Communication method and communication device

Abstract

The invention provides a communication method and a communication device, which can be applied to a non-ground communication network, such as a satellite network, an unmanned aerial vehicle platform, a high-altitude platform and the like. In the method, a source access network device transmits the information to a target access network device through at least one of information of a transmission path between the source access network device and the target access network device, time information, or position information of the source access network device. And determining to switch the terminal equipment to the target equipment by adopting a switching mode based on an interface between the access network equipment or a switching mode based on an interface between the access network equipment and the core network equipment. The switching time delay of the terminal equipment can be reduced.

Description

Technical Field

[0001] The present application relates to the field of communications, and more specifically, to a communication method and a communication device. Background Art

[0002] Non-terrestrial communication networks (NTN) include satellite networks, high-altitude platforms and drones, which together with mobile communication systems constitute a global integrated communication network with seamless coverage of sea, land, air, space and ground, which can meet the needs of various businesses.

[0003] In NTN, satellite nodes can use a variety of switching methods to execute the mobility management process of user equipment (UE) within the coverage of the satellite nodes. How to choose a reasonable switching method has become an urgent problem to be solved. Summary of the invention

[0004] The present application provides a communication method and a communication device, which can select a reasonable switching mode for a terminal device and reduce the switching delay.

[0005] In a first aspect, a communication method is provided, which can be executed by a source access network device, or can also be executed by a module (such as a chip or circuit) of the source access network device, or can also be executed by a logical node, a logical module or software that can implement all or part of the functions of the source access network device. This application is not limited to this. The following is an example of the method being executed by the source access network device.

[0006] The method includes: the source access network device determines, based on first information, to use a first switching method to switch the terminal device to the target access network device, the first switching method being a switching method based on an interface between access network devices or a switching method based on an interface between an access network device and a core network device; switching the terminal device to the target access network device based on the first switching method; wherein the first information includes at least one of the following: information on a transmission path between the source access network device and the target access network device, time information, or location information of the source access network device.

[0007] Based on the above scheme, by determining a switching method for switching the terminal device to the target access network device based on at least one of the information of the transmission path between the source access network device and the target access network device, the time information, or the location information of the source access network device, and switching the terminal device to the target access network device based on the switching method, the switching delay of the terminal device can be reduced.

[0008] Exemplarily, the interface between the access network devices is an Xn interface; the interface between the access network device and the core network device is an N2 interface.

[0009] In combination with the first aspect, in certain implementations of the first aspect, the switching method based on the interface between access network devices is Xn switching; or, the switching method based on the interface between the access network device and the core network device is N2 switching.

[0010] In combination with the first aspect, in certain implementations of the first aspect, the information of the transmission path includes at least one of the following: the number of hops of the transmission path, the delay of the transmission path, and the distance of the transmission path.

[0011] Based on the above scheme, by considering at least one of the number of hops, delay or distance of the transmission path between the source access network devices when determining whether to use Xn switching or N2 switching to switch the terminal device to the target access network device, a reasonable switching method can be selected to switch the terminal device to the target access network device, thereby reducing the switching delay of the terminal device.

[0012] In combination with the first aspect, in certain implementations of the first aspect, the source access network device determines the number of hops of the transmission path based on ephemeris information and time information; or, the source access network device determines the number of hops of the transmission path based on a topological structure of the transmission path.

[0013] Based on the above scheme, the number of hops of the transmission path between source access network devices can be determined through ephemeris information or the network topology structure of the transmission path, so that the source access network device can select a reasonable switching method according to the number of hops of the transmission path to switch the terminal device to the target access network device, which can reduce the switching delay of the terminal device.

[0014] In combination with the first aspect, in certain implementations of the first aspect, the delay of the transmission path includes: the Xn switching delay and / or N2 switching delay from the source access network device to the target access network device stored by the source access network device, or the Xn switching delay and / or N2 switching delay from the source access network device to the target access network device measured by the source access network device.

[0015] Based on the above scheme, the delay of the transmission path between the source access network devices can be determined by the Xn switching delay and / or N2 switching delay stored in the source access network device, or at least one of the measured Xn switching delay and / or N2 switching delay, so that the source access network device can select a reasonable switching method to switch the terminal device to the target access network device according to the delay of the transmission path, thereby reducing the switching delay of the terminal device.

[0016] In combination with the first aspect, in some implementations of the first aspect, the source access network device measures an Xn switching delay and / or an N2 switching delay from the source access network device to the target access network device.

[0017] In combination with the first aspect, in certain implementations of the first aspect, the source access network device sends a measurement signal to the target access network device; the source access network device receives a response signal from the target access network device, and the response signal is sent based on the measurement signal; the source access network device determines the Xn switching delay based on the time of sending the measurement signal and the time of receiving the response signal.

[0018] Based on the above scheme, the Xn switching delay can be measured by the source access network device, so that a reasonable switching method can be selected according to the Xn switching delay to switch the terminal device to the target access network device, which can reduce the switching delay of the terminal device.

[0019] In combination with the first aspect, in certain implementations of the first aspect, the source access network device sends indication information to the target access network device, and the indication information indicates measuring the information transmission delay between the target access network device and the core network device; the source access network device receives the N2 switching delay from the source access network device to the target access network device measured by the target access network device, and the N2 switching delay is determined based on the information transmission delay.

[0020] Based on the above scheme, the N2 switching delay can be measured by the source access network device, so that a reasonable switching method can be selected according to the N2 switching delay to switch the terminal device to the target access network device, which can reduce the switching delay of the terminal device.

[0021] In combination with the first aspect, in certain implementations of the first aspect, the source access network device sends a measurement signal to the core network device, the measurement signal including the identifier of the target access network device and a first timestamp; the source access network device receives a response signal from the core network device through the target access network device, the response signal including a second timestamp; and the N2 switching delay from the source access network device to the target access network device measured according to the first timestamp and the first timestamp.

[0022] Based on the above scheme, the N2 switching delay can be measured by the source access network device, so that a reasonable switching method can be selected according to the N2 switching delay to switch the terminal device to the target access network device, which can reduce the switching delay of the terminal device.

[0023] In combination with the first aspect, in certain implementations of the first aspect, when the delay of the transmission path includes the Xn switching delay and the N2 switching delay measured by the source access network device from the source access network device to the target access network device, if the Xn switching delay is greater than the N2 switching delay, then it is determined that the first switching mode is a switching mode based on the interface between the access network device and the core network device; or, if the Xn switching delay is less than or equal to the N2 switching delay, then it is determined that the first switching mode is a switching mode based on the interface between access network devices.

[0024] Based on the above scheme, the source access network device can determine a reasonable switching method to switch the terminal device to the target access network device according to the size relationship between the Xn switching delay and the N2 switching delay, thereby reducing the switching delay of the terminal device.

[0025] In combination with the first aspect, in certain implementations of the first aspect, when the first information includes the time information, or the location information of the source access network device, the source access network device determines to use the first switching method to switch the terminal device to the target access network device based on the first information and the first correspondence, and the first correspondence includes the correspondence between the time information and / or location information and the switching method.

[0026] Based on the above scheme, the source access network device can determine a reasonable switching method to switch the terminal device to the target access network device according to the current time and / or location and the correspondence between the time information and / or location information and the switching method, thereby reducing the switching delay of the terminal device.

[0027] In combination with the first aspect, in certain implementations of the first aspect, when the first information includes information about the transmission path between the source access network device and the target access network device, the source access network device determines to use the first switching method to switch the terminal device to the target access network device based on the information about the transmission path and a threshold corresponding to the information about the transmission path.

[0028] In combination with the first aspect, in certain implementations of the first aspect, the source access network device determines, based on the information of the transmission path and a threshold value corresponding to the information of the transmission path, that the first switching mode is a switching mode based on the interface between the access network device and the core network device if the information of the transmission path is greater than the threshold value corresponding to the information of the transmission path; or, if the information of the transmission path is less than or equal to the threshold value corresponding to the information of the transmission path, determines that the first switching mode is a switching mode based on the interface between access network devices.

[0029] Based on the above scheme, the source access network device can determine a reasonable switching method to switch the terminal device to the target access network device according to the determined transmission path information and the threshold corresponding to the transmission path information, thereby reducing the switching delay of the terminal device.

[0030] In combination with the first aspect, in certain implementations of the first aspect, when the switching method is a switching method based on an interface between an access network device and a core network device, the source access network device sends the context information of the terminal device to the core network device through the interface.

[0031] In combination with the first aspect, in certain implementations of the first aspect, when the switching method is a switching method based on an interface between access network devices, the source access network device sends the context information of the terminal device to the target access network device through the interface.

[0032] In combination with the first aspect, in some implementations of the first aspect, the source access network device and the target access network device are deployed on different satellites.

[0033] In a second aspect, a communication device is provided, which includes a processing unit, and the processing unit is used to determine, based on first information, to use a first switching method to switch a terminal device to a target access network device, and the first switching method is a switching method based on an interface between access network devices or a switching method based on an interface between an access network device and a core network device; the processing unit is also used to switch the terminal device to the target access network device based on the first switching method; wherein the first information includes at least one of the following: information on a transmission path between the device and the target access network device, time information, or location information of the device.

[0034] Exemplarily, the interface between the access network devices is an Xn interface; the interface between the access network device and the core network device is an N2 interface.

[0035] In combination with the second aspect, in certain implementations of the second aspect, the switching method based on the interface between access network devices is Xn switching; or, the switching method based on the interface between the access network device and the core network device is N2 switching.

[0036] In combination with the second aspect, in some implementations of the second aspect, the information of the transmission path includes at least one of the following: the number of hops of the transmission path, the delay of the transmission path, and the distance of the transmission path.

[0037] In combination with the second aspect, in certain implementations of the second aspect, the processing unit is further used to: determine the number of hops of the transmission path based on ephemeris information and time information; or determine the number of hops of the transmission path based on a topological structure of the transmission path.

[0038] In combination with the second aspect, in certain implementations of the second aspect, the delay of the transmission path includes: the Xn switching delay and / or N2 switching delay from the device to the target access network device stored by the device, or the Xn switching delay and / or N2 switching delay from the device to the target access network device measured by the processing unit.

[0039] In combination with the second aspect, in some implementations of the second aspect, the processing unit is further used to: measure an Xn switching delay and / or an N2 switching delay from the apparatus to the target access network device.

[0040] In combination with the second aspect, in certain implementations of the second aspect, the device also includes a transceiver unit, which is used to send a measurement signal to the target access network device; receive a response signal from the target access network device, and the response signal is sent based on the measurement signal; the processing unit is specifically used to determine the Xn switching delay based on the time of sending the measurement signal and the time of receiving the response signal.

[0041] In combination with the second aspect, in certain implementations of the second aspect, the device also includes a transceiver unit, which is used to send indication information to the target access network device, and the indication information indicates the measurement of the information transmission delay between the target access network device and the core network device; and receive the N2 switching delay from the device to the target access network device measured by the target access network device, and the N2 switching delay is determined based on the information transmission delay.

