Method and apparatus for switching between satellite base station and terminal, communication device, and storage medium

Abstract

The present application relates to a method and apparatus for switching between a satellite base station and a terminal, a communication device, a storage medium, and a computer program product. The satellite base station comprises a first distributed unit and a second distributed unit for resource sharing. The method is applied to a user terminal connected to the satellite base station. The method comprises: receiving an RRC reconfiguration message sent by a first distributed unit; and within a time window configured in the RRC reconfiguration message, sending an RRC reconfiguration complete message to a second distributed unit.

Description

Satellite base station and terminal switching method, device, communication equipment and storage medium

[0001] Related applications

[0002] This application claims priority to Chinese patent application number 2024103886107, filed on April 1, 2024, entitled “Satellite base station and terminal switching method, device, communication equipment and storage medium,” the entire text of which is hereby incorporated by reference. Technical Field

[0003] The present application relates to the field of wireless communication technology, and in particular to a satellite base station and terminal switching method, apparatus, communication equipment, storage medium, and computer program product. Background Art

[0004] Land mobile communication networks are constrained by factors such as deployment costs and geographical conditions, making them unable to provide seamless global coverage. Satellite communication networks offer wide coverage and are less affected by geographical conditions, making them a suitable complement to terrestrial cellular networks and providing seamless global coverage. However, satellite networks move at high speeds along their orbits, particularly for low-orbit satellites. Their coverage area constantly fluctuates relative to the ground, leading to frequent handoffs between onboard base stations and ground nodes.

[0005] When satellite access is used as a 3GPP (3rd Generation Partnership Project) access method, the gNB-DU (base station-distributed unit) function can be implemented on the satellite. The DU on the satellite and the CU (centralized unit) on the ground are connected via the F1 interface, which is carried on the satellite radio interface SRI. In traditional technology, a distribution unit (for example, called the first distribution unit) is deployed on the onboard base station of a satellite to provide services to various user terminals on the ground. When the satellite moves, the onboard base station on the satellite is disconnected from the first ground node. The first distribution unit of the moved satellite base station re-establishes a connection with the second ground node to provide services to the user terminals on the ground.

[0006] However, in traditional technologies, frequent switching of interfaces between satellite-borne base stations and ground nodes not only causes service interruptions, but also generates a large amount of signaling overhead, increasing the signaling load.

[0007] Summary of the Invention

[0008] Embodiments of the present application provide a satellite base station and terminal switching method, apparatus, communication equipment, storage medium, and computer program product.

[0009] An embodiment of the present application provides a method for handover between a satellite base station and a terminal. The satellite base station includes a first distribution unit and a second distribution unit for sharing resources. The method is applied to a user terminal connected to the satellite base station. The method includes:

[0010] receiving an RRC reconfiguration message sent by the first distributed unit;

[0011] Send an RRC reconfiguration complete message to the second distributed unit within a time window configured in the RRC reconfiguration message.

[0012] In one of the embodiments, the RRC reconfiguration message includes information for instructing the user terminal to access the second distribution unit.

[0013] An embodiment of the present application provides a method for handover between a satellite base station and a terminal. The satellite base station includes a first distributed unit and a second distributed unit for sharing resources. The method is applied to a first centralized unit for accessing the first distributed unit. The method includes:

[0014] Sending a user terminal context modification message to the first distributed unit, so that the second distributed unit can clearly define the F1AP context between the second centralized unit used to access the second distributed unit; and

[0015] Receive the user terminal context modification response message fed back by the first distribution unit to implement the handover between the satellite base station and the user terminal.

[0016] In one embodiment, the user terminal context modification message includes an RRC reconfiguration message and an F1AP context; the user terminal context modification message is used to instruct the first distribution unit to forward the RRC reconfiguration message to the current user terminal;

[0017] In one embodiment, before sending the user terminal context modification message to the first distributed unit, the method further includes:

[0018] Sending a handover request message to the second centralized unit according to the satellite ephemeris information; the handover request message includes the NTN UE context and the identification information of the second distributed unit;

[0019] Receive a handover request confirmation message fed back by the second centralized unit, where the handover request confirmation message includes an F1AP context and an RRC reconfiguration message; the NTN UE context and the F1AP context are used to clarify shared resources between the first distributed unit and the second distributed unit; and the shared resources are used to implement handover between the satellite base station and the user terminal.

[0020] In one embodiment, the NTN UE context is carried by an NTN UE context reference container; the NTN UE context reference container includes: cell group configuration, configured measurement gap parameters, gNB-DU UE F1AP identifier, data radio bearer DRB establishment information, and low-layer configuration information for the user terminal.

[0021] In one embodiment, the F1AP context is carried by an F1AP context container; the F1AP context container includes: a user terminal context establishment / modification request message sent by the second centralized unit to the second distributed unit;

[0022] The user terminal context establishment / modification request message includes the first distribution unit gNB-DU UE F1AP identifier, the new distribution unit gNB-DU UE F1AP identifier, the control signaling radio bearer SRB and the data radio bearer DRB for establishing or modifying the user terminal.

[0023] In one embodiment, the method further comprises:

[0024] receiving an interface establishment request message sent by the first distribution unit, wherein the interface establishment request message includes satellite information and an interface establishment time window; and

[0025] Feedback an interface establishment request response message to the first distribution unit.

[0026] In one embodiment, the method further comprises:

[0027] When the interface establishment time window expires, the connection between the first distribution unit and the first centralized unit is suspended or released.

[0028] In one embodiment, the method further comprises:

[0029] receiving an interface configuration update message sent by the first distribution unit; the interface configuration update message includes updated satellite information and an updated interface establishment time window; and

[0030] Feedback an interface configuration update confirmation message to the first distribution unit.

[0031] An embodiment of the present application provides a method for handover between a satellite base station and a terminal. The satellite base station includes a first distributed unit and a second distributed unit for sharing resources. The method is applied to a second centralized unit for accessing the second distributed unit. The method includes:

[0032] receiving a switching request message sent by the first centralized unit;

[0033] Feedback a handover request confirmation message to the first centralized unit; the handover request confirmation message includes an interface application protocol F1AP context and an RRC reconfiguration message; the F1AP context includes a user terminal context establishment / modification request message sent by the second centralized unit to the second distributed unit;

[0034] When the second centralized unit establishes an interface connection with the second distributed unit, receiving a user terminal context establishment / modification response message sent by the second distributed unit; and

[0035] Receive an RRC reconfiguration complete message sent by the user terminal.

