Communication method and apparatus, and readable storage medium and computer program product

Abstract

A communication method and apparatus, and a readable storage medium and a computer program product, which relate to the technical field of communications, and are used for increasing a handover success rate of a terminal apparatus. The method of the present application comprises: a repeater apparatus establishing a connection with a target network apparatus; and the repeater apparatus releasing a connection with a source network apparatus and maintaining the synchronization with the source network apparatus, or maintaining the connection with the source network apparatus. In this way, after a connection with a target network apparatus is established, a repeater apparatus can still forward information of a source network apparatus, such that a terminal apparatus can communicate with the source network apparatus and the target network apparatus by means of the repeater apparatus, thereby enabling a successful handover of the terminal apparatus to the target network apparatus. The solution can avoid a handover failure of the terminal apparatus caused by the repeater apparatus preferentially performing a handover from the source network apparatus to the target network apparatus, thereby increasing a handover success rate of the terminal apparatus.

Description

A communication method, apparatus, readable storage medium, and computer program product Technical Field

[0001] This application relates to the field of communication technology, and in particular to a communication method, apparatus, readable storage medium, and computer program product. Background Technology

[0002] Currently, the 5th generation (5G) New Radio (NR) technology is evolving from Release 18 to Release 19. Simultaneously, NR technology has moved from the standardization phase to the commercial deployment phase. The NR standard protocol was initially designed for wireless communication in terrestrial cellular network scenarios, providing users with ultra-low latency, ultra-reliability, ultra-high speed, and massive connectivity wireless communication services. Compared to terrestrial communication, non-terrestrial networks (NTN) communication features large coverage areas and flexible networking, achieving seamless global network coverage. NTN communication includes networking using equipment such as drones, high-altitude platforms, and satellites to provide data transmission, voice communication, and other services to user equipment (UE).

[0003] In satellite communication systems, terminal devices can transmit data to gateway stations or ground stations via satellite to establish connections with the core network or the internet. However, deploying a large number of gateway and ground stations increases costs. Therefore, reducing costs is a pressing issue.

[0004] Summary of the Invention

[0005] This application provides a communication method, apparatus, readable storage medium, and computer program product for enabling a relay device to maintain a connection / synchronization with the source network device after establishing a connection with the target network device. This allows the relay device to forward information from both the source and target network devices, thereby improving the handover success rate of terminal devices within the relay device's signal coverage area. Furthermore, this solution can improve the success rate of terminal devices switching network devices in scenarios where the relay device needs to switch networks. Moreover, this solution enables information transmission via relay devices in satellite communication scenarios. Since relay devices can be deployed in satellite communication scenarios, the number of gateway stations and ground stations can be reduced, thereby lowering communication costs.

[0006] The following example further illustrates the beneficial effects of this application.

[0007] For example, in a satellite communication scenario, relay devices are deployed on the ground. As the satellite moves, the relay device needs to switch satellites, and the terminal devices within its signal coverage area also need to switch satellites. If the relay device switches to the target satellite first, it will release its connection with the source satellite, thus preventing it from relaying information between the source satellite and the terminal devices. However, some terminal devices within the relay device's signal coverage area may not have switched from the source satellite to the target satellite, and these terminal devices still need to transmit signals with the source satellite. But because the relay device can no longer relay signals between the source satellite and the terminal devices, some terminal devices within its signal coverage area will experience switching failures.

[0008] To address this issue, this application provides a possible implementation method in which the relay device can maintain synchronization / connection with the source satellite after establishing a connection with the target satellite. In this way, the relay device can forward signals from both the source and target satellites, thereby enabling the terminal device to communicate with both the source and target network devices through the relay device, thus improving the success rate of terminal device handover.

[0009] The above scenario is one possible example. The relay device in this embodiment can also be deployed in the air, and the network device to be switched by the relay device can also be deployed on the ground. Related content is similar and will not be repeated here.

[0010] Firstly, embodiments of this application provide a communication method that can be executed by a relay device. The relay device can be a relay equipment or a chip (or chip system, circuit, or module unit) within a relay equipment. The relay equipment can be satellite equipment or a network equipment deployed on the ground. For example, the relay equipment may include an integrated access and backhaul (IAB)-mobile termination (MT), a network-controlled repeater (NCR)-MT, or a wireless access backhaul (WAB)-MT, etc.

[0011] A connection is established between the relay device and the target network device. The relay device releases its connection with the source network device and maintains synchronization with it, or the relay device maintains its connection with the source network device. The relay device sends first information to the source network device and / or forwards second information from the source network device, the first information and / or the second information being used by terminal devices within the relay device's signal coverage area to switch from the source network device to the target network device.

[0012] Because the relay device establishes a connection with the target network device, it can forward information from the target network device (or the relay device is enabled or has the capability to forward information from the target network device). Furthermore, because the relay device maintains synchronization / connection with the source network device, it can forward information from the source network device (or the relay device is enabled or has the capability to forward information from the source network device). Since the relay device can forward information from both the source and target network devices, the success rate of terminal device handover can be improved. On another front, because the relay device establishes a connection with the target network device first, and the subsequent terminal device only switches to the target network device, this avoids the situation where terminal devices in the relay device's signal coverage area drop out and reconnect to the system due to a failure to establish a connection with the target network device.

[0013] For example, this application can be applied to NTN scenarios. For example, at least one of the following is satisfied: at least one of the relay device, the source network device, or the target network device is located on the NTN device; the relay device communicates with the source network device through the NTN device; or, the relay device communicates with the target network device through the NTN device.

[0014] An NTN device can be an NTN equipment or a chip (or chip system, circuit, or module unit) within an NTN equipment. For example, an NTN equipment can include terminal equipment, relay equipment, or network equipment. For example, the NTN equipment can also act as a relay to provide access services to other devices. For example, NTN equipment includes satellites, drones, or high-altitude platforms. As another example, NTN equipment includes aircraft (or other flying vehicles), or terminals on aircraft (or other flying vehicles), ground mobile terminals, drone terminals, aircraft terminals, satellites, or satellite terminals. The satellite or satellite terminal can operate in transparent mode or regenerative mode.

[0015] In NTN scenarios, as the NTN device moves, both the relay device and the terminal device need to switch network devices. To improve the success rate of terminal devices in this scenario, the solution provided in this application ensures that the relay device maintains its connection / synchronization with the source network device after establishing a connection with the target network device. This improves the handover success rate of terminal devices in this scenario and allows for the deployment of relay devices in NTN scenarios. Furthermore, this solution enables information transmission via relay devices in satellite communication scenarios. Since relay devices can be deployed in satellite communication scenarios, the number of gateway stations and ground stations can be reduced, thereby lowering communication costs. In this application, "connection / synchronization" can be replaced with "connection, and / or synchronization," and will not be described again.

[0016] In one possible implementation, the relay device receives a first instruction message, which instructs the relay device to perform a first operation. The first operation includes at least one of the following: ceasing to maintain synchronization with the source network device, releasing the connection with the source network device, or ceasing to forward information from the source network device. The relay device performs the first operation in response to the first instruction message. This can save energy consumption of the relay device.

[0017] In one possible implementation, the first indication information includes at least one of the following: indication information that the relay device stops maintaining synchronization with the source network device; indication information that the relay device releases its connection with the source network device; indication information that the relay device stops forwarding information from the source network device; first time information; information on the number of terminal devices within the signal coverage area of ​​the relay device that have switched from the source network device to the target network device; information on the number of terminal devices within the signal coverage area of ​​the relay device that have not switched from the source network device to the target network device; or, information indicating that all terminal devices within the signal coverage area of ​​the relay device that need to switch to the target network device have switched from the source network device to the target network device; information indicating that the source network device cannot provide communication services to the terminal devices within the signal coverage area of ​​the relay device; or, identification information of the relay device. The time indicated by the first time information includes / is at least one of the following: the time when the relay device stops maintaining synchronization with the source network device, or the time when the relay device releases its connection with the source network device, or the time when the relay device stops forwarding information from the source network device.

[0018] When the first indication information includes first time information, the relay device can actively perform the first operation at the time indicated by the first time information, thereby improving the timeliness and accuracy of the operation.

[0019] If the first indication information includes the number of terminal devices within the signal coverage area of ​​the relay device that have switched from the source network device to the target network device; and / or the number of terminal devices within the signal coverage area of ​​the relay device that have not switched from the source network device to the target network device, the relay device and / or the target network device know how many terminal devices have successfully switched and how many terminal devices have not successfully switched, and can then allocate resources more rationally and improve communication performance.

[0020] If the first indication information includes information indicating that all terminal devices within the signal coverage area of ​​the relay device that need to switch to the target network device have switched from the source network device to the target network device, the relay device can stop synchronizing / connecting with the source network device only after all terminal devices within the signal coverage area of ​​the relay device have successfully switched, thereby saving the power consumption of the relay device while ensuring the success rate of switching.

[0021] In one possible implementation, the first indication information further includes second time information, the second time information indicating the time when the relay device begins forwarding information from the source network device. Thus, the relay device can start forwarding information from the source network device from a certain time according to the indication, thereby reducing the power consumption of the relay device.

[0022] The solution provided in this application can be applied to the dual active protocol stack (DAPS) mechanism. For example, a relay device can activate two protocol stacks for a period of time. For instance, the relay device activates the protocol stack corresponding to the target network device; the relay device maintains the active state of the protocol stack corresponding to the source network device. As another example, if the relay device subsequently needs to release the connection with the source network device and / or needs to stop forwarding information from the source network device, the relay device can deactivate the protocol stack corresponding to the source network device. It can be seen that the solution provided in this application can be used in conjunction with the DAPS mechanism, thereby reducing the complexity of implementing the solution and making it more compatible with existing technologies.

[0023] In one possible implementation, the relay device receives first configuration information, which instructs the relay device to forward information from a source network device. This source network device information includes information received from and / or sent to the source network device. The relay device forwards the source network device information according to the first configuration information. For example, the first configuration information includes at least one of the following corresponding to the relay device forwarding the source network device information: resource information, beam information, reference signal information, routing information, frequency information, power information, port information, or signal transmission mode information. The signal transmission mode includes transparent forwarding or regenerative forwarding. In this way, the relay device and the source network device can align some configurations of the information, thereby improving the transmission speed of the signal transmission according to the first configuration information, improving signal transmission quality, and consequently improving communication performance.

[0024] Secondly, embodiments of this application provide a communication method that can be executed by a source network device. The source network device can be a network device or a chip (or chip system, circuit, or module unit) within a network device. The network device can be deployed on the ground or in the air. For example, the network device can include access network equipment, ground stations, gateways, relay devices, base stations, hosts, parent nodes, or nodes, etc. As another example, the network device can include an IAB, or an NCR, or a WAB, etc.

[0025] The source network device sends a third message, which instructs the relay device to establish a connection with the target network device. The source network device receives a first message from the relay device and / or sends a second message to the relay device. The first and / or second messages are used by terminal devices within the signal coverage area of ​​the relay device to switch from the source network device to the target network device.

[0026] Since the relay device can maintain synchronization / connection with the source network device after establishing a connection with the target network device, the relay device can forward information between the source network device and the target network device, thereby improving the success rate of terminal device handover.

[0027] In one possible implementation, at least one of the following is satisfied: the relay device, the source network device, or the target network device is located on the NTN device; the relay device communicates with the source network device via the NTN device; or, the relay device communicates with the target network device via the NTN device.

[0028] The relevant descriptions and beneficial effects can be found in the possible implementations of the first aspect mentioned above, and will not be repeated here.

[0029] In one possible implementation, the source network device sends a fourth message indicating whether to release the connection with the source network device and maintain synchronization with it, or to maintain the connection with the source network device. The relay device can then maintain its connection / synchronization with the source network device based on this fourth message. This allows the relay device to maintain synchronization / connection with the source network device even after establishing a connection with the target network device. Therefore, the relay device can forward information from both the source and target network devices, thereby improving the success rate of terminal device handover.

[0030] In one possible implementation, the source network device sends a third instruction message, which instructs at least one of the following: to stop maintaining synchronization with the source network device, to release the connection with the source network device, or to stop forwarding information from the source network device. This can save energy consumption of the relay device.

[0031] In one possible implementation, the third indication information is sent when at least one of the following conditions is met: a terminal device within the signal coverage area of ​​the relay device that has established a connection with the source network device has switched from the source network device to the target network device; the source network device is unable to provide communication services to the terminal device within the signal coverage area of ​​the relay device; or information indicating at least one of the following is received: stop maintaining synchronization with the source network device, release the connection with the source network device, or stop forwarding information from the source network device. This can save power consumption of the relay device while ensuring a high success rate of handover.

[0032] In one possible implementation, the third indication information includes at least one of the following: indication information that the relay device stops maintaining synchronization with the source network device; indication information that the relay device releases its connection with the source network device; indication information that the relay device stops forwarding information from the source network device; first time information; information on the number of terminal devices within the signal coverage area of ​​the relay device that have switched from the source network device to the target network device; information on the number of terminal devices within the signal coverage area of ​​the relay device that have not switched from the source network device to the target network device; or, information indicating that all terminal devices within the signal coverage area of ​​the relay device that need to switch to the target network device have switched from the source network device to the target network device; information indicating that the source network device cannot provide communication services to terminal devices within the signal coverage area of ​​the relay device; or, identification information of the relay device.

[0033] For first-time information and other relevant descriptions and beneficial effects, please refer to the relevant content of the first instruction information in the possible implementation of the first aspect mentioned above, which will not be repeated here.

[0034] In one possible implementation, the source network device sends first configuration information. A description and benefits of the first configuration information can be found in the relevant content of the possible implementation of the first aspect described above, and will not be repeated here.

[0035] The descriptions and beneficial effects of the second aspect and its possible implementations can be found in the foregoing descriptions of the first aspect and its possible implementations, and will not be repeated hereafter.

[0036] Thirdly, embodiments of this application provide a communication method that can be executed by a target network device. The target network device can be a network device or a chip (or chip system, circuit, or module unit) within a network device. The network device can be deployed on the ground or in the air. For example, the network device can include access network equipment, ground stations, gateways, relay devices, base stations, hosts, parent nodes, or nodes, etc. As another example, the network device can include an IAB, or an NCR, or a WAB, etc.

[0037] The target network device receives information from the relay device and / or sends information to the relay device. The target network device receives second instruction information. The second instruction information instructs at least one of the following: the relay device stops maintaining synchronization with the source network device, the relay device releases its connection with the source network device, or the relay device stops forwarding information from the source network device. In response to the second instruction information, the target network device sends first instruction information to the relay device, which instructs the relay device to perform a first operation. The first operation includes at least one of the following: stopping maintaining synchronization with the source network device, releasing the connection with the source network device, or stopping forwarding information from the source network device. Thus, in the event of a disconnection between the relay device and the source network device, the target network device can send the first instruction information to the relay device, thereby saving the relay device's power consumption.

[0038] In one possible implementation, at least one of the following is satisfied: the relay device, the source network device, or the target network device is located on the NTN device; the relay device communicates with the source network device via the NTN device; or, the relay device communicates with the target network device via the NTN device.

[0039] The relevant descriptions and beneficial effects can be found in the possible implementations of the first aspect mentioned above, and will not be repeated here.

[0040] In one possible implementation, the first indication information and / or the second indication information includes at least one of the following: indication information that the relay device stops maintaining synchronization with the source network device; indication information that the relay device releases its connection with the source network device; indication information that the relay device stops forwarding information from the source network device; first time information; information on the number of terminal devices within the signal coverage area of ​​the relay device that have switched from the source network device to the target network device; information on the number of terminal devices within the signal coverage area of ​​the relay device that have not switched from the source network device to the target network device; or, information indicating that all terminal devices within the signal coverage area of ​​the relay device that need to switch to the target network device have switched from the source network device to the target network device; information indicating that the source network device cannot provide communication services to terminal devices within the signal coverage area of ​​the relay device; or, identification information of the relay device.

[0041] The first instruction information and the second instruction information may be the same or different. For a description and beneficial effect related to the first instruction information and the second instruction information, please refer to the relevant content of the first instruction information in the possible embodiments of the first aspect above, and it will not be repeated here. For a description and beneficial effect related to the first timing information, please refer to the relevant content in the possible embodiments of the first aspect above, and it will not be repeated here.

[0042] In one possible implementation, the first indication information and / or the second indication information further include second time information, the time indicated by the second time information including / the time when the relay device begins forwarding information from the source network device.

[0043] In one possible implementation, the target network device receives first configuration information, which instructs the relay device to forward information from the source network device. The target network device then sends the first configuration information to the relay device. Thus, even if the connection between the relay device and the source network device is lost, the target network device can still send the first configuration information to the relay device. A description of the first configuration information and its beneficial effects can be found in the relevant content of the possible implementation of the first aspect described above, and will not be repeated here.

[0044] Fourthly, embodiments of this application provide a communication method that can be executed by a terminal device. The terminal device can be a terminal equipment or a chip (or chip system, or circuit, or module unit) inside the terminal equipment.

[0045] The terminal device receives fifth information from the source network device via a relay device. This fifth information instructs the terminal device to switch from the source network device to the target network device. In response to the fifth information, the terminal device switches to the target network device. The terminal device communicates with the target network device via the relay device.

[0046] Since the relay device can maintain synchronization / connection with the source network device after establishing a connection with the target network device, the relay device can forward information between the source network device and the target network device, thereby improving the success rate of terminal device handover.

[0047] Fifthly, embodiments of this application provide a communication method that can be executed by a relay device. The relay device can be a relay equipment or a chip (or chip system, circuit, or module unit) within a relay equipment. The relay equipment can be satellite equipment or a network equipment deployed on the ground. For example, the relay equipment may include IAB-MT, NCR-MT, or WAB-MT, etc.

[0048] The relay device receives a fourth instruction message, which instructs the relay device to establish synchronization or a connection with the target network device. In response to the fourth instruction message, the relay device establishes synchronization or a connection with the target network device. The relay device forwards information from the target network device, including information received from and / or sent to the target network device. The relay device sends a first message to the source network device, and / or forwards a second message from the source network device. The first and / or second messages are used by terminal devices within the relay device's signal coverage area to switch from the source network device to the target network device.

[0049] Because the relay device can maintain a connection with the source network device, it can forward information from the source network device (or the relay device is enabled or has the capability to forward information from the source network device). Furthermore, because the relay device can establish synchronization or a connection with the target network device, it can forward information from the target network device (or the relay device is enabled or has the capability to forward information from the target network device). Since the relay device can forward information from both the source and target network devices, this scheme allows the terminal device to communicate with both the source and target network devices through the relay device, thereby enabling successful handover and improving the success rate of terminal device handover.

