Communication method, apparatus, storage medium, and program product

Abstract

Provided in the present application are a communication method, an apparatus, a storage medium, and a program product, which can be applied in a satellite communication system, such as an NTN. The method comprises: a terminal apparatus being capable of receiving configuration information sent by a first network device, wherein the configuration information is used for indicating a TCI state, and the first network device and one or more candidate network devices associated with the TCI state. The one or more candidate network devices are not required to separately configure TCI states for the terminal apparatus. When receiving a switching indicator, for example, receiving first information, the terminal apparatus can receive, on the basis of the TCI state after switching to a second network device, a downlink reference signal, data, etc., sent by the second network device; thus, the switching between TCI states is not required during the switching between network devices, thereby reducing system signaling overheads.

Description

Communication methods, devices, storage media and software products

[0001] This application claims priority to Chinese Patent Application No. 202411550327.6, filed on October 31, 2024, entitled "Communication Method, Apparatus, Storage Medium and Program Product", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of communications, and more particularly to a communication method, apparatus, storage medium, and program product. Background Technology

[0003] Due to the high speed of satellite movement, the service coverage area provided by network equipment deployed on satellites also moves, requiring connected terminal devices to frequently switch between different network devices to ensure service continuity.

[0004] When current network devices instruct terminal devices to switch network devices, they need to instruct the terminal devices to switch the transmission configuration indicator (TCI) state so that the terminal devices can communicate with the target network devices based on the TCI state, resulting in large signaling overhead. Summary of the Invention

[0005] This application provides a communication method, apparatus, storage medium, and program product to reduce system signaling overhead.

[0006] Firstly, a communication method is provided, which can be applied to a terminal device. The terminal device in this application can be a terminal equipment or a component of a terminal equipment, such as a communication module, circuits or chips responsible for communication functions (e.g., modem chips, also known as baseband chips, or system-on-chip (SoC) chips or system-in-package (SIP) chips containing modem cores), chip systems, or processors, etc., or logic modules or software capable of implementing all or part of the functions of the terminal equipment.

[0007] For example, the method includes: a terminal device receiving configuration information sent by a first network device, the configuration information indicating a TCI state, and a first network device and one or more candidate network devices associated with the TCI state. The terminal device also receives first information sent by the first network device, the first information indicating a handover to a second network device, the second network device belonging to one or more candidate network devices; the terminal device can receive downlink reference signals and data from the second network device according to the TCI state.

[0008] As can be seen, the terminal device can receive configuration information about the TCI status sent by the first network device, and one or more candidate network devices do not need to configure the TCI status for the terminal device separately. When the terminal device receives a handover instruction, such as receiving the first information, it can receive downlink reference signals and data sent by the second network device according to the TCI status after handover to the second network device. There is no need to switch the TCI status during network device handover, reducing system signaling overhead.

[0009] In conjunction with the first aspect, in some implementations of the first aspect, the TCI state can be configured with an SSB index corresponding to the first network device and an SSB index corresponding to the second network device. The terminal device can receive downlink reference signals and data about the TCI state sent by different network devices based on the resources corresponding to the SSB indices of different network devices.

[0010] In conjunction with the first aspect, in some implementations of the first aspect, the SSB index corresponding to the first network device and the SSB index corresponding to the second network device can be the same; that is, the first network device and the second network device use the same SSB. The terminal device can receive second information sent by the first network device, which indicates the signal transmission time difference between the SSB sent by the first network device and the SSB sent by the second network device. The terminal device can distinguish the SSBs sent by different network devices based on this signal transmission time difference and perform signal quality measurement, thereby sending the measurement result to the first network device. The measurement result is used by the first network device to determine whether to instruct a handover to the second network device. Reusing a limited number of SSB indices can avoid affecting other cells.

[0011] In conjunction with the first aspect, in some implementations of the first aspect, the SSB index corresponding to the first network device and the SSB index corresponding to the second network device can be different; that is, the first network device and the second network device use different SSBs. The terminal device can distinguish the SSB of the SSB sent by the first network device from the SSB sent by the second network device based on the SSB index of the received SSB, and generate measurement results based on the signal quality of the different SSBs. Then, it sends the measurement results to the first network device.

[0012] Secondly, a communication method is provided, which can be applied to a first network device. For example, the method can be executed by a first network device, which can be a first network device itself, or a component of the first network device, such as a communication module, processor, chip, chip system, or circuit in the first network device. It can also be a logic module or software that can implement all or part of the functions of the first network device. The following description uses a first network device as an example.

[0013] For example, the method includes: sending configuration information to a terminal device, the configuration information indicating a TCI state, a first network device associated with the TCI state, and one or more candidate network devices; and sending first information to the terminal device, the first information indicating a switch to a second network device, the second network device belonging to one or more candidate network devices.

[0014] As can be seen, the first network device can send configuration information about the TCI status to the terminal device, and one or more candidate network devices do not need to configure the TCI status for the terminal device separately. When instructing the terminal device to switch network devices, there is no need to switch the TCI status, reducing system signaling overhead.

[0015] In conjunction with the second aspect, in some implementations of the second aspect, the TCI state can be configured with an SSB index corresponding to the first network device and an SSB index corresponding to the second network device, so as to instruct the terminal device to receive downlink reference signals and data about the TCI state sent by different network devices based on the resources corresponding to the SSB indices of different network devices.

[0016] In conjunction with the second aspect, in some implementations of the second aspect, the SSB index corresponding to the first network device and the SSB index corresponding to the second network device can be the same, meaning that the first network device and the second network device use the same SSB. The first network device can indicate the signal transmission time difference between the SSB transmitted by the first network device and the SSB transmitted by the second network device to the terminal device. This allows the terminal device to distinguish the SSBs transmitted by different network devices based on the signal transmission time difference and perform signal quality measurements. The terminal device then sends the measurement results to the first network device, which uses these results to determine whether to instruct a handover to the second network device. Reusing a limited number of SSB indexes can avoid impacting other cells.

[0017] In conjunction with the second aspect, in some implementations of the second aspect, the first network device can send first information to the terminal device based on the measurement results received from the terminal device. The measurement results are obtained by the terminal device measuring the SSB sent by the first network device and the SSB sent by the second network device. Therefore, the first network device's instruction to the terminal device to switch network devices based on the terminal device's measurement results of the SSB signal quality can further guarantee the communication quality of the terminal device.

[0018] For example, the measurement result can be obtained by the terminal device by distinguishing between the SSB sent by the first network device and the SSB sent by the second network device based on the SSB index of the received SSB, and then performing signal quality analysis.

[0019] For example, the measurement result can be obtained by the terminal device based on the signal transmission time difference to distinguish the SSBs sent by different network devices and measure the signal quality.

[0020] In conjunction with the first and second aspects, in some implementations of the first and second aspects, for terminal devices with weak capabilities, the terminal device can receive random access information indicated by the first network device, and the terminal device can achieve downlink synchronization with the second network device based on the random access information, thereby improving the success rate of synchronization.

[0021] In conjunction with the first and second aspects, in some implementations of the first and second aspects, for terminal devices with weak capabilities, the terminal device can receive a timing adjustment instruction from the first network device, and the terminal device can achieve downlink synchronization with the second network device according to the timing adjustment instruction, thereby improving the success rate of synchronization.

[0022] For example, the timing adjustment instruction may be obtained after the terminal device sends a dedicated random access preamble to the second network device.

[0023] In conjunction with the first and second aspects, in some implementations of the first and second aspects, the terminal device can receive a downlink offset indicated by the first network device, and the terminal device can achieve downlink synchronization with the second network device based on the downlink offset, thereby improving the success rate of synchronization.

[0024] In conjunction with the first and second aspects, in some implementations of the first and second aspects, the terminal device can receive a GAP indicated by the first network device, and the terminal device can complete synchronization with the second network device without interference within the GAP, thereby switching to the second network device and reducing the probability of abnormal synchronization with the second network device due to the terminal device's weak capabilities.

[0025] For example, GAP is determined based on the time required for the terminal device to switch network devices.

[0026] In conjunction with the first and second aspects, in some implementations of the first and second aspects, the terminal device may receive a latest time indicated by the first network device for completing the handover to the second network device, such as a first information indicating a first moment. The terminal device may handover to the second network device before the first moment, thereby reducing the synchronization delay with the second network device.

[0027] In conjunction with the first and second aspects, in certain implementations of the first and second aspects, the first information indicates a second time period and a first duration, which are used to characterize a handover to a second network device within a first time period. The start time of the first time period is the second time period, and the duration of the first time period is the first duration. In this case, the terminal device can handover to the second network device within the first time period, thereby reducing the synchronization delay with the second network device.

[0028] In conjunction with the first and second aspects, in some implementations of the first and second aspects, the first information may be carried in a PDCCH command or MAC-CE, thereby increasing the success rate of the terminal device successfully receiving the handover indication (e.g., the first information) sent by the first network device.

[0029] In conjunction with the first and second aspects, in some implementations of the first and second aspects, if the first information is carried on MAC-CE, the terminal device can also receive ephemeris data of the second network device indicated by the first network device through the first information. The ephemeris data is used for uplink synchronization with the second network device, and the terminal device can perform downlink synchronization with the second network device based on the ephemeris data, thereby improving the synchronization success rate.

[0030] In conjunction with the first and second aspects, in some implementations of the first and second aspects, the SSB index of the TCI state configured in the terminal device may change. The terminal device may receive an indication from the first network device of a first SSB index, which is different from the SSB index in the TCI state. The terminal device can update the SSB index in the TCI state based on the first SSB index.

[0031] Thirdly, this application provides a communication device. This communication device has the functionality to implement some or all of the functional embodiments described in the first aspect. This functionality can be implemented in hardware or by hardware executing corresponding software. The hardware or software includes at least one unit or module corresponding to the aforementioned functionality.

[0032] For example, the structure of the communication device may include a transceiver unit, which is used for:

[0033] Receive configuration information, which indicates the TCI status, and the first network device and one or more candidate network devices associated with the TCI status; receive first information sent by the first network device, which indicates a handover to the second network device, which belongs to one or more candidate network devices; and receive downlink reference signals and data from the second network device according to the TCI status.

[0034] In conjunction with the third aspect, in some implementations of the third aspect, the TCI state can be configured with the SSB index corresponding to the first network device and the SSB index corresponding to the second network device.