[0036] An embodiment of the present application provides a satellite base station and a terminal switching device, wherein the satellite base station includes a first distribution unit and a second distribution unit for resource sharing. The device is applied to a user terminal connected to the satellite base station, and includes:

[0037] a receiving module, configured to receive an RRC reconfiguration message sent by the first distributed unit; and

[0038] The sending module is configured to send an RRC reconfiguration completion message to the second distribution unit within a time window configured in the RRC reconfiguration message to access a new satellite cell.

[0039] An embodiment of the present application provides a satellite base station and a terminal switching device, wherein the satellite base station includes a first distribution unit and a second distribution unit for sharing resources, and the device is applied to a first centralized unit for accessing the first distribution unit, and the device includes:

[0040] A first sending module is configured to send a user terminal context modification message to the first distributed unit, so that the second distributed unit can clearly define the F1AP context between the second centralized unit used to access the second distributed unit; and

[0041] The first receiving module is configured to receive a user terminal context modification response message fed back by the first distribution unit, so as to implement the handover between the satellite base station and the user terminal.

[0042] An embodiment of the present application provides a satellite base station and a terminal switching device, wherein the satellite base station includes a first distribution unit and a second distribution unit for sharing resources, and the device is applied to a second centralized unit for accessing the second distribution unit, and the device includes:

[0043] A first receiving module, configured to receive a handover request message sent by the first centralized unit;

[0044] A feedback module is configured to feed back a handover request confirmation message to the first centralized unit; the handover request confirmation message includes an F1AP context and an RRC reconfiguration message; the F1AP context includes a user terminal context establishment / modification request message sent by the second centralized unit to the second distributed unit;

[0045] a second receiving module, configured to receive a user terminal context establishment / modification response message sent by the second distribution unit when the second centralized unit establishes an interface connection with the second distribution unit; and

[0046] The third receiving module is used to receive the RRC reconfiguration completion message sent by the user terminal.

[0047] An embodiment of the present application provides a communication device, including: a transmitter and a receiver;

[0048] The receiver is configured to receive the RRC reconfiguration message sent by the first distribution unit.

[0049] The transmitter is configured to send an RRC reconfiguration completion message to the second distribution unit within a time window configured in the RRC reconfiguration message.

[0050] An embodiment of the present application provides a communication device, including: a transmitter and a receiver;

[0051] The transmitter is configured to send a user terminal context modification message to the first distributed unit, so that the second distributed unit can clearly define the F1AP context between the second centralized unit used to access the second distributed unit;

[0052] The receiver is configured to receive a user terminal context modification response message fed back by the first distribution unit, so as to implement handover between the satellite base station and the user terminal.

[0053] The present invention provides a communication device including a transmitter and a receiver.

[0054] The receiver is configured to receive a switching request message sent by the first centralized unit.

[0055] The transmitter is configured to feed back a handover request confirmation message to the first centralized unit; the handover request confirmation message includes an F1AP context and an RRC reconfiguration message; and the F1AP context includes a user terminal context establishment / modification request message sent by the second centralized unit to the second distributed unit.

[0056] The receiver is further configured to receive a user terminal context establishment / modification response message sent by the second distribution unit when the second centralized unit establishes an interface connection with the second distribution unit; and to receive an RRC reconfiguration completion message sent by the user terminal.

[0057] An embodiment of the present application provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the following steps are implemented:

[0058] receiving an RRC reconfiguration message sent by the first distributed unit;

[0059] Send an RRC reconfiguration complete message to the second distributed unit within a time window configured in the RRC reconfiguration message.

[0060] An embodiment of the present application provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the following steps are implemented:

[0061] Sending a user terminal context modification message to the first distributed unit, so that the second distributed unit can clearly define the F1AP context between the second centralized unit used to access the second distributed unit; and

[0062] Receive the user terminal context modification response message fed back by the first distribution unit to implement the handover between the satellite base station and the user terminal.

[0063] An embodiment of the present application provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the following steps are implemented:

[0064] receiving a switching request message sent by the first centralized unit;

[0065] Feedback a handover request confirmation message to the first centralized unit; the handover request confirmation message includes an F1AP context and an RRC reconfiguration message; the F1AP context includes a user terminal context establishment / modification request message sent by the second centralized unit to the second distributed unit;

[0066] When the second centralized unit establishes an interface connection with the second distributed unit, receiving a user terminal context establishment / modification response message sent by the second distributed unit; and

[0067] Receive an RRC reconfiguration complete message sent by the user terminal.

[0068] An embodiment of the present application provides a computer program product, including a computer program. When the computer program is executed by a processor, the satellite base station and terminal switching method provided in the embodiment of the present application is implemented. The method may be:

[0069] receiving an RRC reconfiguration message sent by the first distributed unit;

[0070] Send an RRC reconfiguration complete message to the second distributed unit within a time window configured in the RRC reconfiguration message.

[0071] An embodiment of the present application provides a computer program product, including a computer program. When the computer program is executed by a processor, the satellite base station and terminal switching method provided in the embodiment of the present application is implemented. The method may be:

[0072] Sending a user terminal context modification message to the first distributed unit, so that the second distributed unit can clearly define the F1AP context between the second centralized unit used to access the second distributed unit; and

[0073] Receive the user terminal context modification response message fed back by the first distribution unit to implement the handover between the satellite base station and the user terminal.

[0074] An embodiment of the present application provides a computer program product, including a computer program. When the computer program is executed by a processor, the satellite base station and terminal switching method provided in the embodiment of the present application is implemented. The method may be:

[0075] receiving a switching request message sent by the first centralized unit;

[0076] Feedback a handover request confirmation message to the first centralized unit; the handover request confirmation message includes an F1AP context and an RRC reconfiguration message; the F1AP context includes a user terminal context establishment / modification request message sent by the second centralized unit to the second distributed unit;

[0077] When the second centralized unit establishes an interface connection with the second distributed unit, receiving a user terminal context establishment / modification response message sent by the second distributed unit; and

[0078] Receive an RRC reconfiguration complete message sent by the user terminal.

[0079] The details of one or more embodiments of the present application are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the present application will become apparent from the description, drawings, and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0080] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the conventional technology, the following briefly introduces the drawings required for use in the embodiments or the conventional technology descriptions. Obviously, the drawings described below are merely embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the disclosed drawings without any creative work.