[0050] In one possible implementation, at least one of the following is satisfied: the relay device, the source network device, or the target network device is located on the NTN device; the relay device communicates with the source network device via the NTN device; or, the relay device communicates with the target network device via the NTN device.

[0051] The relevant descriptions and beneficial effects can be found in the possible implementations of the first aspect mentioned above, and will not be repeated here.

[0052] In one possible implementation, the relay device receives a fifth indication message, which instructs the relay device to perform a second operation. The second operation includes at least one of the following: the relay device switches from a source network device to a target network device; the relay device releases its connection with the source network device; the relay device establishes a connection with the target network device; or the relay device stops forwarding information from the source network device. Establishing a connection with the target network device and releasing the connection with the source network device is an option. The relay device can release its connection with the source network device after receiving the fifth indication message, thereby saving power consumption.

[0053] In one possible implementation, the fifth indication information includes at least one of the following: indication information for the second operation; third time information; information on the number of terminal devices within the signal coverage area of ​​the relay device that have switched from the source network device to the target network device; information on the number of terminal devices within the signal coverage area of ​​the relay device that have not switched from the source network device to the target network device; or, information indicating that all terminal devices within the signal coverage area of ​​the relay device that need to switch to the target network device have switched from the source network device to the target network device; or, information indicating that the source network device cannot provide communication services to the terminal devices within the signal coverage area of ​​the relay device. The time indicated by the third time information includes / is the time when the relay device performs the second operation.

[0054] For relevant descriptions and beneficial effects, please refer to the relevant content of the first instruction information in the possible implementation of the first aspect mentioned above, which will not be repeated here.

[0055] In one possible implementation, the relay device receives second configuration information, which instructs the relay device to forward information from the target network device. The relay device forwards the target network device's information according to the second configuration information. For example, the second configuration information includes at least one of the following corresponding to the relay device forwarding the target network device's information: resource information, beam information, reference signal information, routing information, frequency information, power information, port information, or signal transmission mode information. The signal transmission mode includes transparent forwarding or regenerative forwarding. In this way, the relay device and the target network device can align some configurations of the information, thereby improving the transmission speed of the relay device when transmitting signals according to the first configuration information, improving signal transmission quality, and consequently improving communication performance.

[0056] Sixthly, embodiments of this application provide a communication method that can be executed by a source network device. The source network device can be a network device or a chip (or chip system, circuit, or module unit) within a network device. The network device can be deployed on the ground or in the air. For example, the network device can include access network equipment, ground stations, gateways, relay equipment, base stations, hosts, parent nodes, or nodes, etc. As another example, the network device can include IAB, NCR, or WAB, etc.

[0057] The source network device sends a fourth instruction message, which instructs the relay device to establish synchronization or connection with the target network device. The source network device receives a first message from the relay device and / or sends a second message to the relay device. The first and / or second messages are used by terminal devices within the signal coverage area of ​​the relay device to switch from the source network device to the target network device.

[0058] Since a relay device can maintain a connection with the source network device on the one hand, and establish synchronization or connection with the target network device on the other hand, it can forward information from both the source and target network devices, thereby improving the success rate of terminal device handover.

[0059] In one possible implementation, the source network device sends a fifth indication message to the relay device, which instructs the relay device to switch from the source network device to the target network device. This can save energy consumption of the relay device. For a description and beneficial effect of the fifth indication message, please refer to the relevant content of the fifth indication message in the possible implementations of the fifth aspect above, and will not be repeated here.

[0060] In one possible implementation, the source network device sends a fifth instruction to the relay device if at least one of the following conditions is met: all terminal devices within the relay device's signal coverage area that have established a connection with the source network device have switched from the source network device to the target network device; the source network device is unable to provide communication services to the terminal devices within the relay device's signal coverage area; or, it receives information instructing the relay device to switch from the source network device to the target network device. This can save power consumption of the relay device while ensuring a high success rate for the handover.

[0061] In one possible implementation, the source network device receives second configuration information from the target network device, the second configuration information being used to instruct the relay device to forward information from the target network device. The source network device then sends the second configuration information to the relay device. Thus, even if no connection is established between the relay device and the target network device, the target network device can send the first configuration information to the relay device. A description of the first configuration information and its beneficial effects can be found in the relevant content of the possible implementation of the first aspect described above, and will not be repeated here.

[0062] Seventhly, embodiments of this application provide a communication method that can be executed by a target network device. The target network device can be a network device or a chip (or chip system, circuit, or module unit) within a network device. The network device can be deployed on the ground or in the air. For example, the network device can include access network equipment, ground stations, gateways, relay equipment, base stations, hosts, parent nodes, or nodes, etc. As another example, the network device can include IAB, NCR, or WAB, etc.

[0063] The target network device obtains second configuration information, which instructs the relay device to forward information from the target network device. This information includes information received from and / or sent to the target network device. If the relay device has not established a connection with the target network device, the target network device sends the second configuration information to the source network device.

[0064] Thus, even if no connection is established between the relay device and the target network device, the target network device can send first configuration information to the relay device. The relevant description and beneficial effects of the first configuration information can be found in the relevant content of the possible embodiments of the first aspect described above, and will not be repeated here.

[0065] Eighthly, a communication device is provided, which can be the aforementioned relay device, source network device, target network device, or terminal device. The communication device may include a communication unit and a processing unit to perform any one of the first to seventh aspects, or any possible implementation of the first to seventh aspects. The communication unit is used to perform functions related to transmission and reception. The communication unit may be referred to as a transceiver unit. Optionally, the communication unit includes a receiving unit and a transmitting unit. In one design, the communication device is a communication chip, the processing unit may be one or more processors or processor cores, and the communication unit may be the input / output circuit, input / output interface, or antenna port of the communication chip.

[0066] In another design, the communication unit can be a transmitter and a receiver, or the communication unit can be a transmitter and a receiver.

[0067] Optionally, the communication device may also include modules that can be used to perform any one of the first to seventh aspects described above, or to perform any possible implementation of the first to seventh aspects.

[0068] A ninth aspect provides a communication device, which can be the aforementioned relay device, source network device, target network device, or terminal device. The communication device may include at least one processor and a memory to execute any one of the first to seventh aspects, or to execute any possible implementation of the first to seventh aspects. Optionally, it may also include a transceiver, the memory for storing computer programs or instructions, and the processor for retrieving and executing the computer program or instructions from the memory. When the processor executes the computer program or instructions in the memory, the communication device executes any one of the first to seventh aspects, or to execute any possible implementation of the first to seventh aspects.

[0069] Optionally, there may be one or more processors and one or more memories.

[0070] Optionally, the memory can be integrated with the processor, or the memory can be set up separately from the processor.

[0071] Optionally, the transceiver may include a transmitter and a receiver.

[0072] In a tenth aspect, a communication device is provided, which may be a relay device, a source network device, a target network device, or a terminal device as described above. The communication device may include at least one processor to execute any one of the first to seventh aspects, or to execute any possible implementation of the first to seventh aspects. The processor is coupled to a memory. Optionally, the communication device further includes a memory. Optionally, the communication device further includes a communication interface, to which the processor is coupled.

[0073] In one implementation, when the communication device is a relay device, a source network device, a target network device, or a terminal device, the communication interface can be a transceiver or an input / output interface. Optionally, the transceiver can be a transceiver circuit. Optionally, the input / output interface can be an input / output circuit.

[0074] In another implementation, when the communication device is a chip or chip system, the communication interface can be an input / output interface, interface circuit, output circuit, input circuit, pin, or related circuit on the chip or chip system. The processor can also be manifested as a processing circuit or logic circuit.

[0075] Eleventhly, a system is provided, which includes the aforementioned relay device.

[0076] In one possible implementation, the system may further include at least one of a source network device, a target network device, or a terminal device.

[0077] In a twelfth aspect, a computer program product is provided, comprising: a computer program (also referred to as code or instructions) that, when run, causes a computer to perform any one of the first to seventh aspects described above, or to perform any possible implementation of the first to seventh aspects.

[0078] In a thirteenth aspect, a computer-readable storage medium is provided, which stores a computer program (also referred to as code or instructions) that, when run on a computer, causes the computer to perform any one of the first to seventh aspects described above, or to perform any possible implementation of the first to seventh aspects.

[0079] In a fourteenth aspect, a processing apparatus is provided, comprising: an interface circuit and a processing circuit. The interface circuit may include an input circuit and an output circuit. The processing circuit is configured to receive signals through the input circuit and transmit signals through the output circuit, thereby enabling any of the first to seventh aspects described above, or any possible implementation of the first to seventh aspects, to be implemented.

[0080] In specific implementation, the aforementioned processing device can be a chip, the input circuit can be an input pin, the output circuit can be an output pin, and the processing circuit can be a transistor, gate circuit, flip-flop, and various logic circuits, etc. The input signal received by the input circuit can be received and input by, for example, but not limited to, a receiver, and the signal output by the output circuit can be, for example, but not limited to, output to a transmitter and transmitted by the transmitter. Furthermore, the input circuit and the output circuit can be the same circuit, which is used as the input circuit and output circuit at different times. This application does not limit the specific implementation method of the processor and various circuits.

[0081] In one implementation, the communication device is a relay device, a source network device, a target network device, or a terminal device. The interface circuit can be an RF processing chip in the relay device, source network device, target network device, or terminal device, and the processing circuit can be a baseband processing chip in the relay device, source network device, target network device, or terminal device.

[0082] In another implementation, the communication device can be a component of a relay device, source network device, target network device, or terminal device, such as an integrated circuit product like a system-on-a-chip (SoC) or communication chip. The interface circuit can be an input / output interface, interface circuit, output circuit, input circuit, pin, or related circuit on the chip or chip system. The processing circuit can be the logic circuit on the chip. Attached Figure Description

[0083] Figure 1A is a schematic diagram of a possible architecture of a communication system applicable to an embodiment of this application;

[0084] Figure 1B is a schematic diagram of another possible architecture of a communication system applicable to the embodiments of this application;

[0085] Figure 1C is a schematic diagram of another possible architecture of a communication system applicable to the embodiments of this application;

[0086] Figure 1D is a schematic diagram of another possible architecture of a communication system applicable to the embodiments of this application;

[0087] Figure 1E is a schematic diagram of another possible architecture of a communication system applicable to the embodiments of this application;

[0088] Figure 1F is a schematic diagram of another possible architecture of a communication system applicable to the embodiments of this application;

[0089] Figure 1G is a schematic diagram of another possible architecture of a communication system applicable to the embodiments of this application;

[0090] Figure 1H is a schematic diagram of another possible architecture of a communication system applicable to the embodiments of this application;

[0091] Figure 1I is a schematic diagram of another possible architecture of a communication system applicable to the embodiments of this application;

[0092] Figure 1J is a schematic diagram of another possible architecture of a communication system applicable to the embodiments of this application;

[0093] Figure 1K is a schematic diagram of another possible architecture of a communication system applicable to the embodiments of this application;

[0094] Figure 1L is a schematic diagram of another possible architecture of a communication system applicable to the embodiments of this application;

[0095] Figure 2A is a schematic diagram of another possible architecture of a communication system applicable to the embodiments of this application;

[0096] Figure 2B is a schematic diagram of another possible architecture of a communication system applicable to the embodiments of this application;

[0097] Figure 2C is a schematic diagram of another possible architecture of a communication system applicable to the embodiments of this application;

[0098] Figure 2D is a schematic diagram of another possible architecture of a communication system applicable to the embodiments of this application;

[0099] Figure 2E is a schematic diagram of another possible architecture of a communication system applicable to the embodiments of this application;

[0100] Figure 3 is a schematic diagram of another possible architecture of a communication system applicable to the embodiments of this application;

[0101] Figure 4 is a possible flowchart of a communication method provided in an embodiment of this application;

[0102] Figure 5 is a possible structural diagram of a protocol stack in a relay device provided in an embodiment of this application;

[0103] Figure 6 is a possible flowchart of another communication method provided in an embodiment of this application;

[0104] Figure 7 is a possible flowchart of another communication method provided in an embodiment of this application;

[0105] Figure 8 is a possible flowchart of another communication method provided in an embodiment of this application;

[0106] Figure 9 is a possible structural diagram of another communication scenario provided by an embodiment of this application;

[0107] Figure 10 is a possible structural schematic diagram of a communication device provided in an embodiment of this application;

[0108] Figure 11 is a possible structural schematic diagram of another communication device provided in an embodiment of this application. Detailed Implementation

[0109] The technical solutions of this application can be applied to satellite communication systems, high altitude platform station (HAPS) communication, and non-terrestrial network (NTN) systems such as unmanned aerial vehicles (UAVs). Examples include integrated communication and navigation (ICAN) systems, global navigation satellite systems (GNSS), and ultra-dense low-Earth orbit (LEO) satellite communication systems. Satellite communication systems can be integrated with traditional mobile communication systems. For example, mobile communication systems can be fourth-generation (4G) communication systems (e.g., Long Term Evolution (LTE) systems), worldwide interoperability for microwave access (WiMAX) communication systems, fifth-generation (5G) communication systems (e.g., new radio (NR) systems), and future mobile communication systems.

[0110] Figure 1A exemplarily illustrates an architecture diagram of a communication system 1000 applicable to an embodiment of this application. As shown in Figure 1A, the communication system includes a wireless access network 100 and a core network 200. Optionally, the communication system 1000 may also include an Internet 300. The wireless access network 100 may include at least one wireless access network device (110a and 110b in Figure 1A) and at least one terminal device (120a-120j in Figure 1A). The terminal device is wirelessly connected to the wireless access network device, and the wireless access network device is wirelessly or wiredly connected to the core network. The core network device and the wireless access network device may be independent and different physical devices, or the functions of the core network device and the logical functions of the wireless access network device may be integrated on the same physical device, or a single physical device may integrate some of the functions of the core network device and some of the functions of the wireless access network device. Terminal devices and wireless access network devices may be interconnected via wired or wireless means. Figure 1A is just a schematic diagram. The communication system may also include other network devices, such as wireless relay devices and wireless backhaul devices, which are not shown in Figure 1A.

[0111] The network devices involved in the embodiments of this application include, for example, radio access network (RAN) devices. RAN devices can be base stations, evolved NodeBs (eNodeBs or eNBs), transmission reception points (TRPs), transmission points (TPs), base stations in 5G mobile communication systems, base stations in future mobile communication systems, or access nodes in WiFi systems; they can also be modules or units that perform some of the functions of a base station, for example, they can be central units (CUs), distributed units (DUs), or radio units (RUs). The CU (Radio Control Unit) performs the functions of the radio resource control protocol and packet data convergence protocol (PDCP) of the base station, and can also perform the functions of the service data adaptation protocol (SDAP). The DU (Radio Link Control Unit) performs the functions of the radio link control layer and medium access control (MAC) layer of the base station, and can also perform some or all of the physical layer functions. For specific descriptions of the above-mentioned protocol layers, please refer to the relevant technical specifications of the 3rd Generation Partnership Project (3GPP). The CU and DU can be set up separately, or they can be included in the same network element, such as in the baseband unit (BBU). The RU (Radio Receiver Unit) can be included in radio frequency equipment or radio frequency units, such as in the remote radio unit (RRU), active antenna unit (AAU), or remote radio head (RRH). In different systems, CU, DU, or RU may also have different names, but those skilled in the art will understand their meaning. For example, in an open radio access network (ORAN) system, a CU can also be called an open CU (open-CU, O-CU), a DU can also be called an open DU (open-DU, O-DU), and a RU can also be called an open RU (open-RU, O-RU).In this application, any of the following units—CU (or CU control plane (CU-CP), CU user plane (CU-UP), DU, and RU)—can be implemented through software modules, hardware modules, or a combination of software and hardware modules. CU-CP can also be called open-CU-CP (O-CU-CP), and CU-UP can also be called open-CU-UP (O-CU-UP).

[0112] Wireless access network equipment can be a macro base station (110a in Figure 1A), a micro base station or an indoor station (110b in Figure 1A), or a relay device, relay node, or donor node, etc. The embodiments of this application do not limit the specific technology or equipment form used in the wireless access network equipment. For ease of description, a base station is used as an example of wireless access network equipment in the following description.

[0113] Terminal devices can also be referred to as terminals, user equipment (UE), mobile stations, mobile terminal devices, etc. Terminal devices can be widely used in various scenarios, such as device-to-device (D2D), vehicle-to-everything (V2X) communication, machine-type communication (MTC), Internet of Things (IoT), virtual reality, augmented reality, industrial control, autonomous driving, telemedicine, smart grids, smart furniture, smart offices, smart wearables, smart transportation, smart cities, etc. Terminal devices can be mobile phones, tablets, computers with wireless transceiver capabilities, wearable devices, vehicles, drones, helicopters, airplanes, ships, robots, robotic arms, smart home devices, sensors, etc. The embodiments of this application do not limit the specific technologies or device forms used in the terminal devices.

[0114] The aforementioned terminal devices can establish connections with the operator's network through interfaces provided by the operator's network (such as N1), and use data and / or voice services provided by the operator's network. The terminal devices can also access the Domain Name System (DNS) through the operator's network, and use operator services deployed on the DNS, and / or services provided by third parties. These third parties can be service providers outside of the operator's network and the terminal devices, and can provide other data and / or voice services to the terminal devices. The specific form of these third parties can be determined according to the actual application scenario and is not limited here.

[0115] Base stations and terminal equipment can be fixed or mobile. They can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; on water; or in the air on aircraft, balloons, and satellites. The embodiments of this application do not limit the application scenarios of the base stations and terminal equipment.

[0116] The roles of base stations and terminal devices can be relative. For example, the helicopter or drone 120i in Figure 1A can be configured as a mobile base station. For terminal devices 120j that access the wireless access network 100 through 120i, terminal device 120i is a base station; however, for base station 110a, 120i is a terminal device, meaning that 110a and 120i communicate via a wireless air interface protocol. Of course, 110a and 120i can also communicate via a base station-to-base station interface protocol. In this case, relative to 110a, 120i is also a base station. Therefore, both base stations and terminal devices can be collectively referred to as communication devices. 110a and 110b in Figure 1A can be called communication devices with base station functions, and 120a-120j in Figure 1A can be called communication devices with terminal device functions.

[0117] Communication between base stations and terminal devices, between base stations, and between terminal devices can be conducted using licensed spectrum, unlicensed spectrum, or both simultaneously. Communication can be conducted using spectrum below 6 GHz, spectrum above 6 GHz, or both simultaneously. The embodiments of this application do not limit the spectrum resources used for wireless communication.

[0118] In the embodiments of this application, the functions of the base station can be executed by modules (such as chips) within the base station, or by a control subsystem that includes base station functions. This control subsystem, including base station functions, can be a control center in the aforementioned application scenarios such as smart grids, industrial control, intelligent transportation, and smart cities. Similarly, the functions of the terminal device can be executed by modules (such as chips or modems) within the terminal device, or by a device that includes terminal device functions.

