Communication method, communication device, storage medium, communication system, and chip system

Abstract

The application provides a communication method, a communication device, a storage medium, a communication system and a chip system. The method comprises the following steps: a terminal device determines a target time point as a cut-off time point of an SMTC window validity according to one or more of the following: a Doppler shift, a visibility window, a transmission delay and a validity period of auxiliary information; selects a first SMTC window between a current time point and the target time point based on SMTC configuration information; and measures a reference signal sent by a second network device based on the first SMTC window. The application determines the latest time point for measurement by comprehensively considering multiple information affecting the reception of the reference signal, and measures the reference signal before the latest time point, so that the success rate of the reference signal measurement can be ensured, and the power consumption of the terminal device can be reduced.

Description

Technical Field

[0001] This application relates to the field of communications, and more particularly to a communication method, communication device, storage medium, communication system, and chip system. Background Technology

[0002] Measurement is fundamental to mobility management. Terminal devices can perform cell handover, cell reselection, or cell selection by measuring reference signals (such as synchronization signals or physical broadcast channel blocks, SSBs). To avoid blind measurement by terminal devices, an SSB-based measurement timing configuration (SMTC) technique is introduced. Network devices can send SMTC configuration information to terminal devices, which can then determine their SMTC window based on this information. The terminal device only needs to measure the reference signal within this SMTC window, thus avoiding blind measurement and reducing power consumption.

[0003] However, in complex communication scenarios, such as non-terrestrial network (NTN) communication scenarios, the communication between the terminal device and the NTN network device is affected by a variety of factors (such as Doppler frequency shift, visibility window, etc.). The terminal device may not be able to receive the reference signal from the NTN network device within the SMTC window, which will lead to measurement failure and is not conducive to reducing the power consumption of the terminal device. Summary of the Invention

[0004] This application provides a communication method, communication device, storage medium, communication system, and chip system that can reduce the power consumption of terminal devices.

[0005] Firstly, a communication method is provided. This method can be executed by a terminal device, or by a component (such as a circuit, chip, or chip system) configured in the terminal device, or by a logic module or software capable of implementing all or part of the functions of the terminal device. This application does not limit this approach. The following description uses a terminal device as an example.

[0006] The method includes: receiving SMTC configuration information from a first network device, the SMTC configuration information being used to determine the position of an SMTC window; determining a target time based on first information, the target time being the expiration time of the SMTC window, the first information including one or more of the following: Doppler frequency shift information for a second network device, transmission delay between the terminal device and the second network device, expiration time of the visibility window of the second network device, and validity period of auxiliary information of the second network device, the second network device being a non-terrestrial network device; determining a first SMTC window within a time period between the current time and the target time based on the SMTC configuration information; and measuring a reference signal transmitted by the second network device based on the first SMTC window.

[0007] This application embodiment determines the latest time (i.e., the target time) for measurement based on information affecting reference signal reception (i.e., the first information). The time period before the target time is the validity period of the SMTC window. After the target time, the terminal device may not be able to successfully receive the reference signal from the second network device. Therefore, the terminal device can determine an SMTC window (i.e., the first SMTC window) before the target time and measure the reference signal from the second network device based on the first SMTC window. Since the first SMTC window is located before the target time, the terminal device can theoretically maintain good communication with the second network device within the first SMTC window. That is, the terminal device can successfully receive the reference signal sent by the network device based on the first SMTC window, thereby improving the success rate of signal measurement and reducing the power consumption of the terminal device.

[0008] In some implementations, determining the target time based on the first information includes: determining a first time when the Doppler frequency shift reaches a first threshold based on the Doppler frequency shift information for the second network device; determining a second time when the transmission delay reaches a second threshold based on the transmission delay between the terminal device and the second network device; determining a third time, which is the cutoff time of the visibility window of the second network device; determining a fourth time based on the validity period of the auxiliary information, which is the end time of the validity period; and determining the minimum value among the first time, the second time, the third time, and the fourth time as the target time.