[0035] In conjunction with the third aspect, in some implementations of the third aspect, the SSB index corresponding to the first network device is the same as the SSB index corresponding to the second network device; the transceiver unit is also used for:

[0036] Receive second information sent by the first network device, the second information being used to indicate the signal transmission time difference between the SSB sent by the first network device and the SSB sent by the second network device;

[0037] The measurement results are sent to the first network device to determine whether to switch to the second network device. The measurement results are obtained based on the signal transmission time difference.

[0038] In conjunction with the third aspect, in some implementations of the third aspect, the SSB index corresponding to the first network device is different from the SSB index corresponding to the second network device; the transceiver unit is also used for:

[0039] The measurement results are sent to the first network device, and the measurement results are obtained based on the SSB index corresponding to the first network device and the SSB index corresponding to the second network device.

[0040] The communication device provided in this embodiment can execute the technical solutions in the above method embodiments. Its beneficial effects are similar to those obtained by the first aspect of this application and the corresponding feasible implementation methods, and will not be described again.

[0041] Fourthly, this application provides a communication device. This communication device has the functionality to implement some or all of the functional embodiments described in the second aspect above. This functionality can be implemented in hardware or by hardware executing corresponding software. The hardware or software includes at least one unit or module corresponding to the aforementioned functionality.

[0042] For example, the structure of the communication device may include a transceiver unit, which is used for:

[0043] Send configuration information to the terminal device. The configuration information is used to indicate the TCI status, as well as the first network device and one or more candidate network devices associated with the TCI status.

[0044] Send first information to the terminal device, the first information being used to instruct switching to a second network device, the second network device being one or more candidate network devices.

[0045] In conjunction with the fourth aspect, in some implementations of the fourth aspect, the TCI state includes the SSB index corresponding to the first network device and the SSB index corresponding to the second network device.

[0046] In conjunction with the fourth aspect, in some implementations of the fourth aspect, the SSB index corresponding to the first network device is the same as the SSB index corresponding to the second network device; the transceiver unit is also used for:

[0047] Send a second message to the terminal device, the second message being used to indicate the signal transmission time difference between the SSB sent by the first network device and the SSB sent by the second network device.

[0048] In conjunction with the fourth aspect, in some implementations of the fourth aspect, the transceiver unit is specifically used for:

[0049] Receive measurement results from the terminal device, the measurement results being obtained by the terminal device measuring the SSB sent by the first network device and the SSB sent by the second network device;

[0050] Based on the measurement results, the first information is sent to the terminal device.

[0051] The communication device provided in the fourth aspect of this embodiment can execute the technical solutions in the above method embodiments. Its beneficial effects are similar to those obtained by the second aspect of this application and the corresponding feasible implementation methods, and will not be described again.

[0052] In conjunction with the third and fourth aspects, in some implementations of the third and fourth aspects, the first information is also used to indicate random access information, which is used for uplink synchronization with the second network device.

[0053] In conjunction with the third and fourth aspects, in some implementations of the third and fourth aspects, the random access information includes timed adjustment instructions.

[0054] In conjunction with the third and fourth aspects, in some implementations of the third and fourth aspects, the first information is also used to indicate the downlink offset, which is used for downlink synchronization with the second network device.

[0055] In conjunction with the third and fourth aspects, in some implementations of the third and fourth aspects, the first information is also used to indicate the measurement gap GAP, which is used to characterize the handover to the second network device within the GAP.

[0056] In conjunction with the third and fourth aspects, in some implementations of the third and fourth aspects, the first information is also used to indicate the first moment, which is used to characterize the latest time of switching to the second network device.

[0057] In conjunction with the third and fourth aspects, in some implementations of the third and fourth aspects, the first information is also used to indicate the second time and the first duration, which are used to characterize the handover to the second network device within the first time period, the start time of the first time period being the second time, and the duration of the first time period being the first duration.

[0058] In conjunction with the third and fourth aspects, in certain implementations of the third and fourth aspects, the first information is carried in any of the following signaling methods:

[0059] Physical Downlink Control Channel (PDCCH) commands;

[0060] Media access control - control element MAC-CE.

[0061] In conjunction with the third and fourth aspects, in some implementations of the third and fourth aspects, the first information is carried on the MAC-CE, and the first information is also used to indicate the ephemeris data of the second network device, which is used for uplink synchronization with the second network device.

[0062] In conjunction with the third and fourth aspects, in some implementations of the third and fourth aspects, the first information is also used to indicate a first SSB index, which is different from the SSB index in the TCI state; the first SSB index is used to update the SSB index in the TCI state.

[0063] Fifthly, this application provides a communication device including one or more processors for executing a computer program (also referred to as code or instructions) in a memory, such that the communication device implements the communication method in the first aspect or the second aspect and any possible implementation of the first aspect or the second aspect.

[0064] One possible design is that the device further includes a memory for storing computer programs and data. This memory is coupled to the processor, which, when executing the computer program stored in the memory, can implement the methods described in the first or second aspect above.

[0065] One possible design is that the device also includes a communication interface for communicating with other devices. For example, the communication interface may be a transceiver, circuit, bus, module, or other type of communication interface.

[0066] For example, the device in the third aspect is a terminal, or a component in a terminal, such as a chip, chip system, processor, etc. The device in the fourth aspect is a network device, or a component in a network device, such as a chip, chip system, processor, etc.

[0067] Sixthly, this application provides a chip system including at least one processor for supporting the implementation of the functions involved in the first to second aspects and any possible implementations described above, such as processing the information involved in the methods described above.

[0068] In one possible design, the chip system also includes a memory for storing computer programs and data, which may be located inside or outside the processor.

[0069] The chip system can consist of chips or include chips and other discrete components.

[0070] One possible design is that the chip system also includes a power supply circuit for supplying power to the chip system.

[0071] In a seventh aspect, this application provides a computer-readable storage medium including a computer program that, when run on a computer, causes the computer to implement the methods of the first to fourth aspects and any possible implementation of the first to second aspects.

[0072] Eighthly, this application provides a computer program product comprising: a computer program that, when run, causes a computer to perform the methods of the first to fourth aspects and any possible implementation of the first to second aspects.

[0073] Ninthly, embodiments of this application provide a system including the aforementioned terminal and network device.

[0074] The second to ninth aspects of this application have similar beneficial effects to the first aspect of this application and the corresponding feasible implementation methods, and will not be described again. Attached Figure Description

[0075] Figure 1 is a schematic diagram of the architecture of an example NTN communication system;

[0076] Figure 2 shows the QCL relationship between various reference signals in an example high-frequency communication system;

[0077] Figure 3 is a schematic diagram illustrating how the movement of a network device leads to a switch of terminal devices.

[0078] Figure 4 is a flowchart illustrating a communication method 400 provided in an embodiment of this application;

[0079] Figure 5 is a flowchart illustrating another communication method 500 provided in an embodiment of this application;

[0080] Figure 6 is a schematic diagram of a communication device provided in an embodiment of this application;

[0081] Figure 7 is a schematic diagram of a communication device provided in an embodiment of this application;

[0082] Figure 8 is another schematic block diagram of the communication device provided in an embodiment of this application;

[0083] Figure 9 is a schematic diagram of the structure of the terminal device provided in the embodiment of this application. Detailed Implementation

[0084] The technical solution provided in this application will now be described with reference to the accompanying drawings.

[0085] To facilitate understanding of the embodiments of this application, the following points will be explained first:

[0086] First, in this application, the indication includes explicit indication (also known as direct indication) and implicit indication (also known as indirect indication). Explicit indication information A means including information A; implicit indication information A means indicating information A through the correspondence between information A and information B, and direct indication information B. The correspondence between information A and information B can be predefined, pre-stored, pre-burned, or pre-configured; or it can refer to indicating information A through information B and preset rules.

[0087] Second, in this application, information C is used to determine information D, which includes both determining information D based solely on information C and determining it based on information C and other information. Furthermore, information C can also be used to determine information D indirectly, for example, in the case where information D is determined based on information E, and information E is determined based on information C.

[0088] Third, 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 mean: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The character " / " generally indicates an "or" relationship between the preceding and following related objects, but it does not exclude the possibility of indicating an "and" relationship; the specific meaning can be understood in context. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can mean: a, b, c; a and b; a and c; b and c; or a and b and c. Here, a, b, and c can be single or multiple.

[0089] The technical solutions provided in this application can be applied to satellite communication systems, such as non-terrestrial network (NTN) communication systems. As examples, the NTN system may include a 4G-based NTN system, an NR-based NTN system, a future evolution network-based NTN system, an Internet of Things (IoT)-based NTN system, and a narrowband Internet of Things (NB-IoT)-based NTN system. Figure 1 is a schematic diagram of an example NTN communication system architecture. Figure 1 illustrates a possible, non-limiting system architecture. As shown in Figure 1, the communication system 100 includes at least one terminal device (terminal device 10 and terminal device 20 in Figure 1), at least one network device (network device 30 and network device 40 in Figure 1), a ground station 50, and a core network 60. Exemplarily, terminal device 10 can communicate with network device 30 via a 5G NR interface, and terminal device 20 can communicate with network device 40 via a 5G NR interface. Network device 30 and network device 40 can communicate with ground station 50 via an NG interface. Meanwhile, network device 30 and network device 40 can communicate through the Xn interface to complete signaling interaction between network devices and transmission of user data.

[0090] In the embodiments of this application, the terminal device can be a device with wireless transceiver capabilities, and can also be referred to as a terminal. Specifically, the terminal device can refer to user equipment (UE), access terminal, user unit (subscriber unit), user station, mobile station, customer-premises equipment (CPE), remote station, remote terminal, mobile device, mobile terminal, user terminal, wireless communication device, user agent, or user equipment, etc.