[0119] In this application, the base station sends downlink signals or downlink information to the terminal device, with the downlink information carried on the downlink channel; the terminal device sends uplink signals or uplink information to the base station, with the uplink information carried on the uplink channel. In order to communicate with the base station, the terminal device needs to establish a radio connection with a cell controlled by the base station. The cell with which the terminal device has established a radio connection is called the serving cell of the terminal device. When the terminal device communicates with this serving cell, it is also subject to interference from signals from neighboring cells.

[0120] The core network involved in this application embodiment may include network devices that process and forward user signaling and data. For example, it includes core network devices such as access and mobility management functions (AMF), session management functions (SMF), user plane gateways, and location management devices. The user plane gateway can be a server with functions such as mobility management, routing, and forwarding of user plane data, generally located on the network side, such as a serving gateway (SGW), packet data network gateway (PGW), or user plane function (UPF). AMF and SMF are equivalent to the mobility management entity (MME) in a long-term evolution (LTE) system. AMF is mainly responsible for admission aspects, and SMF is mainly responsible for session management. Of course, the core network may also include other network elements, which are not listed here.

[0121] Figure 1B exemplarily illustrates a schematic diagram of an O-RAN system architecture provided by an embodiment of this application. The O-RAN system in the embodiments provided by this application may include components other than those shown in Figure 1B. As shown in Figure 1B, the access network device (RAN, for example, may be an eNB, a next-generation NodeB (gNB), or an access network device in a future mobile communication system) communicates with the core network (CN) via a backhaul link and with user equipment (UE) via an air interface. For example, the baseband unit (BBU) in the access network device communicates with the core network via a backhaul link, and the radio unit (RU) in the access network device communicates with at least one UE via an air interface. The BBU communicates with at least one RU via a fronthaul link; the BBU and RU may or may not be co-located. The BBU includes at least one control unit (CU) and at least one distributed unit (DU), which can communicate via at least one midhaul link.

[0122] Figure 1C exemplarily illustrates a schematic diagram of an O-RAN system architecture provided in an embodiment of this application. As shown in Figure 1C, O-RAN may include O-CU-CP, O-CU-UP, O-DU, and O-RU. This system architecture may also include an open cloud (O-cloud), a service management and orchestration framework, an open eNB (O-eNB), a near-real-time (RT) RAN Intelligent Controller (RIC), and a non-real-time RIC. The non-RT RIC can monitor, configure, manage, and control radio resources of at least one of multiple O-CU-CP, O-CU-UP, DU, or O-eNB. As shown in Figure 1C, the interfaces defined by 3GPP include, for example: E1, F1 (e.g., F1-c, F1-u), NG (e.g., NG-c, NG-u), Xn (e.g., Xn-c, Xn-u), and X2 (e.g., X2-c, X2-u). For example, O-RAN communication systems also include interfaces such as O1, O2, E2, A1, Open-Fronthaul (FH)-plane (e.g., Open FH M-plane), and Open FH Control, User, and Synchronization (CUS)-plane. The names of the interfaces and the connection methods of the units shown in Figure 1C are an example; in practical applications, O-RAN systems may include more or fewer interfaces, or more or fewer units.

[0123] Based on the content shown in Figures 1A, 1B, and 1C, Figure 1D also exemplarily illustrates a system architecture diagram applicable to another embodiment of this application. As shown in Figure 1D, the communication system includes a terminal device (e.g., a UE), a network device (e.g., a base station), and a relay device. The UE shown in Figure 1D can be replaced by any of the terminal devices shown in Figures 1A, 1B, or 1C. The base station shown in Figure 1D can be replaced by the network device (e.g., an access network device) shown in Figures 1A, 1B, or 1C. The relay device shown in Figure 1D can be the network device shown in Figures 1A, 1B, or 1C, and this relay device has the ability to forward data. Data can be sent and received in the form of signals; therefore, in this embodiment, signals can be replaced by data, and data can also be replaced by signals.

[0124] Figure 1D illustrates this using a network-controlled repeater (NCR) as an example. The NCR can act as a UE access base station (parent node) to receive control signaling from the base station (the control signaling controls the NCR's data forwarding behavior). The NCR can also amplify and forward signals between the UE and the base station.

[0125] Based on the content shown in Figures 1A, 1B, 1C, and 1D, Figure 1E also exemplarily illustrates a system architecture diagram applicable to yet another embodiment of this application. As shown in Figure 1E, the communication system includes a terminal device (e.g., a UE), a network device (e.g., a base station), and a relay device. The UE shown in Figure 1E can be replaced by any of the terminal devices shown in Figures 1A, 1B, 1C, or 1D. The base station shown in Figure 1D can be replaced by the network device (e.g., an access network device) shown in Figures 1A, 1B, 1C, or 1D. The relay device shown in Figure 1E can be the network device shown in Figures 1A, 1B, 1C, or 1D, and this relay device has the capability to forward data.

[0126] As shown in Figure 1E, a relay device (such as an NCR, satellite, or other relay device) includes two functional entities: a mobile termination (MT) entity (the relay device is an NCR, and the MT entity can also be called an NCR MT (or NCR-MT) entity) and a forwarding (Fwd) entity (the relay device is an NCR, and the forwarding entity can also be called an NCR Fwd (or NCR-Fwd) entity).

[0127] A relay unit (MT) can be defined as a functional entity that communicates with the base station via a control link (C-link) to exchange control information. The C-link can be based on the NR Uu interface, meaning the NCR-MT entity and the gNB are connected via the Uu interface. The base station uses the C-link to control the relay device. For example, the relay device can receive control information from the base station (e.g., side information for controlling forwarding entities), beam control information (e.g., beam control information for the control link, backhaul link, or access link), relay device on / off status (the NCR's on / off state), or NCR signal transmit power control, etc., through the C-link. The relay device amplifies and forwards data between the base station and the UE, without needing to decode or perform other data processing on the forwarded data. It is understood that the connection between the MT entity and the base station (such as C-link) can also be based on other future communication interfaces, not limited to the NR Uu interface.

[0128] A forwarding entity is defined as a functional entity that performs amplification and forwarding of uplink (UL) / downlink (DL) radio frequency (RF) signals between the base station and the UE via the backhaul link and access link. The behavior of the forwarding entity can be controlled based on control information received from the base station.

[0129] Figure 1F illustrates an exemplary architecture diagram of a communication system provided in an embodiment of this application. Figure 1F uses an integrated access and backhaul (IAB) communication system architecture as an example for illustration.

[0130] The purpose of IAB is to support wireless backhaul and relay links, enabling flexible and very dense deployment of NR cells without proportionally encrypting the wired transmission network. Typical deployment scenarios include supporting outdoor small cell deployment, indoor small cell deployment, and even mobile relay (e.g., on buses or trains).

[0131] As shown in Figure 1F, the communication system includes a UE and a network device. The UE in Figure 1F can be a terminal device or a chip (or chip system, processor, circuit, or functional module) within the terminal device. For example, the network device can include an IAB-host and an IAB-node. The IAB-donor supports the gNodeB with IAB additional functions, connects to the core network via a non-IAB connection, and can provide access to the UE or IAB-node (e.g., through a backhaul link or an access link). The IAB-node can support NR access (e.g., through an access link) and backhaul (e.g., through a backhaul link). In this embodiment, the host can be written as "donor," and the node can be written as "node." Correspondingly, the IAB-host can be written as "IAB-donor," and the IAB-node can also be written as "IAB-node." The substitution methods for other terms are similar, and will not be repeated elsewhere. Either the IAB-donor or IAB-node shown in Figure 1F can be a satellite device or a chip (or chip system, processor, circuit, or functional module) inside a satellite device, or a ground-deployed network device (such as a ground base station) or a chip (or chip system, processor, circuit, or functional module) inside a network device (such as a ground base station).

[0132] Figure 1G exemplarily illustrates a communication system architecture applicable to an embodiment of this application. The network architecture shown in Figure 1G can be the network architecture involved in IAB-donor and IAB-node in Figure 1F, and related content can also be found in the description in Figure 1F above.

[0133] As shown in Figure 1G, this communication system includes the UE and the 5G Core Network (5GC). 5GC / base station / parent node / gNB can be network devices. As shown in Figure 1G, this communication system also includes base stations (e.g., gNobeB), hosts (illustrated as IAB-host in Figure 1G, which can also be written as IAB-donor), and nodes (illustrated as IAB-node in Figure 1G, which can also be written as IAB-node).

[0134] As shown in Figure 1G, the IAB-node supports NR access and backhaul functions and can include an IAB-node-mobile termination (MT) and an IAB-node-DU. The IAB-node-MT can act as a regular terminal device connected to its parent node or host CU or DU, serving as a control link. The IAB-node-MT sends or receives beam direction information for control backhaul / control link / access link, switches forwarding transmission information, routing-related information, etc. The IAB-node-DU can provide coverage for access-side pole cells under the IAB-node, providing access for regular UEs or lower-level IAB-node-MTs to establish lower-level control links.

[0135] The IAB-donor can support gNodeBs (also known as gNodeB-donors) with IAB-node additional functions and can connect to the core network (e.g., via non-IAB connections), such as fiber optic cables. The IAB-donor can include IAB-host-CU (also known as IAB-donor-CU) and IAB-host-DU (also known as IAB-donor-DU). The IAB-donor-CU provides connectivity for the IAB-donor-DU and IAB-node-DU. The IAB-donor-CU can act as a base station connecting to other base stations (e.g., via the Xn-C interface), allowing the base station to access the 5GC, or the IAB-donor-CU can directly access the 5GC (e.g., via the NG interface). The IAB-donor-DU can provide coverage for access-side pole-mounted cells under the IAB-donor, providing access for ordinary UEs or IAB-nodes to establish lower-level control links.

[0136] The F1 interface is used for the connection between IAB-node-DU and IAB-donor-CU, and is fully inherited from the F1 interface of DU and CU. The Uu interface (e.g., NR Uu interface) is used for the connection between IAB-donor-DU and IAB-node-MT. It can also be used for the connection between IAB-node and UE. As shown in Figure 1G, the IAB-node accesses the IAB-donor as a terminal device and establishes a Uu interface connection. The UE can connect to the IAB-node and then access the IAB-donor-DU.

[0137] Figures 1H and 1I exemplarily illustrate network architecture diagrams of several communication systems applicable to embodiments of this application. The communication system may include satellites, network devices, and terminal devices. The communication system may also include gateways and core network devices. Figures 1H and 1I exemplarily illustrate a converged network architecture of NTN and terrestrial networks. A description is provided below with reference to the accompanying drawings.

[0138] The satellite can be a highly elliptical orbit (HEO) satellite, a geosynchronous orbit (GSO) satellite, a geostationary earth orbit (GEO) satellite, a medium earth orbit (MEO) satellite, or a low-earth orbit (LEO) satellite. This application does not limit the satellite's operating mode; for example, the satellite can operate in transparent mode or regenerative mode. Figure 1H illustrates the example of a satellite operating in transparent mode, and Figure 1I illustrates the example of a satellite operating in regenerative mode.

[0139] When a satellite operates in transparent mode, it provides transparent relay forwarding functionality. A gateway possesses the functions of a network device (such as a base station) or some of the functions of a network device (such as a base station); in this case, the gateway can be considered a network device (such as a base station). Alternatively, the network device (such as a base station) can be deployed separately from the gateway. In this case, the feeder link latency includes both the latency from the satellite to the gateway and the latency from the gateway to the gNB. The transparent mode discussed later assumes that the gateway and gNB are located together or close to each other. For cases where the gateway and gNB are far apart, the feeder link latency is simply the sum of the latency from the satellite to the gateway and the latency from the gateway to the gNB.

[0140] When a satellite is operating in regenerative mode, it has data processing capabilities and functions as a network device (such as a base station) or partially functions as a network device (such as a base station). In this case, the satellite can be regarded as a network device (such as a base station).

[0141] Satellites can communicate wirelessly with terminal devices via broadcast communication signals and navigation signals. Optionally, each satellite can provide communication, navigation, and positioning services to terminal devices through multiple beams. For example, each satellite uses multiple beams to cover the service area, and the relationship between different beams can be one or more of time-division, frequency-division, and space-division.

[0142] A gateway (also known as a ground station, earth station, or gateway) is a network device used to connect satellites and ground-based network equipment (such as ground base stations). One or more satellites can connect to one or more ground-based network devices (such as ground base stations) through one or more gateways; this is not a limitation. The link between the satellite and the terminal device is called a service link, and the link between the satellite and the gateway is called a feeder link. Network equipment can be deployed separately from the gateway; therefore, the latency of the feeder link can include both the latency from the satellite to the gateway and the latency from the gateway to the network equipment.

[0143] The network devices in this application embodiment may include network devices deployed on satellites (such as satellite base stations), network devices deployed on gateways, or network devices deployed on the ground (such as ground base stations). For example, the network devices may be radio access network (RAN) nodes or RAN nodes in O-RAN systems as shown in Figures 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, or 1I. Related details are described above and will not be repeated here.

[0144] The core network (CN) device in this embodiment is a device located on the ground that can communicate with NTN devices in the NTN system. For example, the CN can be the CN involved in Figure 1A, Figure 1B, Figure 1C, Figure 1D, Figure 1E, Figure 1F, Figure 1G, Figure 1H or Figure 1I. For relevant details, please refer to the foregoing description and will not be repeated here.

[0145] The terminal device in the embodiments of this application may be the terminal, terminal equipment or terminal device involved in Figure 1A, Figure 1B, Figure 1C, Figure 1D, Figure 1E, Figure 1F, Figure 1G, Figure 1H or Figure 1I. For relevant content, please refer to the foregoing description and it will not be repeated here.

[0146] The embodiments of this application can also be applied to other communication system architectures, such as air-to-ground (ATG) communication systems, which include at least one network device and at least one high-altitude terminal device. High-altitude terminal devices include, for example, high-altitude aircraft and onboard terminal devices. The satellites in Figures 1F and 1G can also be replaced with other relay devices, such as high-altitude platform stations (HAPS) or other NTN devices. The communication system shown in Figure 1F or 1G is merely an example and does not limit the communication systems to which the methods provided in the embodiments of this application are applicable.

[0147] This application's embodiments can also be applied to air-to-ground (ATG) communication systems. As an example, please refer to Figure 1J, which is a schematic diagram of the network architecture of another communication system to which this application's embodiments apply. This communication system includes at least one network device and at least one high-altitude terminal device. Data forwarding between the network device and the high-altitude terminal device can also be achieved through relay devices. High-altitude terminal devices include, for example, high-altitude aircraft and onboard terminal devices.

[0148] In another example, the embodiments of this application can also be extended to satellite relay and ground relay backhaul forwarding scenarios. Figures 1K and 1L exemplarily illustrate two scenarios to which the embodiments of this application can be applied. In these two scenarios, ground relays can be used to expand congested ISLs, thereby increasing system capacity and reducing transmission path length. This application can replace or supplement existing inter-satellite links (ISLs) with on-demand deployed ground relay equipment and satellite-to-ground forwarding links, reducing satellite payload costs and improving the economics of low-Earth orbit satellite network deployment. As shown in Figure 1L, in this scenario, the ISL is partially congested, and ground relays are deployed to expand inter-satellite backhaul capacity. The ground relays can be relay equipment such as NCR / IAB / WAB. As shown in Figure 1L, for low-cost satellites that may not have inter-satellite links, ground relays can be deployed to quickly form a backhaul network, enabling low-cost satellite network backhaul.

[0149] Figure 2A illustrates, exemplarily, another communication system architecture applicable to embodiments of this application. As shown in Figure 2A, the communication system includes a gateway, a satellite, a ground-based relay device, a ground-based UE, a high-altitude UE (e.g., a high-altitude aircraft or onboard terminal device), and a high-altitude relay device (e.g., the satellite shown in Figure 2A, which may be an NCR / integrated access and backhaul (IAB)-MT entity).

[0150] As shown in Figure 2A, the gateway can transmit base station signals via satellite to ground-based relay equipment. Ground-based relay equipment can then forward the base station signals to UEs on the ground, or UEs in the sky / space (e.g., aircraft, satellite equipment such as NCR-MT, IAB-MT, or WAB-MT, which can be considered MTs). Ground-based relay equipment can also forward base station signals to the next relay equipment, which can be deployed on the ground or in the air. Figure 2A illustrates this with an example of a satellite in the air acting as the next relay equipment. This satellite can act as an NCR, forwarding received data (or forwarding it to other UEs or other relay equipment). Base station signals can originate from ground-based base stations or satellite base stations.

[0151] In another example, the gateway can transmit base station signals via satellite to ground-based relay equipment. The ground-based relay equipment can forward signals from UEs (e.g., ground-based UEs, aircraft in the air, or satellites configured to include IAB-MT entities) or other relay equipment (e.g., satellites configured as NCR in the diagram) to the gateway (e.g., forwarded via satellite or sent directly to the gateway). The gateway then forwards the received UE signals to the base station. The UE signals can originate from ground-based UEs or UEs in the air.

[0152] Figure 2A schematically illustrates relay devices #1, #2, #3, and #4. Relay device #4 can be installed between relay device #3 and terminal device #1. Relay device #4 can improve the signal-to-noise ratio (SNR) of the satellite-to-ground link, thereby improving the transmission spectral efficiency of the terminal. The relay device and the terminal device may be in the same cell or different cells. For example, relay device #2 and terminal device #1 may be in different cells. Alternatively, relay device #4 and terminal device #1 may be in the same cell, and relay device #4 can also act as a terminal device to access the network provided by relay device #3. For example, relay device #4, acting as a MT (e.g., relay device #4-MT), can receive signals from cell #1 (e.g., signal #1) and access cell #1. Therefore, relay device #4-MT can receive broadcast messages from cell #1. Relay device #4 forwards the signals from cell #1 to the ground (e.g., the area where terminal device #1 is located). The relay device in the embodiments of this application can also be regarded as a terminal device, and can be called a relay device or a relay device-MT.

[0153] The relay device in this application embodiment may include an amplify and forward (AF) relay and / or a decode and forward (DF) relay. An amplify and forward relay may refer to a relay device receiving a signal and then directly forwarding it to the next device without decoding or encoding the signal. A decode and forward relay may refer to a relay node receiving a signal, decoding the signal, re-encoding the decoding result, and then forwarding it to the next device.

[0154] Figure 2B illustrates an exemplary communication system architecture applicable to embodiments of this application. As shown in Figure 2B, the communication system includes a UE and a 5G Core Network (5GC). 5GC / base station / parent node / gNB can also be considered as several possible examples of network devices. As shown in Figure 2B, the communication system also includes one or more relay devices, represented in Figure 2B as network-controlled transparent nodes (NCTN). Transparent forwarding nodes have Amplify-and-Forward (AF) relay functionality, where Amplify-and-Forward relay refers to the relay node receiving a signal but not decoding or encoding it, and directly forwarding the received signal to the destination node. As shown in Figure 2B, the communication system also includes a base station (e.g., gNobeB) and a parent node (e.g., gNobeB-NCTN-donor).