[0081] FIG1 is a diagram illustrating an application environment of a satellite base station and a terminal switching method according to an embodiment;

[0082] FIG2 is a schematic flow chart of a method for handing over a satellite base station and a terminal on the user terminal side in one embodiment;

[0083] FIG3 is a schematic flow chart of a method for handing over a satellite base station and a terminal on the first centralized unit side in one embodiment;

[0084] FIG4 is a flow diagram of the steps of exchanging handover request messages between CU1 and CU2 in one embodiment;

[0085] FIG5 is a schematic diagram of a process flow of establishing an interface in one embodiment;

[0086] FIG6 is a schematic diagram of signaling interaction during an interface establishment process in one embodiment;

[0087] FIG7 is a schematic diagram of a process flow of an interface configuration update process according to an embodiment;

[0088] FIG8 is a schematic diagram of signaling interaction during an interface configuration update process in one embodiment;

[0089] FIG9 is a schematic flow chart of a method for handing over a satellite base station and a terminal on the second centralized unit side according to an embodiment;

[0090] FIG10 is a schematic diagram of an application scenario of a satellite base station and terminal switching method according to an embodiment;

[0091] FIG11 is a flowchart of a specific example of a method for handing over a satellite base station and a terminal according to an embodiment;

[0092] FIG12 is a structural block diagram of a satellite base station and a terminal switching device on the user terminal side in one embodiment;

[0093] FIG13 is a structural block diagram of a satellite base station and a terminal switching device on the first centralized unit side in one embodiment;

[0094] FIG14 is a structural block diagram of a satellite base station and a terminal switching device on the second centralized unit side in one embodiment. DETAILED DESCRIPTION

[0095] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0096] Figure 1 is a schematic diagram of an application scenario for a satellite base station and terminal handover method provided in an embodiment of the present application. As shown in Figure 1 , the scenario includes a user terminal 100, a satellite base station 200 (which integrates a logical first distributed unit DU1 and a logical second distributed unit DU2), and a ground node 300 (which includes a centralized unit CU). Data is transmitted between the user terminal 100 and the satellite base station 200 via the ground node 300.

[0097] The user terminal 100 may be a wireless terminal, which may be a device that provides voice and / or other service data connectivity to a user, or a handheld device with wireless connectivity, or other processing device connected to a wireless modem. A wireless terminal may communicate with one or more core networks via a radio access network (RAN). A wireless terminal may be a mobile terminal, such as a mobile phone (or "cellular" phone) or a computer with a mobile terminal. For example, a portable, pocket-sized, handheld, computer-built-in, or vehicle-mounted mobile device may exchange voice and / or data with a radio access network. A wireless terminal may also be referred to as a system, subscriber unit, subscriber station, mobile station, mobile station, remote station, remote terminal, access terminal, user terminal, user agent, user device, or user equipment, without limitation herein.

[0098] When satellite access is used as a 3GPP (3rd Generation Partnership Project) access method, the gNB-DU (base station-distributed unit) function can be implemented on the satellite. The DU on the satellite and the CU (centralized unit) on the ground are connected via the F1 interface, which is carried on the satellite radio interface SRI. In traditional technology, a distribution unit (for example, called the first distribution unit) is deployed on the onboard base station of a satellite to provide services to various user terminals on the ground. When the satellite moves, the onboard base station on the satellite is disconnected from the first ground node. The first distribution unit of the moved satellite base station re-establishes a connection with the second ground node to provide services to the user terminals on the ground.

[0099] In traditional technologies, frequent switching of interfaces between satellite-borne base stations and ground nodes not only causes service interruptions, but also generates a large amount of signaling overhead, increasing the signaling load.

[0100] Based on the above-mentioned traditional technology, an embodiment of the present application provides a satellite base station and terminal switching method, wherein the satellite base station includes a first distribution unit and a second distribution unit, and the first distribution unit and the second distribution unit use the same resources to maintain service to the user terminal, thereby improving service fluency. Moreover, the first distribution unit and the second distribution unit use the same resources to avoid repeated configuration of the user terminal context during the switching process between the distribution unit of the satellite base station and the user terminal, thereby reducing the signaling load of switching all connected user terminals in a short time.

[0101] It should be noted that the beneficial effects or technical problems solved by the embodiments of the present application are not limited to this one, but may also include other implicit or related problems. For details, please refer to the description of the following embodiments.

[0102] Before introducing the specific embodiments of the present invention, the professional terms involved in the present invention are explained:

[0103] CU: Centralized Unit, the central control unit of the ground station, responsible for managing and controlling the communication connection with the satellite.

[0104] DU: Distributed Unit, used to support and enhance the performance of the entire satellite communication system.

[0105] RRC: Radio Resource Control, used for radio resource control in wireless communication technologies such as LTE and 5G.

[0106] SRB: Signaling Radio Bearer, control signaling radio bearer, is usually a virtual channel provided by both the physical layer and the control layer, used to transmit signaling and control information related to connection management.

[0107] DRB: Data Radio Bearer, data radio bearer, provides wireless communication bearer for data transmission in mobile communication networks.

[0108] The following specific embodiments describe in detail the technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0109] In one embodiment, as shown in FIG2 , a method for handover between a satellite base station and a terminal is provided. The method is described by taking the user terminal 100 in FIG1 as an example. The satellite base station includes a first distribution unit and a second distribution unit for resource sharing. The method includes the following steps:

[0110] Step 202: Receive an RRC reconfiguration message sent by the first distributed unit.

[0111] In implementation, a satellite base station is pre-integrated with a logical first distributed unit (hereinafter referred to as the first distributed unit) and a logical second distributed unit (hereinafter referred to as the second distributed unit). The first distributed unit and the second distributed unit correspond to different service areas and have different IDs (identity documents). A first centralized unit (CU1) is used to configure the interface of the first distributed unit (DU1) in the satellite base station. Similarly, a second centralized unit (CU2) is used to configure the interface of the second distributed unit in the satellite base station. When a user terminal accesses the first satellite cell (i.e., satellite cell 1), the first centralized unit and the first distributed unit provide service to the user terminal. In satellite networks, satellites move at high speeds along their orbits. Especially for low-orbit satellites, their coverage area relative to the ground constantly changes. This results in a handover of the interface between the distributed unit (DU) in the satellite-borne base station (also referred to as the satellite base station) and the ground node (CU). Therefore, when a user equipment (UE) and its serving satellite leave the coverage area of ​​the current radio network node on the ground, the user terminal receives an RRC reconfiguration message sent by the first distributed unit.

[0112] Optionally, the first centralized unit may be composed of one or more ground nodes, the second centralized unit and the first centralized unit correspond to different ground nodes, and the second centralized unit and the first centralized unit are connected to different distribution units in the satellite base station and correspond to different service areas. The second centralized unit may also include one or more ground nodes, which is not limited in this embodiment of the present application.

[0113] Step 204: Send an RRC reconfiguration completion message to the second distributed unit within the time window configured in the RRC reconfiguration message.