[0042] In combination with the second aspect, in certain implementations of the second aspect, the device also includes a transceiver unit, which is used to send a measurement signal to a core network device, the measurement signal including an identifier of the target access network device and a first timestamp; receive a response signal from the core network device through the target access network device, the response signal including a second timestamp; the processing unit is specifically used to obtain the N2 switching delay from the device to the target access network device based on the first timestamp and the measured first timestamp.

[0043] In combination with the second aspect, in certain implementations of the second aspect, when the delay of the transmission path includes the Xn switching delay and the N2 switching delay measured by the processing unit from the device to the target access network device, the processing unit is specifically used to: if the Xn switching delay is greater than the N2 switching delay, determine that the first switching mode is a switching mode based on the interface between the access network device and the core network device; or, if the Xn switching delay is less than or equal to the N2 switching delay, determine that the first switching mode is a switching mode based on the interface between access network devices.

[0044] In combination with the second aspect, in certain implementations of the second aspect, when the first information includes the time information, or the location information of the device, the processing unit is specifically used to: determine, based on the first information and the first correspondence, to use the first switching method to switch the terminal device to the target access network device, and the first correspondence includes the correspondence between the time information and / or location information and the switching method.

[0045] In combination with the second aspect, in certain implementations of the second aspect, when the first information includes information about the transmission path between the device and the target access network device, the processing unit is specifically used to: determine to use the first switching method to switch the terminal device to the target access network device based on the information about the transmission path and a threshold corresponding to the information about the transmission path.

[0046] In combination with the second aspect, in certain implementations of the second aspect, the processing unit is specifically used to: if the information of the transmission path is greater than a threshold corresponding to the information of the transmission path, determine that the first switching mode is a switching mode based on the interface between the access network device and the core network device; or, if the information of the transmission path is less than or equal to the threshold corresponding to the information of the transmission path, determine that the first switching mode is a switching mode based on the interface between access network devices.

[0047] In combination with the second aspect, in certain implementations of the second aspect, when the switching method is a switching method based on the interface between the access network device and the core network device, the processing unit is specifically used to: determine to send the context information of the terminal device to the core network device through the interface.

[0048] In combination with the second aspect, in certain implementations of the second aspect, when the switching method is a switching method based on an interface between access network devices, the processing unit is specifically used to: determine to send the context information of the terminal device to the target access network device through the interface.

[0049] In a third aspect, a communication device is provided, which includes a processor, the processor is coupled to a memory, and can be used to execute instructions in the memory to implement any aspect of the above-mentioned first aspect, and a method in any possible implementation manner of the first aspect.

[0050] Optionally, the device further includes a memory, and the memory and the processor may be deployed separately or centrally. Optionally, the device further includes a communication interface, and the processor is coupled to the communication interface.

[0051] In one implementation, the communication interface may be a transceiver, or an input / output interface.

[0052] In another implementation, the device is an access network device, or a chip configured in the access network device, or a logic module or software that can implement all or part of the functions of the access network device. When the device is a chip, the communication interface can be an input / output interface, an interface circuit, an output circuit, an input circuit, a pin or a related circuit on the chip or chip system. The processor can also be embodied as a processing circuit or a logic circuit.

[0053] Optionally, the transceiver may be a transceiver circuit. Optionally, the input / output interface may be an input / output circuit.

[0054] In the specific implementation process, the above-mentioned processor can be one or more chips, the input circuit can be an input pin, the output circuit can be an output pin, and the processing circuit can be a transistor, a gate circuit, a trigger, and various logic circuits. The input signal received by the input circuit can be but not limited to being received and input by the receiver, and the signal output by the output circuit can be but not limited to being output to the transmitter and transmitted by the transmitter, and the input circuit and the output circuit can be the same circuit, which is used as an input circuit and an output circuit at different times. The embodiment of the present application does not limit the specific implementation of the processor and various circuits.

[0055] In a fourth aspect, a communication device is provided, which includes a logic circuit and an input / output interface, wherein the logic circuit is used to couple with the input / output interface and transmit data through the input / output interface to execute any aspect of the above-mentioned first aspect and any possible implementation method of the first aspect.

[0056] In one implementation, the device is an access network device, or a chip configured in the access network device, and may also be a logic module or software that can implement all or part of the functions of the access network device. When the device is a chip, the communication interface may be an input / output interface, an interface circuit, an output circuit, an input circuit, a pin or a related circuit on the chip or chip system. The processor may also be embodied as a processing circuit or a logic circuit.

[0057] In a fifth aspect, the present application provides a chip system, comprising: a processor, the processor being used to execute a computer program or instruction in the memory, so that the chip system implements the method in the above-mentioned first aspect and any possible implementation manner of the first aspect.

[0058] In a sixth aspect, the present application provides a communication system, comprising: an access network device, wherein the access network device is used to execute the method in the above-mentioned first aspect and any possible implementation manner of the first aspect.

[0059] In the seventh aspect, a computer-readable storage medium is provided, which stores a computer program (also referred to as code, or instructions). When the computer-readable storage medium is run on a computer, the computer executes any aspect of the above-mentioned first aspect, as well as a method in any possible implementation of the first aspect.

[0060] In an eighth aspect, a computer program product is provided, which includes: a computer program (also referred to as code, or instruction), which, when executed, enables a computer to execute any aspect of the above-mentioned first aspect, as well as a method in any possible implementation of the first aspect.

[0061] The beneficial effects brought about by the second to eighth aspects mentioned above can be referred to the description of the beneficial effects in the first and second aspects, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 It is a schematic diagram of a system architecture.

[0063] Figure 2 It is a schematic diagram of the NTN system architecture.

[0064] Figure 3 It is a two-dimensional unfolded schematic diagram of a polar orbiting constellation.

[0065] Figure 4 It is a schematic flow chart of Xn switching.

[0066] Figure 5 It is a schematic flow chart of a communication method 500 provided in an embodiment of the present application.

[0067] Figure 6 It is a schematic flow chart of a communication method 600 provided in an embodiment of the present application.

[0068] Figure 7 It is a schematic flow chart of a communication method 700 provided in an embodiment of the present application.

[0069] Figure 8 It is a structural diagram of a communication device provided in an embodiment of the present application.

[0070] Fig. 9 It is a structural diagram of another communication device provided in an embodiment of the present application.

[0071] Fig.10 It is a structural diagram of another communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0072] The technical solution in this application will be described below in conjunction with the accompanying drawings.

[0073] The technical solution provided in this application can be applied to various communication systems, such as: the fifth generation (5th generation, 5G) or new radio (new radio, NR) system, long term evolution (long term evolution, LTE) system, LTE frequency division duplex (frequency division duplex, FDD) system, LTE time division duplex (time division duplex, TDD) system, etc. The technical solution provided in this application can also be applied to future communication systems, such as the sixth generation mobile communication system. The technical solution provided in this application can also be applied to device to device (D2D) communication, vehicle to everything (V2X) communication, machine to machine (M2M) communication, non-terrestrial network (NTN) system, machine type communication (MTC), and Internet of things (IoT) communication system or other communication systems.

[0074] Figure 1 A schematic diagram of a network architecture is shown. Figure 1As shown in the figure, the network architecture takes the 5G system (5GS) as an example. The network architecture may include but is not limited to: network slice selection function (NSSF), authentication server function (AUSF), unified data management (UDM), network exposure function (NEF), network storage function (NF repository function NRF), policy control function (PCF), application function (AF), access and mobility management function (AMF), session management function (SMF), user equipment (UE), radio access network equipment, user plane function (UPF), data network (DN).

[0075] Among them, DN can be the Internet; NSSF, AUSF, UDM, NEF, NRF, PCF, AF, AMF, SMF, and UPF are network elements in the core network. Figure 1 Taking the 5G system as an example, the core network can be called the 5G core network (5G core network, 5GC or 5GCN).

[0076] Below Figure 1 A brief introduction is given to each network element shown in FIG.

[0077] 1. UE: may be referred to as terminal equipment, access terminal, user unit, user station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication equipment, user agent or user device.

[0078] The terminal device may be a device that provides voice / data to users, for example, a handheld device or a vehicle-mounted device with a wireless connection function. At present, some examples of terminals are: mobile phones, tablet computers, laptop computers, PDAs, mobile internet devices (MIDs), wearable devices, virtual reality (VR) devices, augmented reality (AR) devices, wireless terminals in industrial control, wireless terminals in self driving, wireless terminals in remote medical surgery, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, wireless terminals in smart homes, cellular phones, cordless phones, session initiation protocol (SIP) phones, wireless local loop (WLL) stations, personal digital assistants (PDAs), handheld devices with wireless communication capabilities, computing devices or other processing devices connected to wireless modems, wearable devices, terminal devices in 5G networks or future evolved public land mobile communication networks (public land mobile The embodiments of the present application do not limit this.

[0079] As an example but not limitation, in the embodiments of the present application, the terminal device may also be a wearable device. Wearable devices may also be referred to as wearable smart devices, which are a general term for wearable devices that are intelligently designed and developed using wearable technology for daily wear, such as glasses, gloves, watches, clothing, and shoes. A wearable device is a portable device that is worn directly on the body or integrated into the user's clothes or accessories. Wearable devices are not only hardware devices, but also powerful functions achieved through software support, data interaction, and cloud interaction. Broadly speaking, wearable smart devices include full-featured, large-sized, and fully or partially independent of smartphones, such as smart watches or smart glasses, as well as devices that only focus on a certain type of application function and need to be used in conjunction with other devices such as smartphones, such as various types of smart bracelets and smart jewelry for vital sign monitoring.

[0080] In addition, in the embodiments of the present application, the terminal device can also be a terminal device in an IoT system. IoT is an important part of the future development of information technology. Its main technical feature is to connect objects to the network through communication technology, thereby realizing an intelligent network that interconnects people and machines and things.

[0081] It should be noted that the terminal device and the access network device can communicate with each other using a certain air interface technology (such as NR or LTE technology, etc.). The terminal devices can also communicate with each other using a certain air interface technology (such as NR or LTE technology, etc.).

[0082] In the embodiment of the present application, the device for realizing the function of the terminal device can be the terminal device, or it can be a device that can support the terminal device to realize the function, such as a chip system or a chip, which can be installed in the terminal device. In the embodiment of the present application, the chip system can be composed of a chip, or it can include a chip and other discrete devices.

[0083] 2. (Radio) access network (R)AN) node: It can provide the function of accessing the communication network for authorized users in a specific area. It can include wireless network equipment in the 3rd generation partnership project (3GPP) network and access points in non-3GPP networks. For the convenience of description, the following uses RAN nodes.

[0084] The RAN node in the embodiments of the present application may sometimes also be referred to as access network equipment, network equipment, RAN entity or access node, etc.