[0091] Terminal devices can also be satellite phones, cellular phones, smartphones, cordless phones, Session Initiation Protocol (SIP) phones, wireless data cards, wireless modems, tablets, computers with wireless transceiver capabilities, wireless local loop (WLL) stations, personal digital assistants (PDAs), handheld devices with wireless communication capabilities, computing devices or other processing devices connected to a wireless modem, in-vehicle devices, communication devices mounted on high-altitude aircraft, wearable devices, drones, robots, point-of-sale (POS) machines, machine-type communication devices, mobile switching centers, and terminal devices in device-to-device (D2D) communication, vehicle-to-everything (V2X) communication, virtual reality (VR) terminal devices, augmented reality (AR) terminal devices, wireless terminals in industrial control, wireless terminals in self-driving, and remote medical services. Wireless terminals can be used in various applications, including medical devices, smart grids, transportation safety, smart cities, smart homes, and future communication networks. The embodiments of this application do not limit the specific technology or form of the terminal device. All or part of the terminal device's functions can also be implemented through software functions running on hardware, or through virtualization functions instantiated on a platform (e.g., a cloud platform).

[0092] In the embodiments of this application, the network device can be a device with wireless transceiver capabilities. It can be a network device in a satellite communication system (such as NTN), as shown in Figure 1; it can also be a network device in a terrestrial network (TN) communication system. This network device includes, but is not limited to: radio network controller (RNC), base station controller (BSC), home base station (e.g., home evolved node B, or home node B, HNB), baseband unit (BBU), access point (AP), wireless relay node, wireless backhaul node, transmission point (TP), or transmission and reception point (TRP) in a Wi-Fi system; it can also be a gNB or transmission point (TRP or TP) in a 5th generation (5G) new radio access technology (NR) system; or one or a group of antenna panels (including multiple antenna panels) of a base station in a 5G system; or it can be a network node constituting a gNB or transmission point, such as a baseband unit (BBU) or a distributed unit (DU).

[0093] The network devices in this application embodiment may include various forms of macro base stations, micro base stations (also known as small stations), relay stations, access points, etc. They may be base stations (BTS) in GSM or CDMA systems, NBs in WCDMA systems, evolved NodeBs (eNBs or eNodeBs) in LTE systems, radio controllers in cloud radio access networks (CRAN) scenarios, or relay stations, access points, wearable devices or vehicle-mounted devices, wearable devices, network devices in future 5G networks, or network devices in future evolved public land mobile networks (PLMN) networks, etc.

[0094] In satellite communication systems, network equipment can be satellites, base stations deployed on satellites or high-altitude aircraft (i.e., satellite base stations), or TRPs (Telecommunication Terminal Protection Units) installed on satellites or high-altitude aircraft. These devices provide wireless access services to terminal devices, allocate wireless resources to accessing terminal devices, and provide reliable wireless transmission protocols and data encryption protocols. Network equipment in satellite communication can also be satellite communication terminals, such as portable stations, fixed stations, vehicle-mounted or airborne satellite communication terminals. It should be understood that satellite communication terminals and satellite communication systems can act as micro base stations or access points to further provide data interfaces to accessing user equipment.

[0095] Ground station 50 is a ground-based device for satellite communication, installed on the Earth's surface (including on ships and aircraft). Ground station 50 can be used to forward signaling and service data exchanged between network equipment 30 and core network 60.

[0096] Core network 60 can provide services such as user access control, mobility management, session management, user authentication, and billing. Core network 50 consists of multiple functional units, including control plane functional entities and data plane functional entities. The control plane functional entities may include the access and mobility management function (AMF) unit, the session management function (SMF) unit, etc. The user plane functional entities may include the user plane function (UPF) unit, the data network (DN), etc. The AMF unit is responsible for user access management, authentication, and mobility management. The SMF unit manages sessions in the mobile network, such as session establishment, modification, and release. The UPF unit manages user plane data transmission and traffic statistics, and the UPF unit can also interact with the DN for user plane data. The DN provides data transmission services for terminal devices. DN can be a public data network (PDN) network, such as the Internet, or a local access data network (LADN), such as the network of mobile edge computing (MEC) nodes.

[0097] It is understood that Figure 1 is only a schematic diagram, and the communication system may also include other devices, such as wireless relay devices and wireless backhaul devices, which are not shown in Figure 1. The embodiments of this application do not limit the number of core network, network devices, and terminal devices included in the communication system.

[0098] The technical solutions provided in this application can also be applied to various communication systems, such as: Global System for Mobile Communication (GSM) systems, Code Division Multiple Access (CDMA) systems, Wideband Code Division Multiple Access (WCDMA) systems, General Packet Radio Service (GPRS) Long Term Evolution (LTE) systems, LTE Frequency Division Duplex (FDD) systems, LTE Time Division Duplex (TDD) systems, sidelink (SL) communication systems, Universal Mobile Telecommunication System (UMTS), Worldwide Interoperability for Microwave Access (WiMAX) communication systems, and 5G mobile communication systems. Among these, 5G mobile communication systems can include non-standalone (NSA) and / or standalone (SA) networking. The technical solutions provided in this application can also be applied to future communication systems, etc. This application does not limit these applications.

[0099] To better understand the methods provided in the embodiments of this application, the terms involved in this application will be briefly explained below.

[0100] 1. Beam

[0101] A beam is the shape formed on the Earth's surface by electromagnetic waves emitted by an antenna. In high-frequency communication systems, thanks to the smaller carrier wavelength, multiple antenna elements can be arranged in an antenna array at both the transmitting and receiving ends. The transmitting end sends signals with a certain beamforming weight, forming a spatially directional beam. Simultaneously, the receiving end uses an antenna array with a certain beamforming weight to receive the signal, which can improve the received signal power and counteract path loss.

[0102] A beam consists of a transmit beam and a receive beam, wherein the transmit beam is used to transmit signals and the receive beam is used to receive signals.

[0103] When the relative positions of network devices and terminal devices change—for example, a change in the relative position of the network devices—the beams of both devices will change accordingly. The network device can send a signaling message to notify the terminal device of the beam change. Upon receiving the signaling message from the network device, the terminal device updates the beam it uses according to the network device's instructions.

[0104] During data transmission, beam information can be indicated through its corresponding resources. For example, network devices can use the transmission configuration indication (TCI) field in downlink control information (DCI) to instruct terminal devices to receive beam information from the physical downlink shared channel (PDSCH).

[0105] In one possible implementation, multiple beams with the same or similar communication characteristics can be considered as a single beam. A beam may include one or more antenna ports for transmitting data channels, control channels, and probe signals, etc. It is understood that one or more antenna ports forming a beam can also be considered as a set of antenna ports. In NR protocols, a beam can be, for example, a spatial filter. However, it should be understood that this application does not preclude the possibility of defining other terms to represent the same or similar meanings in future protocols.

[0106] 2. Reference signal (RS)

[0107] RS is a known signal provided by the transmitter to the receiver, mainly used for channel estimation or channel sounding. This signal is also often called a "pilot signal," and its main purpose is to help the receiver better understand and adapt to wireless channel conditions, thereby improving communication quality and efficiency.

[0108] RS includes an uplink reference signal and a downlink reference signal.

[0109] The uplink reference signals include: channel sounding reference signal (SRS), physical uplink control channel (PUCCH) demodulation reference signal (DMRS), physical uplink shared channel (PUSCH)-DMRS, phase noise tracking reference signal (PT-RS), and uplink positioning signal (RS).

[0110] Downlink reference signals include: the synchronization signal / physical broadcast channel (PBCH) block (SSB), channel state information-reference signal (CSI-RS), physical downlink control channel (PDCCH)-DMRS, PDSCH-DMRS, PTRS, cell reference signal (CRS) (not present in NR), time / frequency tracking reference signal (TRS) (not present in LTE), and LTE / NR positioning signal (positioning RS), etc. Among these, the synchronization signal / physical broadcast channel block (SSB) can be simply referred to as the synchronization signal block (SSB).

[0111] CSI-RS is a type of reference signal used in NR systems for downlink Channel State Information (CSI) measurement. CSI-RS can also be abbreviated as CSI-RS for CSI. Based on specific functions, CSI-RS can also include CSI-RS for beam management (BM). CSI-RS for BM is specifically used for beam measurement of terminal devices and / or network devices during beam management, enabling them to obtain beamforming weights.

[0112] 3. Quasi-co-location (QCL)

[0113] The 3rd generation partnership project (3GPP) defines QCL as follows: If the characteristics of the channel experienced by a signal transmitted on one antenna port can be inferred from the characteristics of the channel experienced by a signal transmitted on another antenna port, then the two antenna ports can be said to be quasi-co-located.

[0114] Based on the above definition, QCL can be used to represent the relationship between the channel characteristics of two signals. A QCL relationship between two signals indicates that the channel characteristics of one signal can be determined by the channel characteristics of the other signal. For example, if two signals have the same or similar channel characteristics, then that channel characteristic of one signal can be directly determined by the same channel characteristic of the other signal, or the same channel characteristic of one signal can be derived from the same channel characteristic of the other signal.

[0115] The channel characteristics of a signal include: Doppler shift, Doppler spread, average delay, delay spread, and spatial Rx parameter. Doppler shift, Doppler spread, average delay, and delay spread are time-frequency characteristics of the channel, while the spatial Rx parameter is a spatial characteristic. Since the signal travels through multiple paths to reach the receiver (e.g., a terminal device) when transmitted by multiple antennas, the average delay can be understood as the average time taken for the receiver to receive all the multipath signal components under multipath propagation conditions.

[0116] For example, if there is a QCL relationship between the spatial reception parameters of two reference signals, it means that the transmitter uses the same beam to transmit the two reference signals, and similarly, it means that the receiver can use the same beam to receive the two reference signals.

[0117] 4. TCI state

[0118] The TCI state can be used to indicate the QCL relationship between two reference signals. The TCI state may include an identifier of the TCI state and one or more (e.g., two) QCL information (QCL-Info), where each QCL-Info may include:

[0119] The identifier of the serving cell (i.e., the physical cell identifier (PCI));

[0120] The identifier for the bandwidth part (BWP);

[0121] Reference signal resource identifier.

[0122] The serving cell identifier and the BWP identifier can be used to indicate which BWP in which cell the TCI state applies to. The reference signal resource identifier can be used to indicate that the resource using the TCI state and the reference signal resources included in the QCL-Info constitute a QCL relationship. For example, if a TCI state is configured for resource 1, and the resource included in the QCL-Info of the TCI state is resource 2, then it means that resource 1 and resource 2 are QCLs. The reference signal resource identifier includes at least one of the following:

[0123] Non-zero power CSI-RS resource (NZP-CSI-RS-Resource) identifier, namely NZP-CSI-RS-ResourceId;

[0124] The identifier for the non-zero power CSI-RS resource set (NZP-CSI-RS-ResourceSet, NZP-CSI-RS-ResourceSet), namely NZP-CSI-RS-ResourceSetId;

[0125] SSB index.

