Method and communication device

Abstract

The invention relates to a method and a communication device. The method comprises the following steps: when registration of terminal equipment in a non-terrestrial mobile communication network NTN is completed, the terminal equipment enters a first mode; wherein the terminal equipment does not need to initiate periodic registration to the first core network equipment of the NTN in the first mode; the registration completion of the terminal equipment in the NTN can be understood as follows: the terminal equipment sends a first message for requesting registration to the first core network equipment and receives a second message which is from the first core network equipment and indicates to accept the registration request.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to a method and a communication device. Background Art

[0002] In the non-terrestrial network (NTN) communication scenario, the terminal device is connected to the access network equipment and core network equipment in the mobile communication network through satellite to achieve the purpose of communication. Compared with the terrestrial network (TN), since the satellite is far away from the ground terminal, the communication between the terminal device and the satellite will increase the power consumption of the terminal device. Summary of the invention

[0003] Usually, a terminal device that is in the connection management (CM) idle state needs to initiate a periodic registration request to the core network device to maintain the terminal device in a registered state in the network. However, in the NTN communication scenario, if the terminal device periodically executes the registration update process, it will bring a large power consumption overhead to the terminal device. And if the terminal device is a terminal device that uses manual satellite alignment to perform the satellite alignment process, the terminal device cannot automatically perform the satellite alignment process periodically (or it is understood that the terminal device cannot guarantee the initiation of periodic registration updates), which causes the core network to believe that the terminal is unreachable and deregister the terminal device, affecting the timeliness of the communication service of the terminal device. In order to solve the above-mentioned technical problems, the embodiments of the present application provide a method and a communication device, which are conducive to reducing the power consumption of terminal devices in NTN communication scenarios.

[0004] In a first aspect, the present application provides a method. Take a terminal device executing the method as an example. The method includes: when the terminal device completes registration in the NTN, the terminal device enters a first mode; wherein the terminal device does not need to initiate a periodic registration with a first core network device of the NTN in the first mode; or, the period for the terminal device to initiate a periodic registration with the first core network device in the first mode is a first period, the first period is greater than a second period, and the second period is a period for the terminal device to initiate a periodic registration with a second core network device of the terrestrial network TN.

[0005] In the method described in the first aspect, after the terminal device completes registration in the NTN, the terminal device enters a mode in which it does not need to initiate periodic registration to the first core device of the NTN (i.e., the first mode mentioned in the present application), or the terminal device enters a mode in which a periodic registration is initiated with a larger period, thereby reducing the satellite alignment process performed due to periodic registration, which is beneficial to saving power consumption of the terminal device.

[0006] In one possible implementation, the terminal device sends a first message to the first core network device, where the first message is used to request registration; further, the terminal device receives a second message from the first core network device, where the second message indicates that the first core network device accepts the registration request of the terminal device.

[0007] In a possible implementation, the first message includes first information, and the first information indicates that the terminal device cannot guarantee to perform periodic registration, or the first information indicates that the terminal device requests not to perform periodic registration. By implementing this possible implementation, when the terminal device initiates a registration request to the core network device of the NTN (i.e., the first core network device), it requests not to perform periodic registration, which is conducive to reducing its own power consumption.

[0008] In a possible implementation, the first information includes first capability information and / or second capability information; wherein the first capability information indicates whether the terminal device has the capability to support NTN communication, and the second capability information indicates whether the terminal device has the capability of automatic satellite alignment.

[0009] In a possible implementation, the second message includes second information, and the second information indicates that after the terminal device enters the first mode, it is not necessary to initiate periodic registration with the first core network device of the NTN. By implementing this possible implementation, the first core network device can indicate whether the terminal device needs to initiate periodic registration in the first mode during the process of the terminal device registering with the NTN, which is conducive to improving the flexibility of the terminal device initiating periodic registration in the first mode.

[0010] In a possible implementation, the second message also includes third information, which indicates a first duration, which is the duration of the periodic registration timer, and which is related to the duration of the NTN service contract signed by the terminal device; further, in the first mode, the terminal device does not need to initiate periodic registration with the first core network device of the NTN within the first duration. By implementing this possible implementation, the first core network device can indicate whether the terminal device needs to initiate periodic registration in the first mode and how long it does not need to initiate periodic registration during the process of the terminal device registering with the NTN, which is conducive to improving the flexibility of the terminal device in initiating periodic registration in the first mode.

[0011] In a possible implementation, the third information indicates that the periodic registration timer is not activated. By implementing this possible implementation, the first core network device can indicate that the terminal device does not need to initiate periodic registration in the first mode by indicating that the periodic registration timer is not activated during the process of the terminal device registering with the NTN, which is conducive to improving the flexibility of the terminal device in determining whether to initiate periodic registration in the first mode.

[0012] In a possible implementation, the terminal device remains registered and / or out of service in the first mode. By implementing this possible implementation, the terminal device remains registered and / or out of service in the first mode, thereby avoiding the core network device from deregistering the terminal device, which is conducive to improving the timeliness of the terminal device's communication (or is understood to be conducive to the terminal device to communicate quickly).

[0013] In a possible implementation, the terminal device does not need to monitor the paging message from the NTN in the first mode. By implementing this possible implementation, the terminal device does not monitor the paging message from the NTN in the first mode, which is conducive to reducing the power consumption of the terminal device.

[0014] In a possible implementation, when the terminal device completes registration in the non-terrestrial network NTN, the terminal device enters the first mode, including: when the terminal device completes registration and satisfies the first condition, the terminal device enters the first mode; wherein the first condition includes at least one of the following: the terminal device completes data transmission through the NTN; the terminal device switches from the CM connected state to the CM idle state; the terminal device switches from the first state to the second state, in which the terminal device can communicate with the satellite of the NTN in the first state and cannot communicate with the satellite of the NTN in the second state; or, the terminal device stops using the service of the NTN. By implementing this possible implementation, after the terminal device completes registration in the NTN, the terminal device will enter the first mode only if the terminal device does not have the demand for the network service of the NTN (i.e., the first condition is met), and the terminal device will not enter the first mode if the terminal device has the demand for the network service of the NTN, which is conducive to ensuring the reliability of the terminal device service.

[0015] In a possible implementation manner, the terminal device converts from the connection management CM connected state to the CM idle state, including: the terminal device converts from the CM connected state to the CM idle state, and the duration of the terminal device being in the CM idle state is greater than a second duration, and the second duration is greater than 0. By implementing this possible implementation manner, after the terminal device completes registration in the NTN, the terminal device will enter the first mode only if the terminal device does not have a demand for the network service of the NTN (i.e., the first condition is met), and the terminal device will not enter the first mode if the terminal device has a demand for the network service of the NTN, which is conducive to ensuring the reliability of the terminal device service.

[0016] In a possible implementation, after the terminal device enters the first mode, when the terminal device is converted from the second state to the first state, the terminal device sends a first message to the first core network device; wherein the first message is used to request registration or service; in the first state, the terminal device can communicate with the satellite of NTN, and in the second state, the terminal device cannot communicate with the satellite of NTN. By implementing this possible implementation, after the terminal device enters the first mode, if the terminal device can communicate with the satellite of NTN, the terminal device can still register with NTN or request service, which is conducive to ensuring the reliability of the terminal device service.

[0017] In a possible implementation, after the terminal device enters the first mode, the terminal device exits the first mode if the second condition is met; wherein the second condition includes at least one of the following: the terminal device is converted from the second state to the first state, in which the terminal device can communicate with the NTN satellite, and in the second state the terminal device cannot communicate with the NTN satellite; the terminal device is converted from the CM idle state to the CM connected state; or the terminal device detects that a satellite alignment operation is performed. By implementing this possible implementation, after the terminal device enters the first mode, if the terminal device has a demand for NTN network services (for example, the second condition is met), the terminal device will exit the first mode, which is conducive to ensuring the reliability of the terminal device service.

[0018] In a possible implementation manner, the first core network device only serves the NTN, or the first core network device serves the NTN and the TN.

[0019] In a possible implementation, the first core network device only serves NTN; in this case, the terminal device sends a first message to the first core network device through the second core network device of TN; further, the terminal device receives a second message from the first core network device through the second core network device. By implementing this possible implementation, it is helpful to improve the flexibility of terminal devices registering with NTN.

[0020] In a possible implementation, the first message further includes a preference for the first mode; and the second message further includes information confirming acceptance of the preference.

[0021] In a possible implementation, the first message further includes a preference for the first mode, including: when the terminal device does not have the capability of automatic alignment, or the terminal device is selected to use manual alignment for the alignment operation, the first message further includes a preference for the first mode. By implementing this possible implementation, it is helpful to save power consumption of the terminal device that uses manual alignment for the alignment operation.

[0022] In a possible implementation manner, the terminal device receives at least one equivalent public land mobile network EPLMN identifier from the second core network device, where the at least one EPLMN identifier includes a public land mobile network PLMN identifier of the NTN.

[0023] In a possible implementation, the terminal device receives at least one equivalent public land mobile network EPLMN identifier from a third core network device, where the at least one EPLMN identifier includes a public land mobile network PLMN identifier of the NTN, and the third core network device is a core network device where the terminal device registers the PLMN.

[0024] In a possible implementation, the terminal device includes a first user identification module SIM card and a second SIM card; the first SIM card subscribes to a TN service, and the second SIM card subscribes to an NTN service; further, the second SIM card sends a first message through the first SIM card; the first SIM card sends a first message to an access network device of the TN; the first SIM card receives a second message from the access network device of the TN; and the first SIM card sends a second message to the second SIM card.

[0025] In a second aspect, the present application provides a method, taking the first core network device of NTN as an example for executing the method, the method includes: when the terminal device completes registration in NTN, the first core network device of NTN determines that the terminal device enters a first mode; wherein the terminal device does not need to initiate periodic registration to the first core network device of NTN in the first mode.

[0026] Based on the beneficial effects of the method described in the second aspect, reference may be made to the beneficial effects of the method described in the first aspect, which will not be repeated here.

[0027] In one possible implementation, the first core network device receives a first message from a terminal device, where the first message is used to request registration; further, the first core network device sends a second message to the terminal device, where the second message indicates that the first core network device accepts the registration request of the terminal device.

[0028] In a possible implementation, the first message includes first information, where the first information indicates that the terminal device cannot guarantee to perform periodic registration, or the first information indicates that the terminal device requests not to perform periodic registration.