[0155] As shown in Figure 2B, this communication system includes relay devices, which can be devices within the NG-RAN. The relay devices support NR access and backhaul functions and can include NCTN-Mobile Termination (MT) and NCTN-DU. The NCTN-MT can connect to its parent node's CU or NCTN-DU as a control link, functioning as a regular terminal device. The NCTN-MT sends or receives beam direction information for control backhaul / control link / access link, switches forwarded transmission information, routing-related information, etc. The NCTN-DU can provide access for the NCTN-MT / network controlled regenerative node (NCRN)-MT, establishing lower-level control links. The relay device can also include forwarding functionality, providing amplified forwarding (e.g., transparent forwarding) of UL / DL radio frequency signals between the parent node (gNB-donor) / regenerative node and the terminal device.

[0156] The parent node can be a gNodeB (also known as a gNodeB-donor) that supports additional functions of relay devices and can connect to the core network, such as fiber optic cables. The parent node can include NCTN-parent node-CU (also known as NCTN-donor-CU) and NCTN-parent node-DU (also known as NCTN-donor-DU). The NCTN-parent node-CU provides connectivity for the NCTN-parent node-DU and the NCTN-DU of the relay device. The NCTN-parent node-CU can act as a base station connecting to other base stations (e.g., via the Xn-C interface), allowing the base station to access the 5GC, or the NCTN-parent node-CU can directly access the 5GC (e.g., via the NG interface). The NCTN-parent node-DU can provide access for terminal devices or NCTN-MT.

[0157] The F1 interface is used for the connection between NCTN-DU and NCTN-parent node-CU, and is fully inherited from the F1 interface of DU and CU. The Uu interface (e.g., NR Uu interface) is used for the connection between NCTN-parent node-DU and NCTN-MT. It can also be used for the connection between the relay network and the UE. As shown in Figure 2B, the NCTN accesses the parent node as a terminal device and establishes a Uu interface connection. As shown in Figure 2B, the UE can connect to the NCTN forwarding connection, various NCTN forwarding connections, and access the NCTN-parent node-DU.

[0158] Figures 2C, 2D, and 2E exemplarily illustrate several communication system architectures applicable to embodiments of this application.

[0159] The difference between Figure 2C and Figure 2B is that all three relay devices in Figure 2B are NCTN, while one relay device in Figure 2C is an NCRN. As shown in Figure 2B, an NCRN can include NCRN-MT and NCRN-DU. An NCRN-MT can connect to its parent node's DU / NCTN-DU / NCRN-DU as a regular terminal device, serving as a control link and a wireless backhaul link (providing digital forwarding or regenerative forwarding functions, supporting RLC layer forwarding or MAC layer forwarding). An NCRN has decode-and-forward (DF) relay functionality, which means that after receiving a signal, the relay node decodes the signal, re-encodes the decoded result, and finally forwards it to the destination node. An NCRN-DU can provide access for lower-level NCTN-MT / NCRN-MT / terminal devices. Other details in Figure 2C are described in Figure 2B above and will not be repeated here.

[0160] Compared to Figure 2B, the difference in Figure 2D is that the relay devices in Figure 2D include forwarding and NCTN-MT, but not NCTN-DU. The NCTN-MT can connect to its parent node's DU / NCTN-DU / NCRN-DU as a regular terminal device, serving as a control link. It can also send / receive control return / control link / access link beam direction information, switch forwarded transmission information, routing-related information, etc. Forwarding can provide amplified forwarding (transparent forwarding) of UL / DL radio frequency signals between the gNB-donor / NCRN and the terminal device. Other details in Figure 2D are described in Figure 2B above and will not be repeated here.

[0161] The difference between Figure 2E and Figure 2C is that the NCTN in Figure 2E includes forwarding and NCTN-MT, but does not include NCTN-DU. Other details in Figure 2E are described in Figures 2B, 2C, and 2D above, and will not be repeated here.

[0162] Figure 3 exemplarily illustrates a possible scenario applicable to the implementation of this application. As shown in Figure 3, a network device (e.g., a base station or gateway) communicates with a terminal device through at least one relay device. The base station and gateway in this application are interchangeable. The base station and gateway may be deployed together or in separate locations. The relay device can also be a relay node, such as an IAB / NCR / WAB. A wireless access backhaul (WAB) device can be understood as a combination of a base station and a MT. Compared to the combination of a DU and MT in an IAB, the WAB device adds a CU module, which can better realize the functions of a base station. The terminal devices illustrated in Figure 3 include UEs and may also include MTs, such as satellites. These MTs can access the host node, the previous hop, or the relay device as mobile terminals. These MTs may include, for example, NCR-MT, IAB-MT, or WAB-MT. The relay devices shown in Figure 3 include ground-based relay devices and airborne relay devices (e.g., satellite #1 and satellite #2). Figure 3 illustrates one possible example of a ground-based relay device that can forward base station signals to UEs on the ground, UEs in the sky / space (e.g., aircraft, satellite equipment (e.g., satellites including entities such as NCR-MT, IAB-MT, or WAB-MT, which can be considered MTs)), etc.). Satellites shown in the figure that can be considered MTs can also be relay devices; for example, these MTs can act as relay devices to provide communication services to UEs.

[0163] In some scenarios, the movement of certain devices may require relay devices to switch network devices, and terminal devices may also need to switch network devices. For example, in the satellite-to-ground relay scenario shown in Figure 3, taking satellite #1 as the source network device and satellite #2 as the target network device, the relay device deployed on the ground needs to switch satellites (e.g., from satellite #1 to satellite #2; satellite #1 can be called the source satellite, and satellite #2 can be called the target satellite). Terminal devices (e.g., MTs and / or UEs) within the signal coverage area of ​​this relay device also need to switch satellites. In this scenario, both the relay device and the terminal device need to switch, thus exhibiting a two-level switching characteristic. Figure 3 illustrates this with satellite #1 connected to base station #1 / gateway #1 and satellite #2 connected to base station #2 / gateway #2. In actual applications, satellite #1 and satellite #2 may also be connected to the same base station (and / or the same gateway). The base station and gateway in this embodiment can be interchanged. In this application, "satellite" can be replaced with "cell," "base station," or "gateway." For example, "source satellite" can be replaced with "source cell," "source base station," or "source gateway," and "target satellite" can be replaced with "target cell," "target base station," or "target gateway." "Relay device switching satellite" can be replaced with "relay device switching base station," "switching cell," or "switching gateway."

[0164] In scenarios where both relay devices and terminal devices need to switch network devices, one possible implementation is that the relay device first switches from the source network device (e.g., satellite #1) to the target network device (e.g., satellite #2), and then the terminal devices within the relay device's signal coverage area switch from the source network device to the target network device. However, when the relay device switches to the target network device, it disconnects from the source network device and does not synchronize with it, thus preventing it from forwarding information between the source network device and the terminal devices. However, some terminal devices within the relay device's signal coverage area have not yet switched from the source network device to the target network device, and these terminal devices still need to transmit signals with the source network device. Because the relay device can no longer forward signals between the source network device and the terminal devices, some terminal devices within the relay device's signal coverage area experience switching failures.

[0165] To address this issue, this application provides a possible implementation method whereby, after establishing a connection with the target network device, the relay device can still maintain synchronization / connection with the source network device. In this way, the relay device can still forward signals between the source network device and the terminal device, enabling the terminal device to transmit information between itself and the source network device via the relay device, thus ensuring a successful handover. It can be seen that this solution can improve the success rate of terminal device handover.

[0166] In scenarios where both the relay device and the terminal device need to switch network devices, another possible implementation involves the terminal device within the signal coverage area of ​​the relay device first switching from the source network device to the target network device, followed by the relay device switching from the source network device to the target network device. However, since the terminal device needs to switch first, the relay device needs to forward signals between the target network device and the terminal device in order for the terminal device to switch to the target network device. But at this time, the relay device has not yet switched to the target network device, and the relay device still cannot transmit signals between the target network device and the terminal device, resulting in terminal device switching failure and communication failure. The terminal device may need to re-access the system, leading to wasted resources. Based on this problem, this application provides a possible implementation where the relay device can maintain its connection with the source network device and establish synchronization / connection with the target network device. In this way, the relay device can transmit signals between the source network device and the terminal device, as well as signals between the target network device and the terminal device, thereby enabling the terminal device to switch from the source network device to the target network device, thus avoiding the terminal device switching failure problem and improving the communication success rate.

[0167] The above example illustrates the switching of a satellite by a ground-based relay device. This application's embodiments are also applicable to other scenarios. For example, signal scenarios between a satellite relay base station and a ground-based UE, or between a satellite relay base station and a satellite relay-MT (e.g., a satellite-based NCR-MT, IAB-MT, or WAB-MT). In this application's embodiments, the satellite relay may include a relay device deployed on a satellite, or the satellite itself. As the satellite relay moves, it needs to switch the network device (e.g., base station / gateway) connected to it. Terminal devices within the signal coverage area of ​​the satellite relay (e.g., ground-based UEs, and / or satellite relay-MTs) also need to switch the network device (e.g., base station / gateway) connected to it. Since both the relay device and the UE need to switch network devices, this scenario exhibits a two-level switching characteristic. Similarly, the solution provided in this application's embodiments is also applicable to these scenarios; the solution is similar and will not be elaborated further.

[0168] Based on the content shown in at least one of Figures 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I, 1J, 1K, 1L, 2A, 2B, 2C, 2D, 2E, or 3, and the other content described above, Figure 4 exemplarily illustrates a possible flowchart of a communication method provided by an embodiment of this application. For ease of understanding, Figure 4 uses the interaction between a relay device, a source network device, and a target network device as an example for illustration.

[0169] The relay device can be a relay equipment or a chip (or chip system, circuit, or module unit) inside a relay equipment. The relay equipment can be satellite equipment or a network device deployed on the ground. For example, the relay equipment can include an IAB, NCR, or WAB. The source network device can be a network device or a chip (or chip system, circuit, or module unit) inside a network device. The target network device can be a network device or a chip (or chip system, circuit, or module unit) inside a network device. The network device can be deployed on the ground or in the air. For example, the network device can include access network equipment, ground stations, gateways, relay equipment, base stations, hosts, parent nodes, or nodes. As another example, the network device can include an IAB, NCR, or WAB. In the embodiments of this application, the access network equipment and the gateway can be interchanged. The access network equipment and the gateway can be deployed in one device or separately.

[0170] The embodiments of this application can be applied to NTN scenarios, such as when at least one of a relay device, a source network device, or a target network device is located on the NTN device. For example, the relay device communicates with the source network device via the NTN device. For example, the relay device communicates with the source network device via an NTN device (e.g., a satellite). For example, the relay device communicates with the target network device via an NTN device. For example, the relay device communicates with the target network device via an NTN device (e.g., a satellite).

[0171] The NTN device in this application embodiment may include an NTN equipment or a chip (or chip system, or circuit, or module unit) inside the NTN equipment. For example, the NTN equipment may include a satellite, a drone, or a high-altitude platform. Another example is that the NTN equipment includes an aircraft (or other flying vehicle), or a terminal on an aircraft (or other flying vehicle), a ground mobile terminal, a drone terminal, an aircraft terminal, a satellite, or a satellite terminal. The satellite or satellite terminal may operate in transparent mode or regenerative mode. Another example is that the NTN equipment may include IAB-MT, NCR-MT, or WAB-MT. Yet another example is that the NTN equipment may include IAB, NCR, or WAB.

[0172] The solutions provided in this application are applicable to scenarios where both the relay device and the terminal device need to switch network devices. For example, the source network device and the target network device can be two satellites, and the relay device can be a ground-based relay device. Another example is that the relay device is a satellite, and the source network device and the target network device are a source base station and a target base station deployed on the ground. Yet another example is that the source network device, the target network device, and the relay device are all ground-based devices, with the relay device connected to the source network device via satellite #1 and connected to the target network device via satellite #2. These scenarios are examples, and the embodiments of this application are not limited to these scenarios.

[0173] The following explanation is based on Figure 4.

[0174] Step 401: A connection is established between the relay device and the source network device, and the terminal device communicates with the source network device through the relay device.

[0175] The signal coverage area of ​​the relay device includes at least one terminal device, which can communicate with the source network device through the relay device. The relay device can forward information from the source network device, which may include information received from the source network device and / or information sent to the source network device. For example, the source network device sends information to the relay device, and the relay device forwards that information to the terminal device. Or, for another example, the terminal device sends information to the relay device, and the relay device forwards that information to the source network device. The information forwarded by the relay device may include, for example, broadcast messages transmitted between the source network device and the terminal device, information corresponding to service data, or information corresponding to control commands sent by the source network device to the terminal device.

[0176] In this embodiment, the relay device's forwarding of information may include transparent forwarding and / or regenerative forwarding. For example, the relay device may have AF relay functionality, whereby after receiving information, the relay device does not decode or encode the information but directly forwards the received information to the next hop (e.g., a network device or a terminal device). Alternatively, the relay device may have DF relay functionality, where after receiving information, the relay device decodes the information, then re-encodes the decoding result and forwards the re-encoded information to the next hop (e.g., a network device or a terminal device). In this embodiment, the relay device's forwarding of information can be replaced by the relay device sending information; for example, the relay device forwarding information from a network device can be replaced by the relay device sending information from the network device.

[0177] The source network device and the terminal device may include at least one relay device. In this embodiment, one relay device is used as an example for description. For the contents of other relay devices, please refer to the relevant description of the relay device, which will not be repeated here.

[0178] Step 402: Establish a connection between the relay device and the target network device.

[0179] There are several ways for a relay device to determine a target network device. For example, the relay device can determine the target network device itself. For instance, the relay device can measure the signal of the target network device and determine the target network device by comparing the measurement results. For example, the target network device may be a network device that meets the handover execution triggering conditions (the handover execution triggering conditions may include some specified handover conditions, some examples of which are given in Figure 8). Alternatively, the relay device can determine the target network device based on other parameters; this embodiment does not limit this approach.

[0180] For example, the relay device determines the target network device based on the received information. For instance, the source network device sends third information. Correspondingly, the relay device receives the third information. This third information instructs the relay device to establish a connection with the target network device. For example, the third information may include the identification information of the target network device.

[0181] The connection established between the relay device and the target network device can be, for example, an RRC connection. After the relay device establishes a connection with the target network device, it can support communication between the target network device and terminal devices within the signal coverage area of ​​the relay device.

[0182] The relay device in this embodiment can access the target network device as a Mediator (MT). The relay device can also be referred to as a relay device-MT. For example, the relay device-MT can access the target network device and establish a connection through a four-step or two-step random access procedure. Alternatively, the relay device-MT can access the network device through a non-contention-based random access scheme. For instance, the relay device-MT sends MSG1 to the target network device, carrying a dedicated preamble. The target network device then sends an MSG2 message back to the relay device-MT.

[0183] The scheme for establishing a connection between the relay device and the target network device can also refer to the scheme for the terminal device switching to the target network device (e.g., conditional handover (CHO) or traditional handover (HO) methods). The differences from traditional handover methods include: the relay device is treated as the MT switching to the target network device; the relay device-MT may not release the connection with the source network device, or it may release the connection but maintain synchronization with the source network device. The scheme for establishing a connection between the relay device and the target network device can also refer to the exemplary process for establishing a connection between the terminal and the target network device described in Figures 7 and 8 later, which will not be described here.

[0184] After establishing a connection with the target device, the relay device forwards information from the target network device. Alternatively, after establishing a connection with the target device, the relay device begins to support forwarding information from the target network device, or the relay device enables the function of forwarding information from the target network device. If there is information from the target network device that needs to be forwarded, the relay device forwards that information.

[0185] The information forwarded by the relay device to the target network device may include information from the target device or information sent to the target device. For example, the relay device forwarding information to the target network device may include: the relay device receiving information from a terminal device, other relay devices, or other network devices, and then sending that information to the target network device; correspondingly, the target network device receiving that information from the relay device. As another example, the relay device forwarding information to the target network device may include: the target network device sending information to the relay device, and correspondingly, the relay device receiving that information from the target network device and then sending (or forwarding) that information to a terminal device, other relay devices, or other network devices. In the embodiments of this application, the relay device forwarding information to the target network device may include transparent forwarding and / or regenerated forwarding. The relevant content is similar to the description of the relay device forwarding information from the source network device, and will not be repeated here.

[0186] The information of the target network device forwarded by the relay device may include broadcast messages transmitted between the target network device and the terminal device, information corresponding to service data, or information corresponding to control commands (such as control commands sent by the target network device to the terminal device, or information associated with control commands fed back by the terminal device to the target network device). For example, the information of the target network device forwarded by the relay device may include / be related to information during the handover process of the terminal device (such as the information transmitted between the target network device and the terminal in Figures 7 and 8).

[0187] Step 403: The relay device releases its connection with the source network device and maintains synchronization with the source network device, or maintains its connection with the source network device.

[0188] The connection between the relay device and the source network device can be, for example, an RRC connection. When the relay device releases its connection with the source network device, it can release (or delete) its context information with the source network device, and the source network device can also release (or delete) its context information with the relay device. Maintaining synchronization between the relay device and the source network device can, for example, include / become by the relay device receiving a broadcast message from the source network device and performing downlink synchronization (e.g., time-domain synchronization and / or frequency-domain synchronization) based on the broadcast message (e.g., based on the synchronization signal and physical broadcast channel block (SSB), downlink synchronization signal, or downlink synchronization reference signal in the broadcast message). Even if there is no connection between the relay device and the source network device (e.g., no RRC connection), the relay device can still forward information from the source network device because it has synchronized with the source network device.

[0189] In step 403, if the relay device releases its connection with the source network device, steps 402 and 403 can be replaced by the relay device (or relay device-MT) switching from the source network device to the target network device while maintaining synchronization with the source network device. The process of the relay device (or relay device-MT) switching from the source network device to the target network device can be found in the terminal device switching from the source network device to the target network device scheme (e.g., CHO or traditional HO switching methods). Related details can be found in the exemplary flow of the terminal switching from the source network device to the target network device illustrated in Figures 7 and 8, and will not be described here.

[0190] For example, if the relay device releases its connection with the source network device while maintaining synchronization with it, or if the relay device maintains its connection with the source network device, the relay device forwards information from the source network device. As another example, even if the relay device releases its connection with the source network device while maintaining synchronization with it, or if the relay device maintains its connection with the source network device, the relay device still supports forwarding information from the source network device, or the relay device still maintains the function of forwarding information from the target network device. If there is information from the source network device that needs to be forwarded, the relay device forwards that information.