[0085] In one possible scenario, a RAN node may be a base station, an evolved NodeB (eNodeB), an access point (AP), a transmission reception point (TRP), a next generation NodeB (gNB), a next generation base station in a sixth generation (6G) mobile communication system, a base station in a future mobile communication system, or an access node in a WiFi system. A RAN node may be a macro base station (e.g. Figure 1 110a in), micro base stations or indoor stations (such as Figure 1110b in the present application), a relay node or a donor node, or a wireless controller in a CRAN scenario. Optionally, the RAN node may also be a server, a wearable device, a vehicle or an on-board device, etc. For example, the access network device in the V2X technology may be a road side unit (RSU). All or part of the functions of the RAN node in the present application may also be implemented by software functions running on hardware, or by virtualization functions instantiated on a platform (such as a cloud platform). The RAN node in the present application may also be a logical node, a logical module or software that can implement all or part of the functions of the RAN node.

[0086] In another possible scenario, multiple RAN nodes collaborate to assist the terminal in achieving wireless access, and different RAN nodes respectively implement part of the functions of the base station. For example, the RAN node can be a centralized unit (CU), a distributed unit (DU), a CU-control plane (CP), a CU-user plane (UP), or a radio unit (RU). The CU and DU can be set separately, or can also be included in the same network element, such as a baseband unit (BBU). The RU can be included in a radio frequency device or a radio frequency unit, such as a remote radio unit (RRU), an active antenna unit (AAU) or a remote radio head (RRH).

[0087] In different systems, CU (or CU-CP and CU-UP), DU or RU may also have different names, but those skilled in the art can understand their meanings. For example, in an open radio access network (O-RAN) system, CU may also be referred to as an open-central unit (O-CU); DU may also be referred to as an open-distributed unit (O-DU); CU-CP may also be referred to as O-CU-CP, CU-UP may also be referred to as O-CU-UP, and RU may also be referred to as O-RU. For the convenience of description, this application takes CU, CU-CP, CU-UP, DU and RU as examples for description. Any of the CU (or CU-CP, CU-UP), DU and RU in this application may be implemented by a software module, a hardware module, or a combination of a software module and a hardware module.

[0088] 3. AMF: Mainly used for access control, mobility management, attachment and detachment functions.

[0089] 4. SMF: Mainly used for user plane network element selection, user plane network element redirection, Internet protocol (IP) address allocation for terminal devices, as well as session establishment, modification and release and QoS control.

[0090] 5. UPF: Mainly used for receiving and forwarding user plane data. For example, UPF can receive user plane data from DN and send the user plane data to the terminal device through the AN device. UPF can also receive user plane data from the terminal device through the AN device and forward it to the DN.

[0091] 6. NEF: Mainly used to securely open the services and capabilities provided by 3GPP network functions to the outside world.

[0092] 7. PCF: A unified policy framework mainly used to guide network behavior and provide policy rule information for control plane network elements (such as AMF, SMF, etc.).

[0093] 8. AF: Mainly used to provide services to the 3GPP network, such as interacting with the PCF for policy control.

[0094] 9. Network slice selection function (NSSF): mainly used for network slice selection.

[0095] 10. UDM: Mainly used for UE contract data management, including storage and management of UE identification, UE access authorization, etc.

[0096] 11. DN: An operator network mainly used to provide data services to UE, such as the Internet, third-party service networks, and IP multimedia service (IMS) networks.

[0097] 12. AUSF: Mainly used for user authentication, etc.

[0098] 13. NRF: Mainly used to store descriptive information of network functional entities and the services they provide.

[0099] exist Figure 1 In the network architecture shown, each network element can communicate with each other through interfaces. For example, the terminal is connected to the AMF through the N1 interface, the RAN is connected to the AMF through the N2 interface, the RAN is connected to the UPF through the N3 interface, the UPF is connected to the SMF through the N4 interface, and the AMF is connected to the SMF through the N11 interface.

[0100] It should be noted that Figure 1 The names of the various network elements and the communication interfaces between network elements involved are briefly described by taking the current protocol as an example, but the embodiments of the present application are not limited to being applicable only to currently known communication systems. Therefore, the standard names that appear when describing the current protocol as an example are all functional descriptions. The present application does not limit the specific names of network elements, interfaces, or signaling, but only represents the functions of network elements, interfaces, or signaling, which can be correspondingly extended to other systems, such as 2G, 3G, 4G, or future communication systems.

[0101] It should be understood that the above Figure 1 The network architecture shown is only an example, and the network architecture applicable to the embodiments of the present application is not limited to this. Any network architecture that can realize the functions of the above-mentioned network elements is applicable to the embodiments of the present application.

[0102] It should also be understood that Figure 1 The AMF, SMF, UPF, PCF, NSSF, AUSF, UDM, etc. shown in the figure can be understood as network elements used to implement different functions in the core network, for example, they can be combined into network slices as needed. These core network network elements can be independent devices or integrated into the same device to implement different functions. This application does not limit the specific form of the above network elements.

[0103] To facilitate understanding of the embodiments of the present application, a brief description is given of the basic concepts involved in the present application.

[0104] 1. NTN system

[0105] NTN system generally refers to a communication network that uses air or space platforms as transmission equipment relay nodes or base stations. Air or space platforms include but are not limited to drones, hot air balloons, airplanes, satellites, etc.

[0106] Figure 2 (a) is a schematic architecture diagram of an NTN system. Taking the high-altitude platform as a satellite as an example, the architecture may include: a ground station (gateway, GW), a satellite, a user equipment (user equipment, UE), etc. The ground station in the NTN system can provide functions similar to those of a gateway in a terrestrial communication system, for example, establishing a connection with the UE and communicating with a server. In order to distinguish it from a terrestrial communication system, the gateway is referred to as a ground station here. The ground station also has the functions of monitoring and troubleshooting satellites, packet switching of communication data, and interface protocol conversion. The ground station is connected to the core network, the link between the ground station and the satellite is called a feeder link, and the link between the satellite and the user equipment is called a service link.

[0107] Generally speaking, satellites can have two working modes, namely transparent mode and regeneration mode. In transparent mode, the data of the terminal device generally passes through the satellite to the ground station, and then reaches the destination from the ground station. Generally, due to the long distance between the satellite and the terminal device on the ground, for example, more than 1,000 kilometers, the satellite transmits data in this working mode, and the transmission delay is relatively large. In regeneration mode, the satellite can filter, frequency and signal amplify the wireless signal, and it will also involve signal demodulation, decoding, data packet exchange or routing, as well as encoding and modulation. Therefore, a satellite working in regeneration mode basically has some or all of the functions of a base station in a cellular network.

[0108] It should be understood that Figure 2 (a) exemplarily introduces the NTN communication scenario. The communication device in the embodiment of the present application takes a satellite as an example, but the communication device in the embodiment of the present application is not limited to this. The communication device in the present application can also be a ground station, a high-altitude platform, a drone in NTN communication, or a terminal device that assumes the function of a base station in device-to-device (D2D) communication.

[0109] Figure 2 (b) shows the network architecture that integrates satellite communication and 5G technology. Ground UE accesses the network through the 5G new air interface. The 5G access network equipment is deployed on the satellite and connected to the ground core network through a wireless link. At the same time, there is a wireless link between the satellites to complete the signaling interaction and user data transmission between the access network equipment. Figure 2 The network elements and their interfaces in (b) are described as follows:

[0110] Terminal device: A mobile device that supports the 5G new air interface, typically a mobile phone, pad, etc. It can access the satellite network through the air interface and initiate calls, surf the Internet, and other services.

[0111] 5G access network equipment: mainly provides wireless access services, dispatches wireless resources to access terminals, provides reliable wireless transmission protocols and data encryption protocols, such as base stations.

[0112] 5G core network: user access control, mobility management, session management, user security authentication, billing and other services. It consists of multiple functional units, which can be divided into functional entities of control plane and data plane. Access and mobility management unit (AMF) is responsible for user access management, security authentication, and mobility management. User plane function (UPF) is responsible for managing the transmission of user plane data, traffic statistics and other functions.

[0113] Ground station: responsible for forwarding signaling and business data between satellite access network equipment and 5G core network.

[0114] 5G New Air Interface: The wireless link between the terminal and access network equipment.

[0115] Xn interface: The interface between 5G access network equipment and access network equipment, mainly used for signaling interaction such as switching.

[0116] NG interface: The interface between 5G access network equipment and 5G core network, which mainly interacts with the core network's NAS and other signaling, as well as user business data.

[0117] The above network architecture that integrates satellite communication and 5G technology is only an example. Satellite communication can also be integrated with the 4G communication system or future communication system (for example, 6G communication system) architecture.

[0118] 2. Ephemeris information

[0119] The ephemeris information involved in this application includes but is not limited to traditional ephemeris information, satellite map information and deployment information of gateway stations. Among them, traditional ephemeris information includes but is not limited to orbital parameters, or parameters such as the satellite's position calculated based on orbital parameters. It can be understood that traditional ephemeris information can be used to calculate, predict, depict, or track the time, position, speed and other states of satellite flight. Exemplarily, traditional ephemeris information can be 17 bytes of information to represent position (78 bits) and speed (54 bits), or traditional ephemeris information can be 18 bytes of information to represent orbital parameters (such as semi-major axis, range, eccentricity, perigee angular distance and other parameters). Satellite map information can be the range covered by the satellite on the map at each moment.

[0120] The specific form, content and name of the ephemeris information are not limited in this application, and the definition of ephemeris information in the existing protocol can be referred to. For example, the ephemeris information in this application can also be called satellite coverage availability information.

[0121] 3. Intersatellite Link

[0122] Non-geosynchronous satellites move relative to the ground, and often require multiple satellites to form a constellation to achieve continuous coverage of fixed areas such as the ground or sea, and use inter-satellite links to achieve on-board forwarding, eliminating the need to build ground base stations around the world and achieving enhanced coverage capabilities.

[0123] There are two types of intersatellite links: one is the link between satellites in the same orbit, called the same-orbit intersatellite link; the other is the link between orbits, called the different-orbit intersatellite link. Different-orbit intersatellite links are further divided into the same-direction intersatellite link and the reverse-gap link. The same-direction intersatellite link is a link between two adjacent orbital satellites running in the same direction. The same-direction intersatellite link may be disconnected when approaching the poles due to the change in the relative position of the satellites; the reverse-gap link is a link between two satellites running in opposite directions. Since the satellites run in opposite directions, the reverse-gap link is difficult to establish or can only be established for a short time.

[0124] For ease of understanding, combined Figure 3 The intersatellite link is described. Figure 3 It is a two-dimensional unfolded schematic diagram of a polar orbit constellation, with each orbit having a fixed inclination angle of 90 degrees (the satellite orbit passes over the poles).