[0029] In a possible implementation, the first information includes first capability information and / or second capability information; wherein the first capability information indicates whether the terminal device has the capability to support NTN communication, and the second capability information indicates whether the terminal device has the capability to automatically point to a satellite.

[0030] In one possible implementation, the first core network device determines a second message based on the first information; wherein the second message indicates at least one of the following: whether to accept the preferred information; whether the periodic registration timer is activated; when the periodic registration timer is activated, the duration of the periodic registration timer; or whether to perform implicit deregistration on the terminal device.

[0031] In a possible implementation, the second message includes second information, and the second information indicates that after the terminal device enters the first mode, there is no need to initiate periodic registration.

[0032] In a possible implementation, the second message also includes third information, which indicates a first duration, where the first duration is the duration of a periodic registration timer, and the first duration is related to the duration of the NTN service contracted by the terminal device; further, in the first mode, the terminal device does not need to initiate a periodic registration with the first core network device of the NTN within the first duration.

[0033] In a possible implementation manner, the third information further indicates that the periodic registration timer is not activated.

[0034] In a possible implementation, the first core network device keeps the terminal device in the first mode in a registered state and / or out of service.

[0035] In a possible implementation, the first core network device does not need to send a paging message to the terminal device in the first mode.

[0036] In one possible implementation, when the terminal device completes registration in the non-terrestrial network NTN, the first core network device of NTN determines that the terminal device enters the first mode, including: when the terminal device completes registration in the non-terrestrial network NTN and satisfies the third condition, the first core network device of NTN determines that the terminal device enters the first mode; wherein the third condition includes one or more of the following: the terminal device converts from a connection management CM connected state to a CM idle state; the terminal device does not use the network service of NTN within a third time period, and the third time period is greater than 0; or, the first core network device fails to page the terminal device.

[0037] In a possible implementation, the terminal device converts from a connection management CM connected state to a CM idle state, including: the terminal device converts from a CM connected state to a CM idle state, and the duration of the terminal device being in the CM idle state is greater than a second duration, and the second duration is greater than 0.

[0038] In a possible implementation, after determining that the terminal device enters the first mode, the first core network device receives a first message from the terminal device, wherein the first message is used to request registration or request service.

[0039] In one possible implementation, when the fourth condition is met, the first core network device determines that the terminal device exits the first mode; wherein the fourth condition includes one or more of the following: the first core network device receives a first message from the terminal device, and the first message is used to request registration or request service; or, the terminal device switches from a CM idle state to a CM connected state.

[0040] In a possible implementation manner, the first core network device only serves the NTN, or the first core network device serves the NTN and the TN.

[0041] In a possible implementation, the first core network device receives a first message from the terminal device through the second core network device of the TN; the first core network device sends a second message to the terminal device through the second core network device.

[0042] In a possible implementation, the first message also includes a preference for the first mode; and the second message also includes information confirming acceptance of the preference.

[0043] In a third aspect, the present application provides a communication device. Exemplarily, the communication device may be a terminal device, or a device in a terminal device, or a device that can be used in combination with a terminal device. Exemplarily, the communication device may also be a chip system. The communication device may execute the method described in the first aspect. The functions of the communication device may be implemented by hardware, or by hardware executing corresponding software implementations. The hardware or software includes one or more units or modules corresponding to the above functions. The unit or module may be software and / or hardware. The operations and beneficial effects performed by the communication device may refer to the method and beneficial effects described in the first aspect above.

[0044] In a fourth aspect, the present application provides a communication device, which may be a core network device, or a device in a core network device, or a device that can be used in combination with a core network device. The communication device may also be a chip system. The communication device may execute the method described in the second aspect. The functions of the communication device may be implemented by hardware, or by hardware executing corresponding software. The hardware or software includes one or more units or modules corresponding to the above functions. The unit or module may be software and / or hardware. The operations and beneficial effects performed by the communication device may refer to the method and beneficial effects described in the second aspect above.

[0045] In a fifth aspect, the present application provides a communication device, comprising a processor and an interface circuit, wherein the interface circuit is used to receive signals from other communication devices outside the communication device and transmit them to the processor or send signals from the processor to other communication devices outside the communication device, and the processor implements the method as described in the first aspect or the method as described in the second aspect through logic circuits or execution of code instructions.

[0046] In a sixth aspect, the present application provides a computer-readable storage medium, in which a computer program or instruction is stored. When the computer program or instruction is executed by a communication device, the method described in the first aspect or the method described in the second aspect is implemented.

[0047] In a seventh aspect, the present application provides a computer program product comprising instructions, which, when read and executed by a communication device, enables the method described in the first aspect or the method described in the second aspect to be implemented.

[0048] In an eighth aspect, the present application provides a communication system, which includes a communication device for executing the method described in the first aspect, and a communication device for executing the method executed by the core network device described in the second aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 It is a schematic diagram of a network system architecture provided by an embodiment of the present application;

[0050] Figure 2 is a schematic diagram of a CN structure provided in an embodiment of the present application;

[0051] Figure 3a is a schematic diagram of a transparent satellite architecture provided in an embodiment of the present application;

[0052] Figure 3b is a schematic diagram of a regenerative satellite architecture provided in an embodiment of the present application;

[0053] Figure 3c This is a schematic diagram of an implicit deregistration process provided by an embodiment of the present application;

[0054] Figure 4 It is a flow chart of a method provided in an embodiment of the present application;

[0055] Figure 5 It is a schematic diagram of a process of registering a terminal device in NTN provided by an embodiment of the present application;

[0056] Figure 6 is a schematic diagram of third information provided by an embodiment of the present application;

[0057] Figure 7 It is a schematic diagram of another terminal device registration process in NTN provided in an embodiment of the present application;

[0058] Figure 8 It is a schematic diagram of another terminal device registration process in NTN provided in an embodiment of the present application;

[0059] Figure 9a It is a schematic diagram of another terminal device registration process in NTN provided in an embodiment of the present application;

[0060] Figure 9b It is a schematic diagram of another terminal device registration process in NTN provided in an embodiment of the present application;

[0061] Fig.10 It is a schematic diagram of another terminal device registration process in NTN provided in an embodiment of the present application;

[0062] Fig.11 is a structural diagram of a communication device provided in an embodiment of the present application;

[0063] Fig.12 It is a structural diagram of another communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0064] The terms "first" and "second" and the like in the specification, claims and drawings of this application are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device comprising a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products or devices.

[0065] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It should be understood that the embodiments described herein may be combined with other embodiments.

[0066] In order to facilitate a specific understanding of the embodiments of the present application, the system architecture involved in the embodiments of the present application is first introduced below.

[0067] The technical solutions of the embodiments of the present application can be applied to various communication systems, for example: long term evolution (LTE) system, LTE frequency division duplex (FDD) system, LTE time division duplex (TDD), new radio (NR), the 3rd generation partner project (3GPP) service-based network architecture (SBA), and other fifth generation (5G) communication systems or sixth generation (6G) communication systems and other communication systems evolved after 5G.

[0068] See also Figure 1 , Figure 1 Schematic diagram of a network system architecture provided by an embodiment of the present application. Figure 1 As shown, the terminal device can access the wireless network to obtain services of the external network (such as the data network (DN)) through the wireless network, or communicate with other devices through the wireless network, such as communicating with other terminal devices. The wireless network includes a (radio) access network ((radio) access network, (R) AN) and a core network (CN), wherein the (R) AN (hereinafter described as RAN) is used to access the terminal device to the wireless network, and the CN is used to manage the terminal device and provide a gateway for communication with the DN. The following are respectively Figure 1 The terminal equipment, RAN, CN and DN involved in the system architecture are described in detail.

[0069] 1. Terminal equipment

[0070] The terminal device includes a device that provides voice and / or data connectivity to the user. For example, the terminal device is a device with wireless transceiver function, which can be deployed on land, including indoors or outdoors, handheld, wearable or vehicle-mounted; it can also be deployed on the water surface (such as ships, etc.); it can also be deployed in the air (such as airplanes, balloons and satellites, etc.). The terminal device can be a mobile phone, a tablet computer (Pad), a computer with wireless transceiver function, a virtual reality (VR) terminal, an augmented reality (AR) terminal, a wireless terminal in industrial control, a vehicle-mounted terminal, a wireless terminal in self-driving, a wireless terminal in remote medical, a wireless terminal in smart grid, a wireless terminal in transportation safety, a wireless terminal in smart city, a wireless terminal in smart home, a wearable terminal, etc. The embodiments of the present application do not limit the application scenarios. Terminal equipment may sometimes also be referred to as terminal, user equipment (UE), access terminal, vehicle-mounted terminal, industrial control terminal, UE unit, UE station, mobile station, mobile station, remote station, remote terminal, mobile device, UE terminal, wireless communication equipment, UE agent or UE device, etc. The terminal may also be fixed or mobile. It is understood that all or part of the functions of the terminal in this application may also be implemented by software functions running on hardware, or by virtualization functions instantiated on a platform (such as a cloud platform). The terminal device in this application may be a terminal for 5G or a terminal for 6G, and this application does not limit this.

[0071] 2. RAN

[0072] The RAN may include one or more RAN devices (or access network devices). The interface between the access network device and the terminal device may be a Uu interface (or air interface). Of course, in communications that evolve after 5G, the names of these interfaces may remain unchanged, or may be replaced by other names, and this application does not limit this.

[0073] Access network equipment refers to the node or device that connects the terminal device to the wireless network. Access network equipment includes, but is not limited to: next generation node B (gNB), evolved node B (eNB), next generation eNB (ng-eNB), wireless backhaul equipment, radio network controller (RNC), node B (NB), home evolved node B (HeNB) or home node B (HNB), baseband unit (BBU), transmitting and receiving point (TRP), transmitting point (TP), mobile switching center, device-to-device (D2D), vehicle-to-everything (V2X), machine-to-machine (M2M) communication equipment that performs base station functions, etc. It can also include cloud radio access network (cloud radio access network). The RAN in this application may be a RAN for 5G or a RAN for 6G, and this application does not limit this.

[0074] 3. CN

[0075] The CN may include one or more CN devices (which may be understood as network element devices or network function (NF)). In the following text, the CN devices are collectively referred to as core network devices (eg, the first core network device and the second core network device in the following text).