[0191] When there is a connection between the relay device and the source network device, or when the relay device and the source network device are not connected but are synchronized, the relay device can forward information from the source network device. The information from the source network device includes information received from the source network device and / or information sent to the source network device. For example, forwarding information from the source network device by the relay device may include: the relay device receiving first information from a terminal device, other relay devices, or other network devices, and then sending the first information to the source network device. Correspondingly, the source network device receives the first information from the relay device. As another example, forwarding information from the source network device by the relay device may include: the source network device sending second information to the relay device, and correspondingly, the relay device receiving the second information from the source network device and then sending (or forwarding) the second information to a terminal device, other relay devices, or other network devices. The first information and the second information are two examples of information from the source network device. In the embodiments of this application, forwarding information from the source network device by the relay device may include transparent forwarding and / or regenerated forwarding, as described above, and will not be repeated here.

[0192] The information forwarded by the relay device from the source network device may include broadcast messages, service data, or control commands transmitted between the source network device and the terminal device (e.g., control commands sent from the source network device to the terminal device, or information associated with control commands fed back from the terminal device to the source network device). For example, the information forwarded by the relay device from the source network device may include / belong to information related to the handover process of the terminal device (e.g., information transmitted between the source network device and the terminal in Figures 7 and 8). For example, the first information and / or the second information may belong to information corresponding to broadcast messages or service data. Alternatively, the first information and / or the second information may belong to information related to the handover process of the terminal device. For example, the first information and / or the second information are used for terminal devices within the signal coverage area of ​​the relay device to hand over from the source network device to the target network device.

[0193] In one possible implementation, the source network device sends first configuration information. The relay device receives the first configuration information. The first configuration information may also have other names, such as "information" or "forwarding control information." The first configuration information is used to instruct the relay device to forward information from the source network device. The relay device can forward information from the source network device according to the first configuration information.

[0194] There are several methods for relay devices to receive the first configuration information, which will be introduced through several examples below.

[0195] Example 1: If a connection exists between the source network device and the relay device, the source network device can send the first configuration information to the relay device through this connection. Correspondingly, the relay device can directly receive the first configuration information from the source network device. This scheme can improve the transmission speed of the first configuration information.

[0196] Example 2: The source network device can indirectly send the first configuration information to the relay device through other devices. For example, the source network device sends the first configuration information to the target network device (e.g., via the Xn interface between the source and target network devices). The target network device then sends (or forwards) the first configuration information to the relay device. This example can expand the applicability of the embodiments of this application. For example, in scenarios where there is no connection between the source network device and the relay device, the relay device cannot directly receive the first configuration information from the source network device, and thus the relay device can indirectly receive indication information from the source network device through the target network device.

[0197] Example 3: The source network device can indirectly send the first configuration information to the relay device through other devices. For example, the source network device can send the first configuration information to the core network device, and the core network device can send (or forward) the first configuration information to the target network device. The target network device then sends (or forwards) the first configuration information to the relay device. In this embodiment, the core network device may include network elements such as AMF or UPF. This example can expand the applicability of the embodiments of this application. For example, in scenarios where there is no connection between the source network device and the relay device, and no connection between the source network device and the target network device (e.g., no Xn interface), the relay device cannot directly receive the first configuration information from the source network device. Instead, the relay device can indirectly receive the indication information from the source network device through the core network device and the target network device.

[0198] The relay device and the source network device can align the information transmission configuration according to the first configuration information, thereby improving the accuracy, efficiency, and quality of information transmission. For example, the first configuration information can indicate the resource on which the source network device sends information, and the relay device can then receive information on that resource, thereby improving the success rate of the relay device receiving information and also improving the signal quality of the information received by the relay device.

[0199] The first configuration information may include information indicating that the relay device needs to forward information from the source network device. For example, the first configuration information may include: information indicating at least one of the following: resources (information A1), beam (information A2), address (information A3), transmission path (information A4), transmission direction (information A5), transmission mode (information A6), frequency (information A7), power (information A8), port (information A9), or reference signal (information A10) corresponding to the information (e.g., information from the source network device) transmitted (or forwarded) by the relay device.

[0200] Information A1 is information used to indicate the resources for transmitting (or forwarding) information by a relay device.

[0201] Information A1 may include or be replaced by: information on the resources used to indicate the information forwarded by the relay device.

[0202] In this embodiment of the application, the information forwarded by the relay device may include, for example, information received by the relay device from the source network device and to be forwarded, and / or information that the relay device needs to forward to the source network device.

[0203] For example, information A1 may include time-domain resource information and / or frequency-domain resource information. Time-domain resource information may include, for example, information indicating the start position of the time-domain resources occupied by the information forwarded by the relay device; and / or, information indicating the length of the time-domain resources occupied by the information forwarded by the relay device. Frequency-domain resource information may include, for example, information such as the starting RB index and / or the number of RBs. When the relay device subsequently forwards information from the source network device according to the first configuration information, it can use the resources indicated by information A1 to forward the information from the source network device.

[0204] For example, time-domain resource information can be used to indicate: frames / time slots / symbols of downlink forwarding source network device signals, and / or frames / time slots / symbols of uplink forwarding terminal device signals.

[0205] For example, frequency domain resource information can be used to indicate: frequency domain sub-bands or frequency domain resource blocks of downlink forwarding source network device signals, and / or frequency domain sub-bands or frequency domain resource blocks of uplink forwarding terminal device signals.

[0206] Information A2 is information used to indicate the beam of information transmitted (or forwarded) by the relay device.

[0207] Information A2 may include, or be replaced by, information about the beam used to indicate information forwarded by the relay device (e.g., information received by the relay device from the source network device and to be forwarded, and / or information that the relay device needs to forward to the source network device).

[0208] For example, information A2 includes at least one of: a transmitting beam index, transmitting beam direction information, a receiving beam index, or a receiving beam direction. For example, when the relay device subsequently forwards information from the source network device according to the first configuration information, it can use the receiving beam information indicated by information A2 (e.g., the receiving beam index and / or the receiving beam direction information) to receive the information to be forwarded, and then use the transmitting beam information indicated by information A2 (e.g., the transmitting beam index and / or the transmitting beam direction information) to transmit the information to be forwarded.

[0209] Information A3 is used to indicate the sending / receiving address corresponding to the information sent (or forwarded) by the relay device.

[0210] The sending address information indicates the address of the receiving end of the information forwarded by the relay device, or the address information corresponding to the next node to which the relay device forwards the information. The receiving address information indicates the address of the sending end of the information forwarded by the relay device, or the address information corresponding to the previous node to which the relay device forwards the information.

[0211] For example, information A3 may include the sending address of the relay device's forwarding information. This sending address informs the relay device where the information needs to be forwarded. For instance, the sending address could be the target address of the forwarded information on the relay device's side. This sending address could be, for example, the address of the next hop, the address of the source network device, the address of the terminal device, the address of another relay device, or the address of another source network device, etc. As another example, information A3 may include the receiving address of the relay device's forwarding information. This receiving address informs the relay device where to receive the information to be forwarded. For instance, this receiving address could be, for example, the address of the previous hop, the address of the source network device, the address of the terminal device, the address of another relay device, or the address of another source network device, etc.

[0212] Information A4 is used to indicate the transmission path corresponding to the information sent (or forwarded) by the relay device.

[0213] Information A4 may include or be replaced with information indicating the path used by the relay device to forward information. In this embodiment, the path may be replaced with a route; for example, the sending path may be replaced with a sending route, and the path information may be replaced with routing information.

[0214] For example, information A4 may include at least one of the following: the identifier of the path of the information forwarded by the relay device, the address of each node on the path, or the address of the updated node on the path.

[0215] Information A5 is used to indicate the transmission direction of the information sent (or forwarded) by the relay device.

[0216] Information A5 may include or be replaced with: information used to indicate the forwarding direction of information forwarded by the relay device.

[0217] For example, the transmission direction of information forwarded by a relay device may include uplink or downlink. Uplink transmission direction refers to the transmission direction from the terminal device to the source network device, while downlink transmission direction refers to the transmission direction from the source network device to the terminal device. The first configuration information may indicate the transmission direction of the information that the relay device is about to send (or forward).

[0218] Information A6 is information used to indicate the method of transmission of information sent (or forwarded) by the relay device.

[0219] For example, the methods by which a relay device sends information (such as relay device forwarding information) include transparent forwarding or regenerative forwarding. This can also be understood as the relay device operating in transparent forwarding mode or regenerative forwarding mode.

[0220] Information A7 is used to indicate the frequency point corresponding to the information transmitted (or forwarded) by the relay device.

[0221] Information A7 may include or be replaced with: information used to indicate the frequency point for relaying information.

[0222] For example, the frequency corresponding to the information sent by the relay device (such as information forwarded by the relay device) may include 20 gigahertz (GHz) or 30 GHz. The relay device can forward information on these frequencies. Alternatively, the frequency of the information received by the relay device may be different from the frequency on which the relay device forwards the information; the relay device can convert the frequency of the information.

[0223] Information A8 is used to indicate the power corresponding to the information transmitted (or forwarded) by the relay device.

[0224] For example, information A8 may include: transmission power information for relay device forwarding information, or transmission power control information for relay device forwarding information. For example, the relay device may use the power forwarding information indicated by information A8.

[0225] Information A9 is used to indicate the port information corresponding to the information sent (or forwarded) by the relay device.

[0226] For example, information A9 may include: information about the transmitting port used by the relay device to forward information, or information about the receiving port of the relay device to receive information that needs to be forwarded. For example, the relay device may use the receiving port indicated by information A9 to receive information that needs to be forwarded, and / or forward the information through the transmitting port indicated by information A9.

[0227] Information A10 is used to indicate the reference signal corresponding to the information sent (or forwarded) by the relay device.

[0228] The relay device can obtain information about receiving or transmitting reference signals through information A10, and then obtain channel state information between the source network device and the previous or next node through receiving / transmitting these reference signals.

[0229] The first configuration information can be carried in a medium access control element (MAC CE) or other signaling, such as radio resource control (RRC) signaling, downlink control information (DCI) signaling (this scheme can be used when DCI signaling requires feedback of decoding results), etc. In addition to the above-mentioned scheme, this application embodiment can also be applied to other scenarios where the receiver needs to provide feedback of decoding results. For example, the first configuration information can be replaced with control signaling that requires the receiver to provide feedback of decoding results. The related schemes are similar to those provided in this application embodiment and will not be described again.

[0230] As can be seen, in this embodiment, a connection / synchronization is established between the relay device and the target network device, and the relay device can also maintain the connection with the source network device. The relay device can then forward information from the source network device and information from the target network device, thereby enabling terminal devices within the signal coverage area of ​​the relay device that have not yet switched to the target network device to successfully switch to the target network device. The relay device can also provide communication services to terminal devices that have switched to the target network device, thereby ensuring the success rate of terminal device switching, avoiding terminal disconnection and reconnection to the system, and saving network device resources.

[0231] Step 404: The terminal device switches from the source network device to the target network device.

[0232] Because the relay device releases its connection with the source network device while maintaining synchronization with it, or because it maintains its connection with the source network device, the relay device can forward information from the source network device. Because the relay device establishes a connection with the target device, it can also support forwarding information from the target network device. In step 404, the terminal device can communicate with both the source and target network devices via the relay device, thereby achieving the purpose of switching from the source network device to the target network device. For example, the terminal device can receive signals from the target network device and / or the source network device forwarded by the relay device, and use a handover procedure (e.g., CHO or traditional HO method) to switch from the source network device to the target network device. Possible examples of two handover procedures for the terminal device are illustrated in Figures 7 and 8 below. Step 404 will be described later and will not be described here.

[0233] In another possible implementation, the relay device may also perform step 405, which is not mandatory and is therefore indicated by dashed lines in Figure 4.

[0234] Step 405, the relay device performs at least one of the following: stops synchronizing with the source network device, releases the connection with the source network device, or stops forwarding information from the source network device.

[0235] For example, if a relay device stops synchronizing with the source network device or releases its connection with the source network device, the relay device will stop forwarding information from the source network device (such as information transmitted between the source network device and the terminal device; details regarding the source network device's information are provided above and will not be repeated here). As another example, if a relay device stops forwarding information from the source network device, it may have already stopped synchronizing with the source network device, or it may still maintain synchronization. As yet another example, if a relay device stops forwarding information from the source network device, it may have released its connection with the source network device, or it may not have released its connection.

[0236] For ease of understanding, a first operation is defined in the embodiments of this application. The first operation includes at least one of stopping synchronization with the source network device, releasing the connection with the source network device, or stopping forwarding information from the source network device.

[0237] After maintaining synchronization with the source network device for a period of time, the relay device can perform the first operation, thus saving resource consumption.

[0238] The relay device can determine the time to perform the first operation on its own. Alternatively, the relay device can receive first instruction information and perform the first operation according to the received first instruction information. The first instruction information is used to instruct the relay device to perform at least one of the following: stop synchronizing with the source network device, release the connection with the source network device, or stop forwarding information from the source network device.

[0239] In step 403, if the relay device maintains a connection with the source network device, then in step 405, upon receiving the first indication information, the relay device may release the connection between itself and the source network device, and / or stop forwarding information from the source network device. The relay device may release (or delete) the context information between itself and the source network device. The source network device may also release (or delete) the context information between itself and the relay device.

[0240] In step 403, if the relay device has released the connection to the source network device but maintains synchronization with it, then in step 405, upon receiving the first indication information, the relay device may stop maintaining synchronization with the source network device and / or stop forwarding information from the source network device. Stopping synchronization with the source network device may include / be replaced by: the relay device stopping receiving broadcast messages from the source network device, or the relay device stopping detecting reference signals (e.g., SSB) in broadcast messages from the source network device.

[0241] In this embodiment, the relay device can obtain the first indication information in several ways. For example, the source network device may send the first indication information to the relay device through the connection between the source network device and the relay device; or the source network device may send a third indication information to the target network device, and after receiving the third indication information, the target network device may send the first indication information to the relay device based on the third indication information; or the source network device may send the third indication information to the core network device, and the core network device may send a second indication information to the target network device based on the received third indication information, and the target network device may send the first indication information to the relay device based on the received second indication information. Any two of the first, second, or third indication information may be the same or different. At least one of the first, second, or third indication information is used to indicate that the relay device stops maintaining synchronization with the source network device and / or releases the connection with the source network device.

[0242] The following examples illustrate several ways in which relay devices obtain the first indication information.

[0243] Example 1: If a connection exists between the source network device and the relay device, the source network device can send first indication information to the relay device through this connection. In this example, the first indication information can also be replaced with third indication information, which are identical. Correspondingly, the relay device can directly receive the first indication information (i.e., the third indication information) from the source network device. This scheme can improve the transmission speed of the first indication information.

[0244] Example 2: The source network device can indirectly send indication information to the relay device through other devices. For example, the source network device sends third indication information to the target network device (e.g., via the Xn interface between the source and target network devices). After receiving the third indication information, the target network device sends first indication information to the relay device. In this example, the third indication information can also be replaced by second indication information, which is the same as the second indication information. For example, the source network device sends the second indication information to the target network device, and the target network device sends the first indication information to the relay device based on the received second indication information. The first and second indication information can be the same or different. This example can expand the scope of application of the embodiments of this application. For example, in scenarios where there is no connection between the source network device and the relay device, the relay device cannot directly receive indication information from the source network device, and thus the relay device can indirectly receive indication information from the source network device through the target network device.

[0245] Example 3: The source network device can indirectly send indication information to the relay device through other devices. For example, the source network device can send third indication information to the core network device. After receiving the third indication information, the core network device sends second indication information to the target network device based on the third indication information. After receiving the second indication information, the target network device sends first indication information to the relay device based on the second indication information. Any two of the third, second, and first indication information can be the same or different. In this embodiment, the core network device may include network elements such as AMF or UPF. This example can expand the applicability of the embodiments of this application. For example, in scenarios where there is no connection between the source network device and the relay device, and no connection between the source network device and the target network device (e.g., no Xn interface), the relay device cannot directly receive the first indication information from the source network device. Instead, the relay device can indirectly receive indication information from the source network device through the core network device and the target network device.

[0246] In one possible implementation, the source network device may send a third indication message if a first condition is met. The first condition may include, for example, at least one of the following conditions B1, B2, or B3.

[0247] Condition B1: The terminal device within the signal coverage area of ​​the relay device that has established a connection with the source network device has switched from the source network device to the target network device.

[0248] Condition B1 can also be replaced with: All terminal devices within the signal coverage area of ​​the relay device that have established a connection with the source network device have switched from the source network device to the target network device.

[0249] The source network device can determine whether condition B1 is met independently, or it can receive information from the core network that indicates whether condition B1 is met. For example, the source network device may receive information from the core network indicating that all terminal devices connected to the source network device within the signal coverage area of ​​the relay device have switched from the source network device to the target network device, and then the source network device may send a third indication message.

[0250] Condition B2: The source network device is unable to provide communication services to terminal devices within the signal coverage area of ​​the relay device.

[0251] The source network device can determine, based on certain conditions, that it is unable to provide communication services to terminal devices within the signal coverage area of ​​the relay device; or, if other devices determine that the source network device is unable to provide communication services to terminal devices within the signal coverage area of ​​the relay device, they can send information to the source network device, and the source network device can determine, based on the received information, that it is unable to provide communication services to terminal devices within the signal coverage area of ​​the relay device.

[0252] In one possible implementation, the source network device or other device can determine, based on some parameters, whether the source network device can provide communication services to terminal devices within the signal coverage area of ​​the relay device.

[0253] For example, if the parameter value of at least one parameter item corresponding to the source network device is no longer within the specified range of that parameter item, the source network device cannot provide communication services to terminal devices within the signal coverage area of ​​the relay device. Conversely, if the parameter value of at least one parameter item corresponding to the source network device is within the specified range of that parameter item, the source network device can still provide communication services to terminal devices within the signal coverage area of ​​the relay device. This parameter item can be multiple parameters, such as at least one of the following: the elevation angle of the satellite (which can be either the source network device or the relay device); the orbital angle of the satellite (which can be either the source network device or the relay device); at least one of the following: Doppler, Doppler rate, TA rate of change, rate of change of TA rate of change, or signal strength of the signal received by the relay device from the source network device; or at least one of the following: Doppler, Doppler rate, TA rate of change, rate of change of TA rate of change, or signal strength of the signal received by the source network device from the relay device. For example, if the orbital angle of the source network device is no longer within the specified range of orbital angles for providing communication services to the relay device or terminal device, the source network device cannot provide communication services to the terminal device within the signal coverage area of ​​the relay device.

