Feeder link switching methods, devices, base stations and network equipment

Abstract

This application provides a power supply link handover method, apparatus, base station, and network equipment. The method includes: a base station sending a path handover request message to the core network; the path handover request message includes the terminal's identity information and the terminal's user plane downlink tunnel address on the base station side; the base station receiving a path handover acceptance message sent by the core network; the path handover acceptance message includes the terminal's identity information within the target UPF after the link handover, and the user plane uplink tunnel address used by the terminal within the target UPF; wherein, using the user plane uplink tunnel address used by the terminal within the target UPF unit, the base station sends the terminal's uplink data to the target UPF unit. This method avoids establishing the downlink tunnel on the core network side only after the UE successfully accesses the target base station, making it applicable to satellite communication systems using onboard base stations.

Description

Technical Field

[0001] This application relates to the field of wireless technology, and in particular to a power supply link switching method, apparatus, base station and network equipment. Background Technology

[0002] A Low Earth Orbit Satellite (LEO) communication system includes user terminals, satellites, gateway stations, and data networks. The radio link between the user equipment and the satellite is called the service link, also known as the user link, while the radio link between the satellite and the gateway station is called the feeder link.

[0003] In satellite communication systems, because satellites are constantly moving, the ground gateway stations connected to them may no longer be able to continue serving them. Instead, another ground gateway station continues to serve the satellite. This means that the old feeder link between the satellite and the old ground gateway station is interrupted, and a feeder link is established with the new ground gateway station. This is called feeder link switching.

[0004] In the traditional transparent forwarding mode switching method of satellite communication systems, due to changes in the ground base station, information needs to be transmitted between the target base station and the source base station for the terminal UE to use when accessing the target base station. To address this, the core network has adopted a corresponding design: the downlink tunnel on the core network side is only established after the UE successfully accesses the target base station, in order to avoid wasting resources.

[0005] In spaceborne base station mode, the base station remains unchanged, and there are no air interface access issues. Existing traditional feeder link handover methods have overly cumbersome signaling processes and complex processing logic on the air interface. Furthermore, they employ a phased approach to establishing data transmission paths—first establishing uplink and then downlink—resulting in poor user experience and making them unsuitable for spaceborne base station mode. Currently, there is no feeder link handover method suitable for spaceborne base station mode that can resolve the aforementioned problems. Summary of the Invention

[0006] The purpose of this application is to provide a power supply link switching method, apparatus, base station, and network equipment to solve the problem that the existing power supply link switching methods are not applicable to satellite communication systems using onboard base stations.

[0007] This application provides a power supply link handover method, wherein the method is executed by a base station and includes:

[0008] The base station sends a path switching request message to the core network; the path switching request message includes the identity information of the terminal that needs to switch the power supply link, and the user plane downlink tunnel address of the terminal on the base station side;

[0009] The base station receives a path switching acceptance message sent by the core network; the path switching acceptance message includes the identity information of the terminal in the target user plane management function UPF unit after the link switching, and the user plane uplink tunnel address used by the terminal in the target UPF unit;

[0010] Specifically, the base station sends the uplink data of the terminal to the target UPF unit using the user plane uplink tunnel address used by the terminal within the target UPF unit.

[0011] Optionally, in the power supply link switching method, the path switching request message includes at least one first list information, each first list information recording the identity information of a terminal and the user plane downlink tunnel address used by the terminal in the corresponding base station;

[0012] The path switching acceptance message includes at least one second list information, and each second list information records the identity information of a terminal and the user plane uplink tunnel address used by the terminal in the corresponding target UPF unit.

[0013] Optionally, in the power supply link switching method, the identity information of the terminal includes at least one of the following:

[0014] The identity identifier used by the terminal within the base station;

[0015] The terminal uses an identity identifier within the core network.

[0016] Optionally, in the aforementioned power supply link handover method, after the base station receives the path handover acceptance message from the core network, the method further includes:

[0017] The base station buffers the uplink data transmitted by the terminal.

[0018] Based on the user plane uplink tunnel address used by the terminal within the target UPF unit, the cached uplink data is sent to the target UPF unit; and / or, the downlink data cached during the power supply link switching process sent by the target UPF unit is received and sent to the terminal.

[0019] Optionally, the power supply link switching method further includes:

[0020] Determine whether a power supply link switch is required based on at least one of the current satellite position, gateway station position, and ephemeris information.

[0021] When it is determined that a power supply link switch is required, a power supply link switch request is sent to the core network;

[0022] Specifically, after receiving the feeder link switching acceptance message sent by the core network in accordance with the feeder link switching request, a path switching request message is sent to the core network.

[0023] Another embodiment of this application also provides a power supply link switching method, wherein the method is executed by the Session Management Function (SMF) unit of the core network, and the method includes:

[0024] The SMF unit obtains the PDU session update context request sent by the target access and mobility management function AMF unit of the feeder link after the handover; wherein, the PDU session update context request includes the user plane downlink tunnel address used by the terminal performing the feeder link handover within the base station;

[0025] The SMF unit determines the target user plane management function UPF unit of the feeder link after the handover, and allocates the uplink tunnel address and the downlink tunnel address of the N9 interface to the terminal in the target UPF unit.

[0026] After the target UPF unit establishes a session for the post-switching power supply link, the SMF unit sends a PDU session update response message to the target AMF unit; the PDU session update response message includes the uplink tunnel address used by the terminal within the target UPF unit.

[0027] Optionally, the power supply link switching method, after allocating the uplink tunnel address and the downlink tunnel address of the terminal within the target UPF unit, further includes:

[0028] The SMF unit sends a session modification request to the anchor UPF unit; the session modification request includes the downlink tunnel address of the N9 interface in the target UPF unit;

[0029] The SMF unit receives a session modification response message sent by the anchor UPF unit in accordance with the session modification request; the session modification response message includes the uplink tunnel address allocated to the terminal within the anchor UPF unit;

[0030] Specifically, the target UPF unit sends uplink data to the anchor UPF unit through the uplink tunnel address allocated to the terminal within the anchor UPF unit; and the anchor UPF unit sends downlink data to the target UPF unit through the downlink tunnel address of the N9 interface within the target UPF unit.

[0031] Optionally, in the power supply link switching method, after allocating the uplink tunnel address and the downlink tunnel address of the terminal within the target UPF unit, the method further includes:

[0032] Send a session establishment request message to the target UPF unit; the session establishment request message includes the user plane downlink tunnel address of the terminal on the base station side, the uplink tunnel address used by the terminal in the target UPF unit, and the uplink tunnel address used by the terminal in the anchor UPF unit;

[0033] After receiving the session establishment response message sent by the target UPF unit in accordance with the session establishment request message, it is determined that the target UPF unit has established a session for the feeder link after the handover.

[0034] Optionally, the power supply link switching method further includes:

[0035] After the target UPF unit establishes a session for the feeder link after the handover, a session change request message is sent to the source UPF unit of the feeder link before the handover; the session change request message includes the forwarding tunnel address of the target UPF unit;

[0036] The source UPF unit forwards the downlink data before the handover to the target UPF unit according to the forwarding tunnel address.

[0037] Optionally, the power supply link switching method further includes:

[0038] Obtain the PDU session release context request sent by the source AMF unit of the feeder link before the handover, after learning that the link handover was successful;

[0039] Based on the PDU session release context request, a session release request corresponding to each terminal is sent to the source UPF unit of the feeder link before handover, in order to release the resources on the source side before handover.

[0040] Obtain the session release response message sent by the source UPF unit after releasing the resource.

[0041] This application also provides a power supply link handover method, wherein the method is executed by the Access and Mobility Management Function (AMF) unit of the core network, and the method includes:

[0042] The AMF unit sends a PDU session update context request to the session management function SMF unit; wherein, the PDU session update context request includes the user plane downlink tunnel address used by the terminal in the base station;

[0043] The AMF unit receives the PDU session update response message sent by the SMF unit;

[0044] The PDU session update response message includes the uplink tunnel address used by the terminal in the target UPF unit of the feeder link after the handover, which is used by the base station to send the uplink data of the terminal to the target UPF unit.

[0045] Optionally, the power supply link switching method further includes:

[0046] Obtain the power supply link switching request sent by the base station;

[0047] According to the power supply link handover request, a power supply link handover acceptance message is sent to the base station; the power supply link handover acceptance message includes the failure time of the link before handover and the effective time of the link after handover.

[0048] Optionally, the power supply link switching method further includes:

[0049] The system receives a path switching request message sent by the base station after it has received the power supply link switching acceptance message; the path switching request message includes the identity information of the terminal that needs to perform power supply link switching, and the user plane downlink tunnel address of the terminal on the base station side.

[0050] Specifically, based on the path switching request message, the AMF unit sends the PDU session update context request to the SMF unit.

[0051] Optionally, in the power supply link switching method, after receiving the PDU session update response message sent by the SMF unit, the method further includes:

[0052] Send a path handover acceptance message to the base station; the path handover acceptance message includes the identity information of the terminal in the target user plane management function UPF unit after the link handover, and the user plane uplink tunnel address used by the terminal in the target UPF unit.

[0053] Optionally, the power supply link switching method further includes, before sending a PDU session update context request to the session management function (SMF) unit:

[0054] The system receives a terminal context creation request sent by the source AMF unit of the pre-handover link of the base station; the terminal context creation request includes the user plane downlink tunnel address of the terminal on the base station side.

[0055] Specifically, the source AMF unit acquires the feeder link handover request sent by the base station, sends a feeder link handover acceptance message to the base station based on the feeder link handover request, and after receiving the path handover request message sent by the base station after acquiring the feeder link handover acceptance message, sends the create terminal context request to the target AMF unit; the path handover request message includes the user plane downlink tunnel address of the terminal that needs to perform feeder link handover on the base station side and the identity information of the terminal that needs to perform feeder link handover.

[0056] Optionally, in the power supply link switching method, after receiving the PDU session update response message sent by the SMF unit, the method further includes:

[0057] A Create Terminal Context Response message is sent to the source AMF unit of the link before the handover, causing the source AMF unit to send a path handover acceptance message to the base station; the Create Terminal Context Response message includes the uplink tunnel address used by the terminal in the target UPF unit, and the path handover acceptance message includes the user plane uplink tunnel address of the terminal in the target UPF unit of the link after the handover and the terminal's identity information; the Create Terminal Context Response message includes the user plane uplink tunnel address used by the terminal in the target UPF unit.

[0058] This application also provides a base station, which includes a memory, a transceiver, and a processor:

[0059] A memory for storing computer programs; a transceiver for sending and receiving data under the control of the processor; and a processor for reading the computer programs from the memory and performing the following operations:

[0060] Send a path switching request message to the core network; the path switching request message includes the identity information of the terminal that needs to switch the power supply link, and the user plane downlink tunnel address of the terminal on the base station side;

[0061] Receive a path switching acceptance message sent by the core network; the path switching acceptance message includes the identity information of the terminal in the target user plane management function UPF unit after the link switching, and the user plane uplink tunnel address used by the terminal in the target UPF unit;

[0062] Specifically, the base station transmits the terminal's uplink data to the target UPF unit using the user plane uplink tunnel address used by the terminal within the target UPF unit.

[0063] Optionally, in the base station, the path switching request message includes at least one first list information, each first list information recording the identity information of a terminal and the user plane downlink tunnel address used by the terminal in the corresponding base station;

[0064] The path switching acceptance message includes at least one second list information, and each second list information records the identity information of a terminal and the user plane uplink tunnel address used by the terminal in the corresponding target UPF unit.

[0065] Optionally, in the base station, the identity information of the terminal includes at least one of the following:

[0066] The identity identifier used by the terminal within the base station;

[0067] The terminal uses an identity identifier within the core network.

[0068] Optionally, in the base station, after receiving the path handover acceptance message from the core network, the processor is further configured to:

[0069] Cache the uplink data transmitted from the terminal to the core network;

[0070] Based on the user plane uplink tunnel address used by the terminal within the target UPF unit, the cached uplink data is sent to the target UPF unit; and / or, the downlink data cached during the power supply link switching process sent by the target UPF unit is received and sent to the terminal.