[0114] In implementation, the RRC reconfiguration message carries a pre-configured time window. When the first centralized unit sends a UE context modification message to the user terminal (received by the first distributed unit), the UE context modification message includes not only the RRC reconfiguration message forwarded by the first centralized unit, but also the F1AP context. The F1AP context includes the UE context modification request message sent by the second centralized unit (CU2) to the new distributed unit DU2 (i.e., the second distributed unit). Therefore, after the second centralized unit (CU2) establishes a connection with the second distributed unit (DU2), and DU2 sends a UE context modification response message to CU2 to confirm the UE context modification, the user terminal replies with an RRC reconfiguration completion message to the second distributed unit within the time window of the RRC reconfiguration message to complete the switching of the user terminal.

[0115] Optionally, the F1AP context is carried by a container, that is, the RRC reconfiguration message may also be considered to include the F1AP context container.

[0116] In the above-mentioned satellite base station and terminal handover method, the satellite base station includes a first distributed unit and a second distributed unit, and the first distributed unit and the second distributed unit can share resources. Therefore, the user terminal receives an RRC reconfiguration message sent by the first distributed unit. Within the time window configured in the RRC reconfiguration message, an RRC reconfiguration completion message is sent to the second distributed unit of the satellite base station to complete the handover of the satellite base station. Using this method, the first and second distributed units of the satellite base station use the same resources to maintain service to the user terminal, improving service fluency. In addition, the use of the same resources by the first and second distributed units can avoid repeated configuration of user terminal context during the handover between the satellite base station's distributed units and the user terminal, reducing the signaling load required to switch all connected user terminals in a short period of time.

[0117] In one embodiment, the RRC reconfiguration message includes information for instructing the user terminal to access the second distribution unit.

[0118] In implementation, since the RRC reconfiguration message includes information for instructing the user terminal to access the second distribution unit, during the switching process between the satellite base station and the terminal, the user terminal can directly feedback the RRC reconfiguration completion message to the second distribution unit in the satellite base station based on the RRC reconfiguration message sent by the first distribution unit.

[0119] In one embodiment, a method for handover between a satellite base station and a terminal is provided. As shown in FIG3 , the satellite base station includes a first distributed unit and a second distributed unit for sharing resources. The method is described using an example of a first centralized unit in a ground node 300 in FIG1 for accessing the first distributed unit. The method includes:

[0120] Step 302: Send a user terminal context modification message to the first distributed unit, so that the second distributed unit can clearly define the F1AP context between the second centralized unit and the second distributed unit.

[0121] In implementation, resources are shared between a first centralized unit (CU1) and a second centralized unit (CU2). The first centralized unit (CU1) then sends a UE Context Modification Req message to a first distributed unit (DU1) in a satellite base station. During a handover between the satellite base station and the terminal, the first centralized unit (CU1) can continue to send downlink data of the user terminal to the first distributed unit (DU1). Furthermore, based on the resource sharing between the two distributed units in the satellite base station, the second distributed unit (DU2) can pre-determine the F1AP (an interface protocol) context with the second centralized unit (CU2).

[0122] Step 304: Receive the user terminal context modification response message fed back by the first distribution unit to implement the handover between the satellite base station and the user terminal.

[0123] During implementation, the first centralized unit receives the user terminal context modification response message fed back by the first distributed unit to confirm the modification of the UE context, thereby completing the modification of the context information of the first centralized unit side, the satellite base station and the user terminal to further realize the switching of the user terminal. Specifically, CU1 receives the UE context modification response message fed back by DU1, that is, the user terminal between CU1 and DU1 is switched, and the first access satellite cell corresponding to DU1 (that is, satellite cell 1) is disconnected from the satellite base station, and synchronously, the second access satellite cell (that is, satellite cell 2) accesses the satellite base station.

[0124] In this embodiment, the satellite base station includes a first distribution unit and a second distribution unit, and resources are shared between the first distribution unit and the second distribution unit, so that when switching between the satellite base station and the user terminal, the first centralized unit can only communicate the UE context modification message with the first distribution unit, so that the second distribution unit can clearly communicate with the F1AP context of the second centralized unit, thereby improving the smoothness of the user terminal switching, and avoiding the repeated configuration of the user terminal context during the switching process between the distribution unit of the satellite base station and the user terminal, reducing the signaling load of switching all connected user terminals in a short time.

[0125] In one embodiment, the user terminal context modification message includes an RRC reconfiguration message and an F1AP context. The user terminal context modification message is used to instruct the first distribution unit to forward the RRC reconfiguration message to the current user terminal.

[0126] In implementation, resources are shared between the first centralized unit (CU1) and the second centralized unit (CU2). The first centralized unit (CU1) then sends a UE context modification message (UE Context Modification Req) to the first distributed unit (DU1) in the satellite base station. The UE context modification message instructs the first distributed unit (DU1) to forward an RRC reconfiguration message to the current user terminal.

[0127] In one embodiment, as shown in FIG4 , resources also need to be shared between the first centralized unit and the second centralized unit, so that the second centralized unit can clearly define the context between itself and the corresponding second distributed unit, thereby avoiding the user context configuration process corresponding to the F1 interface and reducing signaling overhead. Therefore, before step 302, the method further includes:

[0128] Step 401: Send a handover request message to the second centralized unit according to satellite ephemeris information.

[0129] The handover request message includes the NTN UE context and identification information of the second distribution unit.

[0130] In implementation, the first centralized unit determines to initiate a handover preparation process for the connected user terminal based on the satellite ephemeris information. Specifically, the first centralized unit sends an Xn (an interface) / NG (a network type) handover request message to the second centralized unit.

[0131] It should be noted that NTN UE refers to non-terrestrial network user equipment (UE). The NTN UE context is carried by the NTN UE context reference container. The NTN UE context in the NTN UE context reference container includes: cell group configuration (CellGroupConfig), measurement gap parameter configuration (MeasGapConfig), gNB-DU UE F1AP identifier (gNB-DU UE F1AP ID), data radio bearer (DRB) establishment information, and low-layer configuration information for the UE. The NTN UE context reference container is used to clarify the shared resources between the first distributed unit and the second distributed unit to the second centralized unit.

[0132] Step 402: Receive a handover request confirmation message fed back by the second centralized unit.

[0133] In implementation, the first centralized unit receives a handover request confirmation message from the second centralized unit. The handover request confirmation message includes an F1AP context and an RRC reconfiguration message. The NTN UE context and the F1AP context are used to inform the first centralized unit of the shared resources between the first and second distributed units. Furthermore, the shared resources between the first and second distributed units enable efficient handover between satellite base stations and user terminals.