[0254] Condition B3: The source network device receives the sixth message, which instructs the relay device to stop synchronizing with the source network device or release the connection with the source network device.

[0255] In condition B3, the sixth message may also include / be replaced with: information indicating that the relay device is switching to the target network device. The sixth message may be sent by the core network device to the source network device. For example, the core network device may send the sixth message if it determines that a terminal device within the relay device's signal coverage area that has established a connection with the source network device has switched from the source network device to the target network device. Alternatively, the core network device may send the sixth message if it determines, based on network load or some policy decisions, that the relay device needs to stop synchronizing with the source network device or release its connection with the source network device.

[0256] At least one of the first instruction information, the second instruction information, or the third instruction information may include at least one of the following: C1, C2, C3, C4, C5, C6, C7, or C8.

[0257] Content C1: Instruction information for the relay device to stop maintaining synchronization with the source network device.

[0258] Content C2: Indication information indicating that the relay device releases its connection to the source network device.

[0259] Content C3: Instructions from the relay device to stop forwarding signals between the source network device and the terminal device.

[0260] Content C4, first-hand information.

[0261] The first time information can be a time value (e.g., time t2) and / or duration information (e.g., 10 milliseconds). When the first time information includes duration information, the time indicated by the first time information can be the time value after that duration (e.g., 10 milliseconds) has elapsed since the specified time. This specified time can be indicated by another device to the relay device, or it can be the time when the relay device receives the first indication information or a specified message. When the first time information is a time value, this time value can be the time indicated by the first time information, or the time indicated by the first time information can be the result of calculating the time value with a specified duration deviation value (e.g., 1 millisecond). For example, if the first time information is time t2, the time indicated by the first time information can be t2, or it could be (t2 + duration deviation value).

[0262] For example, the time indicated by the first time information includes / is the time when the second operation is performed. For example, the time indicated by the first time information includes / is at least one of the following: the time when the relay device stops maintaining synchronization with the source network device, or the time when the relay device releases the connection with the source network device, or the time when the relay device stops forwarding information from the source network device.

[0263] Content C5 contains information on the number of terminal devices within the signal coverage area of ​​the relay device that have switched from the source network device to the target network device.

[0264] The number of terminal devices that have switched from the source network device to the target network device can be either the total number of terminal devices or the percentage of terminal devices that have switched to the target network device out of all terminal devices that need to switch to the target network device.

[0265] This information allows relay devices and / or target network devices to know how many terminal devices have successfully switched over and how many have not yet switched over, enabling more rational allocation of resources and improved communication performance.

[0266] Content C6 contains information on the number of terminal devices within the signal coverage area of ​​the relay device that have not switched from the source network device to the target network device, or information used to indicate that all terminal devices within the signal coverage area of ​​the relay device that need to switch to the target network device have switched from the source network device to the target network device.

[0267] The number of terminal devices that have not switched from the source network device to the target network device can be either the total number of terminal devices or the percentage of terminal devices that have not switched to the target network device among all terminal devices that need to switch to the target network device.

[0268] Content C7 is used to indicate information that the source network device is unable to provide communication services to terminal devices within the signal coverage area of ​​the relay device.

[0269] Content C8, identification information of the relay device.

[0270] For example, the third instruction information sent by the source network device to the target network device includes the identification information of the relay device. After receiving the information, the target network device can determine which relay device needs to be instructed to release its connection with the source network device and / or stop synchronizing with the source network device.

[0271] Any two of the first, second, or third instruction information may be the same or different. For example, the source network device sends a third instruction information to the target network device. The third instruction information is used to instruct all terminal devices within the signal coverage area of ​​the relay device that need to switch to the target network device to switch from the source network device to the target network device (content C6). After receiving the second instruction information, the target network device sends the first instruction information to the relay device. The first instruction information includes an instruction for the relay device to stop maintaining synchronization with the source network device, and / or an instruction for the relay device to release its connection with the source network device (content C1 and / or content C2). Alternatively, the third instruction information includes the relay device's identification information (content C8). After receiving this information, the target network device can determine which relay device needs to be instructed to release its connection with the source network device and / or stop synchronization with the source network device. These are just a few possible examples; in practical applications, the specific forms of the first, second, and third instruction information can be flexibly combined.

[0272] In another possible implementation, any one of the first, second, or third indication information further includes second time information, the time indicated by the second time information including / being the time when the relay device begins forwarding information from the source network device. Thus, the relay device can start forwarding information from the source network device from a certain time according to the indication, thereby reducing the power consumption of the relay device.

[0273] For example, a source network device sends a third indication message to a target network device. This third indication message includes [t1, t2]. Here, t1 and t2 represent two times: t1 is the second time information, and t2 is the first time unit information. The target network device also sends a first indication message to a relay device, which includes [t1, t2]. The relay device can start forwarding information from the source network device at time t1 and continue forwarding it until time t2. The relay device can release its connection with the source network device at time t2 and / or stop synchronizing with it at time t2. Alternatively, the third indication message may only include the first time information, excluding the second time information, for example, denoted as t_end. The relay device can maintain its connection with the source network device and / or maintain synchronization with it before t_end, and release its connection and / or stop synchronizing with it after t_end.

[0274] In one possible implementation, the solution provided in this application can be applied to the dual active protocol stack (DAPS) mechanism. It can be seen that the solution provided in this application can be used in conjunction with the DAPS mechanism, thereby reducing the complexity of implementing the solution and making it more compatible with existing technologies.

[0275] For example, step 401 above may include / be replaced by: the relay device can activate the protocol stack corresponding to the source network device. Step 402 above may include / be replaced by: the relay device can activate the protocol stack corresponding to the target network device. Step 403 may include / be replaced by: the relay device can maintain the activation state of the protocol stack corresponding to the source network device. Step 405 may include / be replaced by: deactivating the protocol stack corresponding to the source network device. The protocol stack in this embodiment may be referred to as a protocol stack in the standard. For example, a protocol stack refers to a set of layered communication protocols that work together to realize the transmission of data in the network. In communication technology, a protocol stack usually includes multiple layers, each layer responsible for different functions. Other steps of this implementation can be referred to in the description of Figure 4 above. For example, this implementation may also include step 404 above, etc. The relevant content is described above and will not be repeated here.

[0276] Figure 5 illustrates a possible structural diagram of a protocol stack in a relay device according to an embodiment of this application. As shown in Figure 5, the relay device first establishes and activates the protocol stack on the source network device side. This activated protocol stack is used to forward information from the source network device. After receiving a handover command instructing the relay device to switch to the target network device, the relay device can establish a protocol stack on the target network device side based on the handover command and the radio resource configuration of the target network device. On the other hand, after receiving a handover command instructing the relay device to switch to the target network device, the relay device can continue to maintain or keep the activation state of the protocol stack on the source network device side, and will not release or deactivate the protocol stack on the source network device side after receiving the handover command. It can be seen that there can be two active protocol stacks inside the relay device. One active protocol stack is used to forward information from the target network device, and the other active protocol stack is used to forward information from the source network device.

[0277] The radio link control (RLC), medium access control (MAC), and physical (PHY) entities of the two protocol stacks are independent and do not need to be shared. For example, RLC_S, MAC_S, and PHY_S in the source network device's protocol stack, and RLC_T, MAC_T, and PHY_T in the target network device's protocol stack. The protocol stacks (or user plane protocol stacks) of the source and target network devices can use a common Packet Data Convergence Protocol (PDCP) entity. To ensure the sequential delivery of data (e.g., user plane data), the PDCP serial number (SN) needs to be continuously maintained throughout the handover process. Therefore, the PDCP entity provides a common reordering and deduplication function for both the source and target network devices. Encryption and decryption, and header compression and decompression, need to be handled separately within the PDCP entity, depending on the source and destination of the downlink or uplink data.

[0278] In the case of DAPS in this application embodiment, the relay device can maintain connections with both the source network device and the target network device, thereby enabling the relay device to forward signals from both the source and target network devices. This avoids premature disconnection of the relay device from the source network device, thus minimizing handover failures for some terminal devices within the relay device's signal coverage area and improving the handover success rate.

[0279] As shown in Figures 4 and 5, after the relay device establishes a connection with the target network device, it can still maintain synchronization / connection with the source network device. Thus, the relay device can still forward signals between the source network device and the terminal device, allowing the terminal device to transmit information between the relay device and the source network device, thereby ensuring a successful handover. This scheme can improve the success rate of terminal device handover. Furthermore, because the relay device switches to the target network device first, and then the subsequent terminal devices switch, it avoids the situation where terminal devices in the relay device's signal coverage area drop out and reconnect to the system due to relay device handover failure. In another possible implementation, the relay device can stop synchronization / connection with the source network device only after all terminal devices within its signal coverage area have successfully switched, or when the source network device is indeed unable to provide communication services to the relay device. This saves power consumption of the relay device while ensuring a high handover success rate.

[0280] Based on the content shown in at least one of Figures 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I, 1J, 1K, 1L, 2A, 2B, 2C, 2D, 2E, 3, 4, or 5, and the other content mentioned above, Figure 6 exemplarily illustrates a possible flowchart of a communication method provided by an embodiment of this application. For ease of understanding, Figure 6 uses the interaction between a relay device, a source network device, and a target network device as an example. This embodiment of the application is applicable to NTN scenarios. For a description of NTN, and the relay device, source network device, target network device, and NTN device, please refer to the description in Figure 4 above, and will not be repeated here.

[0281] The following explanation is based on Figure 6.

[0282] Step 601: A connection is established between the relay device and the source network device, and the terminal device communicates with the source network device through the relay device.

[0283] The content of step 601 can be found in the description of step 401 above, and will not be repeated here.

[0284] Step 602: Establish a connection between the relay device and the target network device, or establish synchronization between the relay device and the target network device.

[0285] Regardless of whether the relay device establishes a connection with the target network device, the relay device does not release (or maintain) the connection with the source network device. Because the relay device maintains the connection with the source network device, it can forward information from the source network device. The content of the information forwarded by the relay device from the source network device can be found in the description of the relay device forwarding information from the source network device in Figure 4 above, and will not be repeated here.

[0286] For example, the source network device sends a fourth indication message. Correspondingly, the relay device receives the fourth indication message. The fourth indication message is used to instruct the relay device to establish a connection / synchronization with the target network device.

[0287] For example, the fourth indication information may include the target network device's physical cell identity (PCI), frequency, polarization, and other information. This can improve the speed of synchronization / connection establishment between the relay device and the target network device.

[0288] In step 602, the relay device can establish a connection with the target network device, for example, the relay device establishes a downlink synchronization and RRC connection with the target network device. The steps for the relay device to establish a connection with the target network device are the same as those in step 402 above, and will not be repeated here.

[0289] Alternatively, in step 602, the relay device does not establish a connection with the target network device, but it synchronizes with the target network device (e.g., downlink synchronization), or the relay device maintains synchronization with the target network device. Maintaining synchronization with the target network device may include / become by: the relay device receiving a broadcast message from the target network device and performing downlink synchronization (e.g., time-domain synchronization and / or frequency-domain synchronization) based on the broadcast message (e.g., based on the SSB in the broadcast message). Even without a connection between the relay device and the target network device, the relay device can still forward information from the target network device because it has synchronized with it.

[0290] The scheme for establishing a connection between the relay device and the target network device can also refer to the scheme for the terminal device switching to the target network device (such as CHO or traditional HO handover methods). The difference from traditional handover methods includes: the relay device can be considered as an MT connected to the target network device, and the relay device-MT connection does not need to release the connection with the source network device. The scheme for establishing a connection between the relay device and the target network device can also refer to the process for establishing a connection between the terminal and the target network device illustrated in Figures 7 and 8, which will not be described here.

[0291] Since a connection is established between the relay device and the target network device, or a synchronization is established between the relay device and the target network device, the relay device can forward information from the target network device, or the relay device has enabled the function of forwarding information from the target network device. The details regarding the relay device's ability to forward information from the target network device, or the relay device's enabled function of forwarding information from the target network device, can be found in a similar description to Figure 4 above, and will not be repeated here.

[0292] In one possible implementation, the target network device sends second configuration information. The relay device receives the second configuration information. The second configuration information may also have other names, such as "information" or "forwarding control information." The second configuration information is used to instruct the relay device to forward information from the target network device. The relay device can forward information from the target network device according to the second configuration information.

[0293] There are several methods for relay devices to receive the second configuration information. Several examples are introduced below.

[0294] Example 1: When a connection exists between the target network device and the relay device, the target network device can send second configuration information to the relay device through this connection. Correspondingly, the relay device can directly receive the second configuration information from the target network device. This scheme can improve the transmission speed of the second configuration information.

[0295] Example 2: The target network device can indirectly send the second configuration information to the relay device through other devices. For example, the target network device sends the second configuration information to the source network device (e.g., via the Xn interface between the source and target network devices). The source network device then sends (or forwards) the second configuration information to the relay device. This example can expand the applicability of the embodiments of this application. For example, in scenarios where there is no connection between the source network device and the relay device, the relay device cannot directly receive the second configuration information from the target network device, and thus the relay device can indirectly receive indication information from the target network device through the source network device.

[0296] Example 3: The target network device can indirectly send the second configuration information to the relay device through other devices. For example, the target network device can send the second configuration information to the core network device, and the core network device can send (or forward) the second configuration information to the source network device. The source network device then sends (or forwards) the second configuration information to the relay device. In this embodiment, the core network device may include network elements such as AMF or UPF. This example can expand the applicability of the embodiments of this application. For example, in scenarios where there is no connection between the target network device and the relay device, and no connection between the source network device and the target network device (e.g., no Xn interface), the relay device cannot directly receive the second configuration information from the target network device. Instead, the relay device can indirectly receive indication information from the target network device through the core network device and the source network device.

[0297] The relay device and the target network device can align the information transmission configuration according to the second configuration information, thereby improving the efficiency and quality of information transmission. For example, the second configuration information can indicate the resource on which the target network device sends information, and the relay device can then receive information on that resource, thereby improving the success rate of the relay device receiving information and also improving the signal quality of the information received by the relay device.

[0298] The second configuration information may include information that indicates whether the relay device needs to forward information from the target network device. The second configuration information is similar to the first configuration information and can be referred to accordingly; therefore, it will not be repeated here. For example, the second configuration information may include at least one of the following:

[0299] Information about the target network device (see Information A1) is used to instruct the relay device to send (or forward) information (e.g., information about the target network device).

[0300] Information about the beam used to indicate information (such as information about the target network device) transmitted (or forwarded) by the relay device; see information A2.

[0301] Information used to indicate the sending address corresponding to the information (e.g., information of the target network device) sent (or forwarded) by the relay device (see information A3);

[0302] Information used to indicate the transmission path corresponding to the information (e.g., information of the target network device) sent (or forwarded) by the relay device (see information A4);

[0303] Information used to indicate the transmission direction corresponding to information (e.g., information of the target network device) sent (or forwarded) by the relay device; see information A5.

[0304] Information used to indicate the transmission method of information (such as information of the target network device) sent (or forwarded) by the relay device (see information A6);

[0305] Information used to indicate the frequency point corresponding to the information (e.g., information of the target network device) sent (or forwarded) by the relay device; see information A7.

[0306] Information used to indicate the power corresponding to the information (e.g., information of the target network device) transmitted (or forwarded) by the relay device (see information A8);

[0307] Information used to indicate the port corresponding to the information sent (or forwarded) by the relay device (e.g., information of the target network device); or,

[0308] Information used to indicate the reference signal corresponding to the information (e.g., information of the target network device) sent (or forwarded) by the relay device (see information A10).

[0309] The second configuration information can be carried, for example, in a medium access control element (MAC CE) or other signaling, such as radio resource control (RRC) signaling or physical layer downlink control information (DCI) signaling (this scheme can be used when DCI signaling requires feedback of decoding results). In addition to the above-mentioned scheme, this application embodiment can also be applied to other scenarios where the receiver needs to provide feedback of decoding results. For example, the second configuration information can be replaced with control signaling that requires the receiver to provide feedback of decoding results. The related schemes are similar to those provided in this application embodiment and will not be described again.

[0310] The content of the information forwarded by the relay device to the target network device can be found in the relevant description of the relay device forwarding the information to the target network device in Figure 4 above, and will not be repeated here.

[0311] Step 603: The terminal device switches from the source network device to the target network device.

[0312] The content of step 603 can be found in the description of step 404 above, and will not be repeated here.

[0313] Step 604, the relay device performs at least one of the following: the relay device switches from the source network device to the target network device, the relay device releases the connection with the source network device, the relay device establishes a connection with the target network device, or the relay device stops forwarding information from the source network device.

[0314] For ease of explanation, embodiments of this application define a second operation, which includes / is replaced by at least one of the following: the relay device switching from the source network device to the target network device, the relay device releasing the connection with the source network device, the relay device establishing a connection with the target network device, or the relay device stopping forwarding information from the source network device.

[0315] For example, the second operation can include / replace with any of the following:

[0316] The relay device switches from the source network device to the target network device;

[0317] The relay device releases the connection with the source network device and establishes a connection with the target network device;

[0318] The relay device stops forwarding information from the source network device and establishes a connection with the target network device.

[0319] The relay device releases its connection to the source network device;

[0320] The relay device stops forwarding information from the source network device.

[0321] In another possible implementation, if the relay device has already established a connection with the target network device in step 602, then in step 604, the relay device may not need to perform the step of establishing a connection with the target network device. If the relay device has not established a connection with the target network device in step 602, then in step 604, the relay device may establish a connection with the target network device.

[0322] The process of a relay device switching from a source network device to a target network device can be referred to the scheme of a terminal device switching from a source network device to a target network device (such as CHO or traditional HO switching methods). Related details can be found in Figures 7 and 8, which exemplarily illustrate the process of a terminal device switching from a source network device to a target network device, and will not be repeated here.

[0323] After maintaining a connection with the source network device for a period of time, the relay device can release the connection and / or stop forwarding information from the source network device, thereby saving resource overhead. The relay device can determine the time for releasing the connection and / or stopping forwarding information from the source network device itself. Alternatively, the source network device sends a fifth instruction message to the relay device, and the relay device receives the fifth instruction message and performs a second operation according to the received fifth instruction message. The fifth instruction message is used to instruct the relay device to perform the second operation. When the relay device can release the connection between the relay device and the source network device, the relay device can release the context information between the relay device and the source network device, and the source network device can also release the context information between the source network device and the relay device.

[0324] In one possible implementation, the source network device may send a fifth indication message if a first condition is met. The first condition may include, for example, at least one of the aforementioned conditions B1, B2, or B3, which will not be described in detail here.

[0325] At least one of the following fifth instruction information may include at least one of the following: D1, D2, D3, D4, or D5.

[0326] Content D1: Instruction information for the relay device to switch from the source network device to the target network device.

