Data transmission method and device during network equipment switching

Abstract

The invention discloses a data transmission method and device during network equipment switching, and relates to the technical field of communication. According to the specific implementation scheme, a first request message sent by an NCF is received, the first request message is used for requesting to establish a data forwarding path between a source network device and a target network device, and the first request message carries a downlink data forwarding address allocated by the target network device; a data forwarding path between a source network device and a target network device is established according to a downlink data forwarding address allocated by the target network device, target data is sent to the target network device through the data forwarding path, and the target data is data sent to the source network device by a UPF during network device switching. Since the data forwarding path between the source network device and the target network device can be established directly based on the downlink data forwarding address allocated by the target network device, the transmission path is simplified, the transmission delay is reduced, and the reliability of data transmission is improved.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to a method and apparatus for data transmission during network device switching. Background Art

[0002] In the low-orbit satellite communication system, since the satellites are constantly moving rapidly, the ground terminals in the communication state constantly change satellites (onboard base stations), that is, the ground terminals need to constantly switch network devices. There are two types of switching processes: switching based on the Xn interface (the interface between two base stations) and switching based on the NG interface (the interface between the base station and the core network). When the Xn interface does not exist, NG-based switching is required.

[0003] In the related technology, in order to ensure the quality of service, data forwarding may be performed during the NG switching process if necessary, and the data is transferred from the source low-orbit satellite base station to the base station of the target low-orbit satellite. In the NG switching process of the traditional ground system, if there is no direct forwarding path, the downlink data needs to be forwarded indirectly, and the indirect forwarding path is source base station → source UPF → target UPF → target base station (in the case of UPF change, if the UPF does not change, the source UPF and the target UPF are the same UPF). Similarly, in the low-orbit satellite communication system, the indirect forwarding data of the source low-orbit satellite base station needs to pass through multiple satellites of the space bearer network (a network composed of satellites) to the UPF on the ground, and the UPF on the ground will then upload the data to the space bearer network, and finally forward it to the target low-orbit satellite base station. This processing method needs to pass through the relevant nodes of the ground and satellite, with poor reliability, long latency, and poor user experience. It is not suitable for the needs of NG switching of satellite-borne base stations in satellite systems, and needs to be improved to simplify the transmission path so that the switching success rate and latency can be improved. Summary of the invention

[0004] The present application provides a method and apparatus for data transmission during network device switching.

[0005] According to a first aspect of the present application, a method for data transmission during network device switching is provided, which is applied to a source network device, and the method includes:

[0006] Receive a first request message sent by a network control function NCF, wherein the first request message is used to request to establish a data forwarding path between the source network device and the target network device, and the first request message carries a downlink data forwarding address allocated by the target network device;

[0007] According to the downlink data forwarding address assigned by the target network device, a data forwarding path is established between the source network device and the target network device to send the target data to the target network device through the data forwarding path, wherein the target data is the data sent to the source network device by the user plane function UPF during network device switching.

[0008] According to a second aspect of the present application, a method for data transmission during network device switching is provided, which is applied to a network control function, and the method includes:

[0009] Receive a second request message sent by the SMF, wherein the second request message carries a downlink data forwarding address assigned by the target network device;

[0010] A first request message is sent to the source network device, wherein the first request message is used to request establishment of a data forwarding path between the source network device and the target network device, and the first request message carries a downlink data forwarding address allocated by the target network device.

[0011] According to a third aspect of the present application, a data transmission device during network device switching is provided, which is applied to a target network device. The method includes:

[0012] Send a switching request confirmation message to the AMF, wherein the switching request confirmation message includes the downlink data forwarding address assigned by the target network device.

[0013] According to a fourth aspect of the present application, a data transmission device during network device switching is provided, comprising a memory, a transceiver, and a processor:

[0014] A memory for storing a computer program; a transceiver for transmitting and receiving data under the control of the processor; and a processor for reading the computer program in the memory and performing the following operations:

[0015] Receive a first request message sent by a network control function NCF, wherein the first request message is used to request to establish a data forwarding path between the source network device and the target network device, and the first request message carries a downlink data forwarding address allocated by the target network device;

[0016] According to the downlink data forwarding address assigned by the target network device, a data forwarding path is established between the source network device and the target network device to send the target data to the target network device through the data forwarding path, wherein the target data is the data sent to the source network device by the user plane function UPF during network device switching.

[0017] According to a fifth aspect of the present application, a data transmission device during network device switching is provided, comprising a memory, a transceiver, and a processor:

[0018] A memory for storing a computer program; a transceiver for transmitting and receiving data under the control of the processor; and a processor for reading the computer program in the memory and performing the following operations:

[0019] Receive a second request message sent by the SMF, wherein the second request message carries a downlink data forwarding address assigned by the target network device;

[0020] A first request message is sent to the source network device, wherein the first request message is used to request establishment of a data forwarding path between the source network device and the target network device, and the first request message carries a downlink data forwarding address allocated by the target network device.

[0021] According to a sixth aspect of the present application, a data transmission device during network device switching is provided, comprising a memory, a transceiver, and a processor:

[0022] A memory for storing a computer program; a transceiver for transmitting and receiving data under the control of the processor; and a processor for reading the computer program in the memory and performing the following operations:

[0023] Send a switching request confirmation message to the AMF, wherein the switching request confirmation message includes the downlink data forwarding address assigned by the target network device.

[0024] According to a seventh aspect of the present application, a data transmission device during network device switching is provided, the device comprising:

[0025] A first receiving unit, configured to receive a first request message sent by a network control function NCF, wherein the first request message is used to request to establish a data forwarding path between the source network device and the target network device, and the first request message carries a downlink data forwarding address assigned by the target network device;

[0026] A first sending unit is used to establish a data forwarding path between the source network device and the target network device according to the downlink data forwarding address assigned by the target network device, so as to send target data to the target network device through the data forwarding path, wherein the target data is data sent to the source network device by the user plane function UPF during network device switching.

[0027] According to an eighth aspect of the present application, a data transmission device during network device switching is provided, the device comprising:

[0028] A second receiving unit, configured to receive a second request message sent by the SMF, wherein the second request message carries a downlink data forwarding address assigned by the target network device;

[0029] The second sending unit is used to send a first request message to the source network device, wherein the first request message is used to request to establish a data forwarding path between the source network device and the target network device, and the first request message carries a downlink data forwarding address allocated by the target network device.

[0030] According to a ninth aspect of the present application, a data transmission device during network device switching is provided, the device comprising:

[0031] The third sending unit is used to send a switching request confirmation message to the AMF, wherein the switching request confirmation message includes a downlink data forwarding address assigned by the target network device.

[0032] According to the tenth aspect of the present application, a processor-readable storage medium is provided, wherein the processor-readable storage medium stores a computer program, and the computer program is used to enable the processor to execute the method described in the embodiment of the first aspect of the present application, or execute the method described in the embodiment of the second aspect of the present application, or execute the method described in the embodiment of the third aspect of the present application.

[0033] The data transmission method and device during network device switching provided by the present application, by receiving a first request message sent by NCF, wherein the first request message is used to request the establishment of a data forwarding path between the source network device and the target network device, and the first request message carries the downlink data forwarding address assigned by the target network device, so as to establish a data forwarding path between the source network device and the target network device according to the downlink data forwarding address assigned by the target network device, so as to send the target data to the target network device through the data forwarding path, wherein the target data is the data sent by the UPF to the source network device during the network device switching. Since the data forwarding path between the source network device and the target network device can be established directly based on the downlink data forwarding address assigned by the target network device, the transmission path is simplified, the transmission delay is reduced, and the reliability of data transmission is improved.

[0034] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present application, nor is it intended to limit the scope of the present application. Other features of the present application will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings are used to better understand the present solution and do not constitute a limitation of the present application.

[0036] Figure 1is a diagram of the satellite communication system architecture in the regeneration mode provided in the first embodiment of the present application;

[0037] Figure 2 is a schematic diagram of an indirect data forwarding path based on NG interface switching provided according to the second embodiment of the present application;

[0038] Figure 3 is a flow chart of a data transmission method during network device switching provided in accordance with the third embodiment of the present application;

[0039] Figure 4 is a flow chart of a data transmission method during network device switching provided in accordance with a fourth embodiment of the present application;

[0040] Figure 5 is a flowchart of a data transmission method during network device switching provided in accordance with a fifth embodiment of the present application;

[0041] Figure 6 It is a schematic diagram of the signaling flow of the existing NG switching in the low-orbit satellite communication system provided in the sixth embodiment of the present application;

[0042] Figure 7 is a schematic diagram of the signaling flow of an improved NG switching in a low-orbit satellite communication system provided in the seventh embodiment of the present application;

[0043] Figure 8 is a schematic diagram of establishing a data forwarding path during a switching process provided in the eighth embodiment of the present application;

[0044] Fig. 9 is a structural schematic diagram of a data transmission device during network device switching provided according to a ninth embodiment of the present application;

[0045] Fig.10 is a structural schematic diagram of a data transmission device during network device switching provided according to the tenth embodiment of the present application;

[0046] Fig.11 is a structural schematic diagram of a data transmission device during network device switching provided according to the eleventh embodiment of the present application;

[0047] Fig.12 is a structural schematic diagram of a data transmission device during network device switching provided according to the twelfth embodiment of the present application;

[0048] Fig.13 is a structural schematic diagram of a data transmission device during network device switching provided according to the thirteenth embodiment of the present application;

[0049] Fig.14It is a structural diagram of a data transmission device during network device switching provided according to the fourteenth embodiment of the present application. DETAILED DESCRIPTION

[0050] In the embodiments of the present application, the term "and / or" describes the association relationship of the associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the associated objects before and after are in an "or" relationship.

[0051] In the embodiments of the present application, the term "plurality" refers to two or more than two, and other quantifiers are similar.

[0052] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0053] Figure 1 1 is a diagram of the satellite communication system architecture in the regeneration mode provided in the first embodiment of the present application. Figure 1 As shown in the figure, the low-orbit satellite communication system includes user equipment, satellites, gateway stations, data networks, etc., among which the wireless link between the user equipment and the satellite is called the service link (Service Link), also known as the user link, the wireless link between the satellite and the gateway station is called the feeder link (Feeder Link), and the wireless link between satellites is called ISL (Inter-Satellite Link).