[0071] Optionally, in the base station, the processor is further configured to:

[0072] Determine whether a power supply link switch is required based on at least one of the current satellite position, gateway station position, and ephemeris information.

[0073] When it is determined that a power supply link switch is required, a power supply link switch request is sent to the core network;

[0074] Specifically, after receiving the feeder link switching acceptance message sent by the core network in accordance with the feeder link switching request, a path switching request message is sent to the core network.

[0075] This application embodiment also provides a network device, wherein the network device is a Session Management Function (SMF) unit of the core network, including a memory, a transceiver, and a processor: the memory is used to store computer programs; the transceiver is used to send and receive data under the control of the processor; the processor is used to read the computer program in the memory and perform the following operations:

[0076] The PDU session update context request sent by the target access and mobility management function (AMF) unit of the feeder link after the handover is obtained; wherein, the PDU session update context request includes the user plane downlink tunnel address used by the terminal performing the feeder link handover within the base station;

[0077] The target user plane management function (UPF) unit of the feeder link after the handover is determined, and the uplink tunnel address and downlink tunnel address of the terminal in the target UPF unit are allocated.

[0078] After the target UPF unit establishes a session for the post-switching power supply link, the SMF unit sends a PDU session update response message to the target AMF unit; the PDU session update response message includes the uplink tunnel address used by the terminal within the target UPF unit.

[0079] Optionally, in the network device, after allocating the uplink tunnel address and the downlink tunnel address of the N9 interface for the terminal within the target UPF unit, the processor is further configured to:

[0080] Send a session modification request to the anchor UPF unit; the session modification request includes the downlink tunnel address of the N9 interface in the target UPF unit;

[0081] Receive a session modification response message sent by the anchor point UPF unit in accordance with the session modification request; the session modification response message includes the uplink tunnel address allocated to the terminal within the anchor point UPF unit;

[0082] Specifically, the target UPF unit sends uplink data to the anchor UPF unit through the uplink tunnel address allocated to the terminal within the anchor UPF unit; and the anchor UPF unit sends downlink data to the target UPF unit through the downlink tunnel address of the N9 interface within the target UPF unit.

[0083] Optionally, in the network device, after allocating the uplink tunnel address and the downlink tunnel address of the N9 interface for the terminal within the target UPF unit, the processor is further configured to:

[0084] Send a session establishment request message to the target UPF unit; the session establishment request message includes the user plane downlink tunnel address of the terminal on the base station side, the uplink tunnel address used by the terminal in the target UPF unit, and the uplink tunnel address used by the terminal in the anchor UPF unit;

[0085] After receiving the session establishment response message sent by the target UPF unit in accordance with the session establishment request message, it is determined that the target UPF unit has established a session for the feeder link after the handover.

[0086] Optionally, in the network device, the processor is further configured to:

[0087] After the target UPF unit establishes a session for the feeder link after the handover, a session change request message is sent to the source UPF unit of the feeder link before the handover; the session change request message includes the forwarding tunnel address of the target UPF unit;

[0088] The source UPF unit forwards the downlink data before the handover to the target UPF unit according to the forwarding tunnel address.

[0089] Optionally, in the network device, the processor is further configured to:

[0090] Obtain the PDU session release context request sent by the source AMF unit of the feeder link before the handover, after learning that the link handover was successful;

[0091] Based on the PDU session release context request, a session release request corresponding to each terminal is sent to the source UPF unit of the feeder link before handover, in order to release the resources on the source side before handover.

[0092] Obtain the session release response message sent by the source UPF unit after releasing the resource.

[0093] This application also provides a network device, wherein the network device is an Access and Mobility Management Function (AMF) unit of the core network, including a memory, a transceiver, and a processor.

[0094] A memory for storing computer programs; a transceiver for sending and receiving data under the control of the processor; and a processor for reading the computer programs from the memory and performing the following operations:

[0095] When the AMF unit is the target AMF unit for power supply link handover of the base station, a PDU session update context request is sent to the session management function SMF unit; wherein, the PDU session update context request includes the user plane downlink tunnel address used by the terminal in the base station;

[0096] Receive the PDU session update response message sent by the SMF unit;

[0097] The PDU session update response message includes the uplink tunnel address used by the terminal in the target UPF unit of the feeder link after the handover; the base station sends the uplink data of the terminal to the target UPF unit through the user plane uplink tunnel address used by the terminal in the target UPF unit.

[0098] Optionally, in the network device, the processor is further configured to:

[0099] Obtain the power supply link switching request sent by the base station;

[0100] According to the power supply link handover request, a power supply link handover acceptance message is sent to the base station; the power supply link handover acceptance message includes the failure time of the link before handover and the effective time of the link after handover.

[0101] Optionally, in the network device, the processor is further configured to:

[0102] The system receives a path switching request message sent by the base station after it has received the power supply link switching acceptance message; the path switching request message includes the identity information of the terminal that needs to perform power supply link switching, and the user plane downlink tunnel address of the terminal on the base station side.

[0103] Specifically, based on the path switching request message, the AMF unit sends the PDU session update context request to the SMF unit.

[0104] Optionally, in the network device, after receiving the PDU session update response message sent by the SMF unit, the processor is further configured to:

[0105] Send a path handover acceptance message to the base station; the path handover acceptance message includes the identity information of the terminal in the target user plane management function UPF unit after the link handover, and the user plane uplink tunnel address used by the terminal in the target UPF unit.

[0106] Optionally, in the network device, before sending a PDU session update context request to the Session Management Function (SMF) unit, the processor is further configured to:

[0107] The system receives a terminal context creation request sent by the source AMF unit of the pre-handover link of the base station; the terminal context creation request includes the user plane downlink tunnel address of the terminal on the base station side.

[0108] Specifically, the source AMF unit acquires the feeder link handover request sent by the base station, sends a feeder link handover acceptance message to the base station based on the feeder link handover request, and after receiving the path handover request message sent by the base station after acquiring the feeder link handover acceptance message, sends the create terminal context request to the target AMF unit; the path handover request message includes the user plane downlink tunnel address of the terminal that needs to perform feeder link handover on the base station side and the identity information of the terminal that needs to perform feeder link handover.

[0109] Optionally, in the network device, after receiving the PDU session update response message sent by the SMF unit, the processor is further configured to:

[0110] A Create Terminal Context Response message is sent to the source AMF unit of the link before the handover, causing the source AMF unit to send a path handover acceptance message to the base station; the Create Terminal Context Response message includes the uplink tunnel address used by the terminal in the target UPF unit, and the path handover acceptance message includes the user plane uplink tunnel address of the terminal in the target UPF unit of the link after the handover and the terminal's identity information; the Create Terminal Context Response message includes the user plane uplink tunnel address used by the terminal in the target UPF unit.

[0111] This application embodiment also provides a power supply link switching device, wherein the switching is performed by a base station, and the device includes:

[0112] The first message sending unit is used to send a path switching request message to the core network; the path switching request message includes the identity information of the terminal that needs to switch the power supply link, and the user plane downlink tunnel address of the terminal on the base station side;

[0113] The first message receiving unit is used to receive a path switching acceptance message sent by the core network; the path switching acceptance message includes the identity information of the terminal in the target user plane management function UPF unit after the link switching, and the user plane uplink tunnel address used by the terminal in the target UPF unit.

[0114] Specifically, the base station sends the uplink data of the terminal to the target UPF unit using the user plane uplink tunnel address used by the terminal within the target UPF unit.

[0115] This application embodiment also provides a power supply link switching device, wherein the switching is performed by the Session Management Function (SMF) unit of the core network, and the device includes:

[0116] The request acquisition unit is used to acquire the PDU session update context request sent by the target access and mobility management function (AMF) unit of the feeder link after handover; wherein, the PDU session update context request includes the user plane downlink tunnel address used by the terminal performing the feeder link handover within the base station;

[0117] The determining unit is used to determine the target user plane management function (UPF) unit of the feeder link after the handover, and to allocate the uplink tunnel address and the downlink tunnel address of the N9 interface of the terminal in the target UPF unit.

[0118] The second message sending unit is used to send a PDU session update response message to the target AMF unit after the target UPF unit has established a session for the post-switching power supply link; the PDU session update response message includes the uplink tunnel address used by the terminal in the target UPF unit.

[0119] This application embodiment also provides a power supply link switching device, wherein the switching is performed by the Access and Mobility Management Function (AMF) unit of the core network, and the device includes:

[0120] A request sending unit is configured to send a PDU session update context request to a session management function (SMF) unit; wherein the PDU session update context request includes the user plane downlink tunnel address used by the terminal within the base station;

[0121] The second message receiving unit is used to receive the PDU session update response message sent by the SMF unit;

[0122] The PDU session update response message includes the uplink tunnel address used by the terminal in the target UPF unit of the feeder link after the handover, which is used by the base station to send the uplink data of the terminal to the target UPF unit.

[0123] This application also provides a processor-readable storage medium storing a computer program for causing the processor to perform the steps of the power supply link switching method described in any of the preceding claims.

[0124] At least one of the above technical solutions in the specific embodiments of this application has the following beneficial effects:

[0125] The power supply link handover method described in this application involves sending the user plane downlink tunnel address of the terminal on the base station side to the core network in advance before the power supply link is interrupted. This enables the core network to send the user plane downlink tunnel address of the terminal on the base station side to the target UPF after the link handover. Furthermore, it allows the allocation of the uplink tunnel address of the terminal on the target UPF side and notification to the base station before the power supply link is interrupted, and the establishment of a session for the power supply link after the handover. This ensures timely uplink and downlink data transmission after the power supply link is established. Therefore, compared to the existing traditional transparent forwarding mode handover method, this process eliminates the need for the UE to access the target base station, thus avoiding the problem of establishing the downlink tunnel on the core network side only after the UE successfully accesses the target base station, preventing resource waste. This method is applicable to satellite communication systems using onboard base stations. Attached Figure Description

[0126] Figure 1 This is a schematic diagram of one embodiment of the system to which the power supply link switching method described in this application is applied;

[0127] Figure 2 This is a flowchart illustrating one implementation of the power supply link switching method described in this application.

[0128] Figure 3 A schematic diagram of the processing flow of each network node for using the power supply link switching method described in the embodiments of this application;

[0129] Figure 4 This is a schematic diagram of another implementation of the system to which the power supply link switching method described in this application is applied;

[0130] Figure 5 This is a flowchart illustrating a second implementation of the power supply link switching method described in this application.

[0131] Figure 6 This is a flowchart illustrating a third embodiment of the power supply link switching method described in this application.

[0132] Figure 7 This is a schematic diagram of the structure of one embodiment of the network device described in this application;

[0133] Figure 8 This is a schematic diagram of the structure of the network device described in Embodiment 2 of this application;

[0134] Figure 9 This is a schematic diagram of the structure of the network device described in Embodiment 3 of this application;

[0135] Figure 10 This is a schematic diagram of one embodiment of the power supply link switching device described in this application.

[0136] Figure 11 This is a schematic diagram of a second embodiment of the power supply link switching device described in this application.

[0137] Figure 12 This is a schematic diagram of the third embodiment of the power supply link switching device described in this application. Detailed Implementation

[0138] In the embodiments of this application, the term "and / or" describes the relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A alone, A and B simultaneously, and B alone. The character " / " generally indicates that the preceding and following associated objects have an "or" relationship.

[0139] In the embodiments of this application, the term "multiple" refers to two or more, and other quantifiers are similar.

[0140] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0141] This application provides a power supply link switching method and apparatus to solve the problem that existing power supply link switching methods are not applicable to satellite communication systems using onboard base stations.

[0142] The method and apparatus are based on the same concept of the application. Since the methods and apparatus solve problems in similar ways, the implementation of the apparatus and methods can refer to each other, and the repeated parts will not be described again.