[0126] Each QCL-Info also includes a QCL type. In the NR protocol, QCL relationships can be divided into four types based on different parameters, as shown in Table 1.

[0127] Table 1

[0128] For example, when the QCL type in QCL-Info is type D, it can be considered as spatial QCL. When the antenna ports satisfy the spatial QCL relationship, the QCL relationship between downlink signal ports or between uplink signal ports can be that the two signals have the same receive beam or transmit beam.

[0129] From the transmitting end's perspective, if two antenna ports are spatially QCL (Quadrature Coordinated Linearity), it means that the corresponding beam directions of these two antenna ports are spatially aligned. From the receiving end's perspective, if two antenna ports are spatially QCL, it means that the receiving end can receive the signals transmitted by these two antenna ports in the same beam direction.

[0130] Therefore, the QCL of type D can be understood as a parameter used to indicate the direction information of the received beam.

[0131] Furthermore, various parameters in type A, type B, and type C, such as average delay and Doppler spread, are primarily used for time-domain synchronization. Doppler offset and delay spread, on the other hand, are primarily used for frequency-domain synchronization. Therefore, determining the parameters for other QCL types (such as type A, type B, and type C) can be simply referred to as time-frequency synchronization.

[0132] The TCI state is configured by the network device for each terminal device. The TCI state can be configured globally. In TCI states configured for different cells and different BWPs, if the TCI state index is the same, then the configuration of the corresponding TCI state is also the same.

[0133] For example, Figure 2 shows the QCL relationship between various reference signals in an example high-frequency communication system. As can be seen from the figure, the source of multiple QCL relationships is SSB. That is, when configuring the TCI state, SSB can be configured as the reference signal to be referenced.

[0134] For example, the following explanation uses the configuration of the QCL relationship between SSB and TRS as an example. The reference signal resource identifier in the QCL-Info of the TCI state corresponding to the TRS is configured as the SSB index of the SSB. The SSB index can be configured by the network device to be measured and reported by the terminal device, or it can be obtained through other means such as uplink and downlink beam mapping. This application does not limit this.

[0135] For example, if the SSB index in QCL-Info is SSB Index0, and the terminal device is within the coverage area of ​​the SSB beam corresponding to SSB index0, then the network device configures the QCL relationship between the SSB corresponding to SSB Index0 and the TRS for the terminal device.

[0136] Therefore, it can be seen that the success rate of TRS demodulation can be improved by using QCL relationship. For example, if the SSB corresponding to SSB Index0 is QCL with the TRS, then the terminal device can demodulate the TRS from the SSB through the QCL relationship.

[0137] In one possible implementation, the TCI state can be used to indicate the QCL information of the PDCCH and / or PDSCH, specifically indicating which reference signal the PDCCH-DMRS or PDSCH-DMRS satisfies the QCL relationship. For example, the TCI can specifically indicate which reference signal the PDCCH and / or PDSCH DMRS satisfies the QCL relationship with through a reference signal resource identifier. The terminal device can receive the PDCCH / PDSCH using spatial parameters that are the same as or similar to the spatial parameters of the reference signal.

[0138] For example, network devices can configure a TCI state list for terminal devices via higher-layer signaling (e.g., radio resource control (RRC)). For instance, a network device can configure a TCI state list for a terminal device using the TCI statesToAddModList method in an RRC message. This TCI state list can include multiple TCI states; for example, a network device can configure up to 64 TCI states for each BWP in each cell.

[0139] Subsequently, the network device can activate one or more TCI states via higher-layer signaling (such as the medium access control-control element (MAC-CE)). The activated TCI states are a subset of the TCI state list configured in the aforementioned RRC message. For example, the network device can activate up to eight TCI states per BWP in each cell.

[0140] Subsequently, network devices can also indicate a selected TCI state via the TCI field in physical layer signaling (e.g., DCI). This DCI could be, for example, a DCI used for scheduling physical downlink resources.

[0141] In a TCI state, when the QCL-Info is configured with a QCL type of type A, type B, or type C, the terminal device can demodulate the PDCCH or PDSCH according to the TCI state's indication. When the QCL type is type D, the terminal device can know which transmit beam the network device uses to send signals, and thus determine which receive beam to use to receive signals. The terminal device can determine the receive beam for receiving the PDSCH based on the TCI field in the DCI.

[0142] In a terrestrial network (TN), due to the different geographical locations of different network devices, the TCI state of the channel between each network device and the terminal device is also different. In other words, different network devices configure different TCI states for the terminal devices.

[0143] In satellite communication systems, due to the high-speed movement of satellites, the service coverage area provided by network equipment deployed on satellites also moves, requiring connected terminal devices to frequently switch between different network devices to ensure service continuity. In other words, for each cell, multiple network devices provide network services. Taking low Earth orbit (LEO) satellites as an example, LEO satellites can move at speeds up to 7 km / s, and the service coverage area of ​​network equipment deployed on LEO satellites typically includes geographically fixed service cells. For instance, network equipment deployed on different LEO satellites achieves coverage of the same area on the ground by adjusting the antenna pointing angle. When a network device deployed on one LEO satellite cannot cover an area, it is taken over by a network device deployed on another LEO satellite.

[0144] Figure 3 illustrates a scenario where network device movement causes terminal device handover. As shown in Figure 3, due to satellite movement, at time 1, network device 302 covers the location of terminal device 301. At time 2, network device 303 moves to another location, and network device 303 covers the location of terminal device 301. At time 3, network device 303 moves to another location, and network device 3040 covers the location of terminal device 301. Therefore, the serving cell where terminal device 301 is located is provided with access services by different network devices at different time periods.

[0145] The current protocol supports different network devices configuring different TCI states for terminal devices, which is the same TCI state configuration method used in terrestrial networks in satellite communication systems. During network device handover, the network device after handover or the network device before handover can instruct the terminal device to switch its TCI state, allowing the terminal device to communicate with the new network device using the corresponding TCI state, thus ensuring the continuity and stability of the terminal device's communication service.

[0146] However, because the satellite is in a high-speed moving state, the terminal equipment needs to frequently switch network devices, which requires switching TCI states, resulting in a large system signaling overhead.

[0147] Therefore, this application provides a communication method to configure a TCI state for a terminal device. The TCI state is associated with multiple network devices, meaning the terminal device can communicate with multiple network devices based on this TCI state, for example, receiving downlink reference signals and data sent by multiple network devices. After a network device handover, the terminal device can receive downlink reference signals and data from the switched network device based on the TCI state. In this embodiment, multiple network devices do not need to configure TCI states separately for the terminal device, and there is no need to switch TCI states during network device handover, reducing system signaling overhead.

[0148] The methods provided in the embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0149] Figure 4 is a flowchart of a communication method 400 provided in an embodiment of this application. As shown in Figure 4, the method 400 includes at least the following steps.

[0150] S410, the first network device sends configuration information to the terminal device. The configuration information is used to indicate the TCI status, and the first network device and one or more candidate network devices associated with the TCI status.

[0151] In other words, the terminal device receives configuration information sent by the first network device.

[0152] It should be understood that the terminal device in this application can be a terminal device or a component of a terminal device, such as a communication module, circuits or chips responsible for communication functions (such as modem chips, also known as baseband chips, or system-on-chip (SoC) chips or system-in-package (SIP) chips containing modem cores), chip systems, or processors, etc., which can be applied in the terminal device. It can also be a logic module or software that can implement all or part of the functions of the terminal device. Similarly, the network device in this application can be a network device or a component of a network device, such as a communication module, processor, chip, chip system, or circuits, etc., which can be applied in the network device. It can also be a logic module or software that can implement all or part of the functions of the network device. It should be understood that the above description applies to all network devices in this application, such as the first network device, the second network device, and the candidate network device.

[0153] In one possible implementation, the TCI state indicated by the configuration information can be the TCI state corresponding to any one of a plurality of downlink reference signals. The number of TCI states can be multiple; that is, the first network device can configure multiple TCI states corresponding to the downlink reference signal for the terminal device. For example, these multiple TCI states can be configured in the form of a TCI state list.

[0154] In other words, for any downlink reference signal corresponding to the TCI state, the first network device can be configured using different configuration information.

[0155] In one possible implementation, the configuration information can indicate one or more TCI states corresponding to multiple downlink reference signals, and similarly, these multiple TCI states can be configured in the form of a TCI state list.

[0156] For any downlink reference signal corresponding to a TCI state, the terminal device can receive the downlink reference signal based on the TCI state.

[0157] In one possible implementation, the configuration information indicates the TCI status, and the first network device and one or more candidate network devices associated with the TCI status. For example, the configuration information may include the TCI status, the identifier of the first network device, and the identifiers of one or more candidate network devices.

[0158] For example, the configuration information is shown in Table 2:

[0159] Table 2

[0160] Among them, network device 1, network device 2 and network device 3 are different network devices.

[0161] In one possible implementation, for any TCI state, the configuration information indicates the TCI state and the first network device and one or more candidate network devices associated with the TCI state in a manner that, for example, allows the TCI state to carry the identifier of the first network device and the identifier of one or more candidate network devices.

[0162] In one possible implementation, the TCI state may include:

[0163] TCI status identifier;

[0164] The identifier of the first network device and the identifiers of one or more candidate network devices;

[0165] One or more QCL messages.

[0166] Each QCL information may include: PCI and BWP identifiers, and reference signal resource identifier. The QCL information may also include the QCL type, which can be one of type A, type B, type C, or type D.

[0167] In one possible implementation, the TCI state may include:

[0168] TCI status identifier;

[0169] One or more QCL messages. Each QCL message may include:

[0170] PCI;

[0171] BWP logo;

[0172] Reference signal resource identifier;

[0173] The identifier of the first network device and the identifiers of one or more candidate network devices.

[0174] The identifier of the first network device and the identifiers of one or more candidate network devices can be used to indicate which network devices the TCI state applies to.

[0175] The identifier of the first network device and the identifiers of one or more candidate network devices can be source identifiers, device identifiers, or temporary identifiers configured by signaling, without restriction.