[0076] See also Figure 2 , Figure 2 A schematic diagram of the structure of a CN provided in this application, Figure 2 The CN in Figure 1 is a schematic diagram of the CN in the 5G network architecture. Figure 2The CN shown includes multiple CN devices: network slice selection function (NSSF), network exposure function (NEF), network function repository function (NRF), policy control function (PCF), unified data management (UDM), application function (AF), network control function (NCF), network slice specific authentication and authorization function (NSSAAF), authentication server function (AUSF), access and mobility management function (AMF), session management function (SMF), user plane function (UPF), service communication proxy (SCP), network slice admission control (NSACF). Among them:

[0077] AMF is a control plane function provided by the operator network, responsible for access control and mobility management of terminal devices accessing the operator network, such as mobility status management, allocation of user temporary identities, authentication and authorization of users, etc.

[0078] SMF is a control plane function provided by the operator network, responsible for managing the protocol data unit (PDU) session of the terminal device. A PDU session is a channel for transmitting PDUs. The terminal device needs to transmit PDUs to and from the DN through the PDU session. SMF is responsible for establishing, maintaining and deleting PDU sessions. SMF includes session management (such as session establishment, modification and release, including tunnel maintenance between UPF and RAN), UPF selection and control, service and session continuity (SSC) mode selection, roaming and other session-related functions.

[0079] PCF is a control plane function provided by the operator, including user subscription data management function, policy control function, charging policy control function, quality of service (QoS) control, etc. It is mainly used to provide PDU session policies to SMF. Among them, the policy may include charging-related policies, QoS-related policies, and authorization-related policies.

[0080] UPF is a gateway provided by the operator and is the gateway for the operator network to communicate with the DN. UPF includes user-plane related functions such as packet routing and transmission, packet detection, quality of service (QoS) processing, uplink packet detection, and downlink packet storage.

[0081] UDM is mainly used to manage the user's contract data and authentication data, as well as to perform authentication credit processing, user identity processing, access authorization, registration / mobility management, subscription management, and short message management. In some embodiments, UDM may also include a unified data repository (UDR). Alternatively, in other embodiments, the 3GPP SBA of the 5G system may also include a UDR. Among them, UDR is used to provide storage and retrieval for PCF policies, storage and retrieval of open structured data, and storage of user information requested by application functions.

[0082] NRF is mainly used to register, manage, and detect the status of other NFs to achieve automated management of all NFs. When each NF is started, it must register with NRF to provide services. The registration information includes NF type, address, service list, etc.

[0083] NEF is mainly used to support secure interaction between the network and third-party applications. The network can securely expose network capabilities and events to third parties through NEF to enhance or improve the quality of application services. In addition, the network can securely obtain relevant data from third parties through NEF to enhance the network's intelligent decision-making. At the same time, NEF supports recovering structured data from UDR or storing structured data in UDR.

[0084] AF is mainly used to support interaction with the core network to provide services, such as influencing data routing decisions, policy control functions, or providing some third-party services to the network side.

[0085] The above CN equipment can also be called network element or functional network element. In the 5G communication system, each functional network element can be Figure 2 The names of the functional network elements shown in the figure may still be the same in the communication system evolved after 5G (such as 6G communication system). Figure 2 The names of the various functional network elements shown in the figure may also have other names. For example, in a 5G communication system, the policy control network element may be a PCF. In a communication system evolved after 5G (such as a 6G communication system), the policy control function may still be a PCF, or may have other names, which is not limited in this application.

[0086] Figure 2 Among them, Npcf, Nudm, Naf, Namf, Nsmf, N1, N2, N3, N4, and N6 are interface serial numbers. The meanings of these interface serial numbers can be found in the definitions in the relevant standard protocols and are not limited here.

[0087] 4.DN

[0088] DN, also known as packet data network (PDN), is a network located outside the operator network. The operator network can access multiple DNs. Application servers corresponding to various services can be deployed in the DN to provide a variety of possible services for terminal devices.

[0089] It should be noted that Figure 1 The system architecture shown is merely illustrative and should not be considered as a specific limitation of the technical solution of the present application.

[0090] In order to facilitate understanding of the relevant contents of the embodiments of the present application, some of the terms involved in the embodiments of the present application are explained below. This part is only for ease of understanding and cannot be regarded as a disclosure or specific limitation of the technical solution of the present application.

[0091] 1. NTN

[0092] NTN is a communication system that provides communication services (such as wireless access or backhaul) to terminal devices through non-ground network equipment (such as ships, high-altitude platforms, drones or satellites), thereby achieving seamless communication coverage to improve the reliability of the communication system. For example, 5G NTN or NRNTN and future 6G NTN systems can help meet the needs of wireless connections anytime and anywhere by providing wider regional coverage and ensuring service availability, continuity and scalability. It should be noted that for ease of understanding, the following text only uses the example of a satellite as the non-ground network device in NTN, which should not be regarded as a specific limitation of the present application.

[0093] When the non-terrestrial network equipment is a satellite, it involves low earth orbit (LEO), medium earth orbit (MEO) and geostationary earth orbit (GEO) satellites. The role of the satellite can also be different for different access methods provided by NTN. For example, in Figure 3a In the transparent satellite architecture shown in FIG. 1 , the satellite provides access technology to connect the terminal equipment to the ground network. The role of the satellite is to filter the wireless frequency, perform frequency conversion and amplification. That is, in the transparent satellite architecture, the satellite mainly acts as a layer 1 (abbreviated as L1) relay device between the terminal and the ground base station to regenerate the physical layer signal (i.e., wireless frequency filtering, frequency conversion and amplification processing), without other higher protocol layers. Figure 3b In a regenerative satellite architecture shown, part or all of the functions of the base station are integrated into the satellite. It should be noted that in the regenerative satellite architecture, part or all of the functions of the base station and part or all of the functions of the core network can also be integrated into the satellite, thereby providing a shorter transmission delay.

[0094] Typically, satellites in NTN are connected via gateways (such as Figure 3a or Figure 3b The gateway station shown in the figure communicates with the ground network (including access network equipment and / or core network equipment). The gateway station (also referred to as the ground station) mentioned in this application can be understood as the gateway in the NTN.

[0095] 2. Satellite alignment process of terminal equipment

[0096] In the NTN communication scenario, due to the long distance between the ground terminal and the satellite and the limited link budget, when communicating with the satellite, the terminal equipment needs to perform a satellite alignment process to improve the signal gain and ensure effective communication with the satellite.

[0097] The satellite alignment process of the terminal device can be understood as the process in which the terminal device adjusts the antenna attitude so that the radiation direction of the antenna is aligned with the target satellite, so that the terminal device can communicate with the satellite; adjusting the antenna attitude can be understood as the process in which the terminal device adjusts the azimuth, elevation and polarization angle of the antenna so that the center of the antenna beam of the terminal device is aligned with the satellite.

[0098] In the NTN communication scenario, the terminal device needs to perform the satellite alignment process first, so that the terminal device can communicate with the NTN satellite (or understand that the terminal device is in the satellite alignment state), and then the terminal device can connect to the access network device and the core network device to obtain NTN services (or understand that it is network services). If the terminal device does not perform the satellite alignment process, that is, the terminal device cannot communicate with the NTN satellite (or understand that the terminal device is in the non-satellite alignment state), the terminal device cannot obtain NTN services.

[0099] 3. Periodic registration

[0100] The terminal device needs to be successfully registered with the core network device of the communication network before it can receive the communication services provided by the communication network. The communication network includes but is not limited to NTN or terrestrial network (TN). After the registered terminal device enters the idle state, the core network device of the communication network can know whether the terminal device is reachable by whether the terminal device performs periodic registration. The reachability of the terminal device can ensure that the terminal device can communicate with the network normally in the future.

[0101] Specifically, the terminal device is configured with a periodic registration timer, and the terminal device initiates periodic registration according to the periodic registration timer. It can be understood that when the terminal device enters the idle state, the periodic registration timer is started; when the periodic registration timer times out, the terminal device sends a periodic registration request to the core network device, so that the core network device knows that the terminal device is still reachable; after the terminal device sends the periodic registration request, it resets the periodic registration timer after entering the idle state again, and waits for the next time when the periodic registration timer times out again, and then sends the periodic registration request again. If the terminal device does not send a periodic registration request to the core network device after the periodic registration timer times out, or it is understood that the core network device has not received the periodic registration request, it is deemed that the terminal device has not performed periodic registration on time.

[0102] 4. Register

[0103] Deregistration refers to the process in which the network side (e.g., core network equipment) releases the relevant information of the terminal device (e.g., session information, context information, etc.). After the terminal device is deregistered, the terminal device needs to obtain the service of the communication network again and needs to register again (i.e., perform the initial registration process).

[0104] It should be noted that the implicit deregistration mentioned in this application can be understood as the situation where the core network device performs deregistration on the terminal device without notifying the terminal device. For a detailed explanation of implicit deregistration, please refer to 3GPP TS23.501.

[0105] See also Figure 3c FIG. 1 is a flow chart of an implicit deregistration process provided by an embodiment of the present application. Figure 3c In the core network device, a mobile reachable timer and an implicit deregistration timer are configured, wherein the value of the mobile reachable timer is greater than the value of the periodic registration timer. When the terminal device enters the idle state, the core network device starts the mobile reachable timer; if the mobile reachable timer times out and the core network device still does not receive the registration request message sent by the terminal device, the network side considers that the terminal device is unreachable and starts the implicit deregistration timer; if the terminal device still does not send a registration request message to the core network device after the implicit deregistration timer times out, the core network device implicitly deregisters the terminal device and deletes the relevant information of the terminal device.

[0106] After the terminal device enters the CM idle state, it needs to periodically perform the registration update process according to the requirements of the core network (such as the periodic registration update timer) to ensure that the core network considers the terminal device reachable so that the terminal device can subsequently communicate normally with the network. In the NTN communication scenario, if the terminal device periodically performs the registration update process, it is necessary to periodically perform the satellite alignment process, which brings a large power consumption overhead to the terminal device. In addition, when the terminal device uses manual satellite alignment to perform the satellite alignment process, the terminal device cannot automatically perform the satellite alignment process periodically (or it is understood that the terminal device cannot guarantee to initiate periodic registration updates), which causes the core network to consider the terminal unreachable, thereby deregistering the terminal device, affecting the timeliness of the terminal device's communication services.