[0054] When NG interface switching occurs, since the topology of the satellite network is not fixed (especially in the case of adjacent satellites in different orbits), an adjacent direct forwarding path may not exist. In this case, an indirect forwarding path is required for data forwarding. Assume the following scenario: Satellite A is the source satellite, and Satellite B is the landing satellite on the source side; Satellite C is the target satellite, and Satellite D is the landing satellite on the target side; Satellite A, Satellite 1, Satellite 2, and Satellite B are the inter-satellite routing of the space bearer network on the source side, and Satellite C, Satellite 3, Satellite 4, and Satellite D are the inter-satellite routing of the space bearer network on the target side. S-Router is the router of the space bearer network, S-Feeder is the feeder link, and GW is the ground gateway. The indirect data forwarding path based on NG interface switching is as follows: Figure 2As shown. After the downlink data reaches the source base station, it is transmitted to the target base station through an indirect data forwarding path, and the indirect data forwarding transmission path is: A star → 1 star → 2 stars → B star → GW → UPF → GW → D star → 4 stars → 3 stars → C star. In this indirect data forwarding path, the data passes through multiple satellites through the feeder link to the UPF on the ground, and then is transmitted to the D star through the feeder link, and then is transmitted to the base station of the target satellite (C star) through multiple satellites of the space bearer network. Because the data passes through multiple nodes, the data forwarding delay is too long, the user perception is poor, and the forwarding process needs to pass through the feeder link twice, and the reliability is low.

[0055] Therefore, in order to solve the above problems, an embodiment of the present application provides a data transmission method and apparatus during network device switching, which is used to establish a data forwarding path between the source network device and the target network device directly based on the downlink data forwarding address assigned by the target network device, simplify the transmission path, reduce transmission delay, and improve the reliability of data transmission.

[0056] Among them, the method and the device are based on the same application concept. Since the method and the device solve the problem in a similar principle, the implementation of the device and the method can refer to each other, and the repeated parts will not be repeated.

[0057] The technical solution provided in the embodiment of the present application can be applicable to a variety of systems, especially 5G systems. For example, the applicable system can be a global system of mobile communication (GSM) system, a code division multiple access (CDMA) system, a wideband code division multiple access (WCDMA) general packet radio service (GPRS) system, a long term evolution (LTE) system, a LTE frequency division duplex (FDD) system, a LTE time division duplex (TDD) system, an advanced long term evolution (LTE-A) system, a universal mobile telecommunication system (UMTS), a world-wide interoperability for microwave access (WiMAX) system, a 5G new radio (NR) system, etc. These various systems include terminal equipment and network equipment. The system may also include a core network part, such as an evolved packet system (EPS), a 5G system (5GS), etc.

[0058] The terminal device involved in the embodiment of the present application may be a device that provides voice and / or data connectivity to a user, a handheld device with a wireless connection function, or other processing devices connected to a wireless modem. In different systems, the name of the terminal device may also be different. For example, in a 5G system, the terminal device may be called a user equipment (UE). A wireless terminal device can communicate with one or more core networks (CN) via a radio access network (RAN). The wireless terminal device may be a mobile terminal device, such as a mobile phone (or a "cellular" phone) and a computer with a mobile terminal device. For example, it may be a portable, pocket-sized, handheld, computer-built-in or vehicle-mounted mobile device that exchanges language and / or data with a wireless access network. For example, personal communication service (PCS) phones, cordless phones, session initiation protocol (SIP) phones, wireless local loop (WLL) stations, personal digital assistants (PDAs) and other devices. The wireless terminal device may also be referred to as a system, a subscriber unit, a subscriber station, a mobile station, a mobile station, a remote station, an access point, a remote terminal device, an access terminal device, a user terminal device, a user agent, and a user device, but is not limited in the embodiments of the present application.

[0059] The network device involved in the embodiment of the present application may be a base station, which may include multiple cells providing services for the terminal. Depending on the specific application scenario, the base station may also be called an access point, or may be a device in the access network that communicates with the wireless terminal device through one or more sectors on the air interface, or other names. The network device may be used to interchange received air frames with Internet Protocol (IP) packets, and serve as a router between the wireless terminal device and the rest of the access network, wherein the rest of the access network may include an Internet Protocol (IP) communication network. The network device may also coordinate the attribute management of the air interface. For example, the network device involved in the embodiments of the present application may be a network device (Base Transceiver Station, BTS) in the Global System for Mobile communications (Global System for Mobile communications, GSM) or Code Division Multiple Access (Code Division Multiple Access, CDMA), or a network device (NodeB) in Wide-band Code Division Multiple Access (WCDMA), or an evolutionary network device (evolutional Node B, eNB or e-NodeB) in the long term evolution (long term evolution, LTE) system, a 5G base station (gNB) in the 5G network architecture (next generation system), or a home evolved Node B (Home evolved Node B, HeNB), a relay node, a home base station (femto), a pico base station (pico), etc., which is not limited in the embodiments of the present application. In some network structures, the network device may include a centralized unit (CU) node and a distributed unit (DU) node, and the centralized unit and the distributed unit may also be arranged geographically separately.

[0060] Network devices and terminal devices can each use one or more antennas for multiple-input multiple-output (MIMO) transmission. MIMO transmission can be single-user MIMO (SU-MIMO) or multi-user MIMO (MU-MIMO). Depending on the form and number of antenna combinations, MIMO transmission can be 2D-MIMO, 3D-MIMO, FD-MIMO or massive-MIMO, or it can be diversity transmission, precoded transmission or beamforming transmission, etc.

[0061] The following describes a method and apparatus for data transmission during network device switching according to an embodiment of the present application with reference to the accompanying drawings.

[0062] Figure 3 It is a flowchart of a data transmission method during network device switching provided in accordance with the third embodiment of the present application.

[0063] It should be noted that the data transmission method during network device switching of the embodiment of the present application can be performed by the data transmission device during network device switching provided by the embodiment of the present application. The data transmission device during network device switching can be an electronic device or can be configured in an electronic device.

[0064] like Figure 3 As shown, the data transmission method during the network device switching may include the following steps:

[0065] Step 301: Receive a first request message sent by a network control function NCF, wherein the first request message is used to request to establish a data forwarding path between a source network device and a target network device, and the first request message carries a downlink data forwarding address allocated by the target network device.

[0066] It should be noted that the data transmission method during network device switching of this embodiment is applied to the source network device, wherein the source network device refers to the network device serving the target terminal device before the switching.

[0067] In some embodiments, the source network device may receive a first request message sent by NCF (Network Control Function), wherein the first request message is used to request to establish a data forwarding path between the source network device and the target network device, and the first request message carries a downlink data forwarding address assigned by the target network device.

[0068] The target network device refers to the network device that serves the target terminal device after the handover is completed. Optionally, the target network device may be determined by the AMF (Access and Mobility Management Function) according to the target ID in the handover request message sent by the source network device.

[0069] In some embodiments, the downlink data forwarding address allocated by the target network device carried in the first request message may be sent by the target network device to AMF, sent by AMF to SMF (Session Management Function), and sent by SMF to NCF. For example, in the switching process based on the NG interface, after the target network device receives the handover request message (Handover Request) sent by the AMF, it can reply to the AMF with a handover request confirmation message (Handover Request Acknowledge) if it can serve the target terminal device. The handover request confirmation message includes the N3 (interface between the base station and the UPF) forwarding information list of the target network device and the downlink data forwarding address assigned by the target network device. After that, the AMF sends an SM context update request message (Nsmf_PDUSession_UpdateSMContext Request) to the SMF to inform the SMF of the N3 forwarding information list of the target network device and the downlink data forwarding address assigned by the target network device, so that the SMF directly sends the downlink data forwarding address assigned by the target network device to the NCF, so that after the NCF learns the downlink data forwarding address assigned by the target network device, it directly builds a data forwarding path between the source network device and the target network device based on the address for data forwarding, simplifies the transmission path, and greatly shortens the transmission delay. At the same time, since the number of nodes passed by the forwarding path is reduced, the reliability of data transmission is improved and the switching success rate is improved.

[0070] It should be noted that after SMF obtains the N3 forwarding information list of the target network device and the downlink data forwarding address assigned by the target network device, it only needs to update the N3 forwarding information list of the target network device to UPF by sending a session modification request message (Session ModificationRequest) to UPF. There is no need to inform UPF of the downlink data forwarding address assigned by the target network device, that is, UPF does not need to perform data forwarding processing during switching, which simplifies the processing process.

[0071] Step 302, establish a data forwarding path between the source network device and the target network device according to the downlink data forwarding address assigned by the target network device, so as to send the target data to the target network device through the data forwarding path, wherein the target data is the data sent by the UPF to the source network device during network device switching.

[0072] It should be noted that during the switching process, when the target terminal device finds that it needs to switch network devices, it will generally stop sending uplink data, while the UPF (User Plane Function) on the core network side does not know that it needs to switch and will still send data to the source network device. Therefore, the above-mentioned target data is the data sent by the UPF to the source network device during the network device switching, and does not come from the target terminal device.

[0073] In some embodiments, after receiving the first request message sent by the NCF, the source network device can establish a data forwarding path between the source network device and the target network device based on the downlink data forwarding address assigned by the target network device carried in the first request message, so as to send the target data to the target network device through the data forwarding path. The target data is the data sent by the UPF to the source network device during the network device switching.

[0074] As an example, when the source network device is the source satellite and the target network device is the target satellite, the SMF can send a Create Space Bearer Network Path Request message to the NCF, requesting the space bearer network to build a data forwarding path between the source satellite and the target satellite, wherein the Create Space Bearer Network Path Request message sent by the SMF to the NCF carries the target satellite information and the downlink data forwarding address assigned by the target satellite. Thus, the NCF sends a Create Space Bearer Network Indirect Forwarding Path Request message to the source satellite, requesting the space bearer network to build a data forwarding path between the source satellite and the target satellite, and the message carries the indirect tunnel address (IP address + TEID (Tunnel End Point Identifier)) assigned by the target base station, and then the source satellite sends a Create Space Bearer Network Indirect Forwarding Path Response message to the NCF for confirmation. Therefore, when establishing the space bearer network path, it is possible to use the NCF of the space bearer network to directly build the satellite routes of the source base station and the target base station in the space bearer network, so that the number of satellites crossed is minimized (it may also be necessary to pass through multiple satellites), and the data no longer needs to fall back to the UPF on the ground, which greatly shortens the data forwarding path, reduces the transmission delay, greatly improves the reliability, increases the switching success rate, improves the service quality, and improves the user perception.