[0176] In one possible implementation, the first network device can carry the configuration information via higher-layer signaling, that is, send the configuration information to the terminal device via higher-layer signaling.

[0177] In one possible implementation, the higher-level signaling could be RRC.

[0178] In one possible implementation, the configuration information can be used to indicate other information carrying the TCI status, as well as the identifier of the first network device associated with the TCI status and the identifiers of one or more candidate network devices.

[0179] For example, taking the periodic reference signal CSI-RS as an example, if the TCI state is associated with CSI-RS, the first network device can configure the periodic CSI-RS resource for the terminal device through RRC, and configure the identifier corresponding to the associated CSI-RS resource in the TCI state, thereby realizing the configuration of the associated reference signal CSI-RS for the TCI state.

[0180] It is understood that the first network device and the candidate network device can be network devices that provide services to the cell where the terminal device is located. In other words, the first network device and the candidate network device can take turns providing services to the terminal device in the cell as the satellite moves.

[0181] S420: The first network device sends the first information to the terminal device.

[0182] In other words, the terminal device receives the first information sent by the first network device.

[0183] The first information is used to indicate a switch to a second network device, which belongs to one or more candidate network devices.

[0184] In one possible implementation, if there are multiple candidate network devices associated with the TCI state, the first information may carry the identifier of the second network device, which is used to instruct the terminal device to switch to the second network device among the multiple candidate network devices.

[0185] S430: The terminal device receives downlink reference signals and data from the second network device based on the TCI status.

[0186] In other words, the second network device sends downlink reference signals and data to the terminal device, and the terminal device can receive or parse the downlink reference signals and data according to the TCI state.

[0187] After receiving the first information sent by the first network device, the terminal device can switch the network device providing the service from the first network device to the second network device.

[0188] After switching to the second network device, the terminal device can receive downlink reference signals and data from the second network device according to the TCI state. For example, the downlink reference signal may include PDCCH-DMRS or PDSCH-DMRS, etc. Taking PDCCH-DMRS as an example, the terminal device can receive the PDCCH-DMRS sent by the second network device according to the TCI state corresponding to the PDCCH-DMRS.

[0189] It is understandable that the configuration information in S410 may be sent to the terminal device in advance by the first network device. The terminal device stores the configuration information and communicates with the first network device based on the TCI state indicated by the configuration information, such as receiving the downlink reference signal sent by the first network device according to the TCI state.

[0190] It should be noted that the above description is based on the example of configuring the TCI state for the terminal device using the first network device. The TCI state can also be configured by any one of one or more candidate network devices, and this application does not limit this.

[0191] When a network device handover occurs, for example, after receiving the first information sent by the first network device, the terminal device can receive downlink reference signals and data sent by the switched network device through the configured TCI state.

[0192] In this embodiment, the first network device sends configuration information to the terminal device. This configuration information indicates the TCI state and the first network device and one or more candidate network devices associated with the TCI state. During network device handover, the first network device can instruct the terminal device to switch to the second network device via the first information. Then, the terminal device can receive downlink reference signal data sent by the second network device based on the TCI state. The one or more candidate network devices do not need to configure the TCI state for the terminal device separately, and there is no need to switch the TCI state when instructing the terminal device to perform network device handover, reducing system signaling overhead.

[0193] It should be understood that the second network device in this application can be a second network device or a component of a second network device, such as a communication module, processor, chip, chip system, or circuit that can be applied in the second network device, or a logic module or software that can realize all or part of the functions of the second network device.

[0194] The following explains how the first network device instructs the terminal device to switch network devices.

[0195] For example, the terminal device can perform uplink and downlink synchronization with the second network device to achieve handover to the second network device.

[0196] For terminal devices with weak capabilities, the first network device can indicate random access information to the terminal device, enabling the terminal device to perform uplink synchronization with the second network device based on the random access information.

[0197] In one possible implementation, the first information is further used to indicate random access information. The random access information is used for uplink synchronization with the second network device. In this case, the method further includes: the terminal device performing uplink synchronization with the second network device based on the random access information.

[0198] The first information indicates the manner in which the random access information is carried. For example, the random access information can be carried within the first information, meaning the first information includes the random access information. Alternatively, the random access information can also be carried by other signaling, meaning the first network device sends the random access information through other signaling. The first information can be used to instruct other signaling to carry the random access information, and this application does not limit this.

[0199] In one possible implementation, the random access information may include a random access sequence. The terminal device may initiate a contention for random access to the second network device based on the random access sequence, for example, by sending a random access preamble to the second network device to obtain a timing adjustment instruction. For example, the timing adjustment instruction may be a timing advance, which may also be called a timing advance (TA).

[0200] In one possible implementation, the timing adjustment command can be sent by the first network device. For example, if the timing adjustment command is sent by the first network device, since the terminal device has not yet switched to the second network device, the second network device can send the timing adjustment command to the terminal device through the first network device.

[0201] In one possible implementation, the timing adjustment command can be sent by a second network device. After receiving the random access preamble sent by the terminal device, the second network device can send a timing adjustment command to the terminal device based on the random access preamble. It is understood that in this scenario, the terminal device can receive information sent by the second network device while communicating with the first network device.

[0202] In one possible implementation, the random access information may include a timing adjustment instruction. That is, the first network device can instruct the timing adjustment instruction via the first information, and the timing adjustment signaling is used for uplink synchronization with the second network device. In this case, the specific method by which the terminal device performs uplink synchronization with the second network device based on the random access information can be: the terminal device performs uplink synchronization with the second network device based on the timing adjustment signaling.

[0203] In one possible implementation, the timing adjustment command can be a non-contention-based random access initiated by the terminal device to the second network device. For example, after sending a dedicated random access preamble pre-configured in the terminal device to the second network device, the first network device can directly instruct the timing adjustment command through first information when instructing the terminal device to switch to the second network device. For instance, when the terminal device measures the SSBs sent by multiple network devices (including the first and second network devices), if the measurement result of the SSB of the second network device meets a condition, such as the signal quality meeting a set threshold, the terminal device can send a dedicated random access preamble to the second network device. The second network device can then instruct the terminal device to perform a network device switch through the first network device.

[0204] In one possible implementation, the first information is further used to indicate a downlink offset, which is used for downlink synchronization with the second network device. In this case, the method further includes enabling the terminal device to achieve downlink synchronization with the second network device based on the downlink offset.

[0205] The first information indicates the downlink offset in the following ways: for example, the downlink offset can be carried in the first information, that is, the first information includes the downlink offset. Alternatively, the downlink offset can also be carried by other signaling, that is, the first network device sends the downlink offset through other signaling, and the first information can be used to indicate that other signaling carries the downlink offset. This application does not limit this.

[0206] In one possible implementation, the first information can also be used to indicate a first moment, which characterizes the latest time to switch to the second network device. For example, this latest time could be the moment preceding the first moment, in which case the terminal device and the second network device can be considered to have completed synchronization (e.g., including uplink and downlink synchronization) at and after the first moment. In this case, the method further includes: the terminal device can switch to the second network device before the first moment. For example, the terminal device can switch from its original beam to the beam corresponding to the second network device at or after the first moment, thereby enabling communication with the second network device.

[0207] Alternatively, the latest time could be a first moment, after which the terminal device and the second network device can be considered to have completed synchronization. In this case, the method further includes: the terminal device can switch to the second network device at or before the first moment. For example, the terminal device can switch from its original beam to the beam corresponding to the second network device after the first moment, thereby enabling communication with the second network device.

[0208] For example, the first moment can be a reference time (epoch time).

[0209] The first information indicates the first moment in a manner that, for example, allows the first moment to be carried within the first information, meaning the first information includes the first moment. Alternatively, the first moment can also be carried by other signaling, meaning the first network device sends the first moment through other signaling, and the first information can be used to indicate that other signaling carries the first moment. This application does not limit this.

[0210] In one possible implementation, the first information is further used to indicate a second time and a first duration, which characterize the handover to the second network device within the first time period. For example, the start time of the first time period is the second time, and the duration of the first time period is the first duration. In this case, the method further includes: the terminal device handing over to the second network device within the first time period; and after the end time of the first time period, it can be considered that the terminal device and the second network device have completed synchronization (e.g., including uplink synchronization and downlink synchronization).

[0211] In one possible implementation, during the first duration, the terminal device can communicate with the first network device (i.e., communicate with the sampling source beam) to avoid communication interruption due to the switching of the network device.

[0212] The first information indicates the second time and the first duration in a manner that, for example, allows the second time and the first duration to be carried within the first information, meaning the first information includes the second time and the first duration. Alternatively, the second time and the first duration can also be carried by other signaling, that is, the first network device sends the second time and the first duration through other signaling, and the first information can be used to instruct other signaling to carry the second time and the first duration. This application does not limit this.

[0213] It should be noted that the use of the first information to indicate a first moment, or the use of the first information to indicate a second moment and a first duration—that is, the method by which the terminal device switches to the second network device before the first moment, or switches to the second network device after the second moment and for a first duration—can be considered conditional synchronization. Taking the first information indicating the first moment as an example, the first network device can send the first information to the terminal device in advance, and the terminal device can complete the network device switch before the first moment. At or after the first moment, it is considered that the terminal device has switched to the second network device.

[0214] In this embodiment, for other methods, such as using the first information to indicate random access information (e.g., random access sequence), downlink offset, and the GAP mentioned below, the first network device only sends the first information to the terminal device when it determines that the terminal device needs to switch; that is, the first network device triggers the transmission of the first information in real time. For example, in the following embodiment, the first network device determines whether the terminal device needs to switch to the second network device based on the measurement results sent by the terminal device. Therefore, the first network device's instruction to the terminal device to switch network devices based on the terminal device's measurement results of the SSB signal quality can further guarantee the communication quality of the terminal device.

[0215] In one possible implementation, the first information is also used to indicate a measurement gap (GAP), which represents a handover to a second network device within the GAP, and the terminal device can handover to the second network device within the GAP.

[0216] For example, within this GAP, the terminal device may not need to measure the periodic reference signal configured by the first network device, nor the periodic or statically configured uplink signal sent by the first network device, thus suspending communication services with the first network device. Other resources configured by the first network device for the terminal within the GAP can be released.

[0217] In one possible implementation, if the timing adjustment command is sent by the second network device, then other resources configured by the second network device for the terminal within the GAP can be released.