[0125] 4. Satellite constellations

[0126] A satellite constellation is a collection of satellites that are launched into orbit and can work normally. It is usually a satellite network composed of some satellites configured in a certain way. The main satellite constellations include the Global Positioning System (GPS) satellite constellation, the GLONASS satellite constellation, the Galileo satellite constellation and the BeiDou satellite constellation.

[0127] The constellation types mainly involved in this application include:

[0128] Low earth orbit (LEO) polar orbit constellation, medium earth orbit (MEO) polar orbit constellation, LEO inclined orbit constellation and MEO inclined orbit constellation, etc.

[0129] exist Figure 3In the network architecture shown, the UE may need to switch from the source RAN (source RAN, S-RAN) to the target RAN (target RAN, T-RAN) based on signal strength, load balancing, UE location change, etc. Based on the different interfaces for transmitting signaling or data between satellites, the UE switching can include two methods. The two methods are a switching method based on the Xn interface (denoted as Xn switching) and a switching method based on the N2 interface (denoted as N2 switching).

[0130] Among them, Xn switching means that there is an interface between S-RAN and T-RAN (this interface is called Xn interface), and S-RAN can directly send the UE context to T-RAN through the Xn interface.

[0131] Figure 4 FIG. 1 is a schematic flow chart of Xn switching. Xn switching may include the following steps.

[0132] S401, air interface switching process.

[0133] This step may be interactively performed by the UE, S-RAN, and T-RAN. Air interface handover may refer to a handover preparation and execution phase, as described in 3GPP TS 38.300.

[0134] S402, T-RAN sends an N2 path switch request message to AMF. Correspondingly, AMF receives the N2 path switch request from T-RAN.

[0135] Exemplarily, after the air interface handover is completed, T-RAN sends an N2 path switch request message to AMF to notify the core network to switch the N3 path to T-RAN. The message may include the successfully switched PDU session and its N2 information (such as QoS flow, etc.), the failed PDU session and its N2 information, UE location information, etc.

[0136] S403, AMF initiates PDU session update to SMF.

[0137] Exemplarily, AMF sends an update context request (Nsmf_PDUSession_UpdateSMContextRequest) message to SMF to initiate a PDU session update.

[0138] The update context request message may include the following information: AN tunnel information (AN tunnel info) assigned by T-RAN for the PDU session, and RAN UE NGAP ID (NGAP is NG application protocol) assigned by T-RAN for the UE. It should be noted that AN tunnel information is at the PDU session granularity, which can be understood as the address of RAN when UPF transmits downlink messages through a certain session.

[0139] S404, SMF re-establishes the N3 connection between RAN and UPF.

[0140] S405, SMF sends AN tunnel information to AMF. Correspondingly, AMF receives AN tunnel information from SMF.

[0141] Exemplarily, the AN tunnel information may be carried in an update context response (Nsmf_PDUSession_UpdateSMContext Response) message.

[0142] S406, AMF sends an N2 path switch response request confirmation (N2 path switch request Ack) message to T-RAN.

[0143] S407, T-RAN sends a release resource message to S-RAN to release resources on the S-RAN side. Correspondingly, S-RAN receives the release resource message from T-RAN.

[0144] In the case where there is no interface between S-RAN and T-RAN, S-RAN switches the UE to T-RAN based on the N2 interface, and this switching method is N2 switching. In N2 switching, S-RAN can send the UE context to T-RAN through the core network. For example, S-RAN sends the UE context to AMF through the N2 interface between RAN and AMF; AMF then sends the UE context to T-RAN through the N2 interface between AMF and T-RAN.

[0145] N2 handover may include N2 handover preparation and N2 handover. Among them, after the S-RAN node initiates the handover process, the N2 handover preparation stage may include allocating resources for the target side core network and the wireless network. For example, the handover preparation stage may mainly include: SMF selects a new T-UPF as the intermediate UPF, establishes an N9 interface tunnel between T-UPF and PSA UPF, T-RAN allocates wireless resources, establishes an N3 interface tunnel between T-RAN and T-UPF, and establishes the context of the UE on T-AMF. For example, S-RAN sends a handover request message (Handover Required) to T-AMF through the N2 interface, and the message includes a list of PDU sessions that need to be switched, and a source to target transparent container, which includes the context of the UE sent by S-RAN to T-RAN.

[0146] In the N2 handover phase, AMF sends a handover command to S-RAN, including the destination to source transport container, a list of PDU sessions that can be switched to T-RAN, and a list of PDU sessions that failed to switch; after receiving the handover command, S-RAN sends a handover command to UE, including a UE container; after UE synchronizes with the destination cell, UE sends a handover confirm message to T-RAN; after receiving the handover confirm message, T-RAN sends a handover notify to AMF, indicating that the UE has successfully switched; AMF sends N2 SM information to SMF, which may include tunnel information allocated by T-RAN for PDU sessions; SMF may configure UPF according to T-RAN tunnel information. The specific process of the N2 handover process can refer to the description in the existing protocol and will not be repeated here.

[0147] In the regenerative satellite scenario, it is generally assumed that an inter-satellite link (ISL) exists between two satellites, that is, an Xn interface exists. When the Xn interface exists, the satellite performs UE switching based on the Xn interface. However, due to the continuous movement of the satellite, the path of the inter-satellite link is not fixed, and the switching method using the Xn interface may cause a large switching delay.

[0148] That is, in NTN, satellite nodes can use multiple switching modes to execute the mobility management process of UE within the coverage of satellite nodes. How to choose a reasonable switching mode becomes an urgent problem to be solved.

[0149] In order to facilitate understanding of the embodiments of the present application, the following explanations are made.

[0150] First, in the various embodiments of the present application, unless otherwise specified or logically conflicting, the terms and / or descriptions between the different embodiments are consistent and can be referenced to each other, and the technical features in the different embodiments can be combined to form new embodiments according to their inherent logical relationships.

[0151] Second, "at least one" shown in the present application refers to one or more, and "multiple" refers to two or more. In addition, in the embodiments of the present application, "first", "second" and various digital numbers (for example, "#1", "#2", etc.) are only for the convenience of description, and are not used to limit the scope of the embodiments of the present application. The size of the sequence number of each process below does not mean the order of execution. The execution order of each process should be determined by its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present application. It should be understood that the objects described in this way can be interchanged in appropriate circumstances so as to be able to describe the schemes other than the embodiments of the present application. In addition, in the embodiments of the present application, words such as "S510" are only marks made for the convenience of description, and are not used to limit the order of execution steps.

[0152] Third, in the embodiments of the present application, words such as "exemplarily" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "exemplarily" or "for example" in the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplarily" or "for example" is intended to present related concepts in a specific way.

[0153] Fourth, in the embodiments of the present application, the words "of", "corresponding, relevant", "corresponding" and "associate" can sometimes be used interchangeably. It should be pointed out that when the distinction between them is not emphasized, the meanings they intend to express are consistent.

[0154] Fifth, in the embodiments of the present application, "under the circumstances", "when", and "if" can sometimes be used interchangeably. It should be pointed out that when the distinction between them is not emphasized, the meanings they intend to express are consistent.

[0155] Sixth, the term "and / or" in this article is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0156] Figure 5is a schematic flow chart of a communication method 500. The method may include the following steps.

[0157] S510, the source access network device (S-RAN) determines to use a first switching method to switch the terminal device to the target access network device (T-RAN) according to the first information.

[0158] The first switching mode is a switching mode based on an interface between access network devices, or the first switching mode is a switching mode based on an interface between an access network device and a core network device.

[0159] S-RAN determines, based on the first information, to adopt the first switching method to switch the terminal device to T-RAN, which can be understood as: S-RAN determines, based on the first information, to adopt a switching method based on the interface between access network devices, or to adopt a switching method based on the interface between the access network device and the core network device, to switch the terminal device to T-RAN. In other words, S-RAN determines, based on the first information, to adopt a switching method based on the interface between access network devices, or to adopt a switching method based on the interface between the access network device and the core network device, to switch the terminal device to T-RAN.

[0160] In other words, S-RAN determines a switching method for switching the terminal device to T-RAN based on the first information. The switching method may be a switching method based on an interface between access network devices and a switching method based on an interface between an access network device and a core network device.

[0161] Among them, the interface between the access network devices is an Xn interface; the interface between the access network device and the core network device is an N2 interface. The switching method based on the interface between the access network devices can be an Xn switching; the switching method based on the interface between the access network device and the core network device can be an N2 switching. In other words, the switching method based on the interface between the access network devices can be a switching based on the Xn interface; the switching method based on the interface between the access network device and the core network device can be a switching based on the N2 interface.

[0162] The first information may include at least one of the following information: information about a transmission path between the S-RAN and the T-RAN, time information, or location information of the S-RAN.

[0163] The information of the transmission path between the S-RAN and the T-RAN may be at least one of the number of hops of the transmission path, the delay of the transmission path, and the distance of the transmission path.

[0164] Specifically, S-RAN and T-RAN can be different satellites, or access network devices deployed on different satellites. S-RAN can communicate with T-RAN through an inter-satellite link or a satellite-to-ground link, that is, the transmission path between S-RAN and T-RAN can be an inter-satellite link or a satellite-to-ground link.

[0165] Among them, if S-RAN and T-RAN communicate directly through the Xn interface, the transmission path between S-RAN and T-RAN is the inter-satellite link between S-RAN and T-RAN; if S-RAN and T-RAN communicate through other satellites, the transmission path between S-RAN and T-RAN includes the inter-satellite link between the S-RAN and other satellites, and the inter-satellite link between the other satellite and the T-RAN. Further, when the other satellites are two or more satellites, the inter-satellite link also includes the inter-satellite link between the other satellites. For example, S-RAN is connected to T-RAN through RAN1 and RAN2, then the transmission path includes the inter-satellite links between S-RAN and RAN1, RAN1 and RAN2, and RAN2 and T-RAN; if S-RAN and T-RAN communicate through core network equipment, the transmission path between S-RAN and T-RAN may include a satellite-to-ground link. The satellite-to-ground link includes the satellite-to-ground link between the S-RAN and a core network device (for example, an access management network element or a user plane network element), and the satellite-to-ground link between the core network device and the T-RAN.

[0166] Among them, "satellite-to-ground link" can be replaced by "feeder link", "ground link", "feeder connection" or "ground connection" without restriction.

[0167] The following describes in detail the information of the transmission path between the S-RAN and the T-RAN.

[0168] The number of hops of the transmission path may be represented by the number of satellites that the information or data passes through when the S-RAN sends the information or data to the T-RAN. The satellites that the information or data passes through may include the T-RAN.

[0169] The "number of hops in the transmission path" can be replaced by "the number of hops included in the transmission path", "the number of hops experienced by the transmission path", "the number of satellites included in the transmission path", "the number of hops in the intersatellite link", etc., without limitation.