[0327] Content D2, third time information.

[0328] The third time information can be either a time value or a duration information. When the first time information is duration information, the time indicated by the first time information can be a time value elapsed after that duration from a specified time. This specified time can be indicated by other devices to the relay device, or it can be the time when the relay device receives the fifth indication information or a specified information. When the third time information is a time value, this time value can be the time indicated by the third time information, or the time indicated by the third time information can be the result of calculating the time value with a specified duration deviation value (e.g., 1 millisecond). For example, if the third time information is time t3, the time indicated by the third time information can be t3, or it could be (t3 + duration deviation value).

[0329] The time indicated by the third time information may include, for example, the time when the second operation is performed. For instance, the time indicated by the third time information may include, at least one of the following: the time when the relay device releases its connection with the source network device, the time when the relay device switches from the source network device to the target network device, or the time when it stops forwarding information from the source network device. As another example, if the relay device has not yet established a connection with the target network device, the time indicated by the third time information may also be the time when the relay device establishes a connection with the target network device.

[0330] Content D3 contains information on the number of terminal devices within the signal coverage area of ​​the relay device that have switched from the source network device to the target network device.

[0331] For details on content D3, please refer to the description in the aforementioned content C5, which will not be repeated here.

[0332] Content D4 contains information on the number of terminal devices within the signal coverage area of ​​the relay device that have not switched from the source network device to the target network device, or information used to indicate that all terminal devices within the signal coverage area of ​​the relay device that need to switch to the target network device have switched from the source network device to the target network device.

[0333] For content D4, please refer to the description of content C6 above, and it will not be repeated here.

[0334] Content D5 is used to indicate information that the source network device is unable to provide communication services to terminal devices within the signal coverage area of ​​the relay device.

[0335] For details on content D5, please refer to the description in content C7 above, and we will not repeat it here.

[0336] As can be seen, in this embodiment, a connection / synchronization is established between the relay device and the target network device, and the relay device can also maintain the connection with the source network device. The relay device can then forward information from the source network device and information from the target network device, thereby enabling terminal devices within the signal coverage area of ​​the relay device that have not yet switched to the target network device to successfully switch to the target network device. The relay device can also provide communication services to terminal devices that have switched to the target network device, thereby ensuring the success rate of terminal device switching, avoiding terminal disconnection and reconnection to the system, and saving network device resources.

[0337] In this application embodiment, both the relay device and the terminal device need to perform a handover procedure. Two possible handover procedures (cell handover procedure and conditional handover procedure) are illustrated below using Figures 7 and 8, with the terminal device handover procedure as the example. The connection establishment process between the relay device and the target network device involved in Figures 4 and 6 can be referred to the connection establishment process between the terminal device and the target network device in Figures 7 and 8. The relay device (or relay device-MT) can execute the terminal device-side scheme. The connection release process between the relay device and the source network device involved in Figures 4 and 6 can be referred to the connection release process between the terminal device and the source network device in Figures 7 and 8. The relay device (or relay device-MT) can execute the terminal device-side scheme. Figure 7 illustrates the cell handover procedure using the scheme provided in this application embodiment as an example. Figure 7 uses the AMF as an example of a core network device; the AMF can also be replaced with other core network devices.

[0338] As shown in Figure 7, the method includes:

[0339] Step 701: The source network device sends a measurement control message to the terminal device.

[0340] Correspondingly, the terminal device receives measurement and control messages.

[0341] Measurement control messages may include, for example, the measurement object (same frequency / different frequency), measurement report configuration, measurement gap configuration, etc.

[0342] Step 702: The terminal device sends the response information of the measurement and control message back to the source network device.

[0343] Correspondingly, the source network device receives response information from the measurement and control messages.

[0344] The response information for measurement control messages is, for example, RRC configuration complete (RRCReconfigurationComplete).

[0345] Step 703: The terminal device sends the measurement result information to the source network device.

[0346] Correspondingly, the source network device receives the measurement result information. This measurement result information can be referred to as a measurement report, for example.

[0347] In step 703, the terminal device may, for example, perform a measurement based on the received measurement control message, and after determining that the event condition has been met, report the measurement result information to the source network device.

[0348] Step 704: The source network device determines the target network device based on the measurement result information.

[0349] Step 704 can also be replaced by the source network device making a handover strategy and a decision on the target network device based on the measurement report. The target network device can be, for example, the first network device. In the embodiments of this application, the decision on the target network device can also be replaced by a decision on a target small / frequency point.

[0350] Step 705: The source network device sends a handover request to the core network device.

[0351] Correspondingly, the core network device receives the handover request.

[0352] A handover request may include, for example, the identifier of the target network device (which can be considered as an example of information that is the first indication), a list of packet data unit (PDU) sessions to perform data forwarding, etc.

[0353] Step 706: The core network device sends a handover request to the target network device.

[0354] Correspondingly, the target network device receives the handover request.

[0355] In this embodiment, the source network device can send a message (e.g., a handover request) to the core network device (e.g., the core network device) requesting a handover to the target network device. Then, the core network device (e.g., the core network device) can send a message to the target network device requesting a handover to the first network device. Alternatively, steps 705 and 706 can be replaced by the source network device (second network device) sending a message (e.g., a handover request) to the target network device requesting a handover to the target network device.

[0356] Step 707: The target network device sends a handover request response to the core network device.

[0357] Correspondingly, the core network device receives the handover request response.

[0358] For example, in step 707, after receiving the handover request, the target network device can perform admission control, allowing the terminal device to be admitted and allocating instance and transmission resources to the terminal device. The target base station can send a handover request response back to the core network device; for example, the handover request response can indicate that the terminal device is allowed to hand over to the target network device. If some packet data unit (PDU) sessions fail to hand over, the handover request response can carry a list of failed PDU sessions.

[0359] Step 708: The core network device sends a handover command to the source network device.

[0360] Correspondingly, the source network device receives the handover command.

[0361] The switching command in step 708 may include, for example, an address and a list of tunnel endpoint identification (TEID) for forwarding, or a list of bearers that need to be released.

[0362] Step 709: The source network device sends a message to the terminal device instructing the terminal device to switch to the target network device.

[0363] Correspondingly, the terminal device can receive messages that instruct the terminal device to switch to the target network device.

[0364] Step 710: The source network device sends the PDCP SN number to the core network device.

[0365] Correspondingly, the core network device receives the PDCP SN number. For example, the PDCP SN number is carried in the uplink RAN ​​status transfer.

[0366] Step 711: The core network device sends the PDCP SN number to the target network device.

[0367] Correspondingly, the target network device receives the PDCP SN. For example, the PDCP SN is carried in the downlink RAN ​​status transfer.

[0368] Step 712: The terminal device sends MSG1 to the target network device, carrying a special preamble.

[0369] The terminal device initiates a non-contention-based random access in the target cell of the target network device, and MSG1 is a step in the non-contention-based random access process.

[0370] Step 713: The target network device sends an MSG2 message back to the terminal device.

[0371] Step 714: The terminal device sends the RRC configuration completion message to the target network device.

[0372] Correspondingly, the target network device receives the RRC reconfiguration complete message.

[0373] The terminal device completes the handover to the target network device via the air interface.

[0374] Step 715: The target network device sends a handover notification to the core network device.

[0375] Correspondingly, the core network device receives a handover notification. The handover notification is used to inform the core network device that the terminal device has accessed the target network device's cell and that the NG-based handover has been completed.

[0376] Step 716: The core network device sends a UE context release command to the source network device.

[0377] Correspondingly, the source network device receives a UE context release command. Upon receiving this message, the source network device can release the connection (and / or context) of the terminal device that has completed the handover.

[0378] Step 717: The source network device sends a UE context release complete message to the core network device.

[0379] Correspondingly, the core network device receives the UE context release complete message.

[0380] Figure 8 illustrates an example of a conditional handover process using the solution provided in this embodiment. This process may include handover preparation and handover execution. Handover preparation may include steps 801 to 805, and handover execution may include steps 806 to 809. The solution provided in this embodiment can be applied to the handover preparation and / or handover execution sections.

[0381] As shown in Figure 8, the method includes:

[0382] Step 801: The source network device sends a measurement control message to the terminal device.

[0383] Correspondingly, the terminal device receives measurement and control messages.

[0384] Step 802: The terminal device sends the measurement result information to the source network device.

[0385] Correspondingly, the source network device receives the measurement result information.

[0386] Step 802 can be referred to in step 703 above, and will not be repeated here.

[0387] Step 803: The source network device identifies candidate target network devices.

[0388] There are multiple implementation methods in step 803. For example, the source network device can determine multiple candidate target network devices based on the measurement result information in step 802.

[0389] Step 804: The source network device sends a handover request to the candidate target network device.

[0390] Correspondingly, the candidate target network device receives a handover request. The handover request is used to request the candidate target network device to perform a conditional handover.

[0391] Step 804 can be implemented in various ways. For example, the source network device can send a handover request to the core network device (e.g., the core network device), and then the core network device (e.g., the core network device) can send a handover request to the candidate target network device. Alternatively, the source network device can send a handover request to the candidate target network device.

[0392] Step 805: At least one candidate target network device sends a handover request response to the source target network device.

[0393] Correspondingly, the source and target network devices receive the handover request response.

[0394] For example, each candidate target network device undergoes handover admission. If admission is granted, the candidate target network device sends a handover request response to the source network device. After successful admission, the candidate target network device reserves radio resources for the terminal device until it receives a handover cancellation message from the source network device.

[0395] Step 806: The source network device sends an RRC configuration message with a CHO handover command to the terminal device.

[0396] The corresponding terminal device receives the RRC configuration message of the CHO switching command.

[0397] The RRC configuration message of the CHO handover command can include, for example, the radio interface configuration of all candidate target base stations and the handover execution trigger conditions.

[0398] Step 807: The terminal device sends an RRC configuration complete message to the source network device.

[0399] The terminal device will not immediately initiate a handover action to any candidate target network device, but will continue to maintain the connection and transmission with the source network device. The terminal device will continuously determine whether there is a target network device that meets the handover execution triggering conditions.

[0400] Step 808: The terminal device determines the target network device from at least one candidate target network device.

[0401] The target network device can refer to a device that meets the handover execution triggering conditions. For example, the handover execution triggering condition can refer to the configuration of a certain measurement event, such as the A3 event, where the source base station's measurement control configuration allows the UE to report a measurement report when it measures that the RSRP of a neighboring cell is 1dB higher than that of the source cell. Other handover execution triggering conditions may also exist, which will not be elaborated further.

[0402] Step 809: A connection is established between the terminal device and the target network device.

[0403] For example, a terminal device can perform random access to the target network device and establish an RRC connection, while simultaneously disconnecting from the source network device station.

[0404] Step 810: The target network device sends a handover completion message to the terminal device.

[0405] Correspondingly, the terminal device receives a handover success message.

[0406] Step 811: The source network device sends an SN status transmission message to the target network device.

[0407] Correspondingly, the target network device receives the SN status transfer message.

[0408] Step 812: The source network device sends a handover cancellation message to other candidate target network devices.

[0409] Correspondingly, other candidate network devices receive a handover cancellation message. This message informs these candidate network devices to release reserved resources and cached data.

[0410] Step 813: The target network device sends a path switching request to the core network device.

[0411] Correspondingly, the core network device receives a path switch request.

[0412] Step 814: The core network device completes the path switching.

[0413] Step 815: The core network device sends a path switching request response to the target network device.

[0414] Correspondingly, the target network device receives a path seitch request acknowledge response.

[0415] The schemes provided in Figures 7 and / or 8 are applied to step 404 of Figure 4 and step 604 of Figure 6, so that the terminal device switches from the source network device to the target network device according to the schemes provided in Figures 7 and / or 8. The terminal device can execute the schemes described above. Figures 7 and 8 involve signaling transmitted between the target network device and the terminal device. When the terminal device is a terminal device, this signaling can be forwarded through a relay device. For example, the relay device forwards information sent by the target network device to the terminal device, and the relay device can also forward information from the terminal device to the target network device. Figures 7 and 8 involve signaling transmitted between the source network device and the terminal device. When the terminal device is a terminal device, this signaling can be forwarded through a relay device. For example, the relay device forwards information sent by the source network device to the terminal device, and the relay device can also forward information from the terminal device to the source network device.

[0416] The schemes provided in Figures 7 and / or 8 are applied to step 402 of Figure 4 above, so that the relay device (or relay device-MT) establishes a connection with the target network device according to the schemes provided in Figures 7 and / or 8. The relay device-MT can execute the schemes of the terminal device described above. The difference is that the relay device may not release the connection with the source network device (e.g., not execute steps 716 and 717, or may not release the relay device's connection after the source network device receives the UE context release command), or the relay device may release the connection with the source network device but maintain synchronization with the source network device. When the relay is the relay device-MT, the signaling between the target network device or source network device and the terminal device involved in Figures 7 and 8 refers to the signaling between the target network device or source network device and the relay device-MT. For example, the signaling sent by the target network device to the terminal device refers to the signaling sent by the target network device to the relay device-MT; the signaling sent by the source network device to the terminal device refers to the signaling sent by the source network device to the relay device-MT; and the signaling sent by the terminal device to the target network device or the source network device refers to the signaling sent by the relay device-MT to the target network device or the source network device.

[0417] In the embodiments of this application, the signaling or information (such as at least one of first configuration information, second configuration information, second information, third information, fourth information, fifth information, third indication information, second indication information, fourth indication information, or fifth indication information) sent by the network device (e.g., a source network device or a target network device) can have multiple transmission methods. For example, any one of these signaling or information can be carried in at least one of the broadcast information of system information block (SIB) 1, SIB 19, other system information (OSI), master information block (MIB), physical broadcast channel message, etc. The signaling or information sent by the network device (e.g., at least one of first configuration information, second configuration information, second information, third information, fourth information, fifth information, third indication information, second indication information, fourth indication information, or fifth indication information) sent by the source network device or the target network device is broadcast, multicast, or unicast to the relay device. Broadcasting or multicasting the above signaling to relay devices can avoid scheduling different resources for different relay devices in order to send the above signaling, thus saving the signaling overhead of scheduling resources and reducing the complexity of system scheduling.

[0418] In another possible implementation, if the signaling or information sent by the network device (e.g., the source network device or the target network device) during the radio resource control (RRC) connection establishment phase and subsequent communication process (e.g., at least one of the following: first configuration information, second configuration information, second information, third information, fourth information, fifth information, third indication information, second indication information, fourth indication information, or fifth indication information), can be carried in at least one of the following: RRC signaling (e.g., RRC setup message, RRC reconfiguration message, RRC recovery message, etc.), DCI, group DCI, media access control (MAC) control element (CE), and timing advance command (TAC). Signaling or information sent by network devices (e.g., source network devices or target network devices) (such as at least one of the following: first configuration information, second configuration information, second information, third information, fourth information, fifth information, third indication information, second indication information, fourth indication information, or fifth indication information) can be indicated in the form of information or tables, or sent to relay devices unicast or multicast along with data transmission or in a separately allocated PDSCH bearer. The advantage of sending the above signaling to relay devices individually or in groups is that it allows for flexible control of the parameter values ​​of each / group of relay devices. Different parameter values ​​can be configured for relay devices based on their different locations or regions to optimize system parameters and improve the communication performance of relay devices / the overall system communication performance.

[0419] It is understood that, in order to achieve the functions in the above embodiments, the terminal device, relay device, and network device may include hardware structures and / or software modules corresponding to the execution of each function. Those skilled in the art should readily recognize that, based on the units and method steps of the various examples described in conjunction with the embodiments disclosed in this application, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed in hardware or by computer software driving hardware depends on the specific application scenario and design constraints of the technical solution.

[0420] Based on the same concept, and based on the content shown in at least one of Figures 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I, 1J, 1K, 1L, 2A, 2B, 2C, 2D, 2E, 3, 4, 5, 6, 7, or 8, as well as the other content mentioned above, Figures 9, 10, and 11 are schematic diagrams of possible communication devices provided in embodiments of this application. These communication devices can be used to implement the functions of terminal devices, relay devices, or network devices in the method embodiments of Figures 4 or 6, and therefore can also achieve the beneficial effects of the above method embodiments. In the embodiments of this application, the communication device may be a relay device or a chip (or chip system, circuit, or unit module) inside a relay device as shown in Figures 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I, 1J, 1K, 1L, 2A, 2B, 2C, 2D, 2E, and 3; it may also be a network device or a chip (or chip system, circuit, or unit module) inside a network device; or it may be a terminal device or a chip (or chip system, circuit, or unit module) inside a terminal device.

[0421] As shown in Figure 9, the communication device 1300 includes a processing unit 1310 and a transceiver unit 1320. The transceiver unit 1320 can also be referred to as a communication unit. The transceiver unit 1320 may include a transmitting unit and a receiving unit.

[0422] When the communication device 1300 is used to implement the function of the relay device in the method embodiment shown in FIG4, in one possible implementation, the processing unit 1310 is used to: establish a connection with the target network device through the transceiver unit 1320; release the connection with the source network device and maintain synchronization with the source network device, or maintain the connection with the source network device; and forward information from the source network device.

[0423] When the communication device 1300 is used to implement the function of the relay device in the method embodiment shown in FIG4, in one possible implementation, the processing unit 1310 is used to: receive first indication information through the transceiver unit 1320, and in response to the first indication information, stop maintaining synchronization with the source network device and / or release the connection with the source network device.

[0424] When the communication device 1300 is used to implement the function of the relay device in the method embodiment shown in FIG4, in one possible implementation, the processing unit 1310 is used to: activate the protocol stack corresponding to the target network device; maintain the activation state of the protocol stack corresponding to the source network device; and deactivate the protocol stack corresponding to the source network device.

[0425] When the communication device 1300 is used to implement the function of the relay device in the method embodiment shown in FIG4, in one possible implementation, the processing unit 1310 is used to: receive first configuration information through the transceiver unit 1320, and forward the information of the source network device according to the first configuration information.

[0426] When the communication device 1300 is used to implement the function of the source network device in the method embodiment shown in FIG4, in one possible implementation, the transceiver unit 1320 is used to: send third information, send fourth information, receive first information from the relay device, and / or send second information to the relay device.

[0427] When the communication device 1300 is used to implement the function of the source network device in the method embodiment shown in FIG4, in one possible implementation, the transceiver unit 1320 is used to: send third instruction information.

[0428] When the communication device 1300 is used to implement the function of the source network device in the method embodiment shown in FIG4, in one possible implementation, the transceiver unit 1320 is used to: send first configuration information.

[0429] When the communication device 1300 is used to implement the function of the target network device in the method embodiment shown in FIG4, in one possible implementation, the transceiver unit 1320 is used to: receive information from the relay device, and / or send information to the relay device; receive second indication information, and in response to the second indication information, send first indication information to the relay device.