[0075] In some embodiments, when the source network device is a source satellite and the target network device is a target satellite, the data forwarding path established between the source network device and the target network device is an intersatellite link, that is, a wireless link between satellites, so that the data no longer needs to fall back to the UPF on the ground, and the UPF no longer needs to allocate data forwarding tunnels, which simplifies the processing process, reduces transmission delay, and improves the reliability of data transmission.

[0076] The data transmission method during network device switching provided by the present application, the source network device receives a first request message sent by NCF, wherein the first request message is used to request the establishment of a data forwarding path between the source network device and the target network device, and the first request message carries the downlink data forwarding address assigned by the target network device, so as to establish a data forwarding path between the source network device and the target network device according to the downlink data forwarding address assigned by the target network device, so as to send the target data to the target network device through the data forwarding path, wherein the target data is the data sent by the UPF to the source network device during the network device switching. Since the data forwarding path between the source network device and the target network device can be established directly based on the downlink data forwarding address assigned by the target network device, the transmission path is simplified, the transmission delay is reduced, and the reliability of data transmission is improved.

[0077] The above embodiment describes a possible implementation of a data transmission method during network device switching from the perspective of a source network device. Figure 4 , describes a possible implementation of a data transmission method during network device switching from the perspective of NCF, Figure 4 It is a flowchart of a data transmission method during network device switching provided according to the fourth embodiment of the present application.

[0078] like Figure 4 As shown, the data transmission method during the network device switching may include the following steps:

[0079] Step 401: Receive a second request message sent by the SMF, wherein the second request message carries a downlink data forwarding address assigned by the target network device.

[0080] It should be noted that the data transmission method during network device switching in this embodiment is applied to NCF.

[0081] In some embodiments, the NCF may obtain the downlink data forwarding address allocated by the target network device by receiving the second request message sent by the SMF.

[0082] Optionally, in the case where the source network device is a source satellite and the target network device is a target satellite, the second request message is used to request the establishment of a downlink data transmission path between the target satellite and the landing satellite corresponding to the target satellite, and to request the establishment of a data forwarding path between the source satellite and the target network. That is to say, the second request message sent by the SMF to the NCF is used to request the establishment of two paths, one of which is a downlink data transmission path between the target satellite and the landing satellite corresponding to the target satellite, which is used for the landing satellite corresponding to the target satellite to send the downlink data from the UPF to the target satellite after the network device switching is completed, and the other is a data forwarding path between the source satellite and the target network, which is used for the source satellite to send the target data to the target satellite during the network device switching, wherein the target data is the data sent by the UPF to the source network device during the network device switching, and these two paths are two different paths.

[0083] As an example, when the source network device is a source satellite and the target network device is a target satellite, SMF can send a request message for creating a space bearer network path to NCF, requesting the space bearer network to establish a satellite route for downlink data from the landing satellite on the target satellite side to the target satellite, and requesting the space bearer network to build a data forwarding path between the source satellite and the target satellite, wherein the SMF sends a request message for creating a space bearer network path to NCF, carrying the target satellite information and the downlink data forwarding address assigned by the target satellite. NCF sends a request message for creating a space bearer network path to the landing satellite on the target satellite side, requesting the space bearer network to build a satellite route for downlink data from the landing satellite on the target satellite side to the target satellite, and the landing satellite on the target satellite side sends a response message for creating a space bearer network path to NCF for confirmation. And NCF sends a request message for creating an indirect forwarding path of a space bearer network to the source satellite, requesting the space bearer network to build a data forwarding path between the source satellite and the target satellite, and the source satellite sends a response message for creating an indirect forwarding path of a space bearer network to NCF for confirmation. Among them, the request message for creating an indirect forwarding path of a space bearer network sent by NCF to the source satellite carries the indirect tunnel address (IP address + TEID) assigned by the target base station.

[0084] It should be noted that when the source network device is the source satellite and the target network device is the target satellite, in addition to establishing a downlink data transmission path between the target satellite and the landing satellite corresponding to the target satellite, it is also necessary to establish an uplink data transmission path between the target satellite and the landing satellite corresponding to the target satellite, so that the landing satellite corresponding to the target satellite can send the uplink data from the UPF to the target satellite after the network device switching is completed.

[0085] Step 402: Send a first request message to the source network device, wherein the first request message is used to request to establish a data forwarding path between the source network device and the target network device, and the first request message carries a downlink data forwarding address allocated by the target network device.

[0086] In some embodiments, after receiving the second request message sent by the SMF, the NCF may send a first request message to the source network device to send the downlink data forwarding address allocated by the target network device carried in the second message to the source network device through the first request message.

[0087] Optionally, when the source network device is a source satellite and the target network device is a target satellite, the data forwarding path requested to be established between the source network device and the target network device is an intersatellite link, which is used for the source satellite to send target data to the target satellite during network device switching, wherein the target data is the data sent by the UPF to the source network device during network device switching.

[0088] In some embodiments, the downlink data forwarding address can be sent by the target network device to AMF, sent by AMF to SMF, and sent by SMF to NCF.

[0089] In some embodiments, the target network device may be determined by the AMF according to the target identifier Target ID in the switching request message sent by the source network device.

[0090] The data transmission method during network device switching provided in the present application is that NCF receives a second request message sent by SMF, wherein the second request message carries the downlink data forwarding address assigned by the target network device, thereby sending a first request message to the source network device, wherein the first request message is used to request the establishment of a data forwarding path between the source network device and the target network device, and the first request message carries the downlink data forwarding address assigned by the target network device. Therefore, after learning the downlink data forwarding address assigned by the target network device, NCF can send the downlink data forwarding address assigned by the target network device to the source network device, thereby directly building a data forwarding path between the source network device and the target network device based on the downlink data forwarding address for data forwarding, thereby simplifying the transmission path and greatly shortening the transmission delay. At the same time, since the number of nodes passed by the forwarding path is reduced, the reliability of data transmission is improved, and the switching success rate is improved.

[0091] Combine the following Figure 5 , describes a possible implementation of a data transmission method during network device switching from the perspective of the target network device, Figure 5 It is a flowchart of a data transmission method during network device switching provided in accordance with the fifth embodiment of the present application.

[0092] like Figure 5 As shown, the data transmission method during the network device switching may include the following steps:

[0093] Step 501: Send a switching request confirmation message to the AMF, wherein the switching request confirmation message includes a downlink data forwarding address assigned by the target network device.

[0094] It should be noted that the data transmission method during the network device switching of this embodiment is applied to the target network device. The target network device refers to the network device that serves the target terminal device after the switching is completed. Optionally, the target network device can be determined by the AMF according to the target ID in the switching request message sent by the source network device.

[0095] In some embodiments, after receiving the handover request message (HandoverRequest) sent by AMF, the target network device can reply to AMF with a handover request confirmation message (Handover Request Acknowledge) if it can serve the target terminal device, wherein the handover request confirmation message includes the downlink data forwarding address assigned by the target network device. For example, in the handover process based on the NG interface, AMF can determine the target network device according to the target identifier Target ID in the handover request message sent by the source network device, thereby sending a handover request message to the target network device to request the establishment of wireless side network resources, wherein the handover request message sent by AMF to the target network device includes the location information of the target terminal device, so that the target network device can better analyze and process. Specifically, the target network device can determine whether it can provide services for the target terminal device according to the current network device resources. If not, the handover is rejected. Otherwise, the target network device records the N3 tunnel information on the UPF side and pre-allocates wireless resources. Optionally, if the target network device can serve the target terminal device, it replies to the handover request confirmation message to AMF, and the target network device is ready to receive PDU. Among them, the switching request confirmation message that the target network device replies to the AMF includes a list of switchable PDU sessions and a list of non-switchable PDU sessions, wherein the N2 (interface between the base station and AMF) SM information of each PDU session in the switchable PDU session list includes the N3 address and tunnel information of the target network device, as well as the downlink data forwarding address assigned by the target network device.

[0096] The present application provides a method for data transmission during network device switching, in which the target network device sends a switching request confirmation message including a downlink data forwarding address assigned by the target network device to the AMF, so that the downlink data forwarding address assigned by the target network device is sent to the SMF through the AMF, and then the downlink data forwarding address assigned by the target network device is sent to the NCF through the SMF, so that after the NCF learns the downlink data forwarding address assigned by the target network device, it directly builds a data forwarding path between the source network device and the target network device based on the address for data forwarding, simplifies the transmission path, and greatly shortens the transmission delay. At the same time, since the number of nodes passed by the forwarding path is reduced, the reliability of data transmission is improved, and the switching success rate is improved.

[0097] In order to clearly illustrate the above embodiment, an example is now given for illustration.

[0098] Figure 6 It is a schematic diagram of the signaling flow of the existing NG switching in the low-orbit satellite communication system provided according to the sixth embodiment of the present application.

[0099] Among them, UE refers to user equipment (target terminal device); s-gNB refers to satellite base station; S-Router is the satellite router; S-Feeder is the satellite feeder link module; UPF is located on the ground and is the user plane function; AMF is the access and mobility management function; SMF is the session management function; NCF is located on the ground and is the network control function, responsible for the routing selection of the space bearer network and the establishment of service channels.

[0100] like Figure 6 As shown in the figure, the signaling process is described as follows:

[0101] Step 600: The UE and the source satellite transmit uplink and downlink data via the UPF on the ground and the landing satellite on the source satellite side.

[0102] Step 601: UE sends a Measurement Report to the onboard base station of the source satellite.

[0103] During the communication process, the UE will start the reporting process of the measurement report message (Measurement Report). Specifically, the UE reports the signal quality (RSRP (Reference Signal Receiving Power, Reference Signal Received Power) / RSRQ (Reference Signal Receiving Quality, Reference Signal Received Quality)), location information (latitude and longitude or parameters that can represent a certain geographical location) and so on to the source satellite through the Measurement Report.