[0170] For example, Figure 3As shown in , assuming that the S-RAN is satellite A and the T-RAN is satellite D, if the S-RAN sends information or data to the T-RAN through the transmission path "satellite A→satellite B→satellite C→satellite D", the satellites traversed by the information or data include satellite B, satellite C and satellite D, that is, the number of satellites traversed by the information or data is 3, that is, the number of hops of the transmission path between the S-RAN and the T-RAN is 3.

[0171] The delay of the transmission path may be a delay in sending information or data between the S-RAN and the T-RAN through the transmission path between the S-RAN and the T-RAN, or in other words, the delay of the transmission path is a time required for information or data to be sent from the S-RAN to the T-RAN through the transmission path.

[0172] Specifically, the transmission path may include an intersatellite link that directly connects the S-RAN and the T-RAN, or a transmission path that connects the S-RAN and the T-RAN through one or more other satellites and intersatellite links between satellites. The delay of the transmission path may refer to the delay of the S-RAN transmitting information or data to the T-RAN through the intersatellite link, or in other words, the delay of the transmission path is the delay of the S-RAN transmitting information or data to the T-RAN through the Xn interface. In this case, the "delay of the transmission path" can be replaced by "Xn switching delay" or "switching delay based on the Xn interface".

[0173] by Figure 3 For example, satellite A is the S-RAN and satellite D is the T-RAN, the delay of the transmission path may refer to the delay of satellite A sending information or data to satellite D via satellite B and satellite C. Alternatively, the delay of the transmission path may refer to the delay of satellite A sending information or data directly to satellite D via an intersatellite link.

[0174] If the transmission path includes a satellite-to-ground link, the latency of the transmission path may refer to the latency of the S-RAN sending information or data to the T-RAN via the satellite-to-ground link between the S-RAN and the core network device, and the satellite-to-ground link between the core network device and the T-TAN. In other words, the latency of the transmission path includes the latency of the S-RAN sending information or data to the core network device via the N2 interface between the S-RAN and the core network device, and the latency of the core network device sending information or data to the T-RAN via the N2 interface between the core network device and the T-RAN. In this case, the "latency of the transmission path" may be replaced by "N2 switching latency" or "switching latency based on the N2 interface".

[0175] The distance of the transmission path may refer to the length of an inter-satellite link or a satellite-to-ground link between the S-RAN and the T-RAN.

[0176] Optionally, the method further includes: the S-RAN determines information of the transmission path. That is, the S-RAN determines at least one of the number of hops of the transmission path, the delay of the transmission path, and the distance of the transmission path. The following describes the specific manners in which the S-RAN determines the number of hops of the transmission path, the delay of the transmission path, and the distance of the transmission path.

[0177] Specifically, the S-RAN determining the number of hops of the transmission path may include: the S-RAN determining the number of hops of the transmission path according to the ephemeris information and the time information, wherein the time information may be the current time, or the time information includes the moment when the S-RAN determines the number of hops of the transmission path.

[0178] The S-RAN determining the number of hops of the transmission path may also include: the S-RAN determining the number of hops of the transmission path according to the topological structure of the transmission path. The topological structure of the transmission path may refer to the layout of the access network devices included in the transmission path, or the topological structure of the transmission path may refer to the connection relationship between the access network devices included in the transmission path. The topological structure of the transmission path may be added to the interconnected access network devices by configuration.

[0179] For example, the topology of the transmission path is Figure 3 The connection relationship between satellite A and satellite D shown in , the topological structure of the transmission path can be configured as shown in Table 1. Assuming that the S-RAN is satellite A, if the T-RAN is satellite C, the number of hops of the transmission path is 2 hops, and the access network equipment passed by the transmission path includes the satellite B; if the T-RAN is satellite D, the number of hops of the transmission path is 3 hops, and the access network equipment passed by the transmission path includes the satellite B and satellite C.

[0180] Optionally, the topological structure of the transmission path includes the distance between the S-RAN and the T-RAN, that is, the S-RAN may also determine the distance of the transmission path according to the topological structure of the transmission path. As shown in Table 1, when the S-RAN is satellite A and the T-RAN is satellite C, the distance of the transmission path is 50 kilometers (Km); when the S-RAN is satellite A and the T-RAN is satellite C, the distance of the transmission path is 100Km.

[0181] Table 1

[0182] T-RAN ID Hop count / distance Access network equipment that the transmission path passes through Satellite C 2 jumps / 50Km Satellite B Satellite D 3 jumps / 100Km Satellite B, Satellite C

[0183] The S-RAN may determine the delay of the transmission path by way of method one and / or way two.

[0184] Method 1: The S-RAN measures and obtains the Xn switching delay and / or N2 switching delay from the S-RAN to the T-RAN.

[0185] Exemplarily, the S-RAN measures the Xn switching delay from the S-RAN to the T-RAN by measuring the transmission delay of a signal sent by the S-RAN to the T-RAN.

[0186] For example, the S-RAN sends a measurement signal to the T-RAN, for example, the S-RAN sends the measurement signal to the T-RAN through an Xn interface; accordingly, the T-RAN receives the measurement signal from the S-RAN, and sends a response signal to the S-RAN in response to the measurement signal; the S-RAN determines the Xn switching delay according to the time when the measurement signal is sent and the time when the response signal is received, that is, the S-RAN determines the Xn delay by measuring the round-trip delay of the signal transmission; or, in a case where the response signal carries a timestamp added by the T-RAN, the S-RAN may determine the Xn switching delay according to the time when the measurement signal is sent and the timestamp.

[0187] The S-RAN may measure the N2 handover delay from the S-RAN to the T-RAN by measuring the delay of control plane signaling transmission between the T-RAN and a core network device (e.g., an access management network element), or by measuring the delay of user plane signaling transmission between the S-RAN and a core network device (e.g., a user plane function network element). In other words, the N2 handover delay from the S-RAN to the T-RAN may be equivalent to the delay of control plane signaling transmission between the T-RAN and a core network device, or the delay of user plane signaling transmission between the S-RAN and a core network device.

[0188] For example, the S-RAN sends indication information to the T-RAN, where the indication information indicates measuring the information transmission delay between the T-RAN and the core network device; the T-RAN sends a measurement signal to the core network device according to the indication information; in response to the measurement signal, the core network device sends a response signal to the T-RAN; the T-RAN determines the N2 switching delay according to the time of sending the measurement signal and the time of receiving the response signal, and feeds back the measured N2 switching delay from the S-RAN to the T-RAN to the S-RAN.

[0189] For another example, the S-RAN sends a measurement signal to a core network device, where the measurement signal includes an identifier of the T-RAN and a first timestamp; the core network device sends a response signal carrying a second timestamp to the T-RAN based on the measurement signal; the T-RAN sends the response signal to the S-RAN, so that the S-RAN measures the N2 switching delay from the S-RAN to the T-RAN based on the second timestamp and the first timestamp.

[0190] In a second method, the S-RAN determines the Xn switching delay and / or N2 switching delay between the S-RAN and the T-RAN according to the historical delay information.

[0191] The historical delay information may include one or more Xn switching delays and / or N2 switching delays between the S-RAN and the T-RAN stored in the S-RAN, for example, the one Xn switching delay and / or N2 switching delay is the Xn switching delay and / or N2 switching delay between the S-RAN and the T-RAN obtained by the most recent measurement; the multiple Xn switching delays and / or N2 switching delays are the Xn switching delays and / or N2 switching delays between the S-RAN and the T-RAN obtained by the most recent measurements.

[0192] That is, the S-RAN may determine a stored Xn switching delay and / or N2 switching delay between the S-RAN and the T-RAN as the delay of the transmission path. Alternatively, the S-RAN determines the delay of the transmission path based on multiple stored Xn switching delays and / or N2 switching delays between the S-RAN and the T-RAN. The present application does not limit the specific manner of determining the delay based on the multiple stored Xn switching delays and / or N2 switching delays. For example, the S-RAN may obtain the delay of the transmission path based on multiple stored Xn switching delays and / or N2 switching delays between the S-RAN and the T-RAN and model prediction; for another example, the S-RAN may determine the delay of the transmission path by determining the average value of multiple stored Xn switching delays and / or N2 switching delays between the S-RAN and the T-RAN.

[0193] The historical delay information may also include the Xn switching delay and / or N2 switching delay between the S-RAN and T-RAN when the S-RAN is at the same location. At this time, the S-RAN can determine, based on the ephemeris information, that the current location is the same as the location of the S-RAN when the switching occurs in the stored historical delay information. The historical delay information may also include the Xn switching delay and / or N2 switching delay between the S-RAN and T-RAN at a time one or more cycles ago. At this time, the S-RAN can determine, based on the ephemeris information, that the time interval between the current time and the stored historical delay information when the switching between the S-RAN and T-RAN occurs is an integer multiple of the period that the S-RAN covers a location.

[0194] Optionally, the S-RAN determines the delay of the transmission path in combination with Mode 1 and Mode 2. For example, when the S-RAN measures the Xn switching delay and / or N2 switching delay from the S-RAN to the T-RAN, the S-RAN may determine the delay of the transmission path in combination with one or more Xn switching delays and / or N2 switching delays between the S-RAN and the T-RAN stored by the S-RAN.

[0195] The following introduces a specific manner in which the S-RAN determines to use the first switching manner to switch the terminal device to the T-RAN according to the first information.

[0196] In the case where the first information includes information about the transmission path, and the information about the transmission path includes the number of hops of the transmission path, the S-RAN can determine to use the first switching method to switch the terminal device to the T-RAN based on the number of hops of the transmission path and a threshold value (denoted as threshold #1) corresponding to the number of hops of the transmission path.

[0197] Exemplarily, if the number of hops of the transmission path is greater than the threshold #1, the S-RAN determines to use N2 switching to switch the terminal device to T-RAN, or in other words, the S-RAN determines that the first switching method is a switching method based on the N2 interface; if the number of hops of the transmission path is less than the threshold #1, the S-RAN determines to use Xn switching to switch the terminal device to T-RAN, or in other words, the S-RAN determines that the first switching method is a switching method based on the Xn interface.

[0198] It should be understood that the present application does not limit the case where the number of hops of the transmission path is equal to threshold #1. For example, when the number of hops of the transmission path is equal to threshold #1, the S-RAN can use the N2 switching method to switch the terminal device to the T-RAN; or, when the number of hops of the transmission path is equal to threshold #1, the S-RAN can use the Xn switching method to switch the terminal device to the T-RAN.

[0199] It can be understood that when the number of hops of the transmission path is greater than threshold #1, the delay of S-RAN using N2 switching to switch the terminal device to T-RAN may be less than the delay of S-RAN using Xn switching to switch the terminal device to T-RAN; when the number of hops of the transmission path is less than threshold #1, the delay of S-RAN using Xn switching to switch the terminal device to T-RAN may be less than the delay of S-RAN using N2 switching to switch the terminal device to T-RAN.