[0143] Currently, for feeder link handover in transparent forwarding mode, the base station is located on the ground. The handover process involves base station changes. Resources are allocated at the target base station, information is transmitted to the source side, and then notified to the UE. After receiving this information, the UE synchronizes with the target base station, initiates a random access procedure, and finally completes the handover. Therefore, due to the base station change, information needs to be transmitted between the target and source base stations for the UE to use when accessing the target base station. Due to uncertainties such as resource availability at the target base station, the complexity of wireless transmission, and wireless interference, there is a significant probability of failure during downlink synchronization and random access between the UE and the target base station. To address this, the core network has adopted a targeted design: the downlink tunnel on the core network side is only established after the UE successfully accesses the target base station to avoid wasting resources.

[0144] However, the feeder link handover in the traditional transparent forwarding mode is no longer applicable to feeder link handover in the satellite base station mode. This is because in the satellite base station mode, the base station does not change, and the access problem on the air interface no longer exists. That is, the air interface process is continuous and uninterrupted, without failure. Therefore, the core network side no longer needs to adopt the method of establishing the downlink tunnel on the core network side only after the UE successfully accesses the target base station. Therefore, it is necessary to provide a feeder link handover method that can be applied to satellite communication systems using satellite base stations.

[0145] To make the technical problems, technical solutions and advantages of this application clearer, a detailed description will be provided below in conjunction with the accompanying drawings and specific embodiments.

[0146] like Figure 1 This is a schematic diagram of one embodiment of the system using the power supply link switching method described in the embodiments of this application.

[0147] The application system employing the power supply link handover method described in this application includes a base station and a core network. Optionally, the core network includes an Access and Mobility Management Function (AMF) unit, a User Plane Function (UPF) unit, and a Session Management Function (SMF) unit. At any given time, the base station 10 connects to one AMF unit and one UPF unit. The AMF unit and the UPF unit are respectively connected to the SMF unit 60. Through the currently connected UPF unit, the base station 10 transmits the data transmitted between the terminal 20 and the external network to the anchor UPF 30.

[0148] In this embodiment of the application, base station 10 is a satellite-borne base station. The connection between the terminal and the satellite-borne base station remains continuous and will not change. When the power supply link is switched, the link between base station 10 and the core network is switched. The connected power supply link is switched from source AMF (S-AMF) 41 to destination AMF (T-AMF) 51, and from source UPF (S-UPF) 42 to destination UPF (T-UPF) 52.

[0149] This application provides a power supply link switching method, in one embodiment of which the method is executed by a base station, such as... Figure 2 As shown, the method includes:

[0150] S210, Send a path switching request message to the core network; The path switching request message includes the identity information of the terminal that needs to switch the power supply link, and the user plane downlink tunnel address of the terminal on the base station side;

[0151] S220, Receive a path switching acceptance message sent by the core network; the path switching acceptance message includes the identity information of the terminal in the target user plane management function UPF unit after the link switching, and the user plane uplink tunnel address used by the terminal in the target UPF unit;

[0152] Using the user plane uplink tunnel address used by the terminal within the target UPF unit, the base station sends the terminal's uplink data to the target UPF unit.

[0153] Optionally, the core network sends the path switching acceptance message after allocating the uplink tunnel address and downlink tunnel address of the terminal to the target UPF unit after the link switching, and establishing a session for the feeder link after the switching, based on the path switching request message.

[0154] The feeder link handover method described in this application involves sending the user plane downlink tunnel address of the terminal on the base station side to the core network in advance before the feeder link is interrupted. This allows the core network to send the user plane downlink tunnel address of the terminal on the base station side to the target UPF after the link handover. Furthermore, it enables the allocation of the uplink tunnel address of the terminal on the target UPF side and notification to the base station before the feeder link is interrupted, and the establishment of a session for the feeder link after the handover. This allows for timely uplink and downlink data transmission after the feeder link is established. Therefore, compared to the existing traditional transparent forwarding mode handover method, this process eliminates the need for the UE to access the target base station, thus avoiding the problem of wasting resources by only establishing the downlink tunnel on the core network side after the UE successfully accesses the target base station.

[0155] In this embodiment of the application, the method further includes:

[0156] Determine whether a power supply link switch is required based on at least one of the current satellite position, gateway station position, and ephemeris information.

[0157] When it is determined that a power supply link switch is required, a power supply link switch request is sent to the core network;

[0158] Specifically, after receiving the feeder link switching acceptance message sent by the core network in accordance with the feeder link switching request, a path switching request message is sent to the core network.

[0159] Specifically, the base station makes a decision on the power supply link switching. Optionally, it can determine whether a power supply link switching is needed based on at least one of the current satellite position, gateway station position, and ephemeris information. Alternatively, it can analyze the satellite's operating patterns based on the pre-configured information of Operation and Management (O&M) and determine that the original power supply link will no longer be able to provide services to the satellite, in which case a power supply link switching is required.

[0160] The following combination Figure 3 The specific implementation process of the power supply link switching method described in the embodiments of this application is explained.

[0161] See Figure 3 As shown, one embodiment of the power supply link switching method described in this application includes the following specific implementation process:

[0162] S301, the base station gNB determines whether a feeder link handover is needed based on at least one of the current satellite position, gateway station position, and ephemeris information; or, the base station analyzes the satellite's operating patterns based on the O&M's pre-configuration information and determines that the original feeder link will no longer be able to provide services to the satellite, and then makes a decision to perform a feeder link handover.

[0163] S302, the base station gNB sends a feeder link handover request message to the AMF (e.g., marked S-AMF) of the source core network; wherein, the feeder link handover request message is used to request a link handover; optionally, the feeder link handover request message includes information about the target gateway station to be handed over and / or includes information about the target AMF (e.g., marked T-AMF) of the target core network to be handed over; optionally, the feeder link handover request message may also include a handover reason for the feeder link handover, indicating that the message is used for feeder link handover, so that the core network performs corresponding handover processing operations according to the feeder link handover request message;

[0164] S303, the S-AMF responds to the received feeder link handover request by sending a feeder link handover acceptance message to the base station gNB; optionally, the feeder link handover acceptance message includes the failure time of the current link before the handover and the effective time of the link after the handover.

[0165] S304, after receiving the feeder link handover acceptance message sent by S-AMF according to the feeder link handover request, the base station gNB sends a path handover request message to the core network (i.e., S-AMF).

[0166] Optionally, the path handover request message includes the identity information of the terminal requiring power supply link handover, and the user plane downlink tunnel address of the terminal on the base station side; wherein,

[0167] For the identity information of terminals requiring power supply link handover, optionally, the terminal's identity information includes the identity identifier used by the terminal within the base station, such as "RAN UE NGAP ID," used to uniquely identify a UE within the base station; or, the terminal's identity information includes the identity identifier used by the terminal within the core network, such as the identity identifier used within the AMF, such as "AMF UE NGAP ID," used to uniquely identify a UE within the AMF. The AMF can use the terminal's identity identifier to look up the UE's context information.

[0168] The user plane downlink tunnel address of the terminal on the base station side is the downlink tunnel address of the General Packet Radio service (GPRS) tunneling protocol (GTP-U) on the user plane from the base station gNB to the T-UPF side (optionally including the gNB's IP address and the downlink tunnel endpoint identifier (TEID) parameter), denoted as N3-DL-TEID. This is used by the T-UPF to send downlink data to the terminal's user plane downlink tunnel address on the base station side. Since the base station gNB does not change during the feeder link handover, this parameter N3-DL-TEID does not need to be changed during the link handover process.

[0169] In this embodiment, optionally, the path handover request message sent by the base station gNB to the S-AMF includes at least one first list information. Each first list information records the identity information of a terminal and the user plane downlink tunnel address used by the terminal within the corresponding base station. Optionally, different first list information records the identity information of different terminals and the corresponding user plane downlink tunnel address used within the base station. Using this implementation, for multiple terminals requiring handover, the path handover request message is sent to the S-AMF in batches for power supply link handover. Optionally, the path handover request message includes information about the target AMF unit to be handed over.

[0170] S305, the S-AMF determines whether the target AMF unit (e.g., marked as T-AMF) specified in the path handover request message is the S-AMF itself. If it is not the S-AMF itself, it sends a terminal context creation request to the T-AMF to be handed over, such as Namf_Communication_CreateUEContextRequest, to request the establishment of a terminal context in the AMF on the target side of the handover. In this embodiment, the terminal context creation request sent by the S-AMF to the T-AMF includes the user plane downlink tunnel address N3-DL-TEID of the terminal on the base station side;

[0171] In this embodiment of the application, optionally, the S-AMF processes each of the multiple first list information in the path switching request message, determines the T-AMF unit for each terminal UE, and sends a terminal context creation request to the corresponding T-AMF.

[0172] Alternatively, if the S-AMF determines the path switching request message and specifies that the T-AMF used for switching is the S-AMF itself, then the creation terminal context request for this step is abandoned, and the following step S306 is executed directly.

[0173] S306, T-AMF sends a PDU session update context request to SMF, requesting an update to the SM context of the PDU session. Optionally, the PDU session update context request can be marked as Nsmf_PDUSession_UpdateSMContextRequest. In this embodiment, the PDU session update context request sent to SMF includes the user plane downlink tunnel address N3-DL-TEID of the terminal on the base station side.

[0174] S307, the SMF unit determines the target UPF unit of the feeder link after the handover, and allocates the uplink tunnel address (e.g., marked as N3-UL-TEID) and the downlink tunnel address (e.g., marked as N9-DL-TEID) of the N9 interface to the UE in the target UPF unit.

[0175] S308, SMF sends a session modification request to the anchor UPF; specifically, SMF sends the session modification request to the anchor UPF on the N4 interface, and optionally, the session modification request can be marked as N4 Session ModificationRequest;

[0176] The session modification request included the downlink tunnel address of the N9 interface.

[0177] Optionally, the anchor point UPF can also be called the PDU Session Anchor (PSA). Specifically, in the session modification request sent by the SMF to the anchor point UPF, the downlink tunnel address of the N9 interface is the downlink tunnel information DL CN Tunnel Info facing the PSA, enabling the PSA to send downlink data to the T-UPF through the downlink tunnel address of the N9 interface; optionally, the downlink tunnel address of the N9 interface can be identified as N9-DL-TEID, which includes the IP address of the T-UPF and the downlink tunnel endpoint identifier TEID, so that the PSA can know the sending address of the downlink data;

[0178] S309, the anchor UPF (PSA) sends a session modification response message to the SMF; optionally, this session modification response message can be labeled as an N4 Session Modification Response message. Additionally, this session modification response message includes the uplink tunnel address of the terminal within the anchor UPF (PSA) unit, used to enable the T-UPF to send uplink data to the anchor UPF (PSA) unit through the uplink tunnel address of the terminal within the anchor UPF (PSA) unit; optionally, the uplink tunnel address of the terminal within the anchor UPF (PSA) unit can be labeled as N9-UL-TEID, including the IP address of the anchor UPF (PSA) and the uplink tunnel endpoint identifier TEID;

[0179] S310, the SMF sends a session establishment request message to the T-UPF to request the establishment of an N4 session; optionally, the session establishment request message can be represented as an N4 Session Establishment Request message; optionally, the sent session establishment request message includes: the user plane downlink tunnel address N3-DL-TEID used by the terminal in the base station, the uplink tunnel address N3-UL-TEID used by the terminal in the target UPF unit, and the uplink tunnel address N9-UL-TEID used by the terminal in the anchor UPF unit;

[0180] S311, T-UPF successfully established a session and sent a session establishment response message to SMF. This session establishment response message can be represented as an N4 Session Establishment Response message.

[0181] S312, when data forwarding is required, the SMF sends a session change request message to the S-UPF. The session change request message includes the forwarding tunnel address of the target UPF (T-UPF) to inform the forwarding tunnel on the T-UPF side, so that the S-UPF forwards the downlink data to the T-UPF.