[0107] In order to reduce the power consumption of terminal equipment and improve the timeliness of communication services of terminal equipment, the present application provides a method and a communication device. The method and the communication device provided by the embodiments of the present application are described in detail below in conjunction with the accompanying drawings. Figure 4 Schematic diagram of a method provided in an embodiment of the present application. Figure 4As shown, the method includes the following step S401: Figure 4 The method execution subject shown is described by taking the terminal device and the first core network device of NTN as an example. It can be understood that Figure 4 The execution subject of the method shown may also be a module (for example, a chip) in the terminal device and a module (for example, a chip) in the first core network device.

[0108] S401: When the terminal device completes registration in the NTN, the terminal device enters the first mode. Correspondingly, when the terminal device completes registration in the NTN, the first core network device of the NTN determines that the terminal device enters the first mode.

[0109] For the terminal device, after the terminal device enters the first mode, the terminal device does not need to initiate periodic registration with the first core network device of NTN in the first mode; or, it is understood that the period for the terminal device to initiate periodic registration with the first core network device in the first mode (hereinafter referred to as the first period for the sake of description) is greater than the period for the terminal device to initiate periodic registration with the second core network device of TN (hereinafter referred to as the second period for the sake of description). In a possible implementation, the terminal device also has one or more of the following features in the first mode: ① Maintaining a registered state and / or maintaining no service, ② No need to monitor paging messages from NTN. Among them, maintaining no service can be understood as the terminal device entering a no service state.

[0110] For the first core network device of NTN, the terminal device configured in the first mode by the first core network device does not need to send periodic registration to the first core network device of NTN; or, the first period configured by the first core network device is greater than the second period. In one possible implementation, after the first core network device determines that the terminal device has entered the first mode, one or more of the following operations may also be performed: ① Maintain the registration status of the terminal device in the first mode and / or maintain no service. It can be understood that the first core network device will not trigger the process of implicit deregistration of the terminal device, or the first core network device sets the implicit deregistration timer to infinity (or understood as a larger value, or understood as deactivating the implicit registration timer). ② There is no need to send a paging message to the terminal device, or it is understood that there is no need to page the terminal device.

[0111] In a possible implementation, after the terminal device enters the first mode, when the terminal device is converted from the second state to the first state, the terminal device sends a first message to the first core network device. The terminal device can communicate with the satellite of NTN in the second state, and the terminal device cannot communicate with the satellite of NTN in the first state; for example, the second state is a state where the terminal device is not aligned with the satellite (or called a non-aligned state), and the first state is a state where the terminal device is aligned with the satellite (or called a aligned state). The first message is used to request registration or request service, for example, the first message is a registration request message or a service request message. That is, after the terminal device enters the first mode, if the terminal device has a demand for NTN services, the terminal device can be converted from the second state to the first state. After the terminal device is converted to the first state, the terminal device sends a first message to the first core network device via the satellite of NTN to request registration or request service.

[0112] It should be noted that the timing when the terminal device enters the first mode and the timing when the first core network device determines that the terminal device enters the first mode can be the same or different, and this application does not make specific restrictions on this. Correspondingly, the timing when the terminal device exits the first mode and the timing when the first core network device determines that the terminal device exits the first mode can be the same or different, and this application does not make specific restrictions on this.

[0113] The timing when the terminal device enters the first mode, the timing when the terminal device exits the first mode, the timing when the first core network device determines that the terminal device enters the first mode, and the timing when the first core network device determines that the terminal device exits the first mode are explained below.

[0114] 1. The timing when the terminal device enters the first mode.

[0115] In one case, after the terminal device completes registration in the NTN, the terminal device can enter the first mode. That is, in this case, the terminal device meets the condition of completing registration in the NTN and can enter the first mode.

[0116] In another case, in addition to satisfying the condition of completing registration in the NTN, the terminal device should also satisfy the first condition before entering the first mode. The first condition includes at least one of the following conditions:

[0117] Condition 1: The terminal device completes data transmission via NTN. It should be understood that Condition 1 includes any of the following two interpretations: ① When the terminal device completes data transmission via NTN; ② When the terminal device completes data transmission via NTN, and the terminal device does not transmit data via NTN within the fourth time period, and the fourth time period is greater than 0.

[0118] Condition 2: The connection management state of the terminal device is converted from the CM connected state to the CM idle state. It should be understood that condition 2 includes any of the following two understandings: ① When the terminal device is converted from the CM connected state to the CM idle state; ② The terminal device is converted from the CM connected state to the CM idle state, and the duration of the terminal device in the CM idle state is greater than the second duration, wherein the second duration is greater than 0.

[0119] Condition 3: The terminal device is converted from the first state to the second state, wherein in the first state the terminal device can communicate with the satellite of NTN, and in the second state the terminal device cannot communicate with the satellite of NTN. It should be understood that Condition 3 includes any of the following two understandings: ① When the terminal device is converted from the first state to the second state; ② The terminal device is converted from the first state to the second state, and the duration of the terminal device being in the second state is greater than the fifth duration, and the fifth duration is greater than 0.

[0120] Condition 4: The terminal device stops using NTN services. It should be understood that Condition 4 includes any of the following two interpretations: ① When the terminal device changes from using NTN services to stopping using NTN services; ② When the terminal device changes from using NTN services to stopping using NTN services, and the terminal device still does not use NTN services within the sixth time period, and the sixth time period is greater than 0.

[0121] 2. The timing for the terminal device to exit the first mode.

[0122] After the terminal device enters the first mode, the terminal device exits the first mode if a second condition is met; wherein the second condition includes at least one of the following conditions:

[0123] Condition 5: The terminal device is converted from the second state to the first state, wherein in the first state the terminal device can communicate with the satellite of NTN, and in the second state the terminal device cannot communicate with the satellite of NTN.

[0124] Condition 6: When the terminal device needs to switch from the CM idle state to the CM connected state, for example, when the terminal device has uplink signaling or data transmission requirements.

[0125] Condition 7: The terminal device detects that a satellite alignment operation is being performed; that is, the terminal device is performing operations related to the satellite alignment process.

[0126] 3. The first core network device determines the timing for the terminal device to enter the first mode.

[0127] In one case, the terminal device completes registration in the NTN, and the first core network device determines that the terminal device has entered the first mode. That is, in this case, the condition that the terminal device completes registration in the NTN is met, that is, the first core network device determines that the terminal device has entered the first mode.

[0128] In another case, in addition to satisfying the condition of completing registration in the NTN, the first core network device determines that the terminal device has entered the first mode only when a third condition is satisfied. The third condition includes at least one of the following conditions:

[0129] Condition 8: The connection management state of the terminal device is converted from the CM connected state to the CM idle state. It should be understood that condition 8 includes any one of the following two understandings: ① When the first core network device detects that the connection management state of the terminal device is converted from the CM connected state to the CM idle state; ② The first core network device detects that the terminal device is converted from the CM connected state to the CM idle state, and the duration of the terminal device in the CM idle state is greater than the second duration, wherein the second duration is greater than 0.

[0130] Condition 9: The first core network device detects that the terminal device has not used the NTN network service within a third time period, and the third time period is greater than 0.

[0131] Condition 10: When the first core network device fails to page the terminal device. Condition 10 can be understood as when the terminal device is in the CM idle state, the first core network device fails to send a paging message to the terminal device, for example, the first core network device fails to receive a response from the terminal device after sending a paging message to the terminal device.

[0132] 4. The first core network device determines the timing for the terminal device to exit the first mode.

[0133] After the first core network device determines that the terminal device enters the first mode, the first core network device determines that the terminal device exits the first mode if a fourth condition is met. The fourth condition includes one or more of the following conditions:

[0134] Condition 11: The first core network device receives a first message from the terminal device, where the first message is used to request registration or service.

[0135] Condition 12: The first core network device detects that the connection management state of the terminal device is changed from CM idle state to CM connected state.

[0136] In summary, Figure 4 In the described method, after the terminal device completes registration in the NTN, the terminal device can enter a mode in which it does not need to initiate periodic registration to the first core device of the NTN (i.e., the first mode mentioned in the present application), or the terminal device enters a mode in which a periodic registration is initiated with a larger period, thereby reducing the satellite alignment process performed due to periodic registration, which is beneficial to saving power consumption of the terminal device.

[0137] exist Figure 4In the described method, the terminal device completes registration in the NTN, which can be understood as the terminal device performing a registration process in the NTN, which mainly includes the following two steps: S1, the terminal device sends a first message to the first core network device of the NTN, and the first message is used to request registration; S2, the terminal device receives a second message from the first core network device, and the second message indicates that the first core network device accepts the registration request of the terminal device. Figure 4 In the described method, the first core network device can only serve NTN (it can be understood that when the core network device of NTN is different from the core network device of TN, the first core network device is the core network device of NTN), or the first core network device can serve both NTN and TN (it can be understood that when NTN and TN share all the same core network devices or share some core network devices, the first core network device is the core network device shared by NTN and TN). Figure 4 The described method is divided into the following cases to explain in detail the registration process of the terminal device in the NTN.

[0138] Case 1: The operator corresponding to NTN can be the exclusive operator of NTN, mainly operating NTN. In this case, it can be understood that the first core network equipment only serves NTN. The registration process of the terminal equipment in NTN can be found in Figure 5 As shown. Among them:

[0139] S501. A terminal device sends a first message to a first core network device, where the first message is used to request registration.

[0140] After the terminal device performs the satellite alignment process, the terminal device sends a first message (e.g., a registration request message) for requesting registration to the access network device of the NTN, and the access network device of the NTN forwards the first message to the first core network device. It should be noted that the access network device of the NTN may be deployed on a satellite or not, and this application does not make specific limitations; for ease of understanding, in this application, after the terminal device performs the satellite alignment process, it can be understood that the terminal device can communicate with the access network device of the NTN.

[0141] In a possible implementation, the first message includes at least one of the following: preference for the first mode, first information, first capability information, or second capability information. The first information indicates that the terminal device cannot guarantee the execution of periodic registration, or the first information indicates that the terminal device requests not to execute periodic registration; the first capability information indicates whether the terminal device has the ability to support NTN communication; the second capability information indicates whether the terminal device has the ability to automatically point to the satellite. It can be understood that when the first message includes the first information, it may also include other information (such as preference for the first mode, information requested for registration, etc.) in addition to the first information.