[0134] Optionally, the F1AP context is carried by an F1AP context container. The F1AP context of the F1AP context container includes: a user terminal context establishment / modification request message sent by the second centralized unit to the second distributed unit. The user terminal context establishment / modification request message can be used to instruct the second centralized unit to allocate a new gNB-DU UE F1AP identifier (gNB CU UE F1AP ID), establish or modify a control signaling radio bearer (SRB) or a data radio bearer (DRB) for the user terminal. In addition, the F1AP context container may further include: a timer T3. The timer T3 may be used to assist in indicating the time for applying the new configuration. This embodiment of the present application is not limited to this.

[0135] In this embodiment, a container is used for carrying because container transmission involves multiple nodes. For example, node 1 wants to send a message to node 3, but it must be transmitted through node 2 (node ​​2 does not need to interpret the message, it only forwards it). In this case, a container can be used for delivery. In the embodiment of the present application, CU2 sends a message to CU1 (carrying a container), and CU1 does not need to parse the information in the container, but can send the container to DU1. Therefore, in the embodiment of the present application, both the NTN UE context and the F1AP context can be carried by containers, and the specific information carrying method of the NTN UE context and the F1AP context is not limited in the embodiment of the present application.

[0136] In this embodiment, during the F1 interface switching, the two distributed units share the same resources and UE context through the same satellite base station, and then the F1 interface configuration context is shared between the first centralized unit and the second centralized unit, saving the F1 interface UE context configuration process between the second centralized unit and the second distributed unit and reducing the signaling load.

[0137] In an exemplary embodiment, as shown in FIG5 , the method further includes:

[0138] Step 502: Receive an interface establishment request message sent by the first distributed unit.

[0139] The interface establishment request message includes satellite information and an interface establishment time window.

[0140] In practice, the first centralized unit (CU1) receives an interface setup request message (F1SETUP REQUEST) sent by the first distributed unit in the satellite base station. FIG6 shows the interactive process of interface setup, wherein the interface setup request message also includes satellite information and an interface setup time window.

[0141] Among them, the satellite information includes: satellite identification information, NTN type (LEO low earth orbit, MEO medium earth orbit, GEO geosynchronous orbit, OTHER others); interface establishment time window, including: interface establishment start time T1, connection duration T2.

[0142] For time window settings, T1 can be an integer in the range of (0, ..., 549755813887). This field indicates world time information, calculated in 10-millisecond units as the number of UTC seconds since 00:00:00 on January 1, 1970. For signaling of continuous duration T2, the value of continuous duration T2 can be an integer from 1 to N, with each step representing 100 ms (milliseconds), indicating the duration of the interface connection starting from T1.

[0143] Optionally, the current first centralized unit may be any ground node CU, and the first distributed unit DU in the satellite base station is the distributed unit in the satellite base station connected to the CU.

[0144] Step 504: Feedback an interface establishment request response message to the first distributed unit.

[0145] In implementation, the first centralized unit feeds back an interface setup request response message (F1 SETUP RESPONSE) to the first distributed unit to confirm the F1 interface connection between the first centralized unit and the first distributed unit.

[0146] In this embodiment, the F1 interface is established and the configuration updated through signaling interaction between the first centralized unit and the first distributed unit, thereby providing services for the user terminal and improving the reliability, efficiency and management capabilities of communications.

[0147] In an exemplary embodiment, the method further comprises:

[0148] When the interface establishment time window expires, the connection between the first distributed unit and the first centralized unit is suspended or released.

[0149] In implementation, when the interface establishment time window expires, the first centralized unit will automatically suspend or release the connection between the first distributed unit and the first centralized unit to ensure the timeliness of the communication connection and further ensure the security of the communication connection.

[0150] In this embodiment, by setting a time window, the effectiveness of communication between the first distribution unit and the first centralized unit is guaranteed within the time window. When the time window expires, the connection between the first distribution unit and the first centralized unit is suspended or released to ensure the security of the communication connection and realize the management and control of communication, thereby improving communication efficiency and resource utilization.

[0151] In an exemplary embodiment, as shown in FIG7 , the method further includes:

[0152] Step 702: Receive an interface configuration update message sent by the first distribution unit.

[0153] The interface configuration update message includes the updated satellite information and the updated interface establishment time window.

[0154] During implementation, during the connection between the first centralized unit and the first distributed unit, the first centralized unit may update the interface through an interface configuration update message. Specifically, as shown in FIG8 , the first distributed unit sends an interface configuration update message (GNB-DU CONFIGURATION UPDATE) to the first centralized unit, and the first centralized unit receives the interface configuration update message to update the configuration of the interface.

[0155] Step 704: Feedback an interface configuration update confirmation message to the first distribution unit.

[0156] In implementation, after the interface configuration update is completed, the first centralized unit feeds back an interface configuration update confirmation message (GNB-DU CONFIGURATION UPDATE ACKNOWL EDGE) to the first distributed unit to inform the first distributed unit that the interface configuration update has been completed.

[0157] In this embodiment, feeding back the interface configuration update confirmation message to the first distribution unit can ensure timely update of the configuration interface, reduce communication errors, and improve communication efficiency and stability.

[0158] In an exemplary embodiment, as shown in FIG9 , a method for handover between a satellite base station and a terminal is provided. This method is described by taking the second centralized unit in the ground node 300 in FIG1 as an example, wherein the second centralized unit is configured to access the second distributed unit. The method includes the following steps:

[0159] Step 902: Receive a handover request message sent by the first centralized unit.

[0160] In implementations, during a handover between a satellite base station and a user terminal, as the satellite gradually moves beyond a preset coverage area, a first centralized unit connected to a first distributed unit in the satellite base station preemptively sends a handover request message to a second centralized unit. This handover request message includes an NTN UE context reference container and identification information of the second distributed unit, thereby indicating to the second centralized unit the shared resources between the first and second distributed units in the satellite base station.

[0161] The specific NTN UE context reference container includes: cell group configuration (CellGroupConfig), measurement gap parameter configuration (MeasGapConfig), gNB-DU UE F1AP identifier (gNB-DU UE F1AP ID), data radio bearer (DRB) establishment information, and low-layer configuration information for the user terminal.

[0162] Step 904: Feedback a switching request confirmation message to the first centralized unit.

[0163] The handover request confirmation message includes an F1AP context and an RRC reconfiguration message. The F1AP context includes a user terminal context establishment / modification request message sent by the second centralized unit to the second distributed unit.

[0164] In implementation, the second centralized unit (CU2) sends a handover request confirmation message back to the first centralized unit, completing the handover request process. This handover request confirmation message not only confirms the handover request message but also, based on the container content carried between the handover request message and the handover request confirmation message, allows the second centralized unit to clarify the configuration information between the second centralized unit and the second distributed unit to the first centralized unit.