[0182] S313, S-UPF sends a session modification response message to SMF based on the session modification request message to confirm the session modification; optionally, the session modification response message can be represented as a Session Modification Response message;

[0183] S314, the SMF sends a PDU session update response message (e.g., marked as Nsmf_PDUSession_UpdateSMContextResponse) to the T-AMF. This PDU session update response message includes the uplink tunnel address of the UE in the target UPF unit, that is, it includes N3-UL-TEID. The N3-UL-TEID corresponds to (the IP address of the T-UPF and the uplink tunnel endpoint identifier TEID).

[0184] S315, T-AMF sends a terminal context creation response message to S-AMF; wherein, the terminal context response message includes the uplink tunnel address N3-UL-TEID of the terminal in the target UPF unit;

[0185] S316, the S-AMF sends a path handover acceptance message to the base station; wherein, the path handover acceptance message includes the identity information of the terminal in the target UPF (T-UPF) unit after the link handover, and the user plane uplink tunnel address used by the terminal in the target user plane management function UPF; wherein,

[0186] The terminal's identity information includes the identifier used by the terminal within the base station, such as "RAN UE NGAPID," which uniquely identifies a UE within the base station; or, the terminal's identity information includes the identifier used by the terminal within the core network, such as the identifier used within the AMF, such as "AMF UE NGAP ID," which uniquely identifies a UE within the AMF. The base station can use the terminal's identity information to find the context information of the corresponding terminal UE.

[0187] The user plane uplink tunnel address used by the terminal within the target user plane management function UPF, which is the GTP-U uplink tunnel address on the T-UPF side (including the IP address of the T-UPF and the tunnel endpoint identifier parameter TEID), can be represented as N3-UL-TEID, which is used by the base station to send uplink data to this N3-UL-TEID.

[0188] Optionally, in this embodiment of the application, the path switching acceptance message includes at least one second list information, each second list information recording the identity information of a terminal and the user plane uplink tunnel address of the terminal in the corresponding target UPF unit.

[0189] In this context, the terminal listed in each of the second list entries in the path switching acceptance message is the terminal performing the link switching. Optionally, different second list entries record the identity information of different terminals, as well as the corresponding user plane uplink tunnel address within the target UPF unit.

[0190] In this implementation method, the path switching acceptance message is sent to multiple terminals that need to be switched in batch path conversion acceptance form. The message includes all terminals that need to switch links in the form of a list.

[0191] By employing the steps S301 to S316 described above, the uplink data transmission channel and the downlink data transmission channel between the terminal, the base station, and the core network are fully connected.

[0192] Furthermore, after the uplink data transmission channel and the downlink data transmission channel are connected, the method further includes the following steps:

[0193] S317. After the handover feeder link becomes active, in the downlink direction, the T-UPF prioritizes transmitting the buffered downlink forwarding data from the S-UPF to the base station gNB. The base station gNB then transmits the downlink data to the UE. Once the buffered downlink data transmission is complete, it transmits downlink data from the external network. In the uplink direction, the base station gNB first transmits the buffered uplink data to the T-UPF, then transmits the uplink data sent by the UE to the T-UPF. The T-UPF then transmits this data to the external network. Afterwards, the T-AMF sends a session notification message (e.g., Namf_Communication_N2Info Notify message) to the S-AMF to notify the UE that the handover process was successful.

[0194] Based on the above, in this embodiment of the invention, optionally, after the base station receives the path handover acceptance message fed back by the core network, the method further includes:

[0195] The base station buffers the uplink data transmitted by the terminal.

[0196] Based on the user plane uplink tunnel address used by the terminal within the target UPF unit, the cached uplink data is sent to the target UPF unit; and / or, the downlink data cached during the power supply link handover process sent by the target UPF unit is received and sent to the terminal.

[0197] S318, for each UE in communication, the S-AMF sends a notification confirmation message (e.g., Namf_Communication_N2Info Notify Ack message) to the T-AMF in response to the session notification message sent by the T-AMF;

[0198] S319, S-AMF sends a PDU session release context request (e.g., represented as Nsmf_PDUSession_ReleaseSMContextRequest message) to SMF to release the resources corresponding to the UE on the source core network side;

[0199] S320, for each UE, the SMF sends a session release request (e.g., represented as an N4Session ReleaseRequest message) to the S-UPF to release resources on the link source side;

[0200] S321, S-UPF sends a session release response message to SMF, which can be represented as an N4Session Release Response message.

[0201] In this implementation, different gateway stations use different core networks, which may cause changes to the AMF (Application Context). Specifically, the S-AMF and T-AMF in the flowchart above will be in different positions. In this case, the T-AMF does not store the UE's communication context, so it needs to be re-established. Furthermore, although a power supply link switch occurs, the downlink tunnel address on the base station side remains unchanged because the onboard base station itself has not changed (although the gNB could theoretically reassign addresses, such an operation would be meaningless).

[0202] In this implementation, the T-AMF informs the SMF of the user plane downlink tunnel address (N3-DL-TEID) of the terminal on the base station side. The SMF then informs the T-UPF of the user plane downlink tunnel address (N3-DL-TEID), so that the T-UPF knows which tunnel on the satellite gNB to send the downlink data to. The SMF also allocates the uplink tunnel address (N3-UL-TEID) facing the gNB on the T-UPF side and informs the AMF of the uplink tunnel address (N3-UL-TEID) in the corresponding message. The AMF informs the satellite gNB of the uplink tunnel information (N3-UL-TEID), so that the base station knows which tunnel on the T-UPF to send the uplink data to after the new power supply takes effect. The SMF will also assign a downlink tunnel address (N9-DL-TEID) to the T-UPF facing the UPF (PSA). The PSA will send downlink data to the T-UPF through this downlink tunnel address (N9-DL-TEID). At the same time, it will also inform the T-UPF of the uplink tunnel address (N9-UL-TEID) facing the UPF (PSA). The T-UPF will send uplink data to the PSA through this uplink tunnel address (N9-UL-TEID).

[0203] The power supply link handover method described in this application adopts the above-described implementation process to achieve handover of the power supply link using the satellite base station. Before the power supply link is interrupted, the downlink tunnel address (i.e., N3-DL-TEID) allocated by the base station side is informed to the core network in advance. The core network then notifies the T-UPF of this information so that downlink data can be sent in a timely manner after the new power supply is established. Before the power supply link is interrupted, the uplink tunnel on the core network T-UPF side is allocated and the relevant network elements are notified so that uplink data can be sent in a timely manner after the new power supply is established. In addition, in the power supply link handover method described in this application, the downlink tunnel information of all UEs currently communicating is informed to the core network in the form of a list to avoid complex operations and delays caused by a single notification.

[0204] In another embodiment of the power supply link switching method described in this application, alternatively, depending on the network deployment, different gateway stations can use the same core network. In this implementation, the AMF may not change; that is, in the above embodiment, the S-AMF and T-AMF belong to the same device, and the AMF stores the entire communication context of the UE, so it does not need to be re-established. Therefore, although a power supply link switching occurs, since the onboard base station has not changed, the downlink tunnel address on the base station side has not changed. Figure 3 and Figure 4 Using this implementation method, the specific implementation process of the power supply link switching method described in this application embodiment includes:

[0205] The AMF (where S-AMF and T-AMF are the same AMF) informs the SMF of the terminal's user plane downlink tunnel address (N3-DL-TEID) on the base station side. The SMF then informs the T-UPF of this address information, allowing the T-UPF to know which tunnel on the base station to send downlink data to. The SMF also allocates the uplink tunnel address (N3-UL-TEID) for the gNB on the T-UPF side and informs it to the AMF in the corresponding message. The AMF sends this address information to the base station, thus informing the base station which T-UPF tunnel to send uplink data to after the new feeder link becomes active. The SMF will also assign a downlink tunnel address (N9-DL-TEID) to the T-UPF facing the UPF (PSA). The PSA will send downlink data to the T-UPF through this downlink tunnel information (N9-DL-TEID). At the same time, it will also inform the T-UPF of the uplink tunnel address (N9-UL-TEID) facing the UPF (PSA). The T-UPF will send uplink data to the PSA through this uplink tunnel address (N9-UL-TEID).

[0206] Therefore, this implementation method is adopted, combined with Figure 3 In contrast to the fact that S-AMF and T-AMF are different devices, when S-AMF and T-AMF are the same AMF device, it is not necessary to execute the step in step S305 where S-AMF sends a request to T-AMF to create a terminal context. In other steps, S-AMF and T-AMF indicate that they are the same AMF. The specific implementation process will not be described in detail here.

[0207] Another aspect of this application embodiment provides a power supply link switching method, executed by the Session Management Function (SMF) unit of the core network, such as... Figure 5 As shown, the method includes:

[0208] S510, the SMF unit obtains the PDU session update context request sent by the target access and mobility management function AMF unit of the feeder link after the handover; wherein, the PDU session update context request includes the user plane downlink tunnel address used by the terminal performing the feeder link handover in the base station;

[0209] S520, the SMF unit determines the target user plane management function UPF unit of the feeder link after the handover, and allocates the uplink tunnel address and the downlink tunnel address of the N9 interface of the terminal in the target UPF unit.

[0210] S530, after the target UPF unit establishes a session for the post-switching power supply link, the SMF unit sends a PDU session update response message to the target AMF unit; the PDU session update response message includes the uplink tunnel address used by the terminal in the target UPF unit.

[0211] The feeder link handover method described in this application involves the base station sending the user plane downlink tunnel address of the terminal on the base station side to the target AMF unit in advance during the handover. The target AMF unit then sends a PDU session update context request to the SMF unit, which includes the user plane downlink tunnel address of the terminal on the base station side. This ensures that before the feeder link is interrupted, the SMF unit sends the user plane downlink tunnel address of the terminal on the base station side to the target UPF after the handover. Furthermore, it allows the allocation of the uplink tunnel address of the terminal on the target UPF side and notification to the base station before the feeder link is interrupted, and the establishment of a session for the feeder link after the handover. This enables timely uplink and downlink data transmission after the feeder link is established. Therefore, compared to the existing traditional transparent forwarding mode handover method, this process eliminates the need for the UE to access the target base station, thus avoiding the problem of wasting resources by only establishing the downlink tunnel on the core network side after the UE successfully accesses the target base station.

[0212] Optionally, in the embodiments of this application, combined with Figure 3 As shown, in step S510, the SMF unit obtains the PDU session update context request sent by the target access and mobility management function (AMF) unit, which can correspond to... Figure 3 In steps S306 and S520, the SMF unit determines the target UPF unit of the feeder link after the switch and allocates the uplink tunnel address and downlink tunnel address of the terminal within the target UPF unit to correspond to the target UPF unit. Figure 3 In steps S307 and S530, the SMF unit sends a PDU session update response message to the target AMF unit, which can correspond to... Figure 3 Step S314 in the above. For detailed implementation procedures, please refer to the above. Figure 3 The descriptions in the text will not be elaborated upon here.

[0213] In this embodiment of the application, optionally, after allocating the uplink tunnel address and the downlink tunnel address of the N9 interface within the target UPF unit in step S520, the method further includes:

[0214] The SMF unit sends a session modification request to the anchor UPF unit; the session modification request includes the downlink tunnel address of the N9 interface in the target UPF unit;

[0215] The SMF unit receives a session modification response message sent by the anchor UPF unit in accordance with the session modification request; the session modification response message includes the uplink tunnel address allocated to the terminal within the anchor UPF unit;

[0216] Specifically, the target UPF unit sends uplink data to the anchor UPF unit through the uplink tunnel address allocated to the terminal within the anchor UPF unit; and the anchor UPF unit sends downlink data to the target UPF unit through the downlink tunnel address of the N9 interface within the target UPF unit.

[0217] Specifically, the implementation steps of the SMF unit sending a session modification request to the anchor UPF unit, and the SMF unit receiving a session modification response message sent by the anchor UPF unit according to the session modification request, can correspond to... Figure 3 Steps S308 and S309 in the implementation method.