[0104] Step 602: The onboard base station of the source satellite determines whether NG switching is required based on the measurement result.

[0105] The base station predicts handover. The base station makes a decision on NG handover based on information such as the UE location.

[0106] Step 603: The onboard base station of the source satellite sends Handover Required to the AMF.

[0107] The source NG-RAN (Next Generation Radio Access Network) sends a handover request message (Handover Required) to the AMF, which contains the UE's location information and the Target ID parameter.

[0108] Step 604, AMF sends Nsmf_PDUSession_UpdateSMContext Request to SMF.

[0109] AMF sends an SM context update request message (Nsmf_PDUSession_UpdateSMContext Request) to the associated SMF, informing the SMF of the PDU session ID, Target ID, and N2 information that needs to be switched. Among them, the PDU session ID represents the candidate PDU session for N2 (the interface between the base station and AMF) switching.

[0110] Step 605: SMF sends a Session Modification Request to UPF.

[0111] SMF sends a PFCP (Packet Forwarding Control Protocol) session modification request message (Session Modification Request) to UPF.

[0112] Step 606: UPF sends a Session Modification Response to SMF.

[0113] UPF replies with a PFCP session modification request message (Session Modification Response), which carries the N3 (interface between the base station and UPF) tunnel information on the UPF side.

[0114] Step 607, SMF sends Nsmf_PDUSession_UpdateSMContext Response to AMF.

[0115] SMF replies to AMF with an SM context update response message (Nsmf_PDUSession_UpdateSMContextResponse), which carries the PDU session ID and N2 SM information. The N2 SM information includes the N3 user plane address, uplink CN tunnel ID, and QoS parameters.

[0116] Step 608: SMF sends a request to create a spatial bearer network path to NCF.

[0117] The SMF sends a create space bearer network path request message to the NCF, requesting the space bearer network to build an uplink data satellite route from the target satellite to the landing satellite on the target satellite side.

[0118] It should be noted that the uplink data satellite route from the target satellite to the landed satellite on the target satellite side is the route for uplink data transmission of the target satellite after the switching is completed, and is used for the target satellite to send the uplink data to the landed satellite on the target satellite side through the uplink data satellite route after the switching is completed.

[0119] Step 609: NCF sends a request to create a space bearer network path to the onboard router of the target satellite.

[0120] The NCF sends a create space bearer network path request message to the target satellite, requesting the space bearer network to build an uplink data satellite route from the target satellite to the landing satellite on the target satellite side.

[0121] Step 610: The onboard router of the target satellite sends a create space bearer network path response to the NCF.

[0122] The target satellite sends a create space bearer network path response message to the NCF to establish an uplink data satellite route from the target satellite to the landing satellite on the target satellite side.

[0123] Step 611, NCF sends a create spatial bearer network path response to SMF.

[0124] NCF sends a create space bearer network path response message to SMF, informing SMF that an uplink data satellite route to the landing satellite on the target satellite side has been established.

[0125] Thus, the establishment of the uplink data satellite route between the target satellite and the landing satellite can be completed, so that the uplink data transmission between the UE and the target satellite can be realized through the uplink data satellite route after the handover is completed.

[0126] Step 612: AMF sends a Handover Request (PDU Session Resource Setup Request Transfer) to the onboard base station of the target satellite.

[0127] AMF sends a handover request message (Handover Request (PDU Session ResourceSetup Request Transfer)) to the target NG-RAN. It should be noted that before sending the handover request message, AMF also needs to determine the target NG-RAN according to the Target ID, so that AMF sends a handover request message to the target NG-RAN to request the establishment of wireless side network resources. Among them, the handover request message sent by AMF to the target NG-RAN can include the location information of the UE for the target NG-RAN to better analyze and process.

[0128] Step 613: The onboard base station of the target satellite sends a Handover Request Acknowledge (Handover Request Acknowledge Transfer) to the AMF.

[0129] If the target NG-RAN is able to serve the UE, it replies with a Handover Request Acknowledge message (Handover Request Acknowledge Transfer) to the AMF. At this point, the target NG-RAN is ready to receive the PDU.

[0130] Optionally, the switching request confirmation message sent by the target NG-RAN to the AMF includes a list of switchable PDU sessions and a list of non-switchable PDU sessions. The N2SM information of each PDU session in the switchable PDU session list includes the N3 address and tunnel information of the target NG-RAN, and the address of the data forwarding tunnel.

[0131] If the target base station cannot accommodate the user, it will reply a handover failure message (Handover Failure) to the AMF.

[0132] Step 614, AMF sends Nsmf_PDUSession_UpdateSMContext Request to SMF.

[0133] AMF sends a Nsmf_PDUSession_UpdateSMContext Request message to SMF to inform SMF of the N3 forwarding information list of the target NG-RAN.

[0134] Step 615, SMF sends a Session Modification Request to UPF.

[0135] SMF updates the target NG-RAN's SM N3 forwarding information list to UPF by sending a Session Modification Request message to UPF. If the source NG-RAN instructs to establish a forwarding tunnel, SMF sends the downlink data indirect forwarding tunnel address allocated by the target base station to UPF.

[0136] Step 616, UPF sends Session Modification Response to SMF.

[0137] UPF records the N3 inter-tunnel information of the target NG-RAN, and allocates the indirect forwarding tunnel information on the UPF side based on the SMF instruction. UPF replies with a session modification response message (Session Modification Response) to SMF, which carries the UPF's SM N3 forwarding information list.

[0138] Step 617, SMF sends Nsmf_PDUSession_UpdateSMContext Response to AMF.

[0139] SMF responds to AMF with Nsmf_PDUSession_UpdateSMContext Response. SMF includes N2 SM information in the message, which includes the downlink forwarding tunnel information sent to the source NG-RAN.

[0140] Step 618: SMF sends a request to create a spatial bearer network path to NCF.

[0141] SMF sends a create space bearer network path request message to NCF, requesting the space bearer network to build a downlink data satellite route from the landing satellite on the target satellite side to the target satellite.

[0142] It should be noted that this message also includes the downlink data forwarding address on the UPF side.

[0143] Step 619: NCF sends a request to create a space bearer network path to the landing satellite on the target satellite side.

[0144] NCF sends a request message for creating a space bearer network path to the landing satellite on the target satellite side, requesting the space bearer network to build a downlink data satellite route from the landing satellite on the target satellite side to the target satellite, and requesting the space bearer network to establish an indirect data forwarding path from the landing satellite on the target satellite side to the ground UPF.

[0145] It should be noted that the downlink data satellite route from the landing satellite on the target satellite side to the target satellite is the route for downlink data transmission after the switching is completed. The landing satellite on the target satellite side sends the downlink data from the core network to the target satellite through the downlink data satellite route after the switching is completed; the indirect data forwarding path from the landing satellite on the target satellite side to the ground UPF is a temporary route during the switching. The landing satellite on the target satellite side sends the data previously sent to the source satellite (data sent to the source satellite by the UPF during the switching) to the target satellite through the indirect data forwarding path during the switching to ensure uninterrupted business.

[0146] Step 620: The landing satellite on the target satellite side sends a create space bearer network path response to the NCF.

[0147] The landing satellite on the target satellite side sends a create space bearer network path response message to the NCF to establish a downlink data satellite route from the landing satellite on the target satellite side to the target satellite, and an indirect data forwarding path from the landing satellite on the target satellite side to the ground UPF.

[0148] Step 621, NCF sends a create space bearer network path response to SMF.

[0149] NCF sends a create space bearer network path response message to SMF, informing SMF that it has established a downlink data satellite route from the landing satellite on the target satellite side to the target satellite, as well as an indirect data forwarding path from the landing satellite on the target satellite side to the ground UPF.

[0150] Thus, the establishment of a downlink data satellite route between the target satellite and the landing satellite can be completed, so that downlink data transmission between the UE and the target satellite can be realized through the downlink data satellite route after the handover is completed. And the establishment of an indirect data forwarding path from the source satellite to the target satellite can be completed, so that data transmission between the source satellite and the target satellite can be realized through the indirect data forwarding path during the handover.

[0151] Step 622: AMF sends a Handover Command to the onboard base station of the source satellite.

[0152] AMF sends a handover command message (Handover Command) to the source NG-RAN to notify that the handover preparation is complete. The message includes the PDU session list that accepts the handover and the PDU session list that refuses the handover obtained from the target NG-RAN during the handover preparation phase, as well as the N2 SM information of each session. If it is indirect forwarding, the SM forwarding information is the source UPF N3 forwarding tunnel information.

[0153] Step 623: The onboard base station of the source satellite sends an RRC Reconfiguration message to the UE.

[0154] The source NG-RAN sends the RRC (Radio Resource Control) reconfiguration message (RRCReconfiguration) to the UE. After receiving this message, the UE will release the PDU session resources rejected by the target NG-RAN. At this time, the UE will not receive messages.

[0155] Step 624, forwarding of uplink data and spatial bearer network data.

[0156] The source NG-RAN records the UPF's inter-forwarding information; the source NG-RAN starts forwarding downlink data to the target NG-RAN through the indirect forwarding channel. The indirect forwarding path is: the source NG-RAN forwards the data to the UPF via satellite routing, and the UPF forwards it to the target NG-RAN. The target NG-RAN caches the downlink message.

[0157] Step 625: The onboard base station of the source satellite sends an Uplink RAN ​​Status Transfer to the AMF.

[0158] The source NG-RAN sends an Uplink RAN ​​Status Transfer message to the AMF. If all radio bearers of the UE should not be processed in PDCP state preservation, the source NG-RAN may omit sending this message.

[0159] Step 626: AMF sends a Downlink RAN ​​Status Transfer to the onboard base station of the target satellite.

[0160] The AMF sends the information to the target NG-RAN via the Downlink RAN ​​Status Transfer message.

[0161] Step 627: The UE synchronizes to the target base station.

[0162] Step 628: The UE sends an RRC Reconfiguration Complete message to the onboard base station of the target satellite.

[0163] After the UE successfully synchronizes to the target cell, it sends an RRC Reconfiguration Complete message (RRC ReconfigurationComplete) to the target NG-RAN to confirm that the UE handover is successful.