[0165] Step 906: When the second centralized unit establishes an interface connection with the second distributed unit, the second centralized unit receives a user terminal context establishment / modification response message sent by the second distributed unit.

[0166] In implementation, the first centralized unit and the first distributed unit implement context switching interaction for the user terminal by sending a UE Context Modification message and replying to a UE Context Modification Response message. Because the UE Context Modification message includes an RRC Reconfiguration message and an F1AP context, the first distributed unit forwards the RRC Reconfiguration message to the user terminal. This RRC Reconfiguration message is used to indicate the reconfiguration of information between the second centralized unit, the second distributed unit, and the user terminal. At this point, the second centralized unit initiates an F1 interface connection establishment process with the second distributed unit. This connection establishment process is as described in steps 502 to 504 of the above embodiment and is not further described here. Then, when the second centralized unit establishes an interface connection with the second distributed unit, the second centralized unit receives a user terminal context establishment / modification response message sent by the second distributed unit.

[0167] Step 908: Receive an RRC reconfiguration completion message sent by the user terminal.

[0168] During implementation, the user terminal sends an RRC reconfiguration complete message to the second centralized unit within the time window configured in the RRC reconfiguration message and accesses the new second satellite cell (i.e., satellite cell 2). The RRC reconfiguration complete message is forwarded by the second distributed unit in the satellite base station, and the second centralized unit receives the RRC reconfiguration complete message, completing the handover between the satellite base station and the user terminal.

[0169] In this embodiment, the first distribution unit and the second distribution unit of the satellite base station use the same resources to maintain service to the user terminal, thereby improving service fluency. The first centralized unit and the second centralized unit interact through switching request signaling to achieve resource sharing between the first centralized unit and the second centralized unit, thereby avoiding repeated configuration of the user terminal context by the second centralized unit and the second distribution unit during the switching process between the satellite base station and the user terminal, and reducing the signaling load of switching all connected user terminals in a short period of time.

[0170] In an exemplary embodiment, as shown in FIG10 , FIG10 is a schematic diagram of a satellite base station and a terminal switching process. Two logical distribution units (i.e., a first distribution unit DU1 and a second distribution unit DU2) are implemented in the satellite base station. DU1 is connected to CU1. During the UE switching process, a UE context reference container and an F1AP context container are introduced to interact with the target CU2 through the configuration information of the UE in DU1, thereby avoiding CU2 from performing the F1UE context setting process. Therefore, when the UE switches from DU1 to DU2, the same resources are used to maintain service for the UE, effectively alleviating the significant signaling load that may be caused by switching all connected UEs in a short period of time. Specifically, the present application provides a specific example of a satellite base station and terminal switching method, and the example method includes:

[0171] Step 1101: The first centralized unit sends a handover request message (HOReg, carrying an NTN UE context refer container) to the second centralized unit based on satellite ephemeris information. The handover request message includes the NTN UE context refer container and identification information of the second distributed unit.

[0172] In step 1102, the first centralized unit receives a handover request confirmation message (HOReq Ack) fed back by the second centralized unit. The handover request confirmation message includes a F1AP context container and an RRC reconfiguration message. The NTN UE context reference container and the F1AP context container are used to define shared resources between the first distributed unit and the second distributed unit. The shared resources are used to implement handover between the satellite base station and the user terminal.

[0173] In step 1103, the first centralized unit sends a UE Context Modification Req message to the first distributed unit, so that the second distributed unit can clearly define the F1AP context between the second centralized unit and the second distributed unit. The UE Context Modification Req message includes an RRC Reconfiguration message and an F1AP context container. The UE Context Modification Req message instructs the first distributed unit to forward the RRC Reconfiguration message to the current user terminal.

[0174] Step 1104: The first centralized unit receives a user terminal context modification response message (UE Context Modification Response) fed back by the first distributed unit, thereby implementing a handover between the satellite base station and the user terminal.

[0175] Step 1105: The first distributed unit forwards an RRC reconfiguration message (RRC Reconfiguration) to the user terminal.

[0176] Step 1106: The second distributed unit initiates an F1 interface connection establishment procedure (F1 Setup procedure) to the second centralized unit.

[0177] Step 1107: The second distributed unit sends a user terminal context modification response message (UE Context Modification Response) to the second centralized unit to confirm the modification of the user terminal context.

[0178] Step 1108: The user terminal sends an RRC reconfiguration complete message (RRC ReconfigurationComplete) to the second distribution unit within the time window preconfigured in the RRC configuration message, and accesses the new satellite cell.

[0179] Step 1109: The second distributed unit forwards the RRC reconfiguration completion message (Uplink RRC Message Transfer) to the second centralized unit.

[0180] It should be understood that although the steps in the flowcharts of Figures 2 to 5, Figures 7, 9, and 11 are shown in sequence as indicated by the arrows, these steps are not necessarily performed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and these steps can be performed in other orders. Moreover, at least a portion of the steps in Figures 2 to 5, Figures 7, 9, and 11 may include multiple steps or multiple stages, and these steps or stages are not necessarily performed at the same time, but can be performed at different times. The execution order of these steps or stages is not necessarily to be performed in sequence, but can be performed in turn or alternately with other steps or at least a portion of the steps or stages in other steps.

[0181] In one embodiment, as shown in FIG12 , a satellite base station and terminal switching device 1200 is provided. The satellite base station includes a first distribution unit and a second distribution unit for resource sharing. The device 1200 is applied to a user terminal connected to the satellite base station and includes: a receiving module 1210 and a sending module 1220, wherein:

[0182] The receiving module 1210 is configured to receive an RRC reconfiguration message sent by the first distributed unit;

[0183] The sending module 1220 is configured to send an RRC reconfiguration completion message to the second distributed unit within the time window configured in the RRC reconfiguration message, and access the new satellite cell.

[0184] In one embodiment, as shown in FIG13 , a satellite base station and terminal switching apparatus 1300 is provided. The satellite base station includes a first distribution unit and a second distribution unit for resource sharing. The apparatus 1300 is applied to a user terminal connected to the satellite base station and includes: a sending module 1310 and a receiving module 1320, wherein:

[0185] The first sending module 1310 is configured to send a user terminal context modification message to the first distributed unit, so that the second distributed unit can clearly define the F1AP context between the second centralized unit and the second distributed unit.

[0186] The first receiving module 1320 is configured to receive the user terminal context modification response message fed back by the first distribution unit, so as to implement the handover between the satellite base station and the user terminal.