[0218] Optionally, in this embodiment of the application, after assigning the uplink tunnel address and the downlink tunnel address of the terminal in the target UPF unit and the N9 interface in step S520, the method further includes:

[0219] Send a session establishment request message to the target UPF unit; the session establishment request message includes the user plane downlink tunnel address of the terminal on the base station side, the uplink tunnel address used by the terminal in the target UPF unit, and the uplink tunnel address used by the terminal in the anchor UPF unit;

[0220] After receiving the session establishment response message sent by the target UPF unit in accordance with the session establishment request message, it is determined that the target UPF unit has established a session for the feeder link after the handover.

[0221] Specifically, the steps in the above implementation process, namely, the SMF sending a session establishment request message to the target UPF unit and receiving a session establishment response message sent by the target UPF unit according to the session establishment request message, can correspond to... Figure 3 Steps S310 and S311 in the implementation method.

[0222] Optionally, in one embodiment of the power supply link switching method, the method further includes:

[0223] After the target UPF unit establishes a session for the feeder link after the handover, a session change request message is sent to the source UPF unit of the feeder link before the handover; the session change request message includes the forwarding tunnel address of the target UPF unit;

[0224] The source UPF unit forwards the downlink data before the handover to the target UPF unit according to the forwarding tunnel address.

[0225] Specifically, in the above implementation steps, the step of the SMF unit sending a session change request message to the source UPF unit of the switching feedforward link can correspond to Figure 3 Step S312 in the implementation method.

[0226] Optionally, in one embodiment of the power supply link switching method, the method further includes:

[0227] Obtain the PDU session release context request sent by the source AMF unit of the feeder link before the handover, after learning that the link handover was successful;

[0228] Based on the PDU session release context request, a session release request corresponding to each terminal is sent to the source UPF unit of the feeder link before handover, in order to release the resources on the source side before handover.

[0229] Obtain the session release response message sent by the source UPF unit after releasing the resource.

[0230] Specifically, in the above implementation steps, the steps of the SMF unit obtaining the PDU session release context request sent by the source AMF unit of the handover feedforward link, the SMF unit sending a session release request corresponding to each terminal to the source UPF unit of the handover feedforward link, and obtaining the session release response message sent by the source UPF unit after releasing the resource, can correspond to Figure 3 Steps S319 to S321 in the implementation method will not be described in detail here.

[0231] This application also provides another embodiment of the power supply link switching method, which is executed by the Access and Mobility Management Function (AMF) unit of the core network, such as... Figure 6 As shown, the method includes:

[0232] S610, a PDU session update context request is sent to the session management function (SMF) unit; wherein, the PDU session update context request includes the user plane downlink tunnel address used by the terminal in the base station;

[0233] S620, the AMF unit receives the PDU session update response message sent by the SMF unit;

[0234] The PDU session update response message includes the uplink tunnel address used by the terminal in the target UPF unit of the feeder link after the handover, which is used by the base station to send the uplink data of the terminal to the target UPF unit.

[0235] Optionally, the SMF unit determines the target UPF unit for the post-switching power supply link, allocates the uplink tunnel address and the downlink tunnel address of the N9 interface to the terminal within the target UPF unit, and after establishing a session for the post-switching power supply link in the target UPF unit, sends the PDU session update response message to the target AMF unit; the PDU session update response message includes the uplink tunnel address used by the terminal within the target UPF unit.

[0236] The feeder link handover method described in this application involves sending a PDU session update context request to the SMF unit during feeder link handover. This PDU session update context request includes the user plane downlink tunnel address of the terminal on the base station side. This allows the SMF unit to send the user plane downlink tunnel address of the terminal on the base station side to the target UPF after the link handover before the feeder link is interrupted. Furthermore, it enables the allocation of the uplink tunnel address of the terminal on the target UPF side and notification to the base station before the feeder link is interrupted, and the establishment of a session for the feeder link after handover. This allows for timely uplink and downlink data transmission after the feeder link is established. Therefore, compared to the existing traditional transparent forwarding mode handover method, this process eliminates the need for the UE to access the target base station, thus avoiding the problem of wasting resources by establishing the downlink tunnel on the core network side only after the UE successfully accesses the target base station.

[0237] In one embodiment of this application, the method may optionally further include:

[0238] Obtain the power supply link switching request sent by the base station;

[0239] According to the power supply link handover request, a power supply link handover acceptance message is sent to the base station; the power supply link handover acceptance message includes the failure time of the link before handover and the effective time of the link after handover.

[0240] In this implementation, the source AMF unit and the target AMF unit can be the same device. Using this implementation, the AMF unit acts as the source AMF unit, acquiring the feeder link handover request sent by the base station and sending the feeder link handover acceptance message to the base station. This process can correspond to... Figure 3 Steps S302 and S303 in the implementation method will not be described in detail here.

[0241] In one embodiment, optionally, the method further includes:

[0242] The system receives a path switching request message sent by the base station after it has received the power supply link switching acceptance message; the path switching request message includes the identity information of the terminal that needs to perform power supply link switching, and the user plane downlink tunnel address of the terminal on the base station side.

[0243] Specifically, based on the path switching request message, the AMF unit sends the PDU session update context request to the SMF unit.

[0244] In this embodiment, the path switching request message sent by the base station can be received in accordance with... Figure 3 Step S304 in the implementation method will not be described in detail here.

[0245] Optionally, in one embodiment of the power supply link switching method, after receiving the PDU session update response message sent by the SMF unit, the method further includes:

[0246] A path handover acceptance message is sent to the base station; the path handover acceptance message includes the identity information of the terminal in the target UPF unit after the link handover, and the user plane uplink tunnel address used by the terminal in the target UPF unit.

[0247] Optionally, in this embodiment, sending a path handover acceptance message to the base station can correspond to... Figure 3 Step S316 in the implementation method will not be described in detail here.

[0248] In one embodiment of this application, before sending a Protocol Data Unit (PDU) session update context request to the Session Management Function (SMF) unit, the method further includes:

[0249] The system receives a terminal context creation request sent by the source AMF unit of the pre-handover link of the base station; the terminal context creation request includes the user plane downlink tunnel address of the terminal on the base station side.

[0250] Specifically, the source AMF unit acquires the feeder link handover request sent by the base station, sends a feeder link handover acceptance message to the base station based on the feeder link handover request, and after receiving the path handover request message sent by the base station after acquiring the feeder link handover acceptance message, sends the create terminal context request to the target AMF unit; the path handover request message includes the user plane downlink tunnel address of the terminal that needs to perform feeder link handover on the base station side and the identity information of the terminal that needs to perform feeder link handover.

[0251] In this implementation, the AMF unit serves only as the target AMF unit for power supply link switching and also receives a terminal context creation request sent by the source AMF unit. For details of the implementation process, please refer to [link to implementation details]. Figure 3 Steps S302 to S305 in the implementation method will not be described in detail here.

[0252] In another embodiment of this application, optionally, after receiving the PDU session update response message sent by the SMF unit, the method further includes:

[0253] A Create Terminal Context Response message is sent to the source AMF unit of the link before the handover, causing the source AMF unit to send a path handover acceptance message to the base station. The Create Terminal Context Response message includes the uplink tunnel address used by the terminal in the target UPF unit, and the path handover acceptance message includes the user plane uplink tunnel address of the terminal in the target user plane management function UPF unit of the link after the handover and the terminal's identity information. The Create Terminal Context Response message includes the user plane uplink tunnel address used by the terminal in the target UPF unit.

[0254] Specifically, the implementation process can be found in [reference needed]. Figure 3 Step S315 shown will not be described in detail here.

[0255] Another aspect of this application embodiment also provides a base station, such as Figure 7 As shown, it includes a memory 720, a transceiver 700, and a processor 710:

[0256] The memory 720 is used to store computer programs; the transceiver 700 is used to send and receive data under the control of the processor 710; the processor 710 is used to read the computer program in the memory 720 and perform the following operations:

[0257] Send a path switching request message to the core network; the path switching request message includes the identity information of the terminal that needs to switch the power supply link, and the user plane downlink tunnel address of the terminal on the base station side;

[0258] Receive a path switching acceptance message sent by the core network; the path switching acceptance message includes the identity information of the terminal in the target user plane management function UPF unit after the link switching, and the user plane uplink tunnel address used by the terminal in the target UPF unit;

[0259] Specifically, the base station sends the uplink data of the terminal to the target UPF unit using the user plane uplink tunnel address used by the terminal within the target UPF unit.

[0260] Optionally, the core network sends the path switching acceptance message after allocating the uplink tunnel address and downlink tunnel address of the terminal to the target UPF unit after the link switching, and establishing a session for the feeder link after the switching, based on the path switching request message.

[0261] Optionally, in the base station, the path switching request message includes at least one first list information, each first list information recording the identity information of a terminal and the user plane downlink tunnel address used by the terminal in the corresponding base station;

[0262] The path switching acceptance message includes at least one second list information, and each second list information records the identity information of a terminal and the user plane uplink tunnel address used by the terminal in the corresponding target UPF unit.

[0263] Optionally, in the base station, the identity information of the terminal includes at least one of the following:

[0264] The identity identifier used by the terminal within the base station;

[0265] The terminal uses an identity identifier within the core network.

[0266] Optionally, in the base station, the processor 710 is further configured to:

[0267] During the power supply link handover process, the uplink data transmitted by the terminal to the core network is cached; and

[0268] After receiving the path switching acceptance message sent by the core network, the processor 710 is further configured to:

[0269] Based on the user plane uplink tunnel address used by the terminal within the target UPF unit, the cached uplink data is sent to the target UPF unit; and / or

[0270] The system receives downlink data cached during the power supply link switching process from the target UPF unit and sends the downlink data to the terminal.

[0271] Optionally, in the base station, the processor 710 is further configured to:

[0272] Determine whether a power supply link switch is required based on at least one of the current satellite position, gateway station position, and ephemeris information.

[0273] When it is determined that a power supply link switch is required, a power supply link switch request is sent to the core network;

[0274] Specifically, after receiving the feeder link switching acceptance message sent by the core network in accordance with the feeder link switching request, a path switching request message is sent to the core network.

[0275] Among them, Figure 7In this context, the bus architecture can include any number of interconnected buses and bridges, specifically linking various circuits together, represented by one or more processors (processor 710) and memory (memory 720). The bus architecture can also link various other circuits such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art and therefore will not be described further herein. The bus interface provides an interface. The transceiver 700 can be multiple elements, including transmitters and receivers, providing units for communicating with various other devices over transmission media, including wireless channels, wired channels, optical fibers, etc. The processor 710 is responsible for managing the bus architecture and general processing, and the memory 720 can store data used by the processor 710 during operation.

[0276] The processor 710 can be a central processing unit (CPU), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or a complex programmable logic device (CPLD). The processor can also adopt a multi-core architecture.

[0277] Another embodiment of this application provides a network device, wherein the network device is a Session Management Function (SMF) unit of the core network, including a memory 820, a transceiver 800, and a processor 810: the memory 820 is used to store computer programs; the transceiver 800 is used to send and receive data under the control of the processor; the processor 810 is used to read the computer program in the memory and perform the following operations:

[0278] The PDU session update context request sent by the target access and mobility management function (AMF) unit of the feeder link after the handover is obtained; wherein, the PDU session update context request includes the user plane downlink tunnel address used by the terminal performing the feeder link handover within the base station;

[0279] Determine the target UPF unit of the feeder link after the switchover, and allocate the uplink tunnel address and downlink tunnel address of the terminal in the target UPF unit and the N9 interface.

[0280] After the target UPF unit establishes a session for the post-switching power supply link, the SMF unit sends a PDU session update response message to the target AMF unit; the PDU session update response message includes the uplink tunnel address used by the terminal within the target UPF unit.

[0281] Optionally, in the network device, after allocating the uplink tunnel address and the downlink tunnel address of the N9 interface for the terminal within the target UPF unit, the processor 810 is further configured to:

[0282] Send a session modification request to the anchor UPF unit; the session modification request includes the downlink tunnel address of the N9 interface in the target UPF unit;

[0283] Receive a session modification response message sent by the anchor point UPF unit in accordance with the session modification request; the session modification response message includes the uplink tunnel address allocated to the terminal within the anchor point UPF unit;

[0284] Specifically, the target UPF unit sends uplink data to the anchor UPF unit through the uplink tunnel address allocated to the terminal within the anchor UPF unit; and the anchor UPF unit sends downlink data to the target UPF unit through the downlink tunnel address of the N9 interface within the target UPF unit.