[0430] When the communication device 1300 is used to implement the function of the target network device in the method embodiment shown in FIG4, in one possible implementation, the transceiver unit 1320 is used to: receive first configuration information and send the first configuration information to the relay device.

[0431] When the communication device 1300 is used to implement the functions of the terminal device in the method embodiment shown in FIG4, in one possible implementation, the processing unit 1310 is used to perform the following through the transceiver unit 1320: receiving fifth information from the source network device through the relay device, switching to the target network device in response to the fifth information; and communicating with the target network device through the relay device.

[0432] When the communication device 1300 is used to implement the function of the relay device in the method embodiment shown in FIG6, in one possible implementation, the processing unit 1310 is used to: receive fourth indication information through the transceiver unit 1320, and in response to the fourth indication information, establish synchronization or connection with the target network device; forward information of the target network device through the transceiver unit 1320, and forward information of the source network device through the transceiver unit 1320.

[0433] When the communication device 1300 is used to implement the function of the relay device in the method embodiment shown in FIG6, in one possible implementation, the processing unit 1310 is used to: receive the fifth instruction information through the transceiver unit 1320, establish a connection with the target network device without establishing a connection with the target network device, and release the connection with the source network device.

[0434] When the communication device 1300 is used to implement the function of the relay device in the method embodiment shown in FIG6, in one possible implementation, the processing unit 1310 is used to: receive second configuration information through the transceiver unit 1320, and forward the information of the target network device according to the second configuration information.

[0435] When the communication device 1300 is used to implement the function of the source network device in the method embodiment shown in FIG6, in one possible implementation, the transceiver unit 1320 is used to: send fourth indication information; receive first information from the relay device, and / or send second information to the relay device.

[0436] When the communication device 1300 is used to implement the function of the source network device in the method embodiment shown in FIG6, in one possible implementation, the transceiver unit 1320 is used to: send fifth instruction information to the relay device.

[0437] When the communication device 1300 is used to implement the function of the source network device in the method embodiment shown in FIG6, in one possible implementation, the transceiver unit 1320 is used to: receive second configuration information from the target network device and send the second configuration information to the relay device.

[0438] When the communication device 1300 is used to implement the function of the target network device in the method embodiment shown in FIG6, in one possible implementation, the processing unit 1310 is used to: obtain second configuration information, and send the second configuration information to the source network device through the transceiver unit 1320 when the relay device has not established a connection with the target network device.

[0439] For a more detailed description of the processing unit 1310 and the transceiver unit 1320 described above, please refer to the relevant descriptions in the method embodiments shown in Figure 4 or Figure 6.

[0440] As shown in Figure 10, the communication device 1400 includes a processor 1410 and an interface circuit 1420. The processor 1410 and the interface circuit 1420 are coupled to each other. It is understood that the interface circuit 1420 can be a transceiver or an input / output interface. The input / output interface is used for inputting and / or outputting information; output can be understood as sending, and input can be understood as receiving. Optionally, the communication device 1400 may also include a memory 1430 for storing instructions executed by the processor 1410, or storing input data required by the processor 1410 to execute instructions, or storing data generated after the processor 1410 executes instructions.

[0441] When the communication device 1400 is used to implement the method shown in FIG4 or FIG6, the processor 1410 is used to implement the function of the processing unit 1310, and the interface circuit 1420 is used to implement the function of the transceiver unit 1320.

[0442] Please refer to Figure 11. The communication device shown in Figure 11 can also be a schematic diagram of a possible baseband architecture. As shown in Figure 11, the communication device may include a processing system, which may include one or more processors. The processors can be used to execute processes, such as process #1...process #N shown in Figure 11.

[0443] A processing system can be implemented using a bus architecture, typically represented by a bus. A bus can include any number of interconnect buses and bridges, depending on the specific application and overall design constraints of the processing system. The bus communicatively couples various circuits together, including one or more processors (typically represented by a processor), memory, and computer-readable media (typically represented by computer-readable media, such as computer-readable media #1…computer-readable media #N shown in Figure 11). The bus can also link various other circuits, such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art and therefore will not be described further. The bus interface provides the interface between the bus and transceivers, and between the bus and interfaces.

[0444] The communication device may also include a transceiver (not shown in Figure 11), which may be replaced by interface circuitry or a communication interface, etc. The transceiver provides a communication interface or means for communicating with various other devices via a wireless transmission medium. The transceiver may be coupled to an antenna array, and the transceiver and antenna array may be used together for communication with a corresponding network type. At least one interface (e.g., a network interface and / or a user interface) provides a communication interface or means for communication via an internal bus or via an external transmission medium.

[0445] The processor is responsible for managing the bus and general processing, including executing software stored on a computer-readable medium. When executed by the processor, the software causes the processing system to perform the various functions described below for any particular device. Functions achievable by the processor, memory, and computer-readable medium may include: encoding, decoding, rate matching, rate dematching, scrambling, descrambling, modulation, demodulation, layer mapping, fast fourier transform (FFT), inverse fast fourier transform (IFFT), inverse discrete fourier transform (IDFT), precoding, resource element (RE) mapping, channel equalization, RE demapping, digital beamforming (BF), adding a cyclic prefix (CP), removing CP, and one or more of the following.

[0446] The signaling involved in the embodiments of this application can be implemented by a processor, a memory, and a computer-readable medium.

[0447] When the communication device shown in FIG11 is used to implement the method shown in FIG4 or FIG6, the processor is used to implement the function of the processing unit 1310 and the transceiver is used to implement the function of the transceiver unit 1320.

[0448] When the aforementioned communication device is a chip used in a relay device, the chip of the relay device implements the functions of the relay device in the above method embodiments. The chip of the relay device receives information from the base station, which can be understood as the information being first received by other modules (such as radio frequency modules or antennas) in the relay device, and then sent to the chip of the relay device by these modules. The chip of the relay device sends information to the base station, which can be understood as the information being first sent to other modules (such as radio frequency modules or antennas) in the relay device, and then sent to the base station by these modules.

[0449] When the aforementioned communication device is a chip applied to a base station, the base station chip implements the functions of the network device in the above method embodiments. The base station chip receives information from a relay device, which can be understood as the information being first received by other modules in the base station (such as an RF module or antenna), and then sent to the base station chip by these modules. The base station chip sends information to the relay device, which can be understood as the information being sent down to other modules in the base station (such as an RF module or antenna), and then sent back to the relay device by these modules.

[0450] Based on the same concept, embodiments of this application also provide a computer-readable storage medium storing a computer program or instructions that, when executed by a communication device, implement the method shown in Figure 4 or Figure 6.

[0451] Based on the same concept, embodiments of this application also provide a computer program product, which stores a computer program, the computer program including program instructions, which can implement the method shown in Figure 4 or Figure 6 when executed by a computer.

[0452] In this application, entity A sends information to entity B, either directly or indirectly through other entities. Similarly, entity B receives information from entity A, either directly or indirectly through other entities. Entities A and B can be RAN nodes or terminals, or modules within RAN nodes or terminals. Information transmission and reception can be between RAN nodes and terminals, such as between a base station and a terminal; between two RAN nodes, such as between a CU and a DU; or between different modules within a single device, such as between a terminal chip and other modules of the terminal, or between a base station chip and other modules of the base station.

[0453] It is understood that the processor in the embodiments of this application may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. A general-purpose processor may be a microprocessor or any conventional processor.

[0454] The method steps in the embodiments of this application can be implemented in hardware or in software instructions executable by a processor. The software instructions can consist of corresponding software modules, which can be stored in random access memory, flash memory, read-only memory, programmable read-only memory, erasable programmable read-only memory, electrically erasable programmable read-only memory, registers, hard disks, portable hard disks, compact disc read-only memory (CD-ROM), or any other form of storage medium well known in the art. An exemplary storage medium is coupled to a processor, enabling the processor to read information from and write information to the storage medium. The storage medium can also be a component of the processor. The processor and storage medium can reside in an ASIC. Alternatively, the ASIC can reside in a base station or terminal. The processor and storage medium can also exist as discrete components in a base station or terminal.

[0455] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented, in whole or in part, as a computer program product. A computer program product includes one or more computer programs or instructions. When a computer program or instruction is loaded and executed on a computer, all or part of the processes or functions of the embodiments of this application are performed. The computer can be a general-purpose computer, a special-purpose computer, a computer network, a network device, a user equipment, or other programmable device. The computer program or instructions can be stored in a computer-readable storage medium or transferred from one computer-readable storage medium to another. For example, a computer program or instructions can be transferred from one website, computer, server, or data center to another website, computer, server, or data center via wired or wireless means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium, such as a floppy disk, hard disk, or magnetic tape; it can also be an optical medium, such as a digital video optical disc; or it can be a semiconductor medium, such as a solid-state drive. The computer-readable storage medium may be a volatile or non-volatile storage medium, or may include both types of storage media.

[0456] In the various embodiments of this application, unless otherwise specified or in case of logical conflict, the terminology and / or descriptions of different embodiments are consistent and can be referenced by each other. The technical features of different embodiments can be combined to form new embodiments according to their inherent logical relationship.

[0457] In this application, "at least one" means one or more, and "more than one" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. In the textual description of this application, the character " / " generally indicates an "or" relationship between the preceding and following related objects; in the formulas of this application, the character " / " indicates a "division" relationship between the preceding and following related objects. "Including at least one of A, B, or C" can mean: including A; including B; including C; including A and B; including A and C; including B and C; including A, B, and C.

[0458] It is understood that the various numbers involved in the embodiments of this application (such as the numerical numbers "first" and "second", and the letter numbers "A1" and "A2") are only for the convenience of description and are not intended to limit the scope of the embodiments of this application. The order of the above-mentioned process numbers does not imply the order of execution; the execution order of each process should be determined by its function and internal logic.

Claims

1. A communication method, characterized in that, The method is applicable to relay devices in non-terrestrial networks (NTNs), and the method includes: Establish a connection with the target network device; Release the connection with the source network device and maintain synchronization with the source network device, or maintain the connection with the source network device; Sending first information to the source network device and / or forwarding second information from the source network device, wherein the first information and / or the second information are used for terminal devices within the signal coverage area of ​​the relay device to switch from the source network device to the target network device.

2. The method as described in claim 1, characterized in that, At least one of the following must be satisfied: At least one of the relay device, the source network device, or the target network device is located on the NTN device; The relay device communicates with the source network device via an NTN device; or, The relay device communicates with the target network device via an NTN device.

3. The method as described in claim 1 or 2, characterized in that, The method further includes: The relay device receives a first instruction message, which instructs the relay device to perform a first operation, the first operation including at least one of the following: the relay device stops maintaining synchronization with the source network device, the relay device releases the connection with the source network device, or the relay device stops forwarding information from the source network device; In response to the first instruction information, the first operation is performed.

4. The method as described in claim 3, characterized in that, The first indication information includes at least one of the following: The relay device stops maintaining synchronization with the source network device; The relay device releases an indication message indicating its connection to the source network device; The relay device provides an instruction to stop forwarding information from the source network device. First time information, the time indicated by the first time information includes at least one of the following: the time when the relay device stops maintaining synchronization with the source network device, or the time when the relay device releases the connection with the source network device, or the time when the relay device stops forwarding information from the source network device; Information on the number of terminal devices within the signal coverage area of ​​the relay device that have switched from the source network device to the target network device; Information on the number of terminal devices within the signal coverage area of ​​the relay device that have not switched from the source network device to the target network device, or information used to indicate that all terminal devices within the signal coverage area of ​​the relay device that need to switch to the target network device should switch from the source network device to the target network device. Information used to indicate that the source network device is unable to provide communication services to terminal devices within the signal coverage area of ​​the relay device; or; The identification information of the relay device.

5. The method according to any one of claims 1-4, characterized in that, Establishing a connection with the target network device includes: Activate the protocol stack corresponding to the target network device; Maintaining the connection with the source network device includes: Maintain the activation state of the protocol stack corresponding to the source network device.

6. The method according to any one of claims 1-5, characterized in that, The method further includes: Receive first configuration information, which is used to instruct the relay device to forward information from the source network device, wherein the information from the source network device includes information from the source network device and / or information sent to the source network device; The forwarding of information from the source network device includes: The information from the source network device is forwarded according to the first configuration information.

7. A communication method, characterized in that, The method is applicable to source network devices in non-terrestrial networks (NTNs), and the method includes: Send a third message, which instructs the relay device to establish a connection with the target network device; Receive first information from the relay device, and / or send second information to the relay device, wherein the first information and / or the second information are used for terminal devices within the signal coverage area of ​​the relay device to switch from the source network device to the target network device.

8. The method as described in claim 7, characterized in that, At least one of the following must be satisfied: The relay device, the source network device, or the target network device is located on the NTN device; The relay device communicates with the source network device via an NTN device; or, The relay device communicates with the target network device via an NTN device.

9. The method as described in claim 7 or 8, characterized in that, After sending the third information, the following is also included: Send a fourth message, which indicates to release the connection with the source network device and maintain synchronization with the source network device, or to maintain the connection with the source network device.

10. The method according to any one of claims 7-9, characterized in that, The method further includes: Send a third instruction message, the third instruction message being used to instruct at least one of the following: the relay device stops maintaining synchronization with the source network device, the relay device releases the connection with the source network device, or the relay device stops forwarding information from the source network device.

11. The method as described in claim 10, characterized in that, The third instruction information is sent if at least one of the following conditions is met: The terminal device within the signal coverage area of ​​the relay device that has established a connection with the source network device has switched from the source network device to the target network device; The source network device is unable to provide communication services to terminal devices within the signal coverage area of ​​the relay device; or, The relay device receives information indicating at least one of the following: the relay device stops maintaining synchronization with the source network device, the relay device releases its connection with the source network device, or the relay device stops forwarding information from the source network device.

12. The method as described in claim 10 or 11, characterized in that, The third instruction information includes at least one of the following: The relay device stops maintaining synchronization with the source network device; The relay device releases an indication message indicating its connection to the source network device; The relay device provides an instruction to stop forwarding information from the source network device. First time information, the time indicated by the first time information includes at least one of the following: the time when the relay device stops maintaining synchronization with the source network device, or the time when the relay device releases the connection with the source network device, or the time when the relay device stops forwarding information from the source network device; Information on the number of terminal devices within the signal coverage area of ​​the relay device that have switched from the source network device to the target network device; Information on the number of terminal devices within the signal coverage area of ​​the relay device that have not switched from the source network device to the target network device, or information used to indicate that all terminal devices within the signal coverage area of ​​the relay device that need to switch to the target network device should switch from the source network device to the target network device. Information used to indicate that the source network device is unable to provide communication services to terminal devices within the signal coverage area of ​​the relay device; or; The identification information of the relay device.

13. The method according to any one of claims 7-12, characterized in that, The method further includes: Send first configuration information, which is used to instruct the relay device to forward information from the source network device.

14. A communication method, characterized in that, The method is applicable to target network devices in non-terrestrial networks (NTNs), and the method includes: Receive information from the relay device, and / or send information to the relay device; Receive a second indication message, the second indication message being used to indicate at least one of the following: the relay device stops maintaining synchronization with the source network device, the relay device releases the connection with the source network device, or the relay device stops forwarding information from the source network device; In response to the second indication information, a first indication information is sent to the relay device. The first indication information is used to instruct the relay device to perform a first operation, which includes at least one of the following: the relay device stops maintaining synchronization with the source network device, the relay device releases the connection with the source network device, or the relay device stops forwarding information from the source network device.

15. The method as described in claim 14, characterized in that, At least one of the following must be satisfied: The relay device, the source network device, or the target network device is located on the NTN device; The relay device communicates with the source network device via an NTN device; or, The relay device communicates with the target network device via an NTN device.

16. The method as described in claim 14 or 15, characterized in that, The first indication information and / or the second indication information includes at least one of the following: The relay device stops maintaining synchronization with the source network device; The relay device releases an indication message indicating its connection to the source network device; The relay device provides an instruction to stop forwarding information from the source network device. First time information, the time indicated by the first time information includes at least one of the following: the time when the relay device stops maintaining synchronization with the source network device, or the time when the relay device releases the connection with the source network device, or the time when the relay device stops forwarding information from the source network device; Information on the number of terminal devices within the signal coverage area of ​​the relay device that have switched from the source network device to the target network device; Information on the number of terminal devices within the signal coverage area of ​​the relay device that have not switched from the source network device to the target network device, or information used to indicate that all terminal devices within the signal coverage area of ​​the relay device that need to switch to the target network device should switch from the source network device to the target network device. Information used to indicate that the source network device is unable to provide communication services to terminal devices within the signal coverage area of ​​the relay device; or; The identification information of the relay device.

17. The method according to any one of claims 14-16, characterized in that, The method further includes: Receive first configuration information, which is used to instruct the relay device to forward information from the source network device; The first configuration information is sent to the relay device.

18. A communication method, characterized in that, The method is applicable to terminal devices in non-terrestrial networks (NTNs), and the method includes: The terminal device receives fifth information from the source network device via a relay device, the fifth information being used to instruct the terminal device to switch from the source network device to the target network device; In response to the fifth piece of information, the system switches to the target network device; The relay device communicates with the target network device.

19. A communication device, characterized in that, It includes modules for performing the method as described in any one of claims 1 to 6, or modules for performing the method as described in any one of claims 7 to 13, or modules for performing the method as described in any one of claims 14 to 17, or modules for performing the method as described in claim 18.

20. A communication device, characterized in that, The device includes at least one processor and an interface circuit, the interface circuit being used to receive signals from other communication devices and transmit them to the at least one processor or to send signals from the at least one processor to other communication devices, the at least one processor being used, through logic circuits or executing code instructions, to implement the method as described in any one of claims 1 to 6, or to implement the method as described in any one of claims 7 to 13, or to implement the method as described in any one of claims 14 to 17, or to implement the method as described in claim 18.

21. A communication device, characterized in that, The method includes at least one processor, which is configured via logic circuitry or executable code instructions to implement the method as described in any one of claims 1 to 6, or to implement the method as described in any one of claims 7 to 13, or to implement the method as described in any one of claims 14 to 17, or to implement the method as described in claim 18.

22. A computer-readable storage medium, characterized in that, The storage medium stores a computer program or instructions that, when executed by a communication device, implement the method as described in any one of claims 1 to 6, or are used to implement the method as described in any one of claims 7 to 13, or are used to implement the method as described in any one of claims 14 to 17, or are used to implement the method as described in claim 18.

23. A computer program product, characterized in that, The computer program product stores a computer program, the computer program including program instructions, which, when executed by a computer, cause the computer to perform the method as described in any one of claims 1 to 6, or the method as described in any one of claims 7 to 13, or the method as described in any one of claims 14 to 17, or the method as described in claim 18.

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