[0218] In one possible implementation, the length of the gap (GAP) can be determined based on the terminal device's capability information, which may include the time required for the terminal device to switch network devices. For example, when accessing a first network device, the terminal device can report this capability information to the first network device. This allows the first network device to indicate a network device switching instruction, and by indicating the GAP, the terminal device can complete synchronization with the second network device without interference within the GAP, reducing the probability of synchronization anomalies due to the terminal device's weak capabilities and synchronization with the second network device.

[0219] In one possible implementation, after the GAP, the second network device interacts with the first network device in terms of resources and configuration, so that the second network device continues to use the configuration of the first network device, and the terminal device can continue to communicate with the second network device based on the configuration.

[0220] The first information indicates the GAP in a manner that, for example, allows the GAP to be carried within the first information, meaning the first information includes the GAP. Alternatively, the GAP can also be carried by other signaling, meaning the first network device sends the GAP via other signaling, and the first information can be used to instruct other signaling to carry the GAP. This application does not limit this.

[0221] In one possible implementation, the first information can be carried in any of the following signaling methods:

[0222] PDCCH command;

[0223] MAC-CE.

[0224] In other words, the first network device can send the first information via the PDCCH command or MAC-CE.

[0225] In one possible implementation, since the PDCCH has stronger anti-interference capabilities compared to MAC-CE, if the first information is also used to indicate parameters for synchronization, such as random access information and / or downlink offset, and these parameters are carried within the first information, the first network device can send the first information via a PDCCH command. If the first information is only used to indicate handover to the second network device, or to indicate fewer parameters for synchronization, the first network device can send the first information via MAC-CE.

[0226] In one possible implementation, if the first information is carried on the MAC-CE, the first information is also used to indicate the ephemeris data of the second network device. In this case, the method further includes: the terminal device achieving uplink synchronization with the second network device based on the ephemeris data. For example, the ephemeris data may include the location, speed, and time information of the second network device, etc., and the terminal device can achieve accurate uplink synchronization with the second network device based on the ephemeris data.

[0227] For example, the terminal device may perform uplink synchronization with the second network device based on ephemeris data before the first moment. Alternatively, the terminal device may perform uplink synchronization with the second network device based on ephemeris data within a first duration (e.g., a first time period) after the second moment.

[0228] Due to the high-speed movement of satellites, the network device corresponding to the cell where the terminal device is located changes. However, since the cell where the terminal device is located remains the same, that is, the cell will be taken over by different network devices to provide services at different times. The SSB used by the cell is known, that is, one or more SSBs are assigned to the cell. Therefore, when the terminal device is within the range of that cell, regardless of which network device is providing services, that network device can send the SSB corresponding to that cell to the terminal device.

[0229] In this embodiment of the application, multiple network devices providing services to the cell can use the same SSB, which can avoid the impact of using different SSBs on other cells. Alternatively, different SSBs can also be used.

[0230] In one possible implementation, the TCI state includes the SSB index corresponding to the first network device and the SSB index corresponding to one or more candidate network devices, wherein the SSB index corresponding to the one or more candidate network devices includes the SSB index corresponding to the second network device.

[0231] For example, the SSB index corresponding to the first network device and the SSB index corresponding to the second network device can be configured in the QCL information in the TCI state. For example, it can be configured in the reference signal resource identifier of the QCL information.

[0232] In one possible implementation, the reference signal resource identifier can be configured with an SSB index, which corresponds to the first network device and the second network device respectively.

[0233] In one possible implementation, the reference signal resource identifier can be configured with two SSB indices, which can be the first network device and the second network device, respectively.

[0234] In one possible implementation, the SSB index corresponding to the first network device is the same as the SSB index corresponding to the second network device. The terminal device measures the SSBs sent by the first and second network devices, and triggers the first network device to send a handover indication (i.e., first information) based on the measurement result, as detailed in Figure 5.

[0235] Figure 5 is a flowchart of another communication method 500 provided in an embodiment of this application. As shown in Figure 5, the method 500 includes at least the following steps.

[0236] S510, The terminal device receives second information sent by the first network device, the second information being used to indicate the signal transmission time difference between the SSB sent by the first network device and the SSB sent by the second network device.

[0237] If there is a time difference in SSB transmission between the first network device and the second network device, the first network device can indicate the time difference in signal transmission between the SSB transmitted by the first network device and the SSB transmitted by the second network device through the second information.

[0238] In one possible implementation, the second information can be carried on a single signaling message of the PDCCH, meaning that the first network device can send the second information via a single signaling message of the PDCCH.

[0239] The second information indicates the signal transmission time difference in a manner that, for example, could be that the signal transmission time difference is carried within the second information, meaning the second information includes the signal transmission time difference. Alternatively, the signal transmission time difference could also be carried by other signaling, meaning the first network device transmits the signal transmission time difference via other signaling, and the second information could be used to indicate that the other signaling carries the signal transmission time difference; this application does not limit this.

[0240] S520. The terminal device sends the measurement result to the first network device. The measurement result is used to determine whether to switch to the second network device. The measurement result is obtained based on the signal transmission time difference.

[0241] In other words, the first network device can receive measurement results sent by the terminal device.

[0242] The terminal device can measure the signal quality of SSBs transmitted by the first network device and one or more candidate network devices. Since the first and second network devices sample the same SSBs (i.e., the SSB index of the SSB transmitted by the first network device is the same as the SSB index of the SSB transmitted by the second network device), the terminal device can distinguish between the SSBs transmitted by the first network device and the SSBs transmitted by the second network device based on the signal transmission time difference, and generate measurement results based on the signal quality of the different SSBs. The measurement results are then sent to the first network device.

[0243] After receiving the measurement result, the first network device can send first information to the terminal device based on the measurement result. For example, the first network device can determine whether to switch to the second network device based on the measurement result. For instance, if the signal quality of the SSB corresponding to the second network device is greater than a threshold, it can be determined that the terminal device can switch to the second network device.

[0244] In this embodiment, the first network device and the second network device can use the same SSB. The terminal device can then distinguish which network device the SSB originates from based on the signal transmission time difference between the first and second network devices, thereby determining the quality of the SSB from different network devices. Reusing a limited SSB index can avoid impacting other cells.

[0245] In one possible implementation, the SSB index corresponding to the first network device is different from the SSB index corresponding to the second network device. The terminal device measures the SSBs sent by the first and second network devices, and triggers the first network device to send a handover indication (i.e., first information) based on the measurement result. For example, this could be:

[0246] The terminal device can send measurement results to the first network device. The measurement results are obtained based on the SSB index corresponding to the first network device and the SSB index corresponding to the second network device.

[0247] Specifically, the terminal device can measure the signal quality of SSBs transmitted by the first network device and one or more candidate network devices. Since the first and second network devices sample different SSBs—that is, the SSB index of the SSB transmitted by the first network device is different from the SSB index of the SSB transmitted by the second network device—the terminal device can distinguish between the SSBs transmitted by the first and second network devices based on the received SSB index, and generate a measurement result based on the signal quality of the different SSBs. The measurement result is then sent to the first network device.

[0248] The SSB index of the TCI state configured in the terminal device may change. In one possible implementation, the first information is further used to indicate a first SSB index, which is different from the SSB index in the TCI state, and the first SSB index is used to update the SSB in the TCI state. In this case, the method further includes: the terminal device can update the SSB index in the TCI state according to the first SSB index.

[0249] For example, the first information also indicates the identifier of the TCI state corresponding to the first SSB index. The terminal device can determine the TCI state corresponding to the first SSB index from multiple TCI states and update the SSB index in the TCI state to the first SSB index.

[0250] In one possible implementation, if the first network device and the second network device sample the same SSB, then the first SSB index can be used to update the SSB index in the corresponding TCI state. For example, if the TCI state includes one SSB index corresponding to the first network device and the second network device respectively, then the terminal device can update that SSB index to the first SSB index. If the TCI state includes two SSB indices corresponding to the first network device and the second network device respectively, then the terminal device can update both SSB indices to the first SSB index.

[0251] In one possible implementation, if the first network device and the second network device sample different SSBs, the first information is further used to indicate the network device corresponding to the first SSB index. For example, the first SSB index is the index of the SSB corresponding to the second network device, and the terminal device can update the SSB index of the second network device in the corresponding TCI state to the first SSB index.

[0252] The methods provided in the embodiments of this application have been described in detail above with reference to several accompanying drawings. The apparatus provided in the embodiments of this application will now be described with reference to the accompanying drawings.

[0253] Figures 6 to 9 are schematic block diagrams of possible apparatuses provided in the embodiments of this application. These apparatuses can be used to implement the functions of the terminal device or network device in the above method embodiments, and thus can also achieve the beneficial effects of the above method embodiments.

[0254] Figure 6 is a schematic block diagram of the device provided in an embodiment of this application. As shown in Figure 6, the communication device 600 includes a transceiver unit 610.

[0255] One possible design is that the communication device 600 is used to implement the functions of the terminal device in the above method embodiments. For example, the communication device 600 may correspond to the terminal device in FIG4.

[0256] For example, the transceiver unit 610 is used for:

[0257] Receive configuration information, which indicates the TCI status, and a first network device and one or more candidate network devices associated with the TCI status; receive first information sent by the first network device, which indicates a switch to a second network device, which belongs to one or more candidate network devices; and receive downlink reference signals and data from the second network device according to the TCI status.

[0258] In one possible implementation, the TCI state can be configured with an SSB index corresponding to the first network device and an SSB index corresponding to the second network device.

[0259] In one possible implementation, the SSB index corresponding to the first network device is the same as the SSB index corresponding to the second network device. The transceiver unit is also used for:

[0260] The system receives second information sent by the first network device, which indicates the signal transmission time difference between the SSB sent by the first network device and the SSB sent by the second network device.

[0261] The measurement results are sent to the first network device to determine whether to switch to the second network device. The measurement results are obtained based on the signal transmission time difference.

[0262] In one possible implementation, the SSB index corresponding to the first network device is different from the SSB index corresponding to the second network device; the transceiver unit is also used for:

[0263] The measurement results are sent to the first network device, and the measurement results are obtained based on the SSB index corresponding to the first network device and the SSB index corresponding to the second network device.