[0187] In one embodiment, the user terminal context modification message includes an RRC reconfiguration message and an F1AP context; the user terminal context modification message is used to instruct the first distribution unit to forward the RRC reconfiguration message to the current user terminal;

[0188] In one embodiment, the apparatus 1300 further includes:

[0189] A second sending module is configured to send a handover request message to the second centralized unit according to the satellite ephemeris information; the handover request message includes the NTN UE context and identification information of the second distributed unit;

[0190] The second receiving module is used to receive a handover request confirmation message fed back by the second centralized unit, where the handover request confirmation message includes an F1AP context and an RRC reconfiguration message; the NTN UE context and the F1AP context are used to clarify the shared resources between the first distributed unit and the second distributed unit; the shared resources are used to implement handover between the satellite base station and the user terminal.

[0191] In one embodiment, the NTN UE context is carried by an NTN UE context reference container; the NTN UE context reference container includes: cell group configuration, configured measurement gap parameters, gNB-DU UE F1AP identifier, data radio bearer DRB establishment information, and low-layer configuration information for the user terminal.

[0192] In one embodiment, the F1AP context is carried by an F1AP context container; the F1AP context container includes: a user terminal context establishment / modification request message; the user terminal context establishment / modification request message includes the first distribution unit gNB-DU UE F1AP identifier, the new distribution unit gNB-DU UE F1AP identifier, the control signaling radio bearer SRB and the data radio bearer DRB for establishing or modifying the user terminal.

[0193] In one embodiment, the apparatus 1300 further includes:

[0194] A third receiving module is configured to receive an interface establishment request message sent by the first distribution unit, where the interface establishment request message includes satellite information and an interface establishment time window;

[0195] The first feedback module is configured to feed back an interface establishment request response message to the first distribution unit.

[0196] In one embodiment, the apparatus 1300 further includes:

[0197] The processing module is configured to suspend or release the connection between the first distribution unit and the first centralized unit when the interface establishment time window expires.

[0198] In one embodiment, the apparatus 1300 further includes:

[0199] A fourth receiving module is configured to receive an interface configuration update message sent by the first distribution unit; the interface configuration update message includes updated satellite information and an updated interface establishment time window;

[0200] The second feedback module is configured to feed back an interface configuration update confirmation message to the first distribution unit.

[0201] In one embodiment, as shown in FIG14 , a satellite base station and terminal switching device 1400 is provided. The satellite base station includes a first distribution unit and a second distribution unit for resource sharing. The device 1400 is applied to the second centralized unit. The device 1400 includes:

[0202] A first receiving module 1410 is configured to receive a handover request message sent by the first centralized unit;

[0203] Feedback module 1420, configured to feed back a handover request confirmation message to the first centralized unit; the handover request confirmation message includes an F1AP context and an RRC reconfiguration message; the F1AP context includes a user terminal context establishment / modification request message sent by the second centralized unit to the second distributed unit;

[0204] The second receiving module 1430 is configured to receive a user terminal context establishment / modification response message sent by the second distributed unit when the second centralized unit establishes an interface connection with the second distributed unit;

[0205] The third receiving module 1440 is configured to receive an RRC reconfiguration completion message sent by a user terminal.

[0206] For the specific definitions of the satellite base station and terminal switching device, please refer to the definitions of the satellite base station and terminal switching method above and will not be repeated here. The various modules in the above-mentioned satellite base station and terminal switching device can be implemented in whole or in part through software, hardware, or a combination thereof. The above-mentioned modules can be embedded in or independent of the processor in the computer device in hardware form, or can be stored in the memory of the computer device in software form, so that the processor can call and execute the corresponding operations of the above-mentioned modules.

[0207] In one embodiment, a communication device is provided, comprising a receiver and a transmitter, wherein:

[0208] The receiver is configured to receive the RRC reconfiguration message sent by the first distributed unit.

[0209] The transmitter is configured to send an RRC reconfiguration completion message to the second distributed unit within a time window configured in the RRC reconfiguration message.

[0210] In one embodiment, a communication device is provided, comprising a transmitter and a receiver, wherein:

[0211] A transmitter, configured to send a user terminal context modification message to the first distributed unit, so that the second distributed unit can clearly define the F1AP context between the second centralized unit and the second distributed unit;

[0212] The receiver is configured to receive the user terminal context modification response message fed back by the first distribution unit, so as to implement the handover between the satellite base station and the user terminal.

[0213] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0214] Sending a handover request message to the second centralized unit according to the satellite ephemeris information; the handover request message includes the NTN UE context reference container and the identification information of the second distributed unit;

[0215] Receive a handover request confirmation message fed back by the second centralized unit, where the handover request confirmation message includes an F1AP context and an RRC reconfiguration message; the NTN UE context and the F1AP context are used to clarify shared resources between the first distributed unit and the second distributed unit; and the shared resources are used to implement handover between the satellite base station and the user terminal.

[0216] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0217] receiving an interface establishment request message sent by the first distribution unit, where the interface establishment request message includes satellite information and an interface establishment time window;

[0218] Feedback an interface establishment request response message to the first distributed unit.

[0219] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0220] When the interface establishment time window expires, the connection between the first distributed unit and the first centralized unit is suspended or released.

[0221] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0222] receiving an interface configuration update message sent by the first distribution unit; the interface configuration update message includes updated satellite information and an updated interface establishment time window;

[0223] Feedback an interface configuration update confirmation message to the first distribution unit.

[0224] In one embodiment, a communication device is provided, including: a transmitter and a receiver.

[0225] The receiver is configured to receive a switching request message sent by the first centralized unit.

[0226] The transmitter is used to feed back a handover request confirmation message to the first centralized unit; the handover request confirmation message includes an F1AP context and an RRC reconfiguration message; the F1AP context includes a user terminal context establishment / modification request message sent by the second centralized unit to the second distributed unit.

[0227] The receiver is further configured to receive a user terminal context establishment / modification response message sent by the second distributed unit when the second centralized unit establishes an interface connection with the second distributed unit;

[0228] The receiver is further configured to receive an RRC reconfiguration completion message sent by the user terminal.

[0229] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the following steps are implemented:

[0230] receiving an RRC reconfiguration message sent by the first distributed unit;

[0231] Send an RRC reconfiguration complete message to the second distributed unit within the time window configured in the RRC reconfiguration message.

[0232] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the following steps are implemented:

[0233] Sending a user terminal context modification message to the first distributed unit so that the second distributed unit can clearly define the F1AP context between the second centralized unit and the second distributed unit;

[0234] The user terminal context modification response message fed back by the first distribution unit is received to implement the handover between the satellite base station and the user terminal.

[0235] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0236] Sending a handover request message to the second centralized unit according to the satellite ephemeris information; the handover request message includes the NTN UE context reference container and the identification information of the second distributed unit;

[0237] Receive a handover request confirmation message fed back by the second centralized unit, where the handover request confirmation message includes an F1AP context and an RRC reconfiguration message; the NTN UE context and the F1AP context are used to clarify shared resources between the first distributed unit and the second distributed unit; and the shared resources are used to implement handover between the satellite base station and the user terminal.