[0285] Optionally, in the network device, after allocating the uplink tunnel address and the downlink tunnel address of the N9 interface for the terminal within the target UPF unit, the processor 810 is further configured to:

[0286] Send a session establishment request message to the target UPF unit; the session establishment request message includes the user plane downlink tunnel address of the terminal on the base station side, the uplink tunnel address used by the terminal in the target UPF unit, and the uplink tunnel address used by the terminal in the anchor UPF unit;

[0287] After receiving the session establishment response message sent by the target UPF unit in accordance with the session establishment request message, it is determined that the target UPF unit has established a session for the feeder link after the handover.

[0288] Optionally, in the network device, the processor 810 is further configured to:

[0289] After the target UPF unit establishes a session for the feeder link after the handover, a session change request message is sent to the source UPF unit of the feeder link before the handover; the session change request message includes the forwarding tunnel address of the target UPF unit;

[0290] The source UPF unit forwards the downlink data before the handover to the target UPF unit according to the forwarding tunnel address.

[0291] Optionally, in the network device, the processor 810 is further configured to:

[0292] Obtain the PDU session release context request sent by the source AMF unit of the feeder link before the handover, after learning that the link handover was successful;

[0293] Based on the PDU session release context request, a session release request corresponding to each terminal is sent to the source UPF unit of the feeder link before handover, in order to release the resources on the source side before handover.

[0294] Obtain the session release response message sent by the source UPF unit after releasing the resource.

[0295] Among them, Figure 8 In this context, the bus architecture can include any number of interconnected buses and bridges, specifically linking various circuits together, represented by one or more processors (processor 810) and memory (memory 820). The bus architecture can also link various other circuits such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art and therefore will not be described further herein. The bus interface provides an interface. The transceiver 800 can be multiple elements, including transmitters and receivers, providing units for communicating with various other devices over transmission media, including wireless channels, wired channels, optical fibers, etc. The processor 810 is responsible for managing the bus architecture and general processing, and the memory 820 can store data used by the processor 810 during operation.

[0296] The processor 810 can be a central processing unit (CPU), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or a complex programmable logic device (CPLD). The processor can also adopt a multi-core architecture.

[0297] This application also provides a network device, which is an Access and Mobility Management Function (AMF) unit in the core network, such as... Figure 9 As shown, it includes a memory 920, a transceiver 900, and a processor 910:

[0298] The memory 920 is used to store computer programs; the transceiver 900 is used to send and receive data under the control of the processor; the processor 910 is used to read the computer programs in the memory and perform the following operations:

[0299] Send a PDU session update context request to the session management function (SMF) unit; wherein, the PDU session update context request includes the user plane downlink tunnel address used by the terminal within the base station;

[0300] Receive the PDU session update response message sent by the SMF unit;

[0301] The PDU session update response message includes the uplink tunnel address used by the terminal in the target UPF unit of the feeder link after the handover, which is used by the base station to send the uplink data of the terminal to the target UPF unit.

[0302] Optionally, the SMF unit determines the target User Plane Management Function (UPF) unit for the post-switching feeder link, allocates the uplink tunnel address and the downlink tunnel address of the N9 interface to the terminal within the target UPF unit, and after establishing a session for the post-switching feeder link in the target UPF unit, sends the PDU session update response message to the target AMF unit; the PDU session update response message includes the uplink tunnel address used by the terminal within the target UPF unit.

[0303] Optionally, in the network device, the processor 910 is further configured to:

[0304] Obtain the power supply link switching request sent by the base station;

[0305] According to the power supply link handover request, a power supply link handover acceptance message is sent to the base station; the power supply link handover acceptance message includes the failure time of the link before handover and the effective time of the link after handover.

[0306] Optionally, in the network device, the processor 910 is further configured to:

[0307] The system receives a path switching request message sent by the base station after it has received the power supply link switching acceptance message; the path switching request message includes the identity information of the terminal that needs to perform power supply link switching, and the user plane downlink tunnel address of the terminal on the base station side.

[0308] Specifically, based on the path switching request message, the AMF unit sends the PDU session update context request to the SMF unit.

[0309] Optionally, in the network device, after receiving the PDU session update response message sent by the SMF unit, the processor 910 is further configured to:

[0310] Send a path handover acceptance message to the base station; the path handover acceptance message includes the identity information of the terminal in the target user plane management function UPF unit after the link handover, and the user plane uplink tunnel address used by the terminal in the target user plane management function UPF.

[0311] Optionally, in the network device, before sending a Protocol Data Unit (PDU) session update context request to the Session Management Function (SMF) unit, the processor 910 is further configured to:

[0312] The system receives a terminal context creation request sent by the source AMF unit of the pre-handover link of the base station; the terminal context creation request includes the user plane downlink tunnel address of the terminal on the base station side.

[0313] Specifically, the source AMF unit acquires the feeder link handover request sent by the base station, sends a feeder link handover acceptance message to the base station based on the feeder link handover request, and after receiving the path handover request message sent by the base station after acquiring the feeder link handover acceptance message, sends the create terminal context request to the target AMF unit; the path handover request message includes the user plane downlink tunnel address of the terminal that needs to perform feeder link handover on the base station side and the identity information of the terminal that needs to perform feeder link handover.

[0314] Optionally, in the network device, after receiving the PDU session update response message sent by the SMF unit, the processor 910 is further configured to:

[0315] A Create Terminal Context Response message is sent to the source AMF unit of the link before the handover, causing the source AMF unit to send a path handover acceptance message to the base station. The Create Terminal Context Response message includes the uplink tunnel address used by the terminal in the target UPF unit, and the path handover acceptance message includes the user plane uplink tunnel address of the terminal in the target user plane management function UPF unit of the link after the handover and the terminal's identity information. The Create Terminal Context Response message includes the user plane uplink tunnel address used by the terminal in the target UPF unit.

[0316] Among them, Figure 9In this context, the bus architecture can include any number of interconnected buses and bridges, specifically linking various circuits together, represented by one or more processors (processor 910) and memory (memory 920). The bus architecture can also link various other circuits such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art and therefore will not be described further herein. The bus interface provides an interface. The transceiver 900 can be multiple elements, including transmitters and receivers, providing units for communicating with various other devices over transmission media, including wireless channels, wired channels, optical fibers, etc. The processor 910 is responsible for managing the bus architecture and general processing, and the memory 920 can store data used by the processor 910 during operation.

[0317] The processor 810 can be a central processing unit (CPU), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or a complex programmable logic device (CPLD). The processor can also adopt a multi-core architecture.

[0318] Another embodiment of this application also provides a power supply link switching device, which is executed by a base station, such as... Figure 10 As shown, the device includes:

[0319] The first message sending unit 1010 is used to send a path switching request message to the core network when performing a power supply link switch; the path switching request message includes the identity information of the terminal that needs to perform the power supply link switch, and the user plane downlink tunnel address of the terminal on the base station side.

[0320] The first message receiving unit 1020 is used to receive a path switching acceptance message sent by the core network; the path switching acceptance message includes the identity information of the terminal in the target user plane management function UPF unit after the link switching, and the user plane uplink tunnel address used by the terminal in the target UPF unit.

[0321] Specifically, the base station sends the uplink data of the terminal to the target UPF unit using the user plane uplink tunnel address used by the terminal within the target UPF unit.

[0322] Optionally, the core network sends the path switching acceptance message after allocating the uplink tunnel address and downlink tunnel address of the terminal to the target UPF unit after the link switching, and establishing a session for the feeder link after the switching, based on the path switching request message.

[0323] Optionally, in the power supply link switching device, the path switching request message includes at least one first list information, each first list information recording the identity information of a terminal and the user plane downlink tunnel address used by the terminal in the corresponding base station;

[0324] The path switching acceptance message includes at least one second list information, and each second list information records the identity information of a terminal and the user plane uplink tunnel address used by the terminal in the corresponding target UPF unit.

[0325] Optionally, in the power supply link switching device, the identity information of the terminal includes at least one of the following:

[0326] The identity identifier used by the terminal within the base station;

[0327] The terminal uses an identity identifier within the core network.

[0328] Optionally, the power supply link switching device further includes:

[0329] A buffer unit is used to buffer uplink data transmitted by the terminal to the core network during power supply link switching; and

[0330] The device further includes a data transmission unit, which, after the first message receiving unit 1020 receives the path switching acceptance message sent by the core network, is used to:

[0331] Based on the user plane uplink tunnel address used by the terminal within the target UPF unit, the cached uplink data is sent to the target UPF unit; and / or

[0332] The system receives downlink data cached during the power supply link switching process from the target UPF unit and sends the downlink data to the terminal.

[0333] Optionally, the power supply link switching device further includes:

[0334] The switching judgment unit is used to determine whether a power supply link switching is required based on at least one of the current satellite position, gateway station position, and ephemeris information;

[0335] When it is determined that a power supply link switch is required, a power supply link switch request is sent to the core network;

[0336] Specifically, after receiving the feeder link switching acceptance message sent by the core network in accordance with the feeder link switching request, a path switching request message is sent to the core network.

[0337] This application also provides a power supply link switching device, executed by the Session Management Function (SMF) unit of the core network, such as... Figure 11 As shown, the device includes:

[0338] The request acquisition unit 1110 is used to acquire the PDU session update context request sent by the target access and mobility management function (AMF) unit of the feeder link after handover; wherein, the PDU session update context request includes the user plane downlink tunnel address used by the terminal performing the feeder link handover within the base station;

[0339] The determining unit 1120 is used to determine the target user plane management function (UPF) unit of the feeder link after the handover, and to allocate the uplink tunnel address and the downlink tunnel address of the N9 interface of the terminal in the target UPF unit.

[0340] The second message sending unit 1130 is used to send a PDU session update response message to the target AMF unit after the target UPF unit has established a session for the post-switching power supply link; the PDU session update response message includes the uplink tunnel address used by the terminal in the target UPF unit.

[0341] Optionally, in the power supply link switching device, after the determining unit 1120 allocates the uplink tunnel address and the downlink tunnel address of the terminal in the target UPF unit and the N9 interface, the second message sending unit 1130 is further configured to:

[0342] Send a session modification request to the anchor UPF unit; the session modification request includes the downlink tunnel address of the N9 interface in the target UPF unit;

[0343] The request acquisition unit 1110 is further configured to receive a session modification response message sent by the anchor point UPF unit according to the session modification request; the session modification response message includes the uplink tunnel address allocated to the terminal within the anchor point UPF unit;

[0344] Specifically, the target UPF unit sends uplink data to the anchor UPF unit through the uplink tunnel address allocated to the terminal within the anchor UPF unit; and the anchor UPF unit sends downlink data to the target UPF unit through the downlink tunnel address of the N9 interface within the target UPF unit.

[0345] Optionally, in the power supply link switching device, after allocating the uplink tunnel address and the downlink tunnel address of the N9 interface for the terminal in the target UPF unit, the second message sending unit 1130 is further configured to:

[0346] Send a session establishment request message to the target UPF unit; the session establishment request message includes the user plane downlink tunnel address of the terminal on the base station side, the uplink tunnel address used by the terminal in the target UPF unit, and the uplink tunnel address used by the terminal in the anchor UPF unit;

[0347] After receiving the session establishment response message sent by the target UPF unit in accordance with the session establishment request message, it is determined that the target UPF unit has established a session for the feeder link after the handover.

[0348] Optionally, in the power supply link switching device, the second message sending unit 1130 is further configured to:

[0349] After the target UPF unit establishes a session for the feeder link after the handover, a session change request message is sent to the source UPF unit of the feeder link before the handover; the session change request message includes the forwarding tunnel address of the target UPF unit;

[0350] The source UPF unit forwards the downlink data before the handover to the target UPF unit according to the forwarding tunnel address.

