive and / or logically interactive components.

[0083] In addition, with respect to the use of substantially any plural and / or singular terms herein, those skilled in the art may translate from the plural to the singular and / or from the singular to the plural as appropriate, depending on the context and / or application. For clarity, various singular / plural arrangements may be expressly set forth herein.

[0084] Furthermore, those skilled in the art will understand that, in general, the terms used herein, and particularly in the appended claims, such as the bodies of the appended claims, are generally intended as "open" terms, e.g., the term "including" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," and the term "comprising" should be interpreted as "including but not limited to." Those skilled in the art will further understand that if a specific number of introduced claim recitations is intended, such an intent will be explicitly recited in the claim, and in the absence of such a recitation, no such intent is present. For example, to aid understanding, the following appended claims may contain the use of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed as implying that a claim recitation introduced by the indefinite article "a" or "an" will limit any particular claim containing such introduced claim recitation to embodiments containing only one such recitation, even when the same claim includes the introductory phrases "one or more" or "at least one," and indefinite articles such as "a" or "an," e.g., "a" and / or "an" should be construed to mean "at least one" or "one or more;" the same applies to the use of explicit articles introducing claim recitations. Furthermore, even if a specific number of an introduced claim recitation is explicitly recited, one skilled in the art will recognize that such a recitation should be construed to mean at least the recited number, e.g., a bare recitation of "two recitations" without other modifiers means at least two recitations, or two or more recitations. Again, in those cases, the convention is similar to "at least one of A, B, and C, etc." In general, such constructions are used in the sense that one skilled in the art understands the convention, e.g., "a system having at least one of A, B, and C" will include but is not limited to systems having A alone, B alone, C alone, A and B together, A and C together, B and C together, and / or A, B, and C together, etc. In those cases where the convention is similar to "at least one of A, B, or C". In general, such constructions are intended to be used in the sense that one skilled in the art understands the convention, e.g., "a system having at least one of A, B, or C" will include but is not limited to systems having A alone, B alone, C alone, A and B together, A and C together, B and C together, and / or A, B, and C together. One skilled in the art will further understand that any disjunctive words and / or phrases that actually present two or more alternative terms, whether in the specification, claims, or drawings, should be understood to encompass the possibility of including one of the terms, either of the terms, or both of the terms. For example, the phrase "A or B" will be understood to include the possibility of "A" or "B" or "A and B".

[0085] From the above, it will be appreciated that various embodiments of the present invention have been described herein for illustrative purposes, and various modifications may be made without departing from the scope and spirit of the present invention. Therefore, the various embodiments disclosed herein are not intended to be limiting, and their true scope and spirit are indicated by the appended claims.

Claims

1. A method for handling non-access stratum mobility management reasons, comprising: receiving, by a processor of the device, a first message from a network node of the network, wherein the first message includes a specific reason indicating that a public land mobile network is not permitted to operate at a current location of the device; The processor starts a timer; as well as In an event associated with the timer, the processor releases a connection between the apparatus and the public land mobile network.

2. The method of claim 1, wherein: The event includes the expiration of the timer.

3. The method of claim 1, wherein: The event includes: The timer is stopped by the processor in response to receiving a second message, wherein the second message indicates releasing a connection between the apparatus and the public land mobile network.

4. The method of claim 1, wherein: Under the condition that the network corresponds to a fifth generation system, the first message includes at least one of the following items: Registration reject message, service reject message, deregistration request message and downlink non-access stratum transmission message.

5. The method of claim 1, wherein: In the case where the network corresponds to an evolved packet system, the first message includes at least one of the following: Attach reject message, detach request message, service reject message and tracking area update reject message.

6. The method of claim 1, wherein: The specific cause includes EPS Mobility Management or 5GNAS Mobility Management (EMM or 5GMM) cause #78, and wherein the network node includes a satellite.

7. The method of claim 1, wherein: The timer includes timer T3540 or timer T3440.

8. The method of claim 1, wherein: Further including: In response to releasing the connection between the apparatus and the public land mobile network, PLMN selection is performed by the processor.

9. An apparatus for processing non-access stratum mobility management reasons, comprising: a transceiver that communicates with a network node of the network during operation; as well as a processor communicatively coupled to the transceiver, wherein the processor is configured to: receiving, via the transceiver, a first message from the network node, wherein the first message includes a specific reason indicating that a public land mobile network is not permitted to operate at a current location of the device; Start the timer; as well as In an event associated with the timer, a connection between the apparatus and the public land mobile network is released.

10. The device of claim 9, wherein: The event includes the expiration of the timer.

11. The device of claim 9, wherein: In response to receiving a second message, the processor is further configured to stop the timer, wherein the second message indicates releasing the connection between the apparatus and the public land mobile network.

12. The device of claim 9, wherein: Under the condition that the network corresponds to a fifth generation system, the first message includes at least one of the following items: Registration reject message, service reject message, deregistration request message and downlink non-access stratum transmission message.

13. The device of claim 9, wherein: In the case where the network corresponds to an evolved packet system, the first message includes at least one of the following: Attach reject message, detach request message, service reject message and tracking area update reject message.

14. The device of claim 9, wherein: The specific cause includes EPS Mobility Management or 5G NAS Mobility Management (EMM or 5GMM) cause #78, and wherein the network node includes a satellite.

15. The device of claim 9, wherein: The timer includes timer T3540 or timer T3440.

16. The device of claim 9, wherein: In response to releasing the connection between the apparatus and the public land mobile network, the processor is further configured to perform PLMN selection.

17. A method for handling non-access stratum mobility management reasons, comprising: registering, by a processor of the device, with a public land mobile network; receiving, by the processor, a downlink non-access stratum transmission message from a network node, wherein the downlink non-access stratum transmission message includes a specific reason indicating that a public land mobile network is not permitted to operate at a current location of the device; The processor starts a timer; as well as A determination is made by the processor not to access the public land mobile network via a satellite before the timer expires.

18. The method of claim 17, wherein: Further including: storing, by the processor, an identification of the public land mobile network; and The deregistration state is entered by the processor to perform PLMN selection.

19. The method of claim 17, wherein: Further including: The processor determines that the device is allowed to access the public land mobile network under the following conditions: The distance between the geographical location transmitted by the device when receiving the downlink non-access layer transmission message and the current location of the device is greater than a specific value; or the timer expires; or Access is for emergency services.

20. The method of claim 17, wherein: The specific cause includes EPS Mobility Management or 5G NAS Mobility Management (EMM or 5GMM) cause #78, and wherein the network node includes a satellite.

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