[0238] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0239] receiving an interface establishment request message sent by the first distribution unit, where the interface establishment request message includes satellite information and an interface establishment time window;

[0240] Feedback an interface establishment request response message to the first distributed unit.

[0241] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0242] When the interface establishment time window expires, the connection between the first distributed unit and the first centralized unit is suspended or released.

[0243] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0244] receiving an interface configuration update message sent by the first distribution unit; the interface configuration update message includes updated satellite information and an updated interface establishment time window;

[0245] Feedback an interface configuration update confirmation message to the first distribution unit.

[0246] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the following steps are implemented:

[0247] receiving a switching request message sent by the first centralized unit;

[0248] Feedback a handover request confirmation message to the first centralized unit; the handover request confirmation message includes an F1AP context and an RRC reconfiguration message; the F1AP context includes a user terminal context establishment / modification request message sent by the second centralized unit to the second distributed unit;

[0249] When the second centralized unit establishes an interface connection with the second distributed unit, receiving a user terminal context establishment / modification response message sent by the second distributed unit;

[0250] Receive an RRC reconfiguration complete message sent by the user terminal.

[0251] The present application also provides a computer program product comprising instructions, which, when executed on a computer, causes the computer to perform the following steps:

[0252] receiving an RRC reconfiguration message sent by the first distributed unit;

[0253] Send an RRC reconfiguration complete message to the second distributed unit within the time window configured in the RRC reconfiguration message.

[0254] Those skilled in the art will appreciate that all or part of the processes in the above-mentioned embodiment methods can be implemented by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application may include at least one of non-volatile and volatile memory. Non-volatile memory may include read-only memory (ROM), magnetic tape, floppy disk, flash memory or optical memory, etc. Volatile memory may include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0255] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0256] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present application. It should be noted that variations and improvements are possible within the scope of the present application, as would be apparent to one skilled in the art. These variations and improvements fall within the scope of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A method for handover between a satellite base station and a terminal, wherein the satellite base station comprises a first distribution unit and a second distribution unit for sharing resources, and the method is applied to a user terminal connected to the satellite base station, the method comprising: receiving an RRC (Radio Resource Control) reconfiguration message sent by the first distributed unit; as well as Send an RRC reconfiguration complete message to the second distributed unit within a time window configured in the RRC reconfiguration message.

2. The method according to claim 1, wherein The RRC reconfiguration message includes information for instructing the user terminal to access the second distribution unit.

3. A method for handover between a satellite base station and a terminal, wherein the satellite base station includes a first distributed unit and a second distributed unit for sharing resources, the method being applied to a first centralized unit for accessing the first distributed unit, the method comprising: Sending a user terminal context modification message to the first distributed unit, so that the second distributed unit can clearly define the F1AP context between the second centralized unit used to access the second distributed unit; as well as Receive the user terminal context modification response message fed back by the first distribution unit to implement the handover between the satellite base station and the user terminal.

4. The method according to claim 3, wherein: The user terminal context modification message includes an RRC reconfiguration message and an F1AP context; the user terminal context modification message is used to instruct the first distribution unit to forward the RRC reconfiguration message to the current user terminal.

5. The method according to claim 4, wherein Before sending the user terminal context modification message to the first distributed unit, the method further includes: Sending a handover request message to the second centralized unit according to the satellite ephemeris information; the handover request message includes an NTN UE (non-terrestrial network user terminal) context and identification information of the second distributed unit; Receive a handover request confirmation message fed back by the second centralized unit, where the handover request confirmation message includes an F1AP (F1 interface application protocol) context and an RRC reconfiguration message; the NTN UE context and the F1AP context are used to clarify shared resources between the first distributed unit and the second distributed unit; and the shared resources are used to implement handover between the satellite base station and the user terminal.

6. The method according to claim 5, wherein: The NTN UE context is carried by the NTN UE context reference container; The NTN UE context reference container includes: cell group configuration, configured measurement gap parameters, gNB-DU UE F1AP identifier, data radio bearer DRB establishment information, and low-layer configuration information for the user terminal.

7. The method according to claim 4 or 5, wherein: The F1AP context is carried by the F1AP context container; The F1AP context container includes: a user terminal context establishment / modification request message sent by the second centralized unit to the second distributed unit; The user terminal context establishment / modification request message includes the first distribution unit gNB-DU UE F1AP identifier, the new distribution unit gNB-DU UE F1AP identifier, the control signaling radio bearer SRB for establishing or modifying the user terminal, and the data radio bearer DRB.

8. The method according to claim 5, wherein The method further comprises: receiving an interface establishment request message sent by the first distribution unit, wherein the interface establishment request message includes satellite information and an interface establishment time window; and Feedback an interface establishment request response message to the first distribution unit.

9. The method according to claim 8, wherein The method further comprises: When the interface establishment time window expires, the connection between the first distribution unit and the first centralized unit is suspended or released.

10. The method according to claim 3, wherein: The method further comprises: receiving an interface configuration update message sent by the first distribution unit; the interface configuration update message includes updated satellite information and an updated interface establishment time window; and Feedback an interface configuration update confirmation message to the first distribution unit.

11. A method for handover between a satellite base station and a terminal, wherein the satellite base station includes a first distributed unit and a second distributed unit for sharing resources, the method being applied to a second centralized unit for accessing the second distributed unit, the method comprising: receiving a switching request message sent by the first centralized unit; Feedback a handover request confirmation message to the first centralized unit; The handover request confirmation message includes an F1AP context and an RRC reconfiguration message; The F1AP context includes a user terminal context establishment / modification request message sent by the second centralized unit to the second distributed unit; When the second centralized unit establishes an interface connection with the second distributed unit, receiving a user terminal context establishment / modification response message sent by the second distributed unit; as well as Receive an RRC reconfiguration complete message sent by the user terminal.

12. A satellite base station and terminal switching device, wherein the satellite base station includes a first distribution unit and a second distribution unit for resource sharing, and the device is applied to a user terminal connected to the satellite base station, the device comprising: A receiving module, configured to receive an RRC reconfiguration message sent by the first distributed unit; as well as The sending module is configured to send an RRC reconfiguration completion message to the second distribution unit within a time window configured in the RRC reconfiguration message to access a new satellite cell.

13. A communication device comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the method according to any one of claims 1 to 11 when executing the computer program.

14. A computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 11 are implemented.

15. A computer program product comprising a computer program, which, when executed by a processor, implements the steps of the method according to any one of claims 1 to 11.

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