[0351] Optionally, in the power supply link switching device:

[0352] The request acquisition unit 1110 is also used to acquire the PDU session release context request sent by the source AMF unit of the feeder link before the handover after it learns that the link handover is successful.

[0353] The second message sending unit 1130 is further configured to send a session release request corresponding to each terminal to the source UPF unit of the feedforward link before handover, based on the PDU session release context request, for releasing the resources on the source side before handover.

[0354] The request acquisition unit 1110 is further configured to acquire the session release response message sent by the source UPF unit after releasing the resource.

[0355] This application also provides a power supply link switching device, wherein the switching is performed by the Access and Mobility Management Function (AMF) unit of the core network, such as... Figure 12 As shown, the device includes:

[0356] The request sending unit 1210 is used to send a PDU session update context request to the session management function (SMF) unit; wherein, the PDU session update context request includes the user plane downlink tunnel address used by the terminal in the base station;

[0357] The second message receiving unit 1220 is used to receive the PDU session update response message sent by the SMF unit;

[0358] The PDU session update response message includes the uplink tunnel address used by the terminal in the target UPF unit of the feeder link after the handover, which is used by the base station to send the uplink data of the terminal to the target UPF unit.

[0359] Optionally, the SMF unit determines the target User Plane Management Function (UPF) unit for the post-switching feeder link, allocates the uplink tunnel address and the downlink tunnel address of the N9 interface to the terminal within the target UPF unit, and after establishing a session for the post-switching feeder link in the target UPF unit, sends the PDU session update response message to the target AMF unit; the PDU session update response message includes the uplink tunnel address used by the terminal within the target UPF unit.

[0360] Optionally, in the power supply link switching device:

[0361] The second message receiving unit 1220 is further configured to acquire the power supply link switching request sent by the base station;

[0362] The request sending unit 1210 is further configured to send a power supply link handover acceptance message to the base station according to the power supply link handover request; the power supply link handover acceptance message includes the failure time of the link before handover and the effective time of the link after handover.

[0363] Optionally, in the aforementioned power supply link switching device, the second message receiving unit 1220 is further configured to:

[0364] The system receives a path switching request message sent by the base station after it has received the power supply link switching acceptance message; the path switching request message includes the identity information of the terminal that needs to perform power supply link switching, and the user plane downlink tunnel address of the terminal on the base station side.

[0365] Specifically, based on the path switching request message, the AMF unit sends the PDU session update context request to the SMF unit.

[0366] Optionally, in the power supply link switching device, after the second message receiving unit 1220 receives the PDU session update response message sent by the SMF unit, the request sending unit 1210 is further configured to:

[0367] Send a path handover acceptance message to the base station; the path handover acceptance message includes the identity information of the terminal in the target user plane management function UPF unit after the link handover, and the user plane uplink tunnel address used by the terminal in the target user plane management function UPF.

[0368] Optionally, in the power supply link switching device, before the request sending unit 1210 sends a PDU session update context request to the SMF unit, the second message receiving unit 1220 is further configured to:

[0369] The system receives a terminal context creation request sent by the source AMF unit of the pre-handover link of the base station; the terminal context creation request includes the user plane downlink tunnel address of the terminal on the base station side.

[0370] Specifically, the source AMF unit acquires the feeder link handover request sent by the base station, sends a feeder link handover acceptance message to the base station based on the feeder link handover request, and after receiving the path handover request message sent by the base station after acquiring the feeder link handover acceptance message, sends the create terminal context request to the target AMF unit; the path handover request message includes the user plane downlink tunnel address of the terminal that needs to perform feeder link handover on the base station side and the identity information of the terminal that needs to perform feeder link handover.

[0371] Optionally, in the aforementioned power supply link switching device, after the second message receiving unit 1220 receives the PDU session update response message sent by the SMF unit, the request sending unit 1210 is further configured to:

[0372] A Create Terminal Context Response message is sent to the source AMF unit of the link before the handover, causing the source AMF unit to send a path handover acceptance message to the base station; the Create Terminal Context Response message includes the uplink tunnel address used by the terminal in the target UPF unit, and the path handover acceptance message includes the user plane uplink tunnel address of the terminal in the target UPF unit of the link after the handover and the terminal's identity information; the Create Terminal Context Response message includes the user plane uplink tunnel address used by the terminal in the target UPF unit.

[0373] It should be noted that the apparatus provided in this application embodiment can implement all the method steps implemented in the above method embodiment and can achieve the same technical effect. Here, the parts that are the same as those in the method embodiment and the beneficial effects will not be described in detail.

[0374] It should be noted that the division of units in the embodiments of this application is illustrative and only represents one logical functional division. In actual implementation, other division methods may be used. Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated units described above can be implemented in hardware or as software functional units.

[0375] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a processor-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) or processor to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0376] This application also provides a processor-readable storage medium storing a computer program for causing the processor to perform the steps of the power supply link switching method described in any of the preceding claims.

[0377] It should be noted that the processor-readable storage medium can be any available medium or data storage device that the processor can access, including but not limited to magnetic memory (e.g., floppy disk, hard disk, magnetic tape, magneto-optical disk (MO)), optical memory (e.g., CD, DVD, BD, HVD), and semiconductor memory (e.g., ROM, EPROM, EEPROM, non-volatile memory (NAND FLASH), solid-state drive (SSD)).

[0378] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product implemented on one or more computer-usable storage media (including, but not limited to, disk storage and optical storage) containing computer-usable program code.

[0379] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer-executable instructions. These computer-executable instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0380] These processor-executable instructions may also be stored in a processor-readable memory that can direct a computer or other programmable data processing device to operate in a particular manner, such that the instructions stored in the processor-readable memory produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0381] These processors can execute instructions that can also be loaded onto a computer or other programmable data processing device, causing a series of operational steps to be performed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable device for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0382] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A feeder link handover method for a satellite communication system employing a space-borne base station, characterized by, Performed by the base station, the method includes: The base station sends a path switching request message to the core network; the path switching request message includes the identity information of the terminal that needs to switch the power supply link, and the user plane downlink tunnel address of the terminal on the base station side; The base station receives a path handover acceptance message sent by the core network; the path handover acceptance message includes the identity information of the terminal in the target user plane management function (UPF) unit after the link handover, and the user plane uplink tunnel address used by the terminal in the target UPF unit; wherein, through the user plane uplink tunnel address used by the terminal in the target UPF unit, the base station sends the uplink data of the terminal to the target UPF unit.

2. The power supply link switching method according to claim 1, characterized in that, The path switching request message includes at least one first list information, each first list information recording the identity information of a terminal and the user plane downlink tunnel address used by the terminal in the corresponding base station; The path switching acceptance message includes at least one second list information, and each second list information records the identity information of a terminal and the user plane uplink tunnel address used by the terminal in the corresponding target UPF unit.

3. The power supply link switching method according to claim 1, characterized in that, The identity information of the terminal includes at least one of the following: The identity identifier used by the terminal within the base station; The terminal uses an identity identifier within the core network.

4. The power supply link switching method according to claim 1, characterized in that, After the base station receives the path handover acceptance message from the core network, the method further includes: The base station buffers the uplink data transmitted by the terminal. Based on the user plane uplink tunnel address used by the terminal within the target UPF unit, the cached uplink data is sent to the target UPF unit; and / or, the downlink data cached during the power supply link switching process sent by the target UPF unit is received and sent to the terminal.

5. The power supply link switching method according to claim 1, characterized in that, The method further includes: Determine whether a power supply link switch is required based on at least one of the current satellite position, gateway station position, and ephemeris information. When it is determined that a power supply link switch is required, a power supply link switch request is sent to the core network; Specifically, after receiving the feeder link switching acceptance message sent by the core network in accordance with the feeder link switching request, a path switching request message is sent to the core network.

6. A power supply link switching method for a satellite communication system employing a spaceborne base station, characterized in that, Performed by the Session Management Function (SMF) unit of the core network, the method includes: The SMF unit obtains the PDU session update context request sent by the target access and mobility management function AMF unit of the feeder link after the handover; wherein, the PDU session update context request includes the user plane downlink tunnel address used by the terminal performing the feeder link handover within the base station; The SMF unit determines the target user plane management function UPF unit of the feeder link after the handover, and allocates the uplink tunnel address and the downlink tunnel address of the N9 interface to the terminal in the target UPF unit. After the target UPF unit establishes a session for the post-switching power supply link, the SMF unit sends a PDU session update response message to the target AMF unit; the PDU session update response message includes the uplink tunnel address used by the terminal within the target UPF unit.

7. The power supply link switching method according to claim 6, characterized in that, After allocating the uplink tunnel address and the downlink tunnel address of the N9 interface for the terminal within the target UPF unit, the method further includes: The SMF unit sends a session modification request to the anchor UPF unit; the session modification request includes the downlink tunnel address of the N9 interface in the target UPF unit; The SMF unit receives a session modification response message sent by the anchor UPF unit in accordance with the session modification request; the session modification response message includes the uplink tunnel address allocated to the terminal within the anchor UPF unit; Specifically, the target UPF unit sends uplink data to the anchor UPF unit through the uplink tunnel address allocated to the terminal within the anchor UPF unit; and the anchor UPF unit sends downlink data to the target UPF unit through the downlink tunnel address of the N9 interface within the target UPF unit.

8. The power supply link switching method according to claim 7, characterized in that, After allocating the uplink tunnel address and the downlink tunnel address of the N9 interface for the terminal within the target UPF unit, the method further includes: Send a session establishment request message to the target UPF unit; the session establishment request message includes the user plane downlink tunnel address of the terminal on the base station side, the uplink tunnel address used by the terminal in the target UPF unit, and the uplink tunnel address used by the terminal in the anchor UPF unit; After receiving the session establishment response message sent by the target UPF unit in accordance with the session establishment request message, it is determined that the target UPF unit has established a session for the feeder link after the handover.

9. The power supply link switching method according to claim 6, characterized in that, The method further includes: After the target UPF unit establishes a session for the feeder link after the handover, a session change request message is sent to the source UPF unit of the feeder link before the handover; the session change request message includes the forwarding tunnel address of the target UPF unit; The source UPF unit forwards the downlink data before the handover to the target UPF unit according to the forwarding tunnel address.

10. The power supply link switching method according to claim 6, characterized in that, The method further includes: Obtain the PDU session release context request sent by the source AMF unit of the feeder link before the handover, after learning that the link handover was successful; Based on the PDU session release context request, a session release request corresponding to each terminal is sent to the source UPF unit of the feeder link before handover, in order to release the resources on the source side before handover. Obtain the session release response message sent by the source UPF unit after releasing the resource.

11. A power supply link switching method for a satellite communication system employing an onboard base station, characterized in that, Performed by the Access and Mobility Management Function (AMF) unit of the core network, the method includes: The AMF unit sends a PDU session update context request to the session management function SMF unit; wherein, the PDU session update context request includes the user plane downlink tunnel address used by the terminal within the base station; The AMF unit receives the PDU session update response message sent by the SMF unit; The PDU session update response message includes the uplink tunnel address used by the terminal in the target UPF unit of the feeder link after the handover, which is used by the base station to send the uplink data of the terminal to the target UPF unit.

12. The power supply link switching method according to claim 11, characterized in that, The method further includes: Obtain the power supply link switching request sent by the base station; According to the power supply link handover request, a power supply link handover acceptance message is sent to the base station; the power supply link handover acceptance message includes the failure time of the link before handover and the effective time of the link after handover.

13. The power supply link switching method according to claim 12, characterized in that, The method further includes: The system receives a path switching request message sent by the base station after it has received the power supply link switching acceptance message; the path switching request message includes the identity information of the terminal that needs to perform power supply link switching, and the user plane downlink tunnel address of the terminal on the base station side. Specifically, based on the path switching request message, the AMF unit sends the PDU session update context request to the SMF unit.