[0142] When the first message includes a preference for the first mode, it indicates that the terminal device expects to enter the first mode later if the conditions are met; that is, when the terminal device expects to enter the first mode later if the conditions are met, the first message may include a preference for the first mode. In a possible implementation, when the terminal device does not have the ability to automatically align the satellite (or it is understood that the terminal device only has the ability to automatically align the satellite), or when the terminal device is selected by the user to perform a manual alignment operation, the first message includes a preference for the first mode; otherwise, the first message may not include a preference for the first mode. For example, when the terminal device detects NTN, it outputs a prompt message through a user interface (UESR interface, UI), and the prompt message is used to prompt the user whether to enter the first mode and whether the call cannot be received in the first mode; after the user enters confirmation information according to the prompt message, it can be understood that the terminal device is selected by the user to perform a manual alignment operation. In this case, the first message sent by the terminal device to the first core network includes a preference for the first mode.

[0143] In Example 1, the first message includes a preference for the first mode. In this case, after receiving the first message, the first core network device can determine whether to accept the terminal device's preference for the first mode based on the terminal device's subscription information about NTN. For example, when the terminal device's subscription information about NTN includes subscription information that allows entry into the first mode, the first core network device determines to accept the terminal device's preference for the first mode.

[0144] When the first message includes at least one of the first information, the first capability information or the second capability information, the first core network device can determine at least one of the following based on the first information: ① After the terminal device completes registration in the NTN, whether the terminal device can enter the first mode (it can also be understood as determining whether to accept the terminal device's preference for the first mode); ② Whether the periodic registration timer is activated; ③ When the periodic registration timer is activated, the duration of the periodic registration timer; ④ Whether to perform implicit deregistration on the terminal device; or, ⑤ When the periodic registration timer is not activated, the reachable timer and the implicit deregistration timer are not activated, so that the implicit deregistration process is not performed. In a possible implementation, when the second capability information indicates that the terminal device does not have the ability to automatically align with the satellite, it can be understood that the second capability information also indicates that the terminal device cannot guarantee the execution of periodic registration. When the first capability information indicates that the terminal device has the ability to communicate with NTN, and the second capability information indicates that the terminal device does not have the ability to automatically align with the satellite, the first capability information and the second capability information indicate that the terminal device cannot guarantee the execution of periodic registration. It can be understood that, in this possible implementation, the content indicated by the first information is indicated by the first capability information and / or the second capability information, that is, it can be understood that the first information includes the first capability information and / or the second capability information.

[0145] In Example 2, the first message includes first capability information, and the first capability information indicates that the terminal device has the ability to support NTN communication. In this case, the first core network device can determine, based on the first capability information, that after the terminal device completes registration in NTN, the terminal device can enter the first mode. In one possibility of Example 2, the first core network device can also determine to activate the periodic registration timer corresponding to the terminal device based on the contract information of the terminal device regarding NTN (for example, the duration of the terminal device's contract for NTN services), and determine the duration of the periodic registration timer to be the first duration; it can also determine to activate a reachable timer and an implicit deregistration timer, and the duration of the reachable timer is greater than the first duration, and the duration of the implicit deregistration timer is greater than the first duration; and the terminal device is not implicitly deregistered before the implicit deregistration timer times out.

[0146] In Example 3, the first message includes second capability information, and the second capability information indicates that the terminal device does not have the ability to automatically align the satellite, or indicates that the terminal device can only perform the alignment process through manual operation (that is, it indicates that the terminal device only has the ability to manually align the satellite). In this case, the first core network device can determine that after the terminal device completes registration in the NTN based on the second capability information, the terminal device can enter the first mode. In one possibility of Example 3, the first core network device can also determine to activate the periodic registration timer corresponding to the terminal device based on the contract information of the terminal device about the NTN (for example, the duration of the terminal device's contract for the NTN service), and determine the duration of the periodic registration timer to be the first duration; it can also determine to activate the reachable timer and the implicit deregistration timer, and the duration of the reachable timer is greater than the first duration, and the duration of the implicit deregistration timer is greater than the first duration; implicit deregistration of the terminal device is not performed before the implicit deregistration timer times out.

[0147] It should be noted that the first capability information described in this application indicates whether the terminal device has the ability to support NTN communication, including a display indication method and an implicit indication method. The second capability information indicates whether the terminal device has the ability to automatically point to the satellite, also including a display indication method and an implicit indication method. For ease of understanding, the display indication method and the implicit indication method corresponding to the first capability information are used as an example for explanation.

[0148] For example, the first capability information corresponds to field 1. In an explicit indication mode, when the value of field 1 is 0, the first capability information indicates that the terminal device has the ability to support NTN communication, and when the value of field 1 is 1, the first capability information indicates that the terminal device does not have the ability to support NTN communication. In an implicit indication mode, when the first message includes field 1, the first capability information indicates that the terminal device has the ability to support NTN communication, and when the first message does not include field 1, the first capability information indicates that the terminal device does not have the ability to support NTN communication. Alternatively, in another implicit indication mode, when the first message includes field 1, the first capability information indicates that the terminal device does not have the ability to support NTN communication, and when the first message does not include field 1, the first capability information indicates that the terminal device has the ability to support NTN communication.

[0149] S502. The terminal device receives a second message from the first core network device, where the second message indicates that the first core network device accepts the registration request of the terminal device.

[0150] After the first core network device receives the first message through the access network device of the NTN, the first core network device determines to accept the registration request of the terminal device according to the contract information of the terminal device about the NTN. Further, the first core network device sends a second message (for example, a registration acceptance message) to the access network device of the NTN, and the access network device of the NTN forwards the second message to the terminal device.

[0151] In a possible implementation, the second message includes at least one of the following information: information confirming the acceptance of the terminal device's preference for the first mode, the second information, or the third information. The second information indicates that after the terminal device enters the first mode, it is not necessary to initiate a periodic registration with the first core network device of the NTN; the third information indicates a first duration (i.e., the duration of the periodic registration timer, which is related to the duration of the NTN service contract signed by the terminal device), and / or the third information indicates whether the periodic registration timer is activated. In a possible implementation of the third information, the third information consists of two parts, the first part indicates the length of the periodic registration timer, and the second part indicates a multiple (i.e., the unit corresponding to the length of the periodic registration timer, such as 10s, 10min, 1h, etc.); when the second part takes the first value, the third information indicates that the periodic registration timer is not activated; when the second part takes other values ​​(i.e., not the first value), the third information indicates that the periodic registration timer is activated, and the value of the second part (i.e., the other value) indicates the multiple. For example, the third information is as follows: Figure 6 As shown, when the second part indicates 111 (i.e., the first value), the third information indicates that the periodic registration timer is not activated; when the second part indicates 100, the second part indicates that the periodic registration timer is activated, and the multiple is 1h. If the first part indicates that the length of the periodic registration timer is 60, the third information indicates that the first duration is 60h.

[0152] It can be understood that when the second message includes information confirming acceptance of the terminal device's preference for the first mode, or includes the second information, the terminal device can subsequently enter the first mode if the conditions for entering the first mode (such as the aforementioned first condition) are met. When the second message includes the third information, after the terminal device enters the first mode, it is not necessary to initiate a periodic registration with the first core network device within the first duration indicated by the third information.

[0153] For example, following Example 1 in S501, the second message includes information for determining the preference of the receiving terminal device for the first mode.

[0154] For example, following Example 2 in S501, the second message includes the second information. In a possible implementation manner, the second message also includes third information indicating an activation period registration timer and a first duration.

[0155] For example, following Example 3 in S501, the second message includes the second information. In a possible implementation manner, the second message also includes third information indicating an activation period registration timer and a first duration.

[0156] Case 2: The operator corresponding to NTN is different from the operator corresponding to TN. The operator corresponding to NTN has a cooperative relationship with the operator corresponding to TN. That is, it can be understood that there is a communication connection between the first core network device and the second core network device, and they can communicate with each other. In this case, it can be understood that the first core network device only serves NTN. The registration process of the terminal device in NTN can be seen in Figure 7 As shown. Among them:

[0157] S701. The terminal device sends a first message to the first core network device through the second core network device, where the first message is used to request registration.

[0158] That is, the terminal device sends the first message to the second core network device through the TN access network device, and further, the second core network device forwards the first message to the first core network device. For the specific description of the first message, please refer to the specific description of the first message in S501, which will not be repeated here.

[0159] In a possible implementation, the terminal device includes a first subscriber identity module (SIM) card and a second SIM card. The first SIM card is subscribed to a TN service, and the second SIM card is subscribed to an NTN service. In this case, the implementation process of S701 is as follows: Figure 8 As shown, it includes: the terminal device sends a first message to the first SIM card through the second SIM card; the first SIM card sends the first message to the access network device of TN; the access network device of TN sends the first message to the second core network device; the second core network device forwards the first message to the first core network device.

[0160] In a possible implementation, at least one of the first SIM card or the second SIM card is an embedded SIM (Embedded-SIM, eSIM) card.

[0161] S702. The terminal device receives a second message from the first core network device through the second core network device, where the second message indicates acceptance of the registration request of the terminal device.

[0162] That is, after the first core network device receives the first message, the first core network device determines to accept the registration request of the terminal device according to the contract information of the terminal device about the NTN. Further, the first core network device sends a second message to the second core network device, the second core network device sends the second message to the access network device of the TN, and the access network device of the TN sends the second message to the terminal device. For the specific description of the second message, please refer to the specific description of the second message in S502, which will not be repeated here.

[0163] In a possible implementation, the terminal device includes a first SIM card and a second SIM card. The first SIM card is subscribed to a TN service, and the second SIM card is subscribed to an NTN service. In this case, the implementation process of S702 is as follows: Figure 8 As shown, it includes: the first core network device sends a second message to the second core network device; the second core network device sends the second message to the access network device of the TN; the access network device of the TN sends the second message to the first SIM card, and the first SIM card sends the second message to the second SIM card. After the second SIM card receives the second message, it is regarded as the terminal device in S702 receiving the second message.

[0164] Case 3: The public land mobile network (PLMN) corresponding to NTN is different from the PLMN corresponding to TN. For example, the same operator operates both TN and NTN and TN and NTN correspond to different PLMNs, or the operator to which NTN belongs is different from the operator to which TN belongs, but the operator to which NTN belongs has a roaming agreement with the operator to which TN belongs. For example, users of the operator to which TN belongs can roam to NTN with a roaming agreement, and users of the operator to which NTN belongs can also roam to TN with a roaming agreement. In this case, it can be understood that the first core network device only serves NTN, and the registration process of the terminal device in NTN can be found in Figure 9a or Figure 9b shown.