[0200] The threshold #1 may be obtained by measurement or determined based on configuration, and the present application does not limit the method for determining the threshold #1. The S-RAN may obtain the threshold #1 based on local configuration or service level agreement (SLA) configuration; or, the S-RAN obtains the threshold #1 from a core network device (e.g., AMF or SMF); or, the threshold #1 may also be an agreed value, such as agreed by a protocol.

[0201] In the case where the information of the transmission path includes the distance of the transmission path, the S-RAN can determine to use the first switching method to switch the terminal device to the T-RAN based on the distance of the transmission path and a threshold value corresponding to the distance of the transmission path (denoted as threshold #2).

[0202] Exemplarily, if the distance of the transmission path is greater than the threshold #2, the S-RAN determines to use N2 switching to switch the terminal device to T-RAN, or in other words, the S-RAN determines that the first switching method is a switching method based on the N2 interface; if the distance of the transmission path is less than the threshold #2, the S-RAN determines to use Xn switching to switch the terminal device to T-RAN, or in other words, the S-RAN determines that the first switching method is a switching method based on the Xn interface.

[0203] Similarly, the present application does not limit the case where the distance of the transmission path is equal to threshold #2.

[0204] The way in which the S-RAN obtains the threshold #2 may refer to the way in which the threshold #1 is obtained.

[0205] When the information of the transmission path includes the delay of the transmission path, the S-RAN can determine to switch the terminal device to the T-RAN based on the delay of the transmission path and a threshold (denoted as threshold #3) corresponding to the delay of the transmission path, and the delay of the transmission path can be the Xn switching delay or the N2 switching delay.

[0206] Exemplarily, when the delay of the transmission path is the Xn switching delay, if the Xn switching delay is greater than the threshold #3, the S-RAN determines to use N2 switching to switch the terminal device to T-RAN, or in other words, the S-RAN determines that the first switching method is a switching method based on the N2 interface; if the Xn switching delay is less than the threshold #3, the S-RAN determines to use Xn switching to switch the terminal device to T-RAN, or in other words, the S-RAN determines that the first switching method is a switching method based on the Xn interface.

[0207] When the delay of the transmission path is the N2 switching delay, if the N2 switching delay is less than the threshold #3, the S-RAN determines to use N2 switching to switch the terminal device to T-RAN, or in other words, the S-RAN determines that the first switching method is a switching method based on the N2 interface; if the N2 switching delay is greater than the threshold #3, the S-RAN determines to use N2 switching to switch the terminal device to T-RAN, or in other words, the S-RAN determines that the first switching method is a switching method based on the N2 interface.

[0208] Similarly, the present application does not limit the case where the delay of the transmission path is equal to threshold #3.

[0209] The S-RAN may obtain the threshold #3 in a manner similar to the manner of obtaining the threshold #1. In addition, when the delay of the transmission path is in two different situations, namely, Xn switching delay and N2 switching delay, the value of the threshold #3 may be different.

[0210] Optionally, when the delay of the transmission path includes the X switching delay and the N2 switching delay, the S-RAN may also determine a switching method for switching the terminal device to the T-RAN based on a size relationship between the Xn switching delay and the N2 switching delay.

[0211] Specifically, the S-RAN switches the terminal device to the T-RAN in a switching mode with a smaller delay. That is, if the Xn switching delay is less than the N2 switching delay, the S-RAN determines to switch the terminal device to the T-RAN based on the Xn switching mode; if the N2 switching delay is less than the Xn switching delay, the S-RAN switches the terminal device to the T-RAN based on the N2 switching mode.

[0212] Similarly, the present application does not limit the case where the Xn switching delay is equal to the N2 switching delay.

[0213] In the case that the first information includes time information and / or location information, the S-RAN determines a switching method for switching the terminal device to the T-RAN according to the time information and / or location information and the first corresponding relationship.

[0214] Among them, the time information can be the current moment, or the moment when the S-RAN determines the switching mode; the location information can be the current location information of the S-RAN, for example, the longitude and latitude coordinates of the current location of the S-RAN, the XYZ coordinates of the Cartesian or earth-centered earth-fixed (ECEF) coordinate system, or other information or data that can represent the location, etc., without limitation.

[0215] The first correspondence includes a correspondence between time information and / or location information and a switching mode, wherein the time information may indicate a time range; and the location information may indicate a range of information or data used to indicate a location.

[0216] For example, the first corresponding relationship can be as shown in Table 2. When the time range is 9:00 to 10:00, and / or the location information is latitude x1-x2 and longitude y1-y2, the switching method is Xn switching; when the time range is 10:00 to 10:05, and / or the location information is latitude x3-x4 and longitude y3-y4, the switching method is N2 switching.

[0217] In combination with Table 2, an example of the S-RAN determining the switching method for switching the terminal device to T-RAN based on the time information and / or location information and the first correspondence is: if the S-RAN determines that the current time is 9:30, the S-RAN determines that the terminal device is switched to T-RAN using Xn switching based on the first correspondence; or, if the S-RAN determines that the current location is latitude x0, longitude y0, x0∈[x1,x2], y0∈[y1,y2], the S-RAN determines that the terminal device is switched to T-RAN using N2 switching based on the first correspondence.

[0218] Table 2

[0219] Time information / location information Switching mode 9:00-10:00 / latitude x1-x2, longitude y1-y2 Switching based on Xn interface 10:00-10:05 / latitude x3-x4, longitude y3-y4 Switching based on N2 interface

[0220] The first corresponding relationship may be determined by the S-RAN or other access network equipment or an operator according to the ephemeris information and the satellite constellation. The S-RAN may obtain the first corresponding relationship according to a local configuration or an SLA configuration.

[0221] S520: The S-RAN switches the terminal device to the T-RAN based on the first switching mode.

[0222] Specifically, when the switching mode is a switching mode based on an interface between access network devices, the S-RAN may send the context information of the terminal device to the T-RAN through the interface between the access network devices. Exemplarily, the S-RAN sends a source to target transparent container to the T-RAN through an Xn interface. The interface between the access network devices is an Xn interface, and the context information of the terminal device is a source to target transparent container.

[0223] When the switching method is a switching method based on the interface between the access network device and the core network device, the S-RAN sends the context information of the terminal device to the T-RAN through the interface between the access network device and the core network device. Exemplarily, the S-RAN sends a source to target transparent container to the T-RAN through the N2 interface.

[0224] For example, S-RAN can send a source to target transparent container to AMF (an example of a core network device) through the N2 interface; AMF then forwards the source to target transparent container to T-RAN through the N2 interface.

[0225] Figure 6 The schematic diagram of the communication method 600 provided in the embodiment of the present application is shown in FIG. 4. For example, the method 600 can be regarded as a specific implementation of the method 500. The method 600 can include the following steps.

[0226] The S-RAN determines a threshold corresponding to the number of hops or distance of the transmission path.

[0227] For example, in S601a, S-RAN obtains the threshold corresponding to the number of hops of the transmission path from AMF / SMF.

[0228] Alternatively, S601b, the S-RAN determines a threshold corresponding to the number of hops or the distance of the transmission path based on the configuration information.

[0229] S602, S-RAN obtains a correspondence between time information and / or location information and a switching mode (recorded as correspondence #1, an example of a first correspondence).

[0230] For the correspondence relationship #1, reference may be made to the description of the first correspondence relationship in S510.

[0231] For example, the S-RAN may determine the corresponding relationship #1 according to local configuration or SLA configuration.

[0232] S603: The S-RAN determines to hand over the UE to the T-RAN.

[0233] The specific method in which S-RAN determines to switch UE (an example of terminal equipment) to T-RAN can refer to the existing relevant description. For example, S-RAN can determine to switch UE to T-RAN based on UE signal strength, UE location information, etc.

[0234] After determining to hand over the UE to the T-RAN, the S-RAN may execute S604 and S605, or execute S606.

[0235] S604, the S-RAN determines the number of hops or the distance of the transmission path between the S-RAN and the T-RAN.

[0236] The specific manner in which the S-RAN determines the number of hops or the distance of the transmission path between the S-RAN and the T-RAN may refer to the description in S510.

[0237] For example, the S-RAN may determine the number of hops of the transmission path between the S-RAN and the T-RAN through ephemeris information or the topological structure of the transmission path.

[0238] S605, the S-RAN determines a switching method for switching the UE to the T-RAN based on the relationship between the determined number of hops (distance) of the transmission path and the threshold value corresponding to the number of hops (distance).

[0239] For this switching method, refer to the description of the first switching method in S510.

[0240] For the specific implementation of the S-RAN determining the switching method of switching the UE to the T-RAN based on the determined number of hops (distance) of the transmission path and the size relationship between the number of hops (distance) and the corresponding threshold, refer to the description of the specific implementation of the S-RAN determining the switching of the UE to the T-RAN based on the size relationship between the number of hops of the transmission path and threshold #1, and determining the switching of the UE to the T-RAN based on the size relationship between the distance of the transmission path and threshold #2 in S510.

[0241] S606: The S-RAN determines a handover method for handing over the UE to the T-RAN based on the current time and / or current location and the corresponding relationship #1.

[0242] This step may refer to the description in S510 that the S-RAN determines the switching manner of switching the terminal device to the T-RAN according to the time information and / or location information and the first corresponding relationship.

[0243] S607: The S-RAN executes a process of handing over the UE to the T-RAN based on the determined handover mode.

[0244] For example, when the switching mode is the switching mode of the Xn interface, the process can be as follows: Figure 4 When the switching mode is the switching mode of the N2 interface, the process can refer to the relevant description of the N2 switching process above.

[0245] Figure 7 The schematic diagram of the communication method 700 provided in the embodiment of the present application is shown in FIG. 1 . For example, the method 700 can be regarded as a specific implementation of the method 500. The method 700 can include the following steps.

[0246] S701: S-RAN determines to hand over the UE to T-RAN.

[0247] For this step, refer to the description of S601.

[0248] The S-RAN determines the Xn switching delay or N2 switching delay (an example of a delay in a transmission path) between the S-RAN and the T-RAN.

[0249] Exemplarily, at S702, the S-RAN may determine the Xn switching delay or the N2 switching delay between the S-RAN and the T-RAN through historical measurement data.

[0250] For this step, reference may be made to the description of the delay of the S-RAN determining the transmission path in S510.

[0251] Alternatively, the S-RAN may determine the Xn switching delay or the N2 switching delay between the S-RAN and the T-RAN through measurement.

[0252] Exemplarily, the S-RAN measuring the Xn delay may include S703a to S703c:

[0253] S703a, S-RAN sends signal #1 (an example of a measurement signal) to T-RAN via the Xn interface.

[0254] Accordingly, the T-RAN receives signal #1 from the S-RAN.

[0255] S703b, T-RAN sends signal #2 (an example of a response signal) to S-RAN.

[0256] Accordingly, the S-RAN receives signal #2 from the T-RAN.

[0257] S703c, the S-RAN determines the Xn switching delay between the S-RAN and the T-RAN according to the time of sending signal #1 and the time of receiving signal #2.