14. The power supply link switching method according to claim 13, characterized in that, After receiving the PDU session update response message sent by the SMF unit, the method further includes: Send a path handover acceptance message to the base station; the path handover acceptance message includes the identity information of the terminal in the target user plane management function UPF unit after the link handover, and the user plane uplink tunnel address used by the terminal in the target UPF unit.

15. The power supply link switching method according to claim 11, characterized in that, Before sending a PDU session update context request to the Session Management Function (SMF) unit, the method further includes: The system receives a terminal context creation request sent by the source AMF unit of the pre-handover link of the base station; the terminal context creation request includes the user plane downlink tunnel address of the terminal on the base station side. Specifically, the source AMF unit acquires the feeder link handover request sent by the base station, sends a feeder link handover acceptance message to the base station based on the feeder link handover request, and after receiving the path handover request message sent by the base station after acquiring the feeder link handover acceptance message, sends the create terminal context request to the target AMF unit; the path handover request message includes the user plane downlink tunnel address of the terminal that needs to perform feeder link handover on the base station side and the identity information of the terminal that needs to perform feeder link handover.

16. The power supply link switching method according to claim 15, characterized in that, After receiving the PDU session update response message sent by the SMF unit, the method further includes: A Create Terminal Context Response message is sent to the source AMF unit of the link before the handover, causing the source AMF unit to send a path handover acceptance message to the base station; the Create Terminal Context Response message includes the uplink tunnel address used by the terminal in the target UPF unit, and the path handover acceptance message includes the user plane uplink tunnel address of the terminal in the target UPF unit of the link after the handover and the terminal's identity information; the Create Terminal Context Response message includes the user plane uplink tunnel address used by the terminal in the target UPF unit.

17. A base station for a satellite communication system employing a spaceborne base station, characterized in that, Includes memory, transceiver, and processor: A memory for storing computer programs; a transceiver for sending and receiving data under the control of the processor; and a processor for reading the computer programs from the memory and performing the following operations: Send a path switching request message to the core network; the path switching request message includes the identity information of the terminal that needs to switch the power supply link, and the user plane downlink tunnel address of the terminal on the base station side; Receive a path switching acceptance message sent by the core network; the path switching acceptance message includes the identity information of the terminal in the target user plane management function UPF unit after the link switching, and the user plane uplink tunnel address used by the terminal in the target UPF unit; Specifically, the base station sends the uplink data of the terminal to the target UPF unit using the user plane uplink tunnel address used by the terminal within the target UPF unit.

18. The base station according to claim 17, characterized in that, The path switching request message includes at least one first list information, each first list information recording the identity information of a terminal and the user plane downlink tunnel address used by the terminal in the corresponding base station; The path switching acceptance message includes at least one second list information, and each second list information records the identity information of a terminal and the user plane uplink tunnel address used by the terminal in the corresponding target UPF unit.

19. The base station according to claim 17, characterized in that, The identity information of the terminal includes at least one of the following: The identity identifier used by the terminal within the base station; The terminal uses an identity identifier within the core network.

20. The base station according to claim 17, characterized in that, After receiving the path handover acceptance message from the core network, the processor is further configured to: Cache the uplink data transmitted from the terminal to the core network; Based on the user plane uplink tunnel address used by the terminal within the target UPF unit, the cached uplink data is sent to the target UPF unit; and / or, the downlink data cached during the power supply link switching process sent by the target UPF unit is received and sent to the terminal.

21. The base station according to claim 17, characterized in that, The processor is also used for: Determine whether a power supply link switch is required based on at least one of the current satellite position, gateway station position, and ephemeris information. When it is determined that a power supply link switch is required, a power supply link switch request is sent to the core network; Specifically, after receiving the feeder link switching acceptance message sent by the core network in accordance with the feeder link switching request, a path switching request message is sent to the core network.

22. A network device for a satellite communication system employing a satellite-borne base station, characterized in that, The network device is the Session Management Function (SMF) unit of the core network, including a memory, a transceiver, and a processor: the memory is used to store computer programs; Transceiver, used to send and receive data under the control of the processor; Processor, configured to read the computer program in the memory and perform the following operations: The PDU session update context request sent by the target access and mobility management function (AMF) unit of the feeder link after the handover is obtained; wherein, the PDU session update context request includes the user plane downlink tunnel address used by the terminal performing the feeder link handover within the base station; The target user plane management function (UPF) unit of the feeder link after the handover is determined, and the uplink tunnel address and downlink tunnel address of the terminal in the target UPF unit are allocated. After the target UPF unit establishes a session for the post-switching power supply link, the SMF unit sends a PDU session update response message to the target AMF unit; the PDU session update response message includes the uplink tunnel address used by the terminal within the target UPF unit.

23. The network device according to claim 22, characterized in that, After allocating the uplink tunnel address and the downlink tunnel address of the N9 interface within the target UPF unit for the terminal, the processor is further configured to: Send a session modification request to the anchor UPF unit; the session modification request includes the downlink tunnel address of the N9 interface in the target UPF unit; Receive a session modification response message sent by the anchor point UPF unit in accordance with the session modification request; the session modification response message includes the uplink tunnel address allocated to the terminal within the anchor point UPF unit; Specifically, the target UPF unit sends uplink data to the anchor UPF unit through the uplink tunnel address allocated to the terminal within the anchor UPF unit; The anchor UPF unit sends downlink data to the target UPF unit via the downlink tunnel address of the N9 interface within the target UPF unit.

24. The network device according to claim 23, characterized in that, After allocating the uplink tunnel address and the downlink tunnel address of the N9 interface within the target UPF unit for the terminal, the processor is further configured to: Send a session establishment request message to the target UPF unit; the session establishment request message includes the user plane downlink tunnel address of the terminal on the base station side, the uplink tunnel address used by the terminal in the target UPF unit, and the uplink tunnel address used by the terminal in the anchor UPF unit; After receiving the session establishment response message from the target UPF unit in accordance with the session establishment request message, it is determined that the target UPF unit has established a session for the feeder link after the handover.

25. The network device according to claim 22, characterized in that, The processor is also used for: After the target UPF unit establishes a session for the feeder link after the handover, a session change request message is sent to the source UPF unit of the feeder link before the handover; the session change request message includes the forwarding tunnel address of the target UPF unit; The source UPF unit forwards the downlink data before the handover to the target UPF unit according to the forwarding tunnel address.

26. The network device according to claim 22, characterized in that, The processor is also used for: Obtain the PDU session release context request sent by the source AMF unit of the feeder link before the handover, after learning that the link handover was successful; Based on the PDU session release context request, a session release request corresponding to each terminal is sent to the source UPF unit of the feeder link before handover, in order to release the resources on the source side before handover. Obtain the session release response message sent by the source UPF unit after releasing the resource.

27. A network device for a satellite communication system employing a spaceborne base station, characterized in that, The network device is the Access and Mobility Management Function (AMF) unit of the core network, including a memory, transceiver, and processor. The memory is used to store computer programs; the transceiver is used to send and receive data under the control of the processor. Processor, configured to read the computer program in the memory and perform the following operations: Send a PDU session update context request to the Session Management Function (SMF) unit; wherein, the PDU session update context request includes the user plane downlink tunnel address used by the terminal within the base station; Receive the PDU session update response message sent by the SMF unit; The PDU session update response message includes the uplink tunnel address used by the terminal within the target UPF unit of the feeder link after the handover. The base station is used to send the uplink data of the terminal to the target UPF unit.

28. The network device according to claim 27, characterized in that, The processor is also used for: Obtain the power supply link switching request sent by the base station; According to the power supply link handover request, a power supply link handover acceptance message is sent to the base station; the power supply link handover acceptance message includes the failure time of the link before handover and the effective time of the link after handover.

29. The network device according to claim 28, characterized in that, The processor is also used for: The system receives a path switching request message sent by the base station after it has received the power supply link switching acceptance message; the path switching request message includes the identity information of the terminal that needs to perform power supply link switching, and the user plane downlink tunnel address of the terminal on the base station side. Specifically, based on the path switching request message, the AMF unit sends the PDU session update context request to the SMF unit.

30. The network device according to claim 29, characterized in that, After receiving the PDU session update response message sent by the SMF unit, the processor is further configured to: Send a path handover acceptance message to the base station; the path handover acceptance message includes the identity information of the terminal in the target user plane management function UPF unit after the link handover, and the user plane uplink tunnel address used by the terminal in the target UPF unit.

31. The network device according to claim 27, characterized in that, Before sending a PDU session update context request to the Session Management Function (SMF) unit, the processor is also configured to: The system receives a terminal context creation request sent by the source AMF unit of the pre-handover link of the base station; the terminal context creation request includes the user plane downlink tunnel address of the terminal on the base station side. Specifically, the source AMF unit acquires the feeder link handover request sent by the base station, sends a feeder link handover acceptance message to the base station based on the feeder link handover request, and after receiving the path handover request message sent by the base station after acquiring the feeder link handover acceptance message, sends the create terminal context request to the target AMF unit; the path handover request message includes the user plane downlink tunnel address of the terminal that needs to perform feeder link handover on the base station side and the identity information of the terminal that needs to perform feeder link handover.

32. The network device according to claim 31, characterized in that, After receiving the PDU session update response message sent by the SMF unit, the processor is further configured to: A Create Terminal Context Response message is sent to the source AMF unit of the link before the handover, causing the source AMF unit to send a path handover acceptance message to the base station; the Create Terminal Context Response message includes the uplink tunnel address used by the terminal in the target UPF unit, and the path handover acceptance message includes the user plane uplink tunnel address of the terminal in the target UPF unit of the link after the handover and the terminal's identity information; the Create Terminal Context Response message includes the user plane uplink tunnel address used by the terminal in the target UPF unit.

33. A power supply link switching device for a satellite communication system employing a spaceborne base station, characterized in that, The device is used in a base station, and the device includes: The first message sending unit is used to send a path switching request message to the core network; the path switching request message includes the identity information of the terminal that needs to switch the power supply link, and the user plane downlink tunnel address of the terminal on the base station side; The first message receiving unit is used to receive a path switching acceptance message sent by the core network; the path switching acceptance message includes the identity information of the terminal in the target user plane management function UPF unit after the link switching, and the user plane uplink tunnel address used by the terminal in the target UPF unit. Specifically, the base station sends the uplink data of the terminal to the target UPF unit using the user plane uplink tunnel address used by the terminal within the target UPF unit.

34. A power supply link switching device for a satellite communication system employing a spaceborne base station, characterized in that, The device is applied to the Session Management Function (SMF) unit of the core network, and the device includes: The request acquisition unit is used to acquire the PDU session update context request sent by the target access and mobility management function (AMF) unit of the feeder link after handover; wherein, the PDU session update context request includes the user plane downlink tunnel address used by the terminal performing the feeder link handover within the base station; The determining unit is used to determine the target user plane management function (UPF) unit of the feeder link after the handover, and to allocate the uplink tunnel address and the downlink tunnel address of the N9 interface of the terminal in the target UPF unit. The second message sending unit is used to send a PDU session update response message to the target AMF unit after the target UPF unit has established a session for the post-switching power supply link; the PDU session update response message includes the uplink tunnel address used by the terminal in the target UPF unit.

35. A power supply link switching device for a satellite communication system employing a satellite-borne base station, characterized in that, The device is applied to the Access and Mobility Management Function (AMF) unit of the core network, and the device includes: The request sending unit is used to send a PDU session update context request to the session management function (SMF) unit; wherein, the PDU session update context request includes the user plane downlink tunnel address used by the terminal within the base station; The second message receiving unit is used to receive the PDU session update response message sent by the SMF unit; The PDU session update response message includes the uplink tunnel address used by the terminal in the target UPF unit of the feeder link after the handover, which is used by the base station to send the uplink data of the terminal to the target UPF unit.

36. A processor-readable storage medium, characterized in that, The processor-readable storage medium stores a computer program that causes the processor to perform the steps of the power supply link switching method according to any one of claims 1 to 5; or the computer program causes the processor to perform the steps of the power supply link switching method according to any one of claims 6 to 10; or the computer program causes the processor to perform the steps of the power supply link switching method according to any one of claims 11 to 16.

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