[0164] Step 629, forwarding downlink data.

[0165] In the downlink direction, the target NG-RAN sends the buffered downlink data to the UE.

[0166] Step 630: uplink data is sent.

[0167] The uplink data is sent directly, that is, through "UE→target NG-RAN→UPF".

[0168] Step 631: The onboard base station of the target satellite sends a Handover Notify to the AMF.

[0169] The target NG-RAN sends a handover notification message (Handover Notify) to the AMF to inform the AMF that the UE is already in the target cell and the handover is successful.

[0170] Step 632, AMF sends Nsmf_PDUSession_UpdateSMContext Request to SMF.

[0171] AMF sends an SM context update message (Nsmf_PDUSession_UpdateSMContextRequest) to SMF, which carries the completion flag of each PDU session switching, indicating that the N2 switching is successful.

[0172] Step 633, SMF sends a Session Modification Request to UPF.

[0173] The SMF sends a Session Modification Request message to the UPF, which completes the path switch from the UPF to the target NG-RAN. To assist the reordering function in the target NG-RAN, the UPF (PSA) sends one or more "end marker" messages to each N3 tunnel on the old path immediately after the path is switched. The source NG-RAN forwards the "end marker" message to the target NG-RAN via the indirect forwarding tunnel.

[0174] Step 634, UPF sends Session Modification Response to SMF.

[0175] UPF sends an N4 session modification response message to SMF.

[0176] Step 635: SMF sends a request to delete the spatial bearer network path to NCF.

[0177] The SMF sends a request to delete the space bearer network path to the NCF, requesting the space bearer network to delete the uplink data satellite route from the source satellite to the landing satellite on the source target satellite side.

[0178] Step 636: NCF sends a request to delete the space bearer network path to the onboard base station of the source satellite.

[0179] NCF sends a request to delete the space bearer network path to the onboard base station of the source satellite, requesting the space bearer network to delete the uplink data satellite route from the source satellite to the landing satellite on the source target satellite side.

[0180] Step 637: The onboard base station of the source satellite sends a delete space bearer network path response to the NCF.

[0181] The onboard base station of the source satellite sends a delete space bearer network path response to the NCF, deleting the uplink data satellite route from the source satellite to the landing satellite on the source target satellite side.

[0182] Step 638: NCF sends a delete space bearer network path response to SMF.

[0183] NCF sends a delete space bearer network path response to SMF, informing SMF that the uplink data satellite route from the source satellite to the landing satellite on the source target satellite side has been deleted.

[0184] In this way, the uplink data satellite route from the source satellite to the landing satellite on the source target satellite side can be deleted.

[0185] Step 639: SMF sends a request to delete the spatial bearer network path to NCF.

[0186] SMF sends a request to delete the space bearer network path to NCF, requesting the space bearer network to delete the downlink data satellite route from the landing satellite on the source satellite side to the source mark satellite.

[0187] Step 640: NCF sends a request to delete the space bearer network path to the landing satellite on the source satellite side.

[0188] NCF sends a request to delete the space bearer network path to the landing satellite on the source satellite side, requesting the space bearer network to delete the downlink data satellite route from the landing satellite on the source satellite side to the source target satellite.

[0189] Step 641: The landing satellite on the source satellite side sends a delete space bearer network path response to the NCF.

[0190] The landing satellite on the source satellite side sends a delete space bearer network path response to the NCF, deleting the downlink data satellite route from the landing satellite on the source satellite side to the source target satellite.

[0191] Step 642: NCF sends a delete space bearer network path response to SMF.

[0192] NCF sends a delete space bearer network path response to SMF, informing SMF that the downlink data satellite route from the landing satellite on the source satellite side to the source mark satellite has been deleted.

[0193] In this way, the satellite route of downlink data from the landing satellite to the source target satellite on the source satellite side can be deleted.

[0194] In summary, through steps 635 to 642, the service data transmission channel of the space bearer network can be released.

[0195] Step 643: downlink data transmission.

[0196] The downlink data transmission path after switching is "UPF→inter-satellite routing→target NG-RAN→UE".

[0197] Step 644, SMF sends Nsmf_PDUSession_UpdateSMContext Response to AMF.

[0198] Step 645: AMF sends a UE Context Release Command to the onboard base station of the source satellite.

[0199] The AMF sends a UE Context Release Command message (UE Context Release Command) to the onboard base station of the source satellite, notifying the source NG-RAN to release the radio side resources.

[0200] Step 646: The onboard base station of the source satellite sends UE Context Release Complete to the AMF.

[0201] The onboard base station of the source satellite sends a UE Context Release Complete message (UE Context ReleaseComplete) to the AMF, informing the AMF that the radio side resources have been released.

[0202] Step 647: uplink and downlink data transmission.

[0203] The switch is completed, and the uplink and downlink data are Transmission between.

[0204] In summary, during the switching of network equipment, data needs to pass through multiple satellites through the feeder link to the UPF on the ground, and then be transmitted to the landing satellite on the target satellite side through the feeder link, and then be transmitted to the base station of the target satellite through multiple satellites of the space bearer network. Data passes through multiple nodes and passes through the feeder link twice, which has a long time delay and low reliability.

[0205] In response to the above problems, the present application has made the following improvements to the existing NG switching in the low-orbit satellite communication system, so that when establishing the space bearer network path, the NCF of the space bearer network is used to directly build the satellite routes of the source base station and the target base station in the space bearer network, so that the number of satellites crossed is minimized (it may also be necessary to pass through multiple satellites), and the data no longer needs to fall back to the UPF on the ground, thereby greatly shortening the data forwarding path, reducing transmission delay, improving transmission reliability, and increasing the switching success rate. At the same time, the service quality is improved and user perception is improved.

[0206] Figure 7 It is a schematic diagram of the signaling flow of the improved NG switching in the low-orbit satellite communication system provided according to the seventh embodiment of the present application.

[0207] like Figure 7 As shown in the figure, the signaling process is described as follows:

[0208] Step 700: The UE and the source satellite transmit uplink and downlink data via the UPF on the ground and the landing satellite on the source satellite side.

[0209] Step 701: UE sends a Measurement Report to the onboard base station of the source satellite.

[0210] Step 702: The onboard base station of the source satellite determines whether NG switching is required based on the measurement result.

[0211] Step 703: The onboard base station of the source satellite sends Handover Required to the AMF.

[0212] Step 704, AMF sends Nsmf_PDUSession_UpdateSMContext Request to SMF.

[0213] Step 705: SMF sends a Session Modification Request to UPF.

[0214] Step 706: UPF sends a Session Modification Response to SMF.

[0215] Step 707, SMF sends Nsmf_PDUSession_UpdateSMContext Response to AMF.

[0216] Step 708: SMF sends a request to create a spatial bearer network path to NCF.

[0217] Step 709: NCF sends a request to create a space bearer network path to the onboard router of the target satellite.

[0218] Step 710: The onboard router of the target satellite sends a create space bearer network path response to the NCF.

[0219] Step 711, NCF sends a create spatial bearer network path response to SMF.

[0220] It should be noted that the execution process of steps 701-711 may specifically refer to steps 601-611 in the previous embodiment, and the principles are the same, which will not be repeated here.

[0221] Step 712: AMF sends a Handover Request (PDU Session Resource Setup Request Transfer) to the onboard base station of the target satellite.

[0222] AMF sends a handover request message (Handover Request (PDU Session ResourceSetup Request Transfer)) to the target NG-RAN. It should be noted that before sending the handover request message, AMF also needs to determine the target NG-RAN according to the Target ID, so that AMF sends a handover request message to the target NG-RAN to request the establishment of wireless side network resources. Among them, the handover request message sent by AMF to the target NG-RAN can include the location information of the UE for the target NG-RAN to better analyze and process.

[0223] It should be noted that the target NG-RAN can determine whether it can provide services for the UE based on the current satellite resources. If not, the switch is rejected. Otherwise, the target NG-RAN records the N3 tunnel information on the UPF side and pre-allocates wireless resources.

[0224] Step 713: The onboard base station of the target satellite sends a Handover Request Acknowledge (Handover Request Acknowledge Transfer) to the AMF.

[0225] If the target NG-RAN is able to serve the UE, it replies with a Handover Request Acknowledge message (Handover Request Acknowledge Transfer) to the AMF. At this point, the target NG-RAN is ready to receive the PDU.

[0226] Optionally, the switching request confirmation message sent by the target NG-RAN to the AMF includes a list of switchable PDU sessions and a list of non-switchable PDU sessions. The N2SM information of each PDU session in the switchable PDU session list includes the N3 address and tunnel information of the target NG-RAN, and the downlink data forwarding address allocated by the target NG-RAN.

[0227] If the target base station cannot accommodate the user, it will reply a handover failure message (Handover Failure) to the AMF.

[0228] Step 714, AMF sends Nsmf_PDUSession_UpdateSMContext Request to SMF.

[0229] It should be noted that the execution process of this step may specifically refer to step 614 in the previous embodiment, and the principle is the same, which will not be repeated here.

[0230] Step 715, SMF sends a Session Modification Request to UPF.

[0231] SMF updates the SM N3 forwarding information list of the target NG-RAN to UPF by sending a Session Modification Request message to UPF.

[0232] It should be noted that, unlike the existing NG switching signaling process, in this embodiment, the SMF does not need to inform the UPF of the downlink data forwarding address allocated by the target NG-RAN (that is, the UPF does not need to perform data forwarding processing during switching).

[0233] Since the UPF is no longer required to allocate forwarding tunnels, the processing procedure is simplified.

[0234] Step 716, UPF sends Session Modification Response to SMF.

[0235] UPF replies a PFCP Session Modification Response message (PFCP Session Modification Response) to SMF.

[0236] Step 717, SMF sends Nsmf_PDUSession_UpdateSMContext Response to AMF.

[0237] It should be noted that the execution process of this step may specifically refer to step 617 in the previous embodiment, and the principle is the same, which will not be repeated here.

[0238] Step 718: SMF sends a request to create a spatial bearer network path to NCF.

[0239] SMF sends a request message to NCF to create a space bearer network path, requesting the space bearer network to build a downlink data satellite route from the landing satellite on the target satellite side to the target satellite, and at the same time requesting the space bearer network to build a data forwarding satellite path between the source satellite and the target satellite, carrying the target satellite information and the downlink data forwarding address assigned by the target base station.