[0258] Optionally, if signal #2 carries a timestamp, the S-RAN determines the Xn switching delay according to the time when signal #1 is sent and the timestamp.

[0259] The S-RAN measurement of Xn delay may include S703d and S703h, or include S703i and S703L:

[0260] S703d, S-RAN sends indication information #1 to T-RAN.

[0261] Accordingly, the T-RAN receives indication information #1 from the S-RAN.

[0262] The indication information #1 may be used to indicate the measurement of the delay of the signal transmitted between the T-RAN and the AMF.

[0263] S703e, T-RAN sends signal #1 (an example of a measurement signal) to AMF according to the indication information #1.

[0264] Accordingly, the AMF receives signal #1 from the T-RAN.

[0265] S703f, AMF feeds back signal #2 to T-RAN.

[0266] Accordingly, T-RAN receives signal #2 from AMF.

[0267] S703g, T-RAN determines the signal transmission delay between T-RAN and AMF (an example of N2 switching delay) according to the time when signal #1 is sent and the time when signal #2 is received. Optionally, if signal #2 carries a timestamp, T-RAN determines the signal transmission delay according to the time when signal #1 is sent and the timestamp.

[0268] S703h, T-RAN sends the N2 switching delay to S-RAN.

[0269] Accordingly, the S-RAN receives the N2 handover delay from the T-RAN.

[0270] Alternatively, at S703i, S-RAN sends signal #1 (an example of a measurement signal) to UPF.

[0271] Accordingly, UPF receives signal #1 from S-RAN.

[0272] The signal #1 may carry the T-RAN identifier and timestamp #1.

[0273] S703j, UPF feeds back signal #2 to T-RAN.

[0274] Accordingly, T-RAN receives signal #2 from UPF.

[0275] Signal #2 may carry the timestamp #1 identifying the S-RAN and the timestamp #2 corresponding to the received signal #1.

[0276] S703k, T-RAN determines the signal transmission delay between S-RAN and UPF (referred to as delay #1) according to timestamp #1 and timestamp #2.

[0277] It can be understood that since the signal transmission delay between the S-RAN and the UPF is the delay of the satellite-to-ground link, the delay #1 can be equivalent to the N2 switching delay.

[0278] S703L, T-RAN sends the delay #1 to S-RAN.

[0279] Accordingly, the S-RAN receives the delay #1 from the T-RAN.

[0280] Optionally, the method further includes S704a and S705, or includes S704b:

[0281] S704a, the S-RAN determines a threshold corresponding to the Xn handover delay or the N2 handover delay.

[0282] For example, the S-RAN determines a threshold corresponding to the Xn switching delay or the N2 switching delay based on the configuration information.

[0283] This step may be performed at any time before S703 , for example, S703a may be performed before S701 .

[0284] S705: The S-RAN determines a switching mode for switching the UE to the T-RAN based on a relationship between the determined Xn switching delay or the N2 switching delay and a corresponding threshold.

[0285] For this switching method, refer to the description of the first switching method in S510.

[0286] For the specific implementation of this step, refer to the description in S510 of the S-RAN determining to switch the UE to the T-RAN based on the relationship between the delay of the transmission path and the threshold #3.

[0287] S704b, the S-RAN determines a switching mode for switching the UE to the T-RAN based on the determined Xn switching delay and N2 switching delay.

[0288] For example, the S-RAN determines a switching mode for switching the UE to the T-RAN based on the determined relationship between the Xn switching delay and the N2 switching delay.

[0289] S706: The S-RAN executes a process of handing over the UE to the T-RAN based on the determined handover mode.

[0290] For example, when the switching mode is the switching mode of the Xn interface, the process can be as follows: Figure 4 When the switching mode is the switching mode of the N2 interface, the process can refer to the relevant description of the N2 switching process above.

[0291] Above, combined Figures 5 to 7 The communication method provided by the embodiment of the present application is described in detail. Figures 8 to 10The communication device provided in the embodiment of the present application is described in detail. It should be understood that the description of the device embodiment corresponds to the description of the method embodiment, so the contents not described in detail can be referred to the method embodiment above, and will not be repeated here for the sake of brevity.

[0292] Figure 8 A schematic diagram of a communication device 800 provided in an embodiment of the present application is shown. The device 800 includes an interface unit 810, which can be used to implement corresponding communication functions. The interface unit 810 can also be called a communication interface or a communication unit.

[0293] Optionally, the device 800 may further include a processing unit 820, which may be used to perform data processing.

[0294] Optionally, the device 800 also includes a storage unit, which can be used to store instructions and / or data. The processing unit 820 can read the instructions and / or data in the storage unit so that the device implements the actions of different devices in the aforementioned method embodiments.

[0295] In one possible design, the device 800 may be the access network device in the aforementioned embodiment (e.g., source access network device, S-RAN, target access network device, or T-RAN), or a component of the access network device (e.g., a chip). The device 800 may implement the steps or processes performed by the access network device in the above method embodiment. Among them, the interface unit 810 may be used to perform the operations related to the transmission and reception of the access network device in the above method embodiment; the processing unit 820 may be used to perform the operations related to the processing of the access network device in the above method embodiment.

[0296] Fig. 9 9 is a schematic block diagram of a communication device 900 provided in an embodiment of the present application. The device 900 includes a processor 910, and the processor 910 is coupled to a memory 920. Optionally, the memory 920 is further included. The memory 920 is used to store computer programs or instructions and / or data, and the processor 910 is used to execute the computer programs or instructions stored in the memory 920, or read the data stored in the memory 920, so as to execute the methods in the above method embodiments.

[0297] Optionally, there are one or more processors 910 .

[0298] Optionally, the memory 920 is one or more.

[0299] Optionally, the memory 920 is integrated with the processor 910 or provided separately.

[0300] Alternatively, if Fig. 9As shown, the device 900 further includes a transceiver 930, which is used to receive and / or send signals. For example, the processor 910 is used to control the transceiver 930 to receive and / or send signals. The transceiver 930 may also be referred to as an interface.

[0301] As a solution, the apparatus 900 is used to implement the operations performed by the access network device in each of the above method embodiments.

[0302] For example, the processor 910 is configured to execute a computer program or instruction stored in the memory 920 to implement related operations of the access network device in each of the above method embodiments.

[0303] In the implementation process, each step of the above method can be completed by an integrated logic circuit of hardware in the processor 910 or an instruction in the form of software. The method disclosed in conjunction with the embodiment of the present application can be directly embodied as a hardware processor for execution, or a combination of hardware and software modules in the processor for execution. The software module can be located in a mature storage medium in the art such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, etc. The storage medium is located in the memory 920, and the processor 910 reads the information in the memory 920 and completes the steps of the above method in conjunction with its hardware. To avoid repetition, it is not described in detail here.

[0304] It should be understood that in the embodiments of the present application, the processor may be one or more integrated circuits for executing related programs to execute the embodiments of the methods of the present application.

[0305] The processor (e.g., processor 910) may include one or more processors and be implemented as a combination of computing devices. The processor may include one or more of the following: a microprocessor, a microcontroller, a digital signal processor (DSP), a digital signal processing device (DSPD), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a programmable logic device (PLD), a gating logic, a transistor logic, a discrete hardware circuit, a processing circuit or other suitable hardware, firmware and / or a combination of hardware and software for performing the various functions described in the present disclosure. The processor may be a general-purpose processor or a dedicated processor. For example, processor 910 may be a baseband processor or a central processing unit. The baseband processor may be used to process communication protocols and communication data. The central processing unit may be used to enable the device to execute a software program and process data in the software program. In addition, a portion of the processor may also include a non-volatile random access memory. For example, the processor may also store information about the type of device.

[0306] Program in this application is used to refer to software in a broad sense. Non-limiting examples of software include: program code, program, subroutine, instruction, instruction set, code, code segment, software module, application, or software application, etc. The program can be run in a processor and / or computer. So that the device performs various functions and / or processes described in this application.

[0307] The memory (e.g., memory 920) can store data required by the processor (e.g., processor 910) when executing software. The memory can be implemented using any suitable storage technology. For example, the memory can be any available storage medium that can be accessed by the processor and / or computer. Non-limiting examples of storage media include random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), compact disc read-only memory (CD-ROM), static RAM (SRAM), dynamic RAM (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM) and direct rambus RAM (DR RAM), removable media, optical disk storage, magnetic disk storage media, magnetic storage devices, flash memory, registers, state memory, remote mounted storage, local or remote storage components, or any other medium capable of carrying or storing software, data or information and accessible by a processor / computer. It should be noted that the memory described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0308] The memory (e.g., memory 920) and the processor (e.g., processor 910) may be provided separately or integrated together. The memory may be used to connect to the processor so that the processor can read information from the memory and store and / or write information in the memory. The memory may be integrated in the processor. The memory and the processor may be provided in an integrated circuit (e.g., the integrated circuit may be provided in a UE or other network node).

[0309] Fig.10 1 is a schematic block diagram of a chip system 1000 provided in an embodiment of the present application. The chip system 1000 (or also referred to as a processing system) includes a logic circuit 1010 and an input / output interface 1020 .

[0310] Among them, the logic circuit 1010 can be a processing circuit in the chip system 1000. The logic circuit 1010 can be coupled to a storage unit and call instructions in the storage unit so that the chip system 1000 can implement the methods and functions of each embodiment of the present application. The input / output interface 1020 can be an input / output circuit in the chip system 1000, outputting information processed by the chip system 1000, or inputting data or signaling information to be processed into the chip system 1000 for processing.

[0311] As a solution, the chip system 1000 is used to implement the operations performed by the access network device in the above method embodiments.

[0312] For example, the logic circuit 1010 is used to implement the processing-related operations performed by the access network device in the above method embodiment; the input / output interface 1020 is used to implement the sending and / or receiving-related operations performed by the access network device in the above method embodiment.

[0313] An embodiment of the present application also provides a computer-readable storage medium, on which computer instructions are stored for implementing the methods performed by a communication device (e.g., a source access network device, S-RAN, a target access network device, or T-RAN) in the above-mentioned method embodiments.

[0314] An embodiment of the present application also provides a computer program product, comprising instructions, which, when executed by a computer, implement the methods performed by a communication device (e.g., a source access network device, S-RAN, a target access network device, or T-RAN) in the above-mentioned method embodiments.

[0315] An embodiment of the present application also provides a communication system, which includes at least one of the source access network device and the target access network device in the above embodiments.

[0316] The explanation of the relevant contents and beneficial effects of any of the above-mentioned devices can be referred to the corresponding method embodiments provided above, which will not be repeated here.

[0317] In the several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the above units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0318] The units described above as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to implement the solution provided by this application.