[0165] exist Figure 9a In the process diagram shown:

[0166] S901. The second core network device sends at least one equivalent public land mobile network (EPLMN) identifier to the terminal device.

[0167] exist Figure 9aIn the embodiment, the second core network device is the core network device for registering the PLMN of the terminal device. That is to say, during the process of the terminal device registering with the TN, at least one EPLMN identifier sent by the second core network device of the TN can be received. Among them, the at least one EPLMN identifier includes the PLMN identifier of the NTN.

[0168] Specifically, the terminal device sends a registration request message to the second core network device, and the registration request message is used to register the TN (which can be understood as the PLMN registration in the TN network). The second core network device sends a registration acceptance message to the terminal device based on the contract information of the terminal device, and the registration acceptance message indicates the reception of the registration request of the terminal device, and the registration reception message includes at least one EPLMN identifier, and the EPLMN identifier includes the PLMN identifier of the NTN (for example, when the contract information of the terminal device includes the NTN contract, the PLMN identifier includes the PLMN identifier of the NTN). Subsequently, when the terminal device needs to obtain NTN services, for example, when the terminal device moves to an area without the coverage of the registered network, the terminal device performs a satellite operation and registers in the NTN based on the PLMN identifier of the NTN. The registration process in the NTN based on the PLMN identifier of the NTN may include any of the following methods one or two.

[0169] S902 (optional method one): the terminal device sends a first message to the first core network device, where the first message is used to request registration.

[0170] That is, after the terminal device completes registration in the TN, if the terminal device needs to obtain NTN services, for example, when it moves to an area without TN coverage, the terminal device can send a first message for requesting registration with the NTN to the first core network device through the access network device of the NTN. For a detailed description of the first message, please refer to the detailed description of the first message in S501, which will not be repeated here.

[0171] S903 (optional method 1): the terminal device receives a second message from the first core network device, where the second message indicates that the first core network device accepts the registration request of the terminal device.

[0172] That is, after the first core network device receives the first message, the first core network device determines to accept the registration request of the terminal device according to the contract information of the terminal device about the NTN. Further, the first core network device sends a second message to the terminal device through the access network device of the NTN. For the specific description of the second message, please refer to the specific description of the first message in S501, which will not be repeated here.

[0173] S904 (optional method 2): The terminal device sends a first message to the first core network device through the second core network device, where the first message is used to request registration.

[0174] That is to say, after the terminal device completes registration in the TN, the terminal device can also send the first message to the second core network device through the access network device of the TN, and further, the second core network device forwards the first message to the first core network device. For the specific description of the first message, please refer to the specific description of the first message in S501, which will not be repeated here.

[0175] S905 (optional method 2): The terminal device receives a second message from the first core network device through the second core network device, where the second message indicates acceptance of the registration request of the terminal device.

[0176] That is, after the first core network device receives the first message, the first core network device determines to accept the registration request of the terminal device according to the contract information of the terminal device about the NTN. Further, the first core network device sends a second message to the second core network device, the second core network device sends the second message to the access network device of the TN, and the access network device of the TN sends the second message to the terminal device. For the specific description of the second message, please refer to the specific description of the second message in S502, which will not be repeated here.

[0177] exist Figure 9b In the process diagram shown:

[0178] S911. The third core network device sends at least one EPLMN identifier to the terminal device.

[0179] exist Figure 9b In the embodiment, the third core network device is the core network device used when the terminal device registers the PLMN of the TN. That is to say, during the process of the terminal device registering with the TN, at least one EPLMN identifier sent by the third core network device of the TN can be received. Among them, the at least one EPLMN identifier includes the PLMN identifier of the NTN.

[0180] Specifically, the terminal device sends a registration request message to the third core network device, and the registration request message is used to register the TN. The third core network device sends a registration acceptance message to the terminal device based on the contract information of the terminal device, and the registration acceptance message indicates receiving the registration request of the terminal device, and the registration acceptance message includes at least one EPLMN identifier, and the EPLMN identifier includes the PLMN identifier of the NTN. Subsequently, when the terminal device needs to obtain NTN services, for example, after leaving the coverage area of ​​the TN, the terminal device performs a satellite operation and registers in the NTN based on the PLMN identifier of the NTN. The registration process in the NTN based on the PLMN identifier of the NTN may include any one of the following methods one or two.

[0181] S912 (optional method one): the terminal device sends a first message to the first core network device, where the first message is used to request registration.

[0182] S913 (optional method 1): the terminal device receives a second message from the first core network device, where the second message indicates that the first core network device accepts the registration request of the terminal device.

[0183] S914 (optional method two): the terminal device sends a first message to the first core network device through the second core network device, where the first message is used to request registration.

[0184] S915 (optional method two): the terminal device receives a second message from the first core network device through the second core network device, where the second message indicates acceptance of the registration request of the terminal device.

[0185] For the specific implementation of S912 to S915, please refer to the above Figure 9a The specific implementation of S902 to S905 will not be described in detail here. It should be noted that: Figure 9a and Figure 9b The difference is: in Figure 9a In the second method, the second core network device (ie Figure 9a The core network equipment of the TN involved in S904 and S905 in the above), and the core network equipment used when the terminal device registers the PLMN of the TN (ie Figure 9a The core network equipment of TN involved in S901 is the same as that in Figure 9b In the second method, the second core network device (ie Figure 9b The core network equipment of the TN involved in S914 and S915 in the above), and the core network equipment used when the terminal device registers the PLMN of the TN (i.e. Figure 9b The TN core network equipment involved in S911 is different.

[0186] Case 4: NTN and TN correspond to different access technologies under the same PLMN, for example, NTN and TN belong to the same operator. In this case, it can be understood that the first core network device can serve both NTN and TN at the same time, and the terminal device can be connected to the first core network device through the NTN access method or the TN access method. The registration process of the terminal device in NTN can be found in Fig.10 As shown. Among them:

[0187] S1001. A terminal device sends a first message to a first core network device, where the first message is used to request registration. For the description of the first message, please refer to the description of the first message in S501 above, which will not be repeated here.

[0188] Since the first core network device serves NTN and TN, the terminal device can send a first message to the first core network device through an access network device (which can be an access network device of NTN or an access network device of TN). The first message can be used to request registration in NTN, or to request registration in TN and NTN.

[0189] S1002, the terminal device receives a second message from the first core network device, the second message indicating that the first core network device accepts the registration request of the terminal device. For the description of the second message, please refer to the description of the second message in S502 above, which will not be repeated here.

[0190] Furthermore, the terminal device may receive the second message from the first core network device through an access network device (which may be an access network device of NTN or an access network device of TN).

[0191] In a possible implementation of the fourth situation, the period for the terminal device to initiate periodic registration to the first core network device in the first mode (i.e., the first period mentioned in the present application) is greater than the period for the terminal device to initiate periodic registration to the first core network device after exiting the first mode (i.e., the period for the terminal device to initiate periodic registration in the TN, i.e., the second period mentioned in the present application). It can be understood that the duration of the periodic timer configured by the first core network device for the terminal device in the first mode (e.g., the aforementioned first duration) is greater than the duration of the periodic timer configured by the first core network device for the terminal device exiting the first mode; or, the duration of the reachable timer corresponding to the terminal device in the first mode in the first core network device is greater than the duration of the reachable timer corresponding to the terminal device exiting the first mode in the first core network device; or, the duration of the implicit de-registration timer corresponding to the terminal device in the first mode in the first core network device is greater than the duration of the implicit de-registration timer corresponding to the terminal device exiting the first mode in the first core network device.

[0192] It is understandable that in order to implement the functions in the above embodiments, the terminal device includes hardware structures and / or software modules corresponding to the execution of each function. Those skilled in the art should easily realize that, in combination with the units and method steps of each example described in the embodiments disclosed in this application, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in the form of hardware or computer software transceiver components driving hardware depends on the specific application scenario and design constraints of the technical solution.

[0193] Fig.11 and Fig.12 A schematic diagram of the structure of possible communication devices provided for embodiments of the present application. These communication devices can be used to implement the functions of the terminal device in the above method embodiments, and thus can also achieve the beneficial effects possessed by the above method embodiments. In an embodiment of the present application, the communication device can be a terminal device, or a module (such as a chip) applied to a terminal device, or the communication device can be a first core network device, or a module (such as a chip) applied to a first core network device.

[0194] like Fig.11 As shown, the communication device 1100 includes a processing unit 1110 and a transceiver unit 1120. The communication device 1100 is used to implement the above Figure 4 , Figure 7-10 The function of the terminal device in any of the method embodiments shown in the figure, or for implementing the above Figure 4 , Figure 7-10 The function of the first core network device in any of the method embodiments illustrated in the figure.

[0195] When the communication device 1100 is used to implement the function of the terminal device in the embodiment of the present application: when the terminal device completes registration in the non-terrestrial network NTN, the processing unit 1110 is used to control the terminal device to enter the first mode; wherein, the terminal device does not need to initiate periodic registration to the first core network device of the NTN in the first mode.

[0196] In one possible implementation, the transceiver unit 1120 is used to send a first message to the first core network device, where the first message is used to request registration; the transceiver unit 1120 is also used to receive a second message from the first core network device, where the second message indicates that the first core network device accepts the registration request of the terminal device.

[0197] In a possible implementation, the first message includes first information, where the first information indicates that the terminal device cannot guarantee to perform periodic registration, or the first information indicates that the terminal device requests not to perform periodic registration.

[0198] In a possible implementation, the first information includes first capability information and / or second capability information; wherein the first capability information indicates whether the terminal device has the capability to support NTN communication, and the second capability information indicates whether the terminal device has the capability to automatically point to a satellite.

[0199] In a possible implementation, the second message includes second information, where the second information indicates that after the terminal device enters the first mode, it is not necessary to initiate periodic registration with the first core network device of the NTN.

[0200] In a possible implementation, the second message also includes third information, which indicates a first duration, where the first duration is the duration of the periodic registration timer, and the first duration is related to the duration of the NTN service contracted by the terminal device; the aforementioned terminal device does not need to initiate periodic registration with the first core network device of NTN in the first mode, including: the terminal device does not need to initiate periodic registration with the first core network device of NTN within the first duration in the first mode.