[0240] Step 719a: NCF sends a request to create a space bearer network path to the landing satellite on the target satellite side.

[0241] NCF sends a create space bearer network path request message to the landing satellite on the target satellite side, requesting the space bearer network to build a downlink data satellite route from the landing satellite on the target satellite side to the target satellite.

[0242] It should be noted that the downlink data satellite route from the landing satellite on the target satellite side to the target satellite is the route for downlink data transmission after the switching is completed, and is used by the landing satellite on the target satellite side to send the downlink data from the core network to the target satellite through the downlink data satellite route after the switching is completed.

[0243] Step 719b: The landing satellite on the target satellite side sends a create space bearer network path response to the NCF.

[0244] The landing satellite on the target satellite side sends a create space bearer network path response message to the NCF to establish a downlink data satellite route from the landing satellite on the target satellite side to the target satellite.

[0245] Step 720a: NCF sends a request to the source satellite to create an indirect forwarding path of the space bearer network.

[0246] NCF sends a request message for creating an indirect forwarding path of a space bearer network to the source satellite, requesting the space bearer network to build a data forwarding satellite path between the source satellite and the target satellite. The message carries the indirect tunnel address (IP address + TEID) allocated by the target base station.

[0247] It should be noted that the data forwarding satellite path between the source satellite and the target satellite is a temporary route during the switching period. The source satellite is used to send the data previously sent to the source satellite (data sent to the source satellite by the UPF during the switching period) to the target satellite through the data forwarding source satellite path during the switching period to ensure uninterrupted service.

[0248] Step 720b: The source satellite sends a response to the NCF for creating an indirect forwarding path of the space bearer network.

[0249] The source satellite sends a create space bearer network indirect forwarding path response message to the NCF to establish a data forwarding satellite path between the originating satellite and the target satellite.

[0250] Since a data forwarding satellite path is established between the source satellite and the target satellite, the data no longer needs to fall back to the UPF on the ground, which greatly shortens the transmission delay and reduces the nodes passed by the forwarding path. In particular, the old path that requires data forwarding twice through the feeder link is deleted, thereby improving reliability and increasing the switching success rate.

[0251] Step 721, NCF sends a create spatial bearer network path response to SMF.

[0252] NCF sends a create space bearer network path response message to SMF, informing SMF that it has established the downlink data satellite route from the landing satellite on the target satellite side to the target satellite, as well as the data forwarding satellite path between the source satellite and the target satellite.

[0253] Thus, the establishment of a downlink data satellite route between the target satellite and the landing satellite can be completed, so that downlink data transmission between the UE and the target satellite can be realized through the downlink data satellite route after the handover is completed. And the establishment of a data forwarding satellite path between the source satellite and the target satellite can be completed, so that data transmission between the source satellite and the target satellite can be realized through the data forwarding satellite path during the handover.

[0254] Step 722: AMF sends a Handover Command to the onboard base station of the source satellite.

[0255] The AMF sends a Handover Command message to the source NG-RAN to notify that the handover preparation is complete. The message includes the PDU session list that accepts the handover and the PDU session list that refuses the handover obtained from the target NG-RAN during the handover preparation phase, as well as the N2 SM information of each session. If it is indirect forwarding, it also needs to include the downlink data forwarding address assigned by the target NG-RAN.

[0256] Step 723: The onboard base station of the source satellite sends an RRC Reconfiguration message to the UE.

[0257] It should be noted that the execution process of this step may specifically refer to step 624 in the previous embodiment, and the principle is the same, which will not be repeated here.

[0258] Step 724, forwarding of uplink data and spatial bearer network data.

[0259] The source NG-RAN records the forwarding information; the source NG-RAN starts forwarding the downlink data to the target NG-RAN via the data forwarding satellite path (which may pass through multiple satellites). The target NG-RAN caches the downlink message.

[0260] Step 725: The onboard base station of the source satellite sends an Uplink RAN ​​Status Transfer to the AMF.

[0261] Step 726: AMF sends a Downlink RAN ​​Status Transfer to the onboard base station of the target satellite.

[0262] Step 727: The UE synchronizes to the target base station.

[0263] Step 728: The UE sends an RRC Reconfiguration Complete message to the onboard base station of the target satellite.

[0264] It should be noted that the execution process of steps 725-728 may specifically refer to steps 625-628 in the previous embodiment, and the principles are the same, which will not be repeated here.

[0265] Step 729, forwarding downlink data.

[0266] In the downlink direction, the target NG-RAN first sends the cached forwarded downlink data to the UE. Step 730,

[0267] Uplink data sending.

[0268] The uplink data is sent directly, that is, through "UE→target NG-RAN→spatial bearer network→UPF".

[0269] Step 731: The onboard base station of the target satellite sends a Handover Notify to the AMF.

[0270] Step 732, AMF sends Nsmf_PDUSession_UpdateSMContext Request to SMF.

[0271] It should be noted that the execution process of steps 731-732 may specifically refer to steps 631-632 in the previous embodiment, and the principles are the same, which will not be repeated here.

[0272] Step 733, SMF sends a Session Modification Request to UPF.

[0273] SMF sends a Session Modification Request message to UPF. This step completes the path switching from UPF to the target NG-RAN. UPF records the N3 tunnel information of the target NG-RAN.

[0274] It should be noted that the N3 tunnel information of the target NG-RAN recorded by the UPF is the downlink tunnel address of the target NG-RAN, which is used for data transmission after successful switching, and is not the downlink data forwarding address allocated by the target NG-RAN.

[0275] To assist the reordering function in the target NG-RAN, the UPF (PSA) sends one or more 'end marker' messages to each N3 tunnel on the old path immediately after the handover. The source NG-RAN forwards the 'end marker' messages to the target NG-RAN via the indirect forwarding tunnel.

[0276] Step 734, UPF sends Session Modification Response to SMF.

[0277] UPF sends an N4 session modification response message to SMF.

[0278] Step 735: SMF sends a request to delete the spatial bearer network path to NCF.

[0279] Step 736: NCF sends a request to delete the space bearer network path to the onboard base station of the source satellite.

[0280] Step 737: The onboard base station of the source satellite sends a delete space bearer network path response to the NCF.

[0281] Step 738: NCF sends a delete space bearer network path response to SMF.

[0282] Step 739: SMF sends a request to delete the spatial bearer network path to NCF.

[0283] Step 740: NCF sends a request to delete the space bearer network path to the landing satellite on the source satellite side.

[0284] Step 741: The landing satellite on the source satellite side sends a delete space bearer network path response to the NCF.

[0285] Step 742, NCF sends a delete space bearer network path response to SMF.

[0286] It should be noted that the execution process of steps 735-742 may specifically refer to steps 635-642 in the previous embodiment, and the principles are the same, which will not be repeated here.

[0287] Step 743, downlink data transmission.

[0288] The downlink data transmission path after switching is "UPF→inter-satellite routing→target NG-RAN→UE".

[0289] Step 744, SMF sends Nsmf_PDUSession_UpdateSMContext Response to AMF.

[0290] Step 745: AMF sends a UE Context Release Command to the onboard base station of the source satellite.

[0291] Step 746: The onboard base station of the source satellite sends UE Context Release Complete to the AMF.

[0292] It should be noted that the execution process of steps 744-746 may specifically refer to steps 644-646 in the previous embodiment, and the principles are the same, which will not be repeated here.

[0293] Step 747, uplink and downlink data transmission.

[0294] The switch is completed, and the uplink and downlink data are Transmission between.

[0295] In summary, this application is based on the existing NR NG switching process, combined with the characteristics of the satellite communication system onboard base station mode, and modified, which has the following advantages:

[0296] 1. Directly build a satellite route between the source base station and the target base station for data forwarding. The data does not need to fall back to the UPF on the ground, which greatly shortens the delay.

[0297] 2. The number of nodes passed by the forwarding path is reduced, especially the old path that needs to pass through the feeder link twice for data forwarding is deleted, which improves reliability and increases the switching success rate;

[0298] 3. UPF no longer needs to allocate forwarding tunnels, which simplifies the processing process.

[0299] and Figure 2 Corresponding to the indirect data forwarding path based on NG interface switching shown, the present application provides a possible implementation method for establishing a data forwarding path during a switching process. Figure 8This is a schematic diagram of establishing a data forwarding path during the switching process provided in the eighth embodiment of the present application.

[0300] like Figure 8 As shown in the figure, when performing NG switching, the downlink data before the switching is transmitted through the path of "UPF→GW→B satellite→2 satellite→1 satellite→A satellite". During NG switching, if satellite C is selected as the target satellite, the target base station will inform SMF of the address of the allocated indirect forwarding tunnel; SMF will no longer inform UPF of the downlink forwarding address allocated by the target base station (UPF will therefore not allocate the forwarding address on the UPF side), but will inform NCF; after NCF learns the indirect data forwarding address of the target base station, it will directly build an inter-satellite route between the source base station and the target base station (in this example, it is assumed to pass through satellites 5 and 6). The downlink data forwarding path during the switching process is: A star→5 stars→6 stars→C star. Compared with the previous Figure 2 The forwarding path in the network (A star → 1 star → 2 star → B star → GW → UPF → GW → D star → 4 star → 3 star → C star) is greatly shortened, the transmission delay is reduced, the reliability is greatly improved, and at the same time, the switching success rate is increased, the service quality is improved, and the user perception is improved.

[0301] In summary, in the present application, when there is an inter-satellite link during the satellite NG switching process, the SMF does not need to inform the UPF of the data forwarding address on the target base station side, but directly informs the NCF, so that the UPF no longer allocates a data forwarding tunnel; the NCF transmits the data forwarding address on the target base station side to the source base station, rather than the data forwarding address on the UPF side, thereby enabling the NCF to directly build an inter-satellite data forwarding route between the source base station and the target base station, simplifying the transmission path, reducing transmission delay, and improving the reliability of data transmission.