[0319] In addition, each functional unit in each embodiment of the present application may be integrated into one unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0320] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0321] When software is used for implementation, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When loading and executing computer program instructions on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network or other programmable devices. For example, the computer can be a personal computer, a server, or a network device, etc. The computer instruction can be stored in a computer-readable storage medium, or transmitted from a computer-readable storage medium to another computer-readable storage medium, for example, the computer instruction can be transmitted from a website site, a computer, a server or a data center by wired (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.) mode to another website site, computer, server or data center. About computer-readable storage medium, it can be described with reference to the above.

[0322] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A communication method, characterized in that: include: The source access network device determines, based on the first information, to use a first switching mode to switch the terminal device to the target access network device, where the first switching mode is a switching mode based on an interface between access network devices or a switching mode based on an interface between an access network device and a core network device; Switching the terminal device to the target access network device based on the first switching mode; The first information includes at least one of the following: information about the transmission path between the source access network device and the target access network device, time information, or location information of the source access network device.

2. The method according to claim 1, characterized in that The switching mode based on the interface between the access network devices is Xn switching; or, The switching method based on the interface between the access network device and the core network device is N2 switching.

3. The method according to claim 1 or 2, characterized in that: The interface between the access network devices is an Xn interface; The interface between the access network device and the core network device is the N2 interface.

4. The method according to any one of claims 1 to 3, characterized in that The transmission path information includes at least one of the following: The number of hops of the transmission path, the delay of the transmission path, and the distance of the transmission path.

5. The method according to claim 4, characterized in that The method further comprises: The source access network device determines the number of hops of the transmission path according to the ephemeris information and the time information; or, The source access network device determines the number of hops of the transmission path according to the topological structure of the transmission path.

6. The method according to claim 4, characterized in that The delay of the transmission path includes: The Xn switching delay and / or N2 switching delay from the source access network device to the target access network device stored by the source access network device, or the Xn switching delay and / or N2 switching delay from the source access network device to the target access network device measured by the source access network device.

7. The method according to claim 6, characterized in that The method further comprises: The source access network device measures an Xn switching delay and / or an N2 switching delay from the source access network device to the target access network device.

8. The method according to claim 7, characterized in that The source access network device measures the Xn switching delay from the source access network device to the target access network device, including: The source access network device sends a measurement signal to the target access network device; The source access network device receives a response signal from the target access network device, where the response signal is sent according to the measurement signal; The source access network device determines the Xn switching delay according to the time of sending the measurement signal and the time of receiving the response signal.

9. The method according to claim 7, characterized in that: Measuring, by the source access network device, an N2 switching delay from the source access network device to the target access network device, including: The source access network device sends instruction information to the target access network device, where the instruction information indicates measuring the information transmission delay between the target access network device and the core network device; The source access network device receives an N2 switching delay from the source access network device to the target access network device measured by the target access network device, where the N2 switching delay is determined based on the information transmission delay.

10. The method according to claim 7, characterized in that Measuring, by the source access network device, an N2 switching delay from the source access network device to the target access network device, including: The source access network device sends a measurement signal to the core network device, where the measurement signal includes an identifier of the target access network device and a first timestamp; The source access network device receives a response signal from the core network device through the target access network device, wherein the response signal includes a second timestamp; The N2 switching delay from the source access network device to the target access network device measured according to the first timestamp and the first timestamp.

11. The method according to any one of claims 6 to 10, characterized in that In a case where the delay of the transmission path includes the Xn switching delay and the N2 switching delay measured by the source access network device from the source access network device to the target access network device, the source access network device determines, according to the first information, a manner in which the terminal device switches to the target access network device, including: If the Xn switching delay is greater than the N2 switching delay, determining that the first switching mode is a switching mode based on an interface between an access network device and a core network device; or, If the Xn switching delay is less than or equal to the N2 switching delay, it is determined that the first switching mode is a switching mode based on an interface between access network devices.

12. The method according to any one of claims 1 to 10, characterized in that In a case where the first information includes the time information or the location information of the source access network device, the source access network device determines, according to the first information, to use a first switching mode to switch the terminal device to the target access network device, including: The source access network device determines to use the first switching method to switch the terminal device to the target access network device based on the first information and the first corresponding relationship. The first corresponding relationship includes the correspondence between time information and / or location information and the switching method.

13. The method according to any one of claims 1 to 10, characterized in that In a case where the first information includes information about a transmission path between the source access network device and the target access network device, the source access network device determines, according to the first information, to use a first switching mode to switch the terminal device to the target access network device, including: The source access network device determines to use the first switching method to switch the terminal device to the target access network device based on the information of the transmission path and a threshold corresponding to the information of the transmission path.

14. The method according to claim 13, characterized in that The source access network device determines, according to the information of the transmission path and a threshold value corresponding to the information of the transmission path, to use the first switching mode to switch the terminal device to the target access network device, including: If the information of the transmission path is greater than a threshold corresponding to the information of the transmission path, determining that the first switching mode is a switching mode based on an interface between an access network device and a core network device; or, If the information of the transmission path is less than or equal to a threshold corresponding to the information of the transmission path, it is determined that the first switching mode is a switching mode based on an interface between access network devices.

15. The method according to any one of claims 1 to 14, characterized in that When the switching mode is a switching mode based on an interface between an access network device and a core network device, switching the terminal device to the target access network device based on the first switching mode includes: The source access network device sends the context information of the terminal device to the core network device through the interface.

16. The method according to any one of claims 1 to 14, characterized in that When the switching mode is a switching mode based on an interface between access network devices, switching the terminal device to the target access network device based on the first switching mode includes: The source access network device sends the context information of the terminal device to the target access network device through the interface.

17. The method according to any one of claims 1 to 16, characterized in that The source access network device and the target access network device are deployed on different satellites.

18. A communication device, characterized in that: Including processing unit, The processing unit is used to determine, according to the first information, to use a first switching mode to switch the terminal device to the target access network device, wherein the first switching mode is a switching mode based on an interface between access network devices or a switching mode based on an interface between an access network device and a core network device; The processing unit is further configured to switch the terminal device to the target access network device based on the first switching mode; The first information includes at least one of the following: information about a transmission path between the device and the target access network equipment, time information, or location information of the device.

19. The device according to claim 18, characterized in that The switching mode based on the interface between the access network devices is Xn switching; or, The switching method based on the interface between the access network device and the core network device is N2 switching.

20. The device according to claim 18 or 19, characterized in that The interface between the access network devices is an Xn interface; The interface between the access network device and the core network device is the N2 interface.

21. The device according to any one of claims 18 to 20, characterized in that The transmission path information includes at least one of the following: The number of hops of the transmission path, the delay of the transmission path, and the distance of the transmission path.

22. The device according to claim 21, characterized in that The processing unit is also used for: Determine the number of hops of the transmission path according to the ephemeris information and the time information; or, The number of hops of the transmission path is determined according to the topological structure of the transmission path.

23. The device according to claim 21, characterized in that The delay of the transmission path includes: The Xn switching delay and / or N2 switching delay from the device to the target access network device stored by the device, or the Xn switching delay and / or N2 switching delay from the device to the target access network device measured by the processing unit.

24. The device according to claim 23, characterized in that The processing unit is also used for: The Xn switching delay and / or N2 switching delay from the device to the target access network equipment is measured.

25. The device according to claim 24, characterized in that The device also includes a transceiver unit, The transceiver unit is used to send a measurement signal to the target access network device; The transceiver unit is further used to receive a response signal from the target access network device, wherein the response signal is sent according to the measurement signal; The processing unit is specifically configured to determine the Xn switching delay according to a time point of sending the measurement signal and a time point of receiving the response signal.

26. The device according to claim 24, characterized in that The device also includes a transceiver unit, The transceiver unit is used to send indication information to the target access network device, where the indication information indicates to measure the information transmission delay between the target access network device and the core network device; The transceiver unit is further used to receive an N2 switching delay from the device to the target access network device measured by the target access network device, where the N2 switching delay is determined based on the information transmission delay.

27. The device according to claim 24, characterized in that The device also includes a transceiver unit, The transceiver unit is used to send a measurement signal to the core network device, where the measurement signal includes an identifier of the target access network device and a first timestamp; The transceiver unit is further used to receive a response signal from the core network device through the target access network device, wherein the response signal includes a second timestamp; The processing unit is specifically configured to, based on the first timestamp and the N2 switching delay from the device to the target access network device measured by the first timestamp.

28. The device according to any one of claims 23 to 27, characterized in that In a case where the delay of the transmission path includes an Xn switching delay and an N2 switching delay measured by the processing unit from the device to the target access network device, the processing unit is specifically configured to: If the Xn switching delay is greater than the N2 switching delay, determining that the first switching mode is a switching mode based on an interface between an access network device and a core network device; or, If the Xn switching delay is less than or equal to the N2 switching delay, it is determined that the first switching mode is a switching mode based on an interface between access network devices.

29. The device according to any one of claims 18 to 27, characterized in that In a case where the first information includes the time information, or the location information of the device, the processing unit is specifically configured to: According to the first information and the first corresponding relationship, it is determined to use the first switching method to switch the terminal device to the target access network device. The first corresponding relationship includes the corresponding relationship between time information and / or location information and the switching method.

30. The device according to any one of claims 18 to 27, characterized in that In a case where the first information includes information about a transmission path between the apparatus and the target access network device, the processing unit is specifically configured to: According to the information of the transmission path and a threshold value corresponding to the information of the transmission path, it is determined to adopt the first switching mode to switch the terminal device to the target access network device.

31. The device according to claim 30, characterized in that The processing unit is specifically used for: If the information of the transmission path is greater than a threshold corresponding to the information of the transmission path, determining that the first switching mode is a switching mode based on an interface between an access network device and a core network device; or, If the information of the transmission path is less than or equal to a threshold corresponding to the information of the transmission path, it is determined that the first switching mode is a switching mode based on an interface between access network devices.

32. The device according to any one of claims 18 to 31, characterized in that When the switching mode is a switching mode based on an interface between an access network device and a core network device, the processing unit is specifically configured to: Determine to send the context information of the terminal device to the core network device through the interface.

33. The device according to any one of claims 18 to 31, characterized in that When the switching mode is a switching mode based on an interface between access network devices, the processing unit is specifically configured to: Determine to send the context information of the terminal device to the target access network device through the interface.

34. A communication device, characterized in that: The apparatus comprises means for executing the apparatus as claimed in any one of claims 1 to 17.

35. A communication device, characterized in that: include: a processor and a memory, the processor being coupled to the memory; The memory stores instructions, and when the instructions are executed by the processor, the apparatus performs the method according to any one of claims 1 to 17.

36. A computer-readable storage medium, characterized in that: The computer-readable storage medium is used to store a computer program, and when the computer program is run on a computer, the computer is caused to perform the method according to any one of claims 1 to 17.

37. A computer program product, characterized in that The computer program product comprises a computer program code, and when the computer program code is executed by a communication device, the method according to any one of claims 1 to 17 is implemented.

38. A communication system, comprising an access network device, wherein the access network device is used to execute the method according to any one of claims 1 to 17.

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