[0264] In one possible implementation, the first information is also used to indicate random access information, which is used for uplink synchronization with the second network device.

[0265] In one possible implementation, the random access information includes timed adjustment instructions.

[0266] In one possible implementation, the first information is also used to indicate a downlink offset, which is used for downlink synchronization with the second network device.

[0267] In one possible implementation, the first information is also used to indicate the measurement gap (GAP), which is used to characterize the switch to the second network device within the GAP.

[0268] In one possible implementation, the first information is also used to indicate a first moment, which characterizes the latest time to switch to the second network device.

[0269] In one possible implementation, the first information is also used to indicate a second time and a first duration, the second time and the first duration being used to characterize the switching to a second network device within a first time period, the start time of the first time period being the second time, and the duration of the first time period being the first duration.

[0270] In one possible implementation, the first information is carried in any of the following signaling methods:

[0271] Physical Downlink Control Channel (PDCCH) commands;

[0272] Media access control - control element MAC-CE.

[0273] In one possible implementation, the first information is carried on the MAC-CE and is also used to indicate the ephemeris data of the second network device, which is used for uplink synchronization with the second network device.

[0274] In one possible implementation, the first information is also used to indicate a first SSB index, which is different from the SSB index in the TCI state; the first SSB index is used to update the SSB index in the TCI state.

[0275] A more detailed description of the transceiver module 610 can be obtained directly from the relevant descriptions in the above method embodiments, and will not be repeated here.

[0276] Figure 7 is a schematic diagram of the structure of a communication device provided in an embodiment of this application. As shown in Figure 7, the device 700 includes a transceiver unit 710.

[0277] In one possible implementation, device 700 is used to implement the function of the first network device in the above method embodiments. For example, device 700 may correspond to the first network device in FIG4.

[0278] In one possible implementation, the communication device 700 may include a transceiver unit 710 for sending configuration information to a terminal device, the configuration information indicating the TCI status, and a first network device and one or more candidate network devices associated with the TCI status; and sending first information to the terminal device, the first information indicating a switch to a second network device, the second network device belonging to one or more candidate network devices.

[0279] In one possible implementation, the TCI state includes the SSB index corresponding to the first network device and the SSB index corresponding to the second network device.

[0280] In one possible implementation, the SSB index corresponding to the first network device is the same as the SSB index corresponding to the second network device; the transceiver unit is further configured to:

[0281] Send a second message to the terminal device, the second message being used to indicate the signal transmission time difference between the SSB sent by the first network device and the SSB sent by the second network device.

[0282] One possible design is that the transceiver unit is specifically used for:

[0283] The measurement results are received from the terminal device. The measurement results are obtained by the terminal device measuring the SSB sent by the first network device and the SSB sent by the second network device.

[0284] Based on the measurement results, the first information is sent to the terminal device.

[0285] In one possible implementation, the first information is also used to indicate random access information, which is used for uplink synchronization with the second network device.

[0286] In one possible implementation, the random access information includes timed adjustment instructions.

[0287] In one possible implementation, the first information is also used to indicate a downlink offset, which is used for downlink synchronization with the second network device.

[0288] In one possible implementation, the first information is also used to indicate the measurement gap (GAP), which is used to characterize the switch to the second network device within the GAP.

[0289] In one possible implementation, the first information is also used to indicate a first moment, which characterizes the latest time to switch to the second network device.

[0290] In one possible implementation, the first information is also used to indicate a second time and a first duration, the second time and the first duration being used to characterize the switching to a second network device within a first time period, the start time of the first time period being the second time, and the duration of the first time period being the first duration.

[0291] In one possible implementation, the first information is carried in any of the following signaling methods:

[0292] Physical Downlink Control Channel (PDCCH) commands;

[0293] Media access control - control element MAC-CE.

[0294] In one possible implementation, the first information is carried on the MAC-CE and is also used to indicate the ephemeris data of the second network device, which is used for uplink synchronization with the second network device.

[0295] In one possible implementation, the first information is also used to indicate a first SSB index, which is different from the SSB index in the TCI state; the first SSB index is used to update the SSB index in the TCI state.

[0296] A more detailed description of the transceiver module 710 can be obtained directly from the relevant descriptions in the above method embodiments, and will not be repeated here.

[0297] It is understood that the division of units in the above-described device is merely a logical functional division. Each function can correspond to a functional unit, or two or more functions can be integrated into one functional unit. In actual implementation, all or some units can be integrated into a single physical entity, or they can be distributed across different physical entities. Furthermore, the aforementioned functional units can be implemented in hardware, software, or a combination of both. Whether a function is executed in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0298] Figure 8 is another schematic block diagram of the communication device provided in an embodiment of this application. As shown in Figure 8, the communication device 800 includes one or more processors 810. The processor 810 can be a general-purpose processor or a dedicated processor, etc. For example, it can be a baseband processor or a central processing unit. The baseband processor can be used to process communication protocols and communication data, and the central processing unit can be used to control the device (e.g., a vehicle or a chip), execute software programs, and process data from the software programs.

[0299] Optionally, in one design, processor 810 may include a computer program (also referred to as code or instructions) that can be run on processor 810, causing device 800 to perform the methods executed by the terminal device or network device in the above method embodiments. In yet another possible design, device 800 includes circuitry (not shown in FIG8) for implementing the functions of the terminal device or network device in the above method embodiments.

[0300] For example, processor 810 can be used to execute a computer program in memory to implement the steps performed by the terminal device or network device in the method embodiment shown in FIG4 or FIG5.

[0301] Optionally, the communication device 800 may include one or more memories 820 storing computer programs (sometimes referred to as code or instructions) that can be run on the processor 810, causing the communication device 800 to perform the methods performed by the terminal device or network device in the above embodiments.

[0302] Optionally, the processor 810 and / or memory 820 may also store data. The processor and memory may be configured separately or integrated together.

[0303] Optionally, the communication device 800 may further include a communication interface 830. The processor 810, sometimes referred to as a processing unit, controls the device (e.g., a terminal device or a network device). The communication interface 830, sometimes referred to as a transceiver unit, transceiver, transceiver circuit, or transceiver, is used to implement the device's transceiver functions; for example, the communication interface 830 can be used to receive first configuration information.

[0304] Optionally, the communication device 800 also includes a communication interface 830. The processor 810 and the communication interface 830 are coupled to each other. It is understood that the communication interface 830 can be a transceiver or an input / output interface.

[0305] When the communication device 800 is used to implement the method shown in FIG3 or FIG5, the processor 810 can be used to execute the functions of the processing unit 620, and the communication interface 830 can be used to execute the functions of the transceiver unit 610. Whether the communication interface 830 is used for sending or receiving depends on whether the device 800 is used to perform a sending or receiving action in the scheme it is executing.

[0306] When the communication device 800 is a chip applied to a terminal, the chip implements the functions of the terminal device in the above method embodiments. The chip of the terminal device receives signals from other modules (such as radio frequency modules or antennas) in the terminal device, and these signals may be sent to the terminal device by the network device; or, the chip of the terminal device sends signals to other modules (such as radio frequency modules or antennas) in the terminal device, and these signals may be sent to the network device by the terminal.

[0307] When the communication device 800 is a chip applied to a network device, the chip implements the functions of the network device in the above method embodiments. The chip of the network device receives signals from other modules in the network device, which may be signals sent by the terminal to the network device; or, the chip of the network device sends signals to other modules in the network device, which may be signals sent by the network device to the terminal.

[0308] It is understood that when the communication device 800 is a terminal device or a network device, the communication interface 830 can be a transceiver, specifically including a transmitter and a receiver, with the transmitter used to send signals and the receiver used to receive signals. When the communication device 800 is a chip applied to a terminal device or a network device, the communication interface 830 can be an input / output circuit, wherein the input circuit can be used for receiving and the output interface can be used for sending.

[0309] Optionally, the communication device 800 also includes a power supply circuit for supplying power to the communication device 800.

[0310] Figure 9 is a schematic diagram of the terminal device provided in an embodiment of this application. As shown in Figure 9, the terminal device 900 can be applied to the system shown in Figure 1 to perform the functions of the terminal device in the method embodiment shown in Figure 4 or Figure 5. As shown, the terminal device 900 includes a processor 901 and a transceiver 902. Optionally, the terminal device 900 also includes a memory 903. The processor 901, transceiver 902, and memory 903 can communicate with each other through internal connection channels to transmit control and / or data signals. The memory 903 is used to store computer programs, and the processor 901 is used to call and run the computer programs from the memory 903 to control the transceiver 902 to transmit and receive signals. Optionally, the terminal device 900 may also include an antenna 904 for transmitting uplink data or uplink control signaling output by the transceiver 902 via wireless signals.

[0311] The processor 901 and memory 903 can be combined into a single processing device. The processor 901 executes the program code stored in memory 903 to achieve the aforementioned functions. In specific implementations, memory 903 can be integrated into processor 901 or independent of processor 901. The processor 901 can correspond to the processing unit in FIG6 or the processor in FIG7.

[0312] The transceiver 902 described above can correspond to the transceiver unit in Figure 6 or the communication interface in Figure 7. The transceiver 902 may include a receiver (or receiver circuit) and a transmitter (or transmitter circuit). The receiver is used to receive signals, and the transmitter is used to transmit signals.

[0313] It should be understood that the terminal device 900 shown in FIG9 can implement the various processes involving the terminal device in the method embodiments shown in FIG3 or FIG5. The operation and / or function of each module in the terminal device 900 are respectively for implementing the corresponding processes in the above method embodiments. For details, please refer to the description in the above method embodiments; to avoid repetition, detailed descriptions are appropriately omitted here.

[0314] The processor 901 described above can be used to execute the actions implemented internally by the terminal device as described in the preceding method embodiments, while the transceiver 902 can be used to execute the actions described in the preceding method embodiments whereby the network device sends data to the terminal or the terminal receives data from the network device. For details, please refer to the descriptions in the preceding method embodiments; they will not be repeated here.

[0315] Optionally, the terminal device 900 may further include a power supply 905 for providing power to various devices or circuits in the terminal.

[0316] In addition, to make the terminal more functional, the terminal device 900 may also include one or more of the following: an input unit 906, a display unit 907, an audio circuit 908, a camera 909, and a sensor 910. The audio circuit may also include a speaker 908a, a microphone 908b, etc.