[0302] With the above Figure 3 Corresponding to the data transmission method during network device switching provided in the embodiment, the present application also provides a data transmission device during network device switching. Since the data transmission device during network device switching provided in the embodiment of the present application is similar to the above-mentioned Figure 3 The data transmission method during network device switching provided in the embodiment corresponds to the data transmission method during network device switching, so the implementation method of the data transmission method during network device switching is also applicable to the data transmission device during network device switching provided in the embodiment of the present application, and will not be described in detail in the embodiment of the present application.

[0303] Fig. 9 It is a structural diagram of a data transmission device during network device switching provided according to the ninth embodiment of the present application.

[0304] like Fig. 9 As shown, the data transmission device during the network device switching may include a memory 910, a transceiver 920 and a processor 930.

[0305] The memory 910 is used to store computer programs; the transceiver 920 is used to send and receive data under the control of the processor; and the processor 930 is used to read the computer program in the memory and perform the following operations:

[0306] Receiving a first request message sent by a network control function NCF, wherein the first request message is used to request to establish a data forwarding path between a source network device and a target network device, and the first request message carries a downlink data forwarding address allocated by the target network device;

[0307] According to the downlink data forwarding address assigned by the target network device, a data forwarding path is established between the source network device and the target network device to send the target data to the target network device through the data forwarding path, wherein the target data is the data sent to the source network device by the user plane function UPF during network device switching.

[0308] The transceiver 920 is used to receive and send data under the control of the processor 930 .

[0309] Among them, Fig. 9 In the embodiment, the bus architecture may include any number of interconnected buses and bridges, specifically one or more processors represented by processor 930 and various circuits of memory represented by memory 910 are linked together. The bus architecture may also link together various other circuits such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art and are therefore not further described herein. The bus interface provides an interface. The transceiver 920 may be a plurality of components, namely, a transmitter and a receiver, providing a unit for communicating with various other devices on a transmission medium, which transmission medium may include a wireless channel, a wired channel, an optical cable, and other transmission media. The processor 930 is responsible for managing the bus architecture and general processing, and the memory 910 may store data used by the processor 930 when performing operations.

[0310] The processor 930 may 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 may also adopt a multi-core architecture.

[0311] As a possible implementation manner of an embodiment of the present application, when the source network device is a source satellite and the target network device is a target satellite, the data forwarding path is an inter-satellite link.

[0312] As a possible implementation method of an embodiment of the present application, the downlink data forwarding address is sent by the target network device to the access and mobility management function AMF, AMF sends it to SMF, and SMF sends it to NCF.

[0313] As a possible implementation method of an embodiment of the present application, the target network device is determined by the AMF according to the target identifier Target ID in the switching request message sent by the source network device.

[0314] With the above Figure 4 Corresponding to the data transmission method during network device switching provided in the embodiment, the present application also provides a data transmission device during network device switching. Since the data transmission device during network device switching provided in the embodiment of the present application is similar to the above-mentioned Figure 4 The data transmission method during network device switching provided in the embodiment corresponds to the data transmission method during network device switching, so the implementation method of the data transmission method during network device switching is also applicable to the data transmission device during network device switching provided in the embodiment of the present application, and will not be described in detail in the embodiment of the present application.

[0315] Fig.10 It is a structural diagram of a data transmission device during network device switching provided according to the tenth embodiment of the present application.

[0316] like Fig.10 As shown, the data transmission apparatus during network device switching may include a memory 1010 , a transceiver 1020 and a processor 1030 .

[0317] The memory 1010 is used to store computer programs; the transceiver 1020 is used to send and receive data under the control of the processor; and the processor 1030 is used to read the computer program in the memory and perform the following operations:

[0318] Receive a second request message sent by the SMF, wherein the second request message carries a downlink data forwarding address assigned by the target network device;

[0319] A first request message is sent to the source network device, wherein the first request message is used to request to establish a data forwarding path between the source network device and the target network device, and the first request message carries a downlink data forwarding address allocated by the target network device.

[0320] The transceiver 1020 is used to receive and send data under the control of the processor 1030 .

[0321] Among them, Fig.10In the embodiment, the bus architecture may include any number of interconnected buses and bridges, specifically one or more processors represented by processor 1030 and various circuits of memory represented by memory 1010 are linked together. The bus architecture may also link together various other circuits such as peripherals, voltage regulators, and power management circuits, which are well known in the art and are therefore not further described herein. The bus interface provides an interface. The transceiver 1020 may be a plurality of components, namely, a transmitter and a receiver, providing a unit for communicating with various other devices on a transmission medium, which transmission medium may include a wireless channel, a wired channel, an optical cable, and other transmission media. The processor 1030 is responsible for managing the bus architecture and general processing, and the memory 1010 may store data used by the processor 1030 when performing operations.

[0322] The processor 1030 may 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 may also adopt a multi-core architecture.

[0323] As a possible implementation method of an embodiment of the present application, when the source network device is a source satellite and the target network device is a target satellite, the data forwarding path is an intersatellite link, which is used for the source satellite to send target data to the target satellite during network device switching, wherein the target data is the data sent by the UPF to the source network device during network device switching.

[0324] As a possible implementation method of an embodiment of the present application, the downlink data forwarding address is sent by the target network device to the access and mobility management function AMF, AMF sends it to SMF, and SMF sends it to NCF.

[0325] As a possible implementation method of an embodiment of the present application, the target network device is determined by the AMF according to the target identifier Target ID in the switching request message sent by the source network device.

[0326] With the above Figure 5 Corresponding to the data transmission method during network device switching provided in the embodiment, the present application also provides a data transmission device during network device switching. Since the data transmission device during network device switching provided in the embodiment of the present application is similar to the above-mentioned Figure 5The data transmission method during network device switching provided in the embodiment corresponds to the data transmission method during network device switching, so the implementation method of the data transmission method during network device switching is also applicable to the data transmission device during network device switching provided in the embodiment of the present application, and will not be described in detail in the embodiment of the present application.

[0327] Fig.11 It is a structural diagram of a data transmission device during network device switching provided according to the eleventh embodiment of the present application.

[0328] like Fig.11 As shown, the data transmission device during network device switching may include a memory 1110 , a transceiver 1120 and a processor 1130 .

[0329] The memory 1110 is used to store computer programs; the transceiver 1120 is used to send and receive data under the control of the processor; and the processor 1130 is used to read the computer program in the memory and perform the following operations:

[0330] A switching request confirmation message is sent to the AMF, wherein the switching request confirmation message includes the downlink data forwarding address assigned by the target network device.

[0331] The transceiver 1120 is used to receive and send data under the control of the processor 1130 .

[0332] Among them, Fig.11 In the embodiment, the bus architecture may include any number of interconnected buses and bridges, specifically one or more processors represented by processor 1130 and various circuits of memory represented by memory 1110 are linked together. The bus architecture may also link together various other circuits such as peripherals, voltage regulators, and power management circuits, which are well known in the art and are therefore not further described herein. The bus interface provides an interface. The transceiver 1120 may be a plurality of components, namely, a transmitter and a receiver, providing a unit for communicating with various other devices on a transmission medium, which transmission medium may include a wireless channel, a wired channel, an optical cable, and other transmission media. The processor 1130 is responsible for managing the bus architecture and general processing, and the memory 1110 may store data used by the processor 1130 when performing operations.

[0333] The processor 1130 may 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 may also adopt a multi-core architecture.

[0334] As a possible implementation method of an embodiment of the present application, the target network device is determined by the AMF according to the target identifier Target ID in the switching request message sent by the source network device.

[0335] It should be noted here that the above-mentioned device provided in the embodiment of the present application can implement all the method steps implemented in the above-mentioned method embodiment, and can achieve the same technical effect. The parts and beneficial effects of this embodiment that are the same as those in the method embodiment will not be described in detail here.

[0336] With the above Figure 3 Corresponding to the data transmission method during network device switching provided in the embodiment, the present application also provides a data transmission device during network device switching. Since the data transmission device during network device switching provided in the embodiment of the present application is similar to the above-mentioned Figure 3 The data transmission method during network device switching provided in the embodiment corresponds to the data transmission method during network device switching, so the implementation method of the data transmission method during network device switching is also applicable to the data transmission device during network device switching provided in the embodiment of the present application, and will not be described in detail in the embodiment of the present application.

[0337] Fig.12 It is a structural diagram of a data transmission device during network device switching provided according to the twelfth embodiment of the present application.

[0338] like Fig.12 As shown, the data transmission device during the network device switching may include: a first receiving unit 1210 and a first sending unit 1220.

[0339] The first receiving unit 1210 is used to receive a first request message sent by the network control function NCF, wherein the first request message is used to request to establish a data forwarding path between the source network device and the target network device, and the first request message carries a downlink data forwarding address allocated by the target network device;

[0340] The first sending unit 1220 is used to establish a data forwarding path between the source network device and the target network device according to the downlink data forwarding address assigned by the target network device, so as to send the target data to the target network device through the data forwarding path, wherein the target data is the data sent to the source network device by the user plane function UPF during network device switching.

[0341] Optionally, in a possible implementation manner of an embodiment of the present application, when the source network device is a source satellite and the target network device is a target satellite, the data forwarding path is an inter-satellite link.

[0342] Optionally, in a possible implementation of an embodiment of the present application, the downlink data forwarding address is sent by the target network device to the access and mobility management function AMF, the AMF sends it to the SMF, and the SMF sends it to the NCF.

[0343] Optionally, in a possible implementation manner of an embodiment of the present application, the target network device is determined by the AMF according to the target identifier Target ID in the switching request message sent by the source network device.

[0344] With the above Figure 4 Corresponding to the data transmission method during network device switching provided in the embodiment, the present application also provides a data transmission device during network device switching. Since the data transmission device during network device switching provided in the embodiment of the present application is similar to the above-mentioned Figure 4 The data transmission method during network device switching provided in the embodiment corresponds to the data transmission method during network device switching, so the implementation method of the data transmission method during network device switching is also applicable to the data transmission device during network device switching provided in the embodiment of the present application, and will not be described in detail in the embodiment of the present application.

[0345] Fig.13 It is a structural diagram of a data transmission device during network device switching provided according to the thirteenth embodiment of the present application.

[0346] like Fig.13 As shown, the data transmission device during the network device switching may include: a second receiving unit 1310 and a second sending unit 1320.