[0201] In a possible implementation, the third information indicates that the periodic registration timer is not activated.

[0202] In a possible implementation, the processing unit 1110 is configured to control the terminal device to maintain a registered state and / or maintain a no-service state in the first mode.

[0203] In a possible implementation, the terminal device does not need to monitor the paging message from the NTN in the first mode.

[0204] In a possible implementation, when the terminal device is registered and the first condition is met, the processing unit 1110 is configured to control the terminal device to enter the first mode; wherein the first condition includes at least one of the following:

[0205] The terminal device completes data transmission via NTN;

[0206] The terminal equipment switches from the connection management CM connected state to the CM idle state;

[0207] The terminal device is converted from a first state to a second state, in which the terminal device can communicate with the satellite of NTN in the first state and in which the terminal device cannot communicate with the satellite of NTN in the second state; or,

[0208] The terminal equipment stops using NTN services.

[0209] In a possible implementation, the terminal device converts from a connection management CM connected state to a CM idle state, including: the terminal device converts from a CM connected state to a CM idle state, and the duration of the terminal device being in the CM idle state is greater than a second duration, and the second duration is greater than 0.

[0210] In one possible implementation, after the terminal device enters the first mode, when the terminal device is converted from the second state to the first state, the terminal transceiver unit 1120 is used to send a first message to the first core network device; wherein the first message is used to request registration or request service; in the first state, the terminal device can communicate with the satellite of NTN, and in the second state, the terminal device cannot communicate with the satellite of NTN.

[0211] In a possible implementation, when the second condition is met, the processing unit 1110 is used to control the terminal device to exit the first mode; wherein the second condition includes at least one of the following: the terminal device is converted from the second state to the first state, in which the terminal device can communicate with the satellite of NTN, and in the second state the terminal device cannot communicate with the satellite of NTN; the terminal device is converted from the CM idle state to the CM connected state; or the terminal device detects that a satellite operation is performed.

[0212] In a possible implementation, the first core network device only serves the NTN, or the first core network device serves the NTN and the TN.

[0213] In one possible implementation, the first core network device only serves NTN; the transceiver unit 1120 is used to send a first message to the first core network device through the second core network device of TN; the transceiver unit 1120 is used to receive a second message from the first core network device through the second core network device.

[0214] In a possible implementation, the first message also includes a preference for the first mode; and the second message also includes information confirming acceptance of the preference.

[0215] In a possible implementation, when the terminal device does not have the capability of automatic satellite alignment, or the terminal device is selected to use manual satellite alignment to perform the satellite alignment operation, the first message further includes a preference for the first mode.

[0216] In a possible implementation, the transceiver unit 1120 is configured to receive at least one equivalent public land mobile network EPLMN identifier from the second core network device, where the at least one EPLMN identifier includes a public land mobile network PLMN identifier of the NTN.

[0217] In a possible implementation, the transceiver unit 1120 is used to receive at least one equivalent public land mobile network EPLMN identifier from a third core network device, where the at least one EPLMN identifier includes a public land mobile network PLMN identifier of the NTN, and the third core network device is a core network device for registering the PLMN of the terminal device.

[0218] In a possible implementation, the terminal device includes a first SIM card and a second SIM card; the first SIM card subscribes to a TN service, and the second SIM card subscribes to an NTN service; the second SIM card sends a first message to the first SIM card; the first SIM card sends a first message to an access network device of the TN; the first SIM card receives a second message from the access network device; and the first SIM card sends a second message to the second SIM card.

[0219] For a more detailed description of the above-mentioned transceiver unit 1120 and the processing unit 1110, please refer to the relevant description of the terminal device in the embodiment of the present application.

[0220] When the communication device 1100 is used to implement the function of the first core network device in the embodiment of the present application: when the terminal device completes registration in the non-terrestrial network NTN, the processing unit 1110 is used to determine that the terminal device enters the first mode; wherein the terminal device does not need to initiate periodic registration to the first core network device of the NTN in the first mode.

[0221] In one possible implementation, the transceiver unit 1120 is used to receive a first message from a terminal device, where the first message is used to request registration; the transceiver unit 1120 is also used to send a second message to the terminal device, where the second message indicates that the first core network device accepts the registration request of the terminal device.

[0222] In a possible implementation, the first message includes first information, where the first information indicates that the terminal device cannot guarantee to perform periodic registration, or the first information indicates that the terminal device requests not to perform periodic registration.

[0223] In a possible implementation, the first information includes first capability information and / or second capability information; wherein the first capability information indicates whether the terminal device has the capability to support NTN communication, and the second capability information indicates whether the terminal device has the capability to automatically point to a satellite.

[0224] In a possible implementation, the processing unit 1110 is further configured to determine a second message according to the first information; wherein the second message indicates at least one of the following:

[0225] Whether to receive preferred information;

[0226] Whether the periodic registration timer is activated;

[0227] If the periodic registration timer is activated, the duration of the periodic registration timer; or

[0228] Whether to perform implicit deregistration on the terminal device.

[0229] In a possible implementation, the second message includes second information, where the second information indicates that after the terminal device enters the first mode, it is not necessary to initiate periodic registration with the first core network device of the NTN.

[0230] In a possible implementation, the second message also includes third information, which indicates a first duration, and the first duration is the duration of the periodic registration timer, and the first duration is related to the duration of the NTN service signed by the terminal device; the aforementioned terminal device does not need to initiate periodic registration with the first core network device of NTN in the first mode, including: the terminal device does not need to initiate periodic registration with the first core network device of NTN within the first duration in the first mode.

[0231] In a possible implementation, the third information indicates that the periodic registration timer is not activated.

[0232] In a possible implementation, the first core network device keeps the terminal device in the first mode in a registered state and / or keeps it out of service.

[0233] In a possible implementation, the first core network device does not need to send a paging message to the terminal device in the first mode.

[0234] In a possible implementation, when the terminal device completes registration in the non-terrestrial network NTN, when the terminal device completes registration in the non-terrestrial network NTN and satisfies the third condition, the processing unit 1110 is further configured to determine that the terminal device enters the first mode; wherein the third condition includes one or more of the following:

[0235] The terminal equipment changes from the connection management CM connected state to the CM idle state;

[0236] The terminal device does not use NTN's network services during the third time period, and the third time period is greater than 0; or

[0237] When the first core network device fails to page the terminal device.

[0238] In a possible implementation, the terminal device converts from the connection management CM connected state to the CM idle state, including: the terminal device converts from the CM connected state to the CM idle state, and the duration of the terminal device being in the CM idle state is greater than a second duration, and the second duration is greater than 0.

[0239] In a possible implementation, after determining that the terminal device enters the first mode, the transceiver unit 1120 is used to receive a first message from the terminal device, wherein the first message is used to request registration or request service.

[0240] In one possible implementation, when the fourth condition is met, the processing unit 1110 is also used to determine whether the terminal device exits the first mode; wherein the fourth condition includes at least one of the following: the first core network device receives a first message from the terminal device, and the first message is used to request registration or request service; or, the terminal device switches from a CM idle state to a CM connected state.

[0241] In a possible implementation, the first core network device only serves the NTN, or the first core network device serves the NTN and the TN.

[0242] In one possible implementation, the first core network device only serves NTN; the transceiver unit 1120 is also used to receive a first message from the terminal device through the second core network device of TN; the transceiver unit 1120 is also used to send a second message to the terminal device through the second core network device.

[0243] In a possible implementation, the first message also includes a preference for the first mode; and the second message also includes information confirming acceptance of the preference.

[0244] For a more detailed description of the above-mentioned transceiver unit 1120 and the processing unit 1110, please refer to the relevant description of the first core network device in the embodiment of the present application.

[0245] like Fig.12 As shown, the communication device 1200 includes a processor 1210 and an interface circuit 1220. The processor 1210 and the interface circuit 1220 are coupled to each other. It is understood that the interface circuit 1220 can be a transceiver or an input-output interface. Optionally, the communication device 1200 may also include a memory 1230 for storing instructions executed by the processor 1210 or storing input data required by the processor 1210 to execute instructions or storing data generated after the processor 1210 executes instructions.

[0246] When the communication device 1200 is used to implement the method shown in the diagram of the embodiment of the present application, the processor 1210 is used to implement the function of the above-mentioned processing unit 1110, and the interface circuit 1220 is used to implement the function of the above-mentioned transceiver unit 1120.

[0247] When the above-mentioned communication device is a chip applied to a terminal device, the terminal chip implements the functions of the terminal device in the above-mentioned method embodiment. The terminal chip receives information from the base station, which can be understood as the information is first received by other modules in the terminal device (such as a radio frequency module or an antenna), and then sent to the terminal chip by these modules. The terminal chip sends information to the base station, which can be understood as the information is first sent to other modules in the terminal device (such as a radio frequency module or an antenna), and then sent to the base station by these modules.

[0248] When the above-mentioned communication device is a chip applied to the first core network device, the first core network device chip implements the function of the first core network device in the above-mentioned method embodiment. The first core network device chip receives information from the terminal device, which can be understood as the information is first received by other modules (such as radio frequency modules or antennas) in the first core network device, and then sent to the first core network device chip by these modules. The first core network device chip sends information to the terminal, which can be understood as the information is sent to other modules (such as radio frequency modules or antennas) in the network device, and then sent to the terminal by these modules.

[0249] In the present application, when entity A sends information to entity B, it can be that A sends it directly to B, or that A sends it to B indirectly through other entities. Similarly, when entity B receives information from entity A, it can be that entity B directly receives the information sent by entity A, or that entity B indirectly receives the information sent by entity A through other entities. Entities A and B here can be RAN nodes or terminals, or modules inside the RAN nodes or terminals. The sending and receiving of information can be information interaction between a RAN node and a terminal, for example, information interaction between a base station and a terminal; the sending and receiving of information can also be information interaction between two RAN nodes, for example, information interaction between a CU and a DU; the sending and receiving of information can also be information interaction between different modules inside a device, for example, information interaction between a terminal chip and other modules of the terminal, or information interaction between a base station chip and other modules in the base station.

[0250] It is understood that the processor in the embodiments of the present application may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, transistor logic devices, hardware components or any combination thereof. The general-purpose processor may be a microprocessor or any conventional processor.