[0317] It should be noted that the above method embodiments can be applied to a processor, or implemented by a processor. A processor may be an integrated circuit chip with signal processing capabilities. During implementation, each step of the above method embodiments can be completed by integrated logic circuits in the processor's hardware or by software instructions.

[0318] The aforementioned processor can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or any combination thereof. A general-purpose processor can be a microprocessor or any conventional processor.

[0319] The steps of the method disclosed in the embodiments of this application can be directly manifested as being executed by a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor. The software modules can reside in mature storage media in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, or registers. This storage medium is located in memory, and the processor reads information from the memory and, in conjunction with its hardware, completes the steps of the above method.

[0320] The memory in the embodiments of this application can be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. The volatile memory can be random access memory (RAM), which is used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous linked dynamic random access memory (SLDRAM), and direct rambus RAM (DR RAM). It should be noted that the memory used in the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0321] This application also provides a chip system including at least one processor for supporting the implementation of the functions of the terminal device or network device involved in any of the above method embodiments, such as receiving, sending, or processing information involved in the above methods.

[0322] In one possible design, the chip system also includes a memory for storing computer program instructions and data, which may be located inside or outside the processor.

[0323] The chip system can consist of chips or include chips and other discrete components.

[0324] This application also provides a computer program product, which includes a computer program (also referred to as code or instructions), wherein when the computer program is run, the method executed by the terminal in the above method embodiments is executed, or the method executed by the network device is executed.

[0325] This application also provides a computer-readable storage medium storing a computer program (also referred to as code or instructions). When the computer program is run, the method executed by the terminal in the above method embodiments is executed, or the method executed by the network device is executed.

[0326] This application also provides a communication system, which includes the aforementioned terminal and network device.

[0327] The methods provided in the above embodiments can be implemented, in whole or in part, by software, hardware, firmware, or any combination thereof. When implemented in software, they can be implemented, in whole or in part, in the form of a computer program product. This computer program product may include one or more computer instructions. When these computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium may be any available medium accessible to a computer or a data storage device such as a server or data center that integrates one or more available media. The available medium may be a magnetic medium (e.g., floppy disk, hard disk, magnetic disk), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid-state disk (SSD)).

[0328] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0329] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0330] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0331] The unit described as a separate component may or may not be physically separate. The component shown as a unit may or may not be a physical unit; that is, it may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0332] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0333] If this function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, or part of it, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory, random access memory, magnetic disks, or optical disks.

Claims

1. A communication method, characterized in that, The method includes: Receive configuration information, which indicates the TCI status, and the first network device and one or more candidate network devices associated with the TCI status; Receive first information sent by a first network device, the first information being used to indicate switching to a second network device, the second network device belonging to the one or more candidate network devices; Receive downlink reference signals and data from the second network device according to the TCI status.

2. The method as described in claim 1, characterized in that, The TCI status includes the SSB index corresponding to the first network device and the SSB index corresponding to the second network device.

3. The method as described in claim 2, characterized in that, The SSB index corresponding to the first network device is the same as the SSB index corresponding to the second network device; The method further includes: Receive second information sent by the first network device, the second information being used to indicate the signal transmission time difference between the SSB sent by the first network device and the SSB sent by the second network device; The measurement result is sent to the first network device to determine whether to switch to the second network device. The measurement result is obtained based on the signal transmission time difference.

4. The method as described in claim 2, characterized in that, The SSB index corresponding to the first network device is different from the SSB index corresponding to the second network device; The method further includes: The measurement result is sent to the first network device, and the measurement result is obtained based on the SSB index corresponding to the first network device and the SSB index corresponding to the second network device.

5. A communication method, characterized in that, Applied to a first network device, the method includes: Send configuration information to the terminal device, the configuration information being used to indicate the TCI status, and the first network device and one or more candidate network devices associated with the TCI status; Send first information to the terminal device, the first information being used to instruct switching to a second network device, the second network device being one or more candidate network devices.

6. The method as described in claim 5, characterized in that, The TCI status includes the SSB index corresponding to the first network device and the SSB index corresponding to the second network device.

7. The method as described in claim 6, characterized in that, The SSB index corresponding to the first network device is the same as the SSB index corresponding to the second network device; The method further includes: Send a second message to the terminal device, the second message being used to indicate the signal transmission time difference between the SSB sent by the first network device and the SSB sent by the second network device.

8. The method according to any one of claims 5-7, characterized in that, Sending the first information to the terminal device includes: Receive measurement results from the terminal device, the measurement results being obtained by the terminal device measuring the SSB sent by the first network device and the SSB sent by the second network device; Based on the measurement results, the first information is sent to the terminal device.

9. The method according to any one of claims 1-8, characterized in that, The first information is also used to indicate random access information, which is used for uplink synchronization with the second network device.

10. The method as described in claim 9, characterized in that, The random access information includes timed adjustment instructions.

11. The method according to any one of claims 1-10, characterized in that, The first information is also used to indicate a downlink offset, which is used for downlink synchronization with the second network device.

12. The method according to any one of claims 1-11, characterized in that, The first information is also used to indicate a measurement gap (GAP), which is used to characterize a switch to the second network device within the GAP.

13. The method according to any one of claims 1-8, characterized in that, The first information is also used to indicate a first moment, which represents the latest time to switch to the second network device.

14. The method according to any one of claims 1-10, characterized in that, The first information is also used to indicate a second time and a first duration, the second time and the first duration being used to characterize the handover to the second network device within a first time period, the start time of the first time period being the second time, and the duration of the first time period being the first duration.

15. The method according to any one of claims 1-14, characterized in that, The first information is carried in any of the following signaling: Physical Downlink Control Channel (PDCCH) commands; Media access control - control element MAC-CE.

16. The method as described in claim 15, characterized in that, The first information is carried in MAC-CE, and the first information is also used to indicate the ephemeris data of the second network device, the ephemeris data being used for uplink synchronization with the second network device.

17. The method according to any one of claims 1-16, characterized in that, The first information is also used to indicate a first SSB index, which is different from the SSB index in the TCI state; the first SSB index is used to update the SSB index in the TCI state.

18. A communication device, characterized in that, Includes a transceiver unit, used for: Receive configuration information, which indicates the TCI status, and the first network device and one or more candidate network devices associated with the TCI status; Receive first information sent by a first network device, the first information being used to indicate switching to a second network device, the second network device belonging to the one or more candidate network devices; Receive downlink reference signals and data from the second network device according to the TCI status.

19. The apparatus as claimed in claim 18, characterized in that, The TCI status includes the SSB index corresponding to the first network device and the SSB index corresponding to the second network device.

20. The apparatus as claimed in claim 19, characterized in that, The SSB index corresponding to the first network device is the same as the SSB index corresponding to the second network device; the transceiver unit is further configured to: Receive second information sent by the first network device, the second information being used to indicate the signal transmission time difference between the SSB sent by the first network device and the SSB sent by the second network device; The measurement result is sent to the first network device to determine whether to switch to the second network device. The measurement result is obtained based on the signal transmission time difference.

21. The apparatus as claimed in claim 19, characterized in that, The SSB index corresponding to the first network device is different from the SSB index corresponding to the second network device; the transceiver unit is further configured to: The measurement result is sent to the first network device, and the measurement result is obtained based on the SSB index corresponding to the first network device and the SSB index corresponding to the second network device.

22. A communication device, characterized in that, include: Transceiver unit, used for: Send configuration information to the terminal device, the configuration information being used to indicate the TCI status, and the first network device and one or more candidate network devices associated with the TCI status; Send first information to the terminal device, the first information being used to instruct switching to a second network device, the second network device being one or more candidate network devices.

23. The apparatus as claimed in claim 22, characterized in that, The TCI status includes the SSB index corresponding to the first network device and the SSB index corresponding to the second network device.

24. The apparatus as claimed in claim 23, characterized in that, The SSB index corresponding to the first network device is the same as the SSB index corresponding to the second network device; the transceiver unit is further configured to: Send a second message to the terminal device, the second message being used to indicate the signal transmission time difference between the SSB sent by the first network device and the SSB sent by the second network device.

25. The apparatus according to any one of claims 22-24, characterized in that, The transceiver unit is specifically used for: Receive measurement results from the terminal device, the measurement results being obtained by the terminal device measuring the SSB sent by the first network device and the SSB sent by the second network device; Based on the measurement results, the first information is sent to the terminal device.

26. The apparatus according to any one of claims 18-25, characterized in that, The first information is also used to indicate random access information, which is used for uplink synchronization with the second network device.

27. The apparatus as claimed in claim 26, characterized in that, The random access information includes timed adjustment instructions.

28. The apparatus according to any one of claims 18-27, characterized in that, The first information is also used to indicate a downlink offset, which is used for downlink synchronization with the second network device.

29. The apparatus according to any one of claims 18-28, characterized in that, The first information is also used to indicate a measurement gap (GAP), which is used to characterize a switch to the second network device within the GAP.

30. The apparatus according to any one of claims 18-25, characterized in that, The first information is also used to indicate a first moment, which represents the latest time to switch to the second network device.

31. The apparatus according to any one of claims 18-27, characterized in that, The first information is also used to indicate a second time and a first duration, the second time and the first duration being used to characterize the switching to the second network device within a first time period, the start time of the first time period being the second time, and the duration of the first time period being the first duration.

32. The apparatus according to any one of claims 18-31, characterized in that, The first information is carried in any of the following signaling: Physical Downlink Control Channel (PDCCH) commands; Media access control - control element MAC-CE.

33. The apparatus as claimed in claim 32, characterized in that, The first information is carried in MAC-CE, and the first information is also used to indicate the ephemeris data of the second network device, the ephemeris data being used for uplink synchronization with the second network device.

34. The apparatus according to any one of claims 18-33, characterized in that, The first information is also used to indicate a first SSB index, which is different from the SSB index in the TCI state; the first SSB index is used to update the SSB index in the TCI state.

35. A communication device, characterized in that, It includes one or more processors, said one or more processors being configured to execute computer programs or instructions in memory, causing the communication device to perform the method as described in any one of claims 1 to 17.

36. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it causes the method described in any one of claims 1 to 17 to be performed.

37. A computer program product, characterized in that, Includes a computer program, which, when run, causes the method as described in any one of claims 1 to 17 to be performed.

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