[0347] The second receiving unit 1310 is configured to receive a second request message sent by the SMF, wherein the second request message carries a downlink data forwarding address allocated by the target network device;

[0348] The second sending unit 1320 is used to send a first request message to the source network device, wherein the first request message is used to request to establish a data forwarding path between the source network device and the target network device, and the first request message carries a downlink data forwarding address allocated by the target network device.

[0349] Optionally, in a possible implementation of an embodiment of the present application, when the source network device is a source satellite and the target network device is a target satellite, the data forwarding path is an intersatellite link, which is used for the source satellite to send target data to the target satellite during network device switching, wherein the target data is data sent by the UPF to the source network device during network device switching.

[0350] Optionally, in a possible implementation of an embodiment of the present application, the downlink data forwarding address is sent by the target network device to the access and mobility management function AMF, the AMF sends it to the SMF, and the SMF sends it to the NCF.

[0351] Optionally, in a possible implementation manner of an embodiment of the present application, the target network device is determined by the AMF according to the target identifier Target ID in the switching request message sent by the source network device.

[0352] With the above Figure 5 Corresponding to the data transmission method during network device switching provided in the embodiment, the present application also provides a data transmission device during network device switching. Since the data transmission device during network device switching provided in the embodiment of the present application is similar to the above-mentioned Figure 5 The data transmission method during network device switching provided in the embodiment corresponds to the data transmission method during network device switching, so the implementation method of the data transmission method during network device switching is also applicable to the data transmission device during network device switching provided in the embodiment of the present application, and will not be described in detail in the embodiment of the present application.

[0353] Fig.14 It is a structural diagram of a data transmission device during network device switching provided according to the fourteenth embodiment of the present application.

[0354] like Fig.14 As shown, the data transmission device during the network device switching may include: a third sending unit 1410.

[0355] The third sending unit 1410 is used to send a switching request confirmation message to the AMF, wherein the switching request confirmation message includes a downlink data forwarding address assigned by the target network device.

[0356] Optionally, in a possible implementation manner of an embodiment of the present application, the target network device is determined by the AMF according to the target identifier Target ID in the switching request message sent by the source network device.

[0357] It should be noted here that the above-mentioned device provided in the embodiment of the present application can implement all the method steps implemented in the above-mentioned method embodiment, and can achieve the same technical effect. The parts and beneficial effects of this embodiment that are the same as those in the method embodiment will not be described in detail here.

[0358] It should be noted that the division of units in the embodiments of the present application is schematic and is only a logical function division. There may be other division methods in actual implementation. In addition, each functional unit in each embodiment of the present application may be integrated into a processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0359] If the integrated unit is implemented in the form of 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 the present application is essentially 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, and the computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, server, or network device, etc.) or a processor (processor) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (Read-Only Memory, ROM), random access memory (Random Access Memory, RAM), disk or optical disk and other media that can store program codes.

[0360] It should be noted here that the above-mentioned device provided in the embodiment of the present application can implement all the method steps implemented in the above-mentioned method embodiment, and can achieve the same technical effect. The parts and beneficial effects of this embodiment that are the same as those in the method embodiment will not be described in detail here.

[0361] In order to implement the above embodiments, the present application also proposes a processor-readable storage medium. The processor-readable storage medium stores a computer program, which is used to enable the processor to execute the present application. Figures 2 to 5 A data transmission method during network device switching in an embodiment.

[0362] The processor-readable storage medium can be any available medium or data storage device that can be accessed by the processor, including but not limited to magnetic storage (such as floppy disks, hard disks, magnetic tapes, magneto-optical disks (MO), etc.), optical storage (such as CD, DVD, BD, HVD, etc.), and semiconductor storage (such as ROM, EPROM, EEPROM, non-volatile memory (NANDFLASH), solid-state drive (SSD)), etc.

[0363] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt 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, etc.) that contain computer-usable program code.

[0364] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer executable instructions. These computer executable instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0365] 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 specific manner, so that the instructions stored in the processor readable memory produce an article of manufacture including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0366] These processor-executable instructions may also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for executing on the computer or other programmable device to implement the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0367] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A data transmission method during network device switching, characterized in that: Applied to a source network device, the method comprises: Receive a first request message sent by a network control function NCF, wherein the first request message is used to request to establish a data forwarding path between the source network device and the target network device, and the first request message carries a downlink data forwarding address allocated by the target network device; According to the downlink data forwarding address assigned by the target network device, a data forwarding path is established between the source network device and the target network device to send the target data to the target network device through the data forwarding path, wherein the target data is the data sent to the source network device by the user plane function UPF during network device switching.

2. The method according to claim 1, characterized in that When the source network device is a source satellite and the target network device is a target satellite, the data forwarding path is an intersatellite link.

3. The method according to claim 1, characterized in that The downlink data forwarding address is sent by the target network device to the access and mobility management function AMF, the AMF sends it to the SMF, and the SMF sends it to the NCF.

4. The method according to claim 1, characterized in that The target network device is determined by the AMF according to the target identifier TargetID in the switching request message sent by the source network device.

5. A data transmission method during network device switching, characterized in that: Applied to a network control function, the method comprises: Receive a second request message sent by the SMF, wherein the second request message carries a downlink data forwarding address assigned by the target network device; A first request message is sent to the source network device, wherein the first request message is used to request establishment of a data forwarding path between the source network device and the target network device, and the first request message carries a downlink data forwarding address allocated by the target network device.

6. The method according to claim 5, characterized in that When the source network device is a source satellite and the target network device is a target satellite, the data forwarding path is an intersatellite link, which is used by the source satellite to send target data to the target satellite during network device switching, wherein the target data is data sent by the UPF to the source network device during network device switching.

7. The method according to claim 5, characterized in that The downlink data forwarding address is sent by the target network device to the access and mobility management function AMF, the AMF sends it to the SMF, and the SMF sends it to the NCF.

8. The method according to claim 5, characterized in that The target network device is determined by the AMF according to the target identifier TargetID in the switching request message sent by the source network device.

9. A data transmission method during network device switching, characterized in that: Applied to a target network device, the method comprises: Send a switching request confirmation message to the AMF, wherein the switching request confirmation message includes the downlink data forwarding address assigned by the target network device.

10. The method according to claim 9, characterized in that The target network device is determined by the AMF according to the target identifier TargetID in the switching request message sent by the source network device.

11. A data transmission device during network device switching, characterized in that: Including memory, transceiver, processor: A memory for storing a computer program; a transceiver for transmitting and receiving data under the control of the processor; and a processor for reading the computer program in the memory and performing the following operations: Receive a first request message sent by a network control function NCF, wherein the first request message is used to request to establish a data forwarding path between the source network device and the target network device, and the first request message carries a downlink data forwarding address allocated by the target network device; According to the downlink data forwarding address assigned by the target network device, a data forwarding path is established between the source network device and the target network device to send the target data to the target network device through the data forwarding path, wherein the target data is the data sent to the source network device by the user plane function UPF during network device switching.

12. The device according to claim 11, characterized in that When the source network device is a source satellite and the target network device is a target satellite, the data forwarding path is an intersatellite link.

13. The device according to claim 11, characterized in that The downlink data forwarding address is sent by the target network device to the access and mobility management function AMF, the AMF sends it to the SMF, and the SMF sends it to the NCF.

14. The device according to claim 11, characterized in that The target network device is determined by the AMF according to the target identifier TargetID in the switching request message sent by the source network device.

15. A data transmission device during network device switching, characterized in that: Including memory, transceiver, processor: A memory for storing a computer program; a transceiver for transmitting and receiving data under the control of the processor; and a processor for reading the computer program in the memory and performing the following operations: Receive a second request message sent by the SMF, wherein the second request message carries a downlink data forwarding address assigned by the target network device; A first request message is sent to the source network device, wherein the first request message is used to request establishment of a data forwarding path between the source network device and the target network device, and the first request message carries a downlink data forwarding address allocated by the target network device.

16. The device according to claim 15, characterized in that When the source network device is a source satellite and the target network device is a target satellite, the data forwarding path is an intersatellite link, which is used by the source satellite to send target data to the target satellite during network device switching, wherein the target data is data sent by the UPF to the source network device during network device switching.

17. The device according to claim 15, characterized in that The downlink data forwarding address is sent by the target network device to the access and mobility management function AMF, the AMF sends it to the SMF, and the SMF sends it to the NCF.

18. The device according to claim 15, characterized in that The target network device is determined by the AMF according to the target identifier TargetID in the switching request message sent by the source network device.

19. A data transmission device during network device switching, characterized in that: Including memory, transceiver, processor: A memory for storing a computer program; a transceiver for transmitting and receiving data under the control of the processor; and a processor for reading the computer program in the memory and performing the following operations: Send a switching request confirmation message to the AMF, wherein the switching request confirmation message includes the downlink data forwarding address assigned by the target network device.

20. The device according to claim 19, characterized in that The target network device is determined by the AMF according to the target identifier TargetID in the switching request message sent by the source network device.

21. A data transmission device during network device switching, characterized in that: include: A first receiving unit, configured to receive a first request message sent by a network control function NCF, wherein the first request message is used to request to establish a data forwarding path between the source network device and the target network device, and the first request message carries a downlink data forwarding address assigned by the target network device; A first sending unit is used to establish a data forwarding path between the source network device and the target network device according to the downlink data forwarding address assigned by the target network device, so as to send target data to the target network device through the data forwarding path, wherein the target data is data sent to the source network device by the user plane function UPF during network device switching.

22. A data transmission device during network device switching, characterized in that: include: A second receiving unit, configured to receive a second request message sent by the SMF, wherein the second request message carries a downlink data forwarding address assigned by the target network device; The second sending unit is used to send a first request message to the source network device, wherein the first request message is used to request to establish a data forwarding path between the source network device and the target network device, and the first request message carries a downlink data forwarding address allocated by the target network device.

23. A data transmission device during network device switching, characterized in that: include: The third sending unit is used to send a switching request confirmation message to the AMF, wherein the switching request confirmation message includes a downlink data forwarding address assigned by the target network device.

24. A processor-readable storage medium, characterized in that: The processor-readable storage medium stores a computer program, and the computer program is used to enable the processor to execute the method of any one of claims 1 to 4, or the method of any one of claims 5 to 8, or the method of any one of claims 9 to 10.

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