[0251] The method steps in the embodiments of the present application can be implemented in hardware or in software instructions that can be executed by a processor. The software instructions can be composed of corresponding software modules, and the software modules can be stored in random access memory, flash memory, read-only memory, programmable read-only memory, erasable programmable read-only memory, electrically erasable programmable read-only memory, register, hard disk, mobile hard disk, CD-ROM or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor so that the processor can read information from the storage medium and write information to the storage medium. The storage medium can also be a component of the processor. The processor and the storage medium can be located in an ASIC. In addition, the ASIC can be located in a base station or a terminal. The processor and the storage medium can also be present in a base station or a terminal as discrete components.

[0252] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented by software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer program or instruction is loaded and executed on a computer, the process or function described in the embodiment of the present application is executed in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, a network device, a user device or other programmable device. The computer program or instruction may be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer program or instruction may be transmitted from one website site, computer, server or data center to another website site, computer, server or data center by wired or wireless means. The computer-readable storage medium may be any available medium that a computer can access or a data storage device such as a server, data center, etc. that integrates one or more available media. The available medium may be a magnetic medium, for example, a floppy disk, a hard disk, a tape; it may also be an optical medium, for example, a digital video disc; it may also be a semiconductor medium, for example, a solid-state hard disk. The computer-readable storage medium may be a volatile or nonvolatile storage medium, or may include both volatile and nonvolatile types of storage media.

[0253] In the various embodiments of the present application, if there is no special explanation and logical conflict, the terms and / or descriptions between different embodiments are consistent and can be referenced to each other, and the technical features in different embodiments can be combined to form a new embodiment according to their inherent logical relationship. The combined technical solutions are also within the scope of the present application.

[0254] In the present application, "at least one" means one or more, and "more than one" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. In the text description of the present application, the character " / " generally indicates that the previous and next associated objects are in an "or" relationship; in the formula of the present application, the character " / " indicates that the previous and next associated objects are in a "division" relationship. "Including at least one of A, B and C" can mean: including A; including B; including C; including A and B; including A and C; including B and C; including A, B and C.

[0255] It is understood that the various numbers involved in the embodiments of the present application are only for the convenience of description and are not used to limit the scope of the embodiments of the present application. The size of the sequence number of the above-mentioned processes does not mean the order of execution, and the execution order of each process should be determined by its function and internal logic.

Claims

1. A method, characterized in that The method comprises: When the terminal device completes registration in the non-terrestrial network NTN, the terminal device enters the first mode; Wherein, the terminal device does not need to initiate periodic registration with the first core network device of the NTN in the first mode; The terminal device is registered in the non-terrestrial network NTN, including: The terminal device sends a first message to the first core network device, where the first message is used to request registration; The terminal device receives a second message from the first core network device, and the second message indicates that the first core network device accepts the registration request of the terminal device.

2. The method according to claim 1, characterized in that: The first message includes first information; wherein, The first information indicates that the terminal device cannot guarantee to perform periodic registration, or, The first information indicates that the terminal device requests not to perform periodic registration.

3. The method according to claim 2, characterized in that: The first information includes first capability information and / or second capability information; wherein the first capability information indicates whether the terminal device has the capability of supporting NTN communication, and the second capability information indicates whether the terminal device has the capability of automatic satellite alignment.

4. The method according to any one of claims 1 to 3, characterized in that: The second message includes second information, and the second information indicates that after the terminal device enters the first mode, it is not necessary to initiate periodic registration with the first core network device of the NTN; or, The second message includes third information, the third information indicates a first duration, the first duration is the duration of the periodic registration timer, and the first duration is related to the duration of the NTN service contracted by the terminal device; The terminal device does not need to initiate periodic registration with the first core network device of the NTN in the first mode, including: the terminal device does not need to initiate periodic registration with the first core network device of the NTN within the first time period in the first mode; or, The second message includes third information, and the third information indicates that the periodic registration timer is not activated.

5. The method according to any one of claims 1 to 4, characterized in that: The terminal device remains in a registered state and / or remains out of service in the first mode; And / or, the terminal device does not need to monitor a paging message from the NTN in the first mode.

6. The method according to any one of claims 1 to 5, characterized in that: When the terminal device completes registration in the non-terrestrial network NTN, the terminal device enters the first mode, including: when the terminal device completes registration and satisfies a first condition, the terminal device enters the first mode; Wherein, the first condition includes at least one of the following: The terminal device completes data transmission via the NTN; The terminal device is converted from a connection management CM connected state to a CM idle state; The terminal device is converted from a first state to a second state, in which the terminal device can communicate with the satellite of the NTN and in which the terminal device cannot communicate with the satellite of the NTN; or, The terminal device stops using the service of the NTN.

7. The method according to any one of claims 1 to 6, characterized in that After the terminal device enters the first mode, the method includes: When the terminal device is converted from the second state to the first state, the terminal device sends a first message to the first core network device; The first message is used to request registration or service; in the first state, the terminal device can communicate with the satellite of the NTN, and in the second state, the terminal device cannot communicate with the satellite of the NTN.

8. The method according to any one of claims 1 to 7, characterized in that: The method further comprises: When a second condition is met, the terminal device exits the first mode; wherein the second condition includes at least one of the following: The terminal device is converted from a second state to a first state, in which the terminal device can communicate with the satellite of the NTN, and in which the terminal device cannot communicate with the satellite of the NTN; The terminal device is converted from the CM idle state to the CM connected state; or, The terminal device detects that a satellite alignment operation is performed.

9. The method according to any one of claims 1 to 8, characterized in that: In the case that the terminal device does not have the capability of automatic alignment, or the terminal device is selected to use manual alignment to perform the alignment operation, the first message further includes a preference for the first mode.

10. The method according to any one of claims 1 to 9, characterized in that: The method further comprises: The terminal device receives at least one equivalent public land mobile network EPLMN identifier from the second core network device, and the at least one EPLMN identifier includes a public land mobile network PLMN identifier of the NTN.

11. The method according to any one of claims 1 to 10, characterized in that: The method further comprises: The terminal device receives at least one equivalent public land mobile network EPLMN identifier from a third core network device, wherein the at least one EPLMN identifier includes a public land mobile network PLMN identifier of the NTN, and the third core network device is a core network device for registering the PLMN for the terminal device.

12. The method according to any one of claims 1 to 11, characterized in that: The first core network device only serves the NTN; The terminal device sending the first message to the first core network device includes: the terminal device sending the first message to the first core network device through the second core network device of the land network TN; The terminal device receives the second message from the first core network device, including: the terminal device receives the second message from the first core network device through the second core network device.

13. The method according to claim 12, characterized in that: The terminal device includes a first subscriber identity module SIM card and a second SIM card; the first SIM card subscribes to the TN service, and the second SIM card subscribes to the NTN service; the method further includes: The second SIM card sends a first message to the first SIM card; The first SIM card sends the first message to the access network device of the TN; The first SIM card receives a second message from the access network device of the TN; The first SIM card sends the second message to the second SIM card.

14. A method, characterized in that The method comprises: When the terminal device completes registration in the non-terrestrial network NTN, the first core network device of the NTN determines that the terminal device enters the first mode; Wherein, the terminal device does not need to initiate periodic registration with the first core network device of the NTN in the first mode; The terminal device is registered in the non-terrestrial network NTN, including: The first core network device receives a first message from the terminal device, where the first message is used to request registration; The first core network device sends a second message to the terminal device, and the second message indicates that the first core network device accepts the registration request of the terminal device.

15. The method according to claim 14, characterized in that: The first message includes first information; wherein, The first information indicates that the terminal device cannot guarantee to perform periodic registration, or, The first information indicates that the terminal device requests not to perform periodic registration.

16. The method according to claim 15, characterized in that: The first information includes first capability information and / or second capability information; wherein the first capability information indicates whether the terminal device has the capability of supporting NTN communication, and the second capability information indicates whether the terminal device has the capability of automatic satellite alignment.

17. The method according to claim 15 or 16, characterized in that: The method further comprises: The first core network device determines at least one of the following according to the first information: Whether to accept the information of the stated preferences; Whether the periodic registration timer is activated; When the periodic registration timer is activated, the duration of the periodic registration timer; or Whether to perform implicit deregistration on the terminal device.

18. The method according to any one of claims 14 to 17, characterized in that: The second message includes second information, and the second information indicates that after the terminal device enters the first mode, it is not necessary to initiate periodic registration with the first core network device of the NTN; or, The second message further includes third information, where the third information indicates a first duration, where the first duration is the duration of a periodic registration timer, and the first duration is related to the duration of a contract for an NTN service signed by the terminal device; The terminal device does not need to initiate periodic registration with the first core network device of the NTN in the first mode, including: the terminal device does not need to initiate periodic registration with the first core network device of the NTN within the first time period in the first mode; or, The third information indicates that the periodic registration timer is not activated.

19. The method according to any one of claims 14 to 18, characterized in that: The first core network device keeps the terminal device in the first mode in a registered state and / or out of service; Alternatively, the first core network device does not need to send a paging message to the terminal device in the first mode.

20. The method according to any one of claims 14 to 19, characterized in that: When the terminal device completes registration in the non-terrestrial network NTN, the first core network device of the NTN determines that the terminal device enters the first mode, including: when the terminal device completes registration in the non-terrestrial network NTN and satisfies the third condition, the first core network device of the NTN determines that the terminal device enters the first mode; The third condition includes one or more of the following: The terminal device is converted from a connection management CM connected state to a CM idle state; The terminal device does not use the network service of NTN within a third time period, and the third time period is greater than 0; or, When the first core network device fails to page the terminal device.

21. The method according to any one of claims 14 to 19, characterized in that: The first core network device only serves the NTN; The first core network device receiving the first message from the terminal device includes: the first core network device receiving the first message from the terminal device through the second core network device of the TN; The first core network device sends the second message to the terminal device, including: the first core network device sends the second message to the terminal device through the second core network device.

22. A communication device, characterized in that: It includes a processor and an interface circuit, wherein the interface circuit is used to receive signals from other communication devices outside the communication device and transmit them to the processor, or send signals from the processor to other communication devices outside the communication device, and the processor implements the method as described in any one of claims 1 to 13 or the method as described in any one of claims 14 to 21 through a logic circuit or by executing code instructions.

23. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program or instructions, and when the computer program or instructions are executed by the communication device, the method according to any one of claims 1 to 13, or the method according to any one of claims 14 to 21 is implemented.

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