[0009] By determining the latest reception time corresponding to each of the four factors mentioned above, and selecting the time with the smallest value as the target time, it can be ensured that before the target time, the Doppler shift and transmission delay will not exceed the tolerance range of the terminal device, the second network device is visible to the terminal device, and the auxiliary information of the second network device is still valid. The first SMTC window determined before the target time can ensure that the terminal device can receive and parse the reference signal from the second network device within the first SMTC window, thereby reducing the number of invalid measurements and reducing the power consumption of the terminal device.

[0010] In some implementations, the first SMTC window satisfies one or more of the following conditions: it is located within the DRX activation period of the terminal device; it at least partially overlaps with the DRX activation period of the terminal device; or it belongs to the first SMTC window after the current moment. The terminal device can select the first SMTC window based on the above conditions, thereby providing a clear scheme for the selection of the first SMTC window and simplifying the operation of the terminal device.

[0011] In some implementations, determining the first SMTC window includes: if a second SMTC window exists within the time period between the current time and the target time, then the second SMTC window is determined as the first SMTC window; if no second SMTC window exists within the time period between the current time and the target time, then the first SMTC window after the current time is determined as the first SMTC window; wherein the second SMTC window is located within the DRX activation period or at least partially overlaps with the DRX activation period.

[0012] When selecting the first SMTC window, the terminal device can preferentially select an SMTC window that overlaps or at least partially overlaps with the DRX activation period (i.e., the second SMTC window) as the first SMTC window. This avoids multiple wake-ups of the terminal device, allowing it to complete both reference signal measurement and paging processing in a single wake-up process, thus reducing power consumption. If no second SMTC window exists between the current time and the target time, a delay-priority strategy can be used to select the SMTC window closest to the current time as the first SMTC window. This enables the terminal device to complete measurement and cell access as quickly as possible, reducing access latency.

[0013] In some implementations, the step of measuring the reference signal sent by the second network device based on the first SMTC window includes: adjusting the start time of the first SMTC window based on the transmission delay between the terminal device and the second network device to obtain a third SMTC window; and measuring the reference signal sent by the second network device within the third SMTC window.

[0014] After obtaining the first SMTC window, the terminal device can adjust the start time of the first SMTC window based on the transmission delay, so that the reference signal sent by the second network device can fall into the adjusted SMTC window (i.e. the third SMTC window), thereby improving the success rate of reference signal reception and reducing measurement overhead.

[0015] In some implementations, the SMTC configuration information is configuration information matching a first delay, where the first delay is the transmission delay between the terminal device and the second network device determined by the first network device before the current time. The step of adjusting the start time of the first SMTC window based on the transmission delay between the terminal device and the second network device to obtain a third SMTC window includes: determining the difference between the first delay and a second delay, where the second delay is the transmission delay between the terminal device and the second network device at the current time; and adjusting the start time of the first SMTC window based on the difference to obtain the third SMTC window.

[0016] In the above scheme, the first network device can obtain an estimated latency (i.e., the first latency) based on the acquired information (such as the location information of the terminal device, the auxiliary information of the second network device, etc.), and generate SMTC configuration information based on the first latency. This allows the SMTC window obtained based on the SMTC configuration information to compensate for most of the transmission latency. In this way, the terminal device only needs to fine-tune the start time of the first SMTC window based on the transmission latency difference. This can reduce the computational load of the terminal device, which is beneficial to reduce the power consumption of the terminal device and save the power of the terminal device.

[0017] In some implementations, adjusting the start time of the first SMTC window based on the difference to obtain the third SMTC window includes: if the difference is greater than or equal to a third threshold, adjusting the start time of the first SMTC window based on the difference to obtain the third SMTC window; measuring the reference signal sent by the second network device based on the first SMTC window includes: if the difference is less than the third threshold, measuring the reference signal sent by the second network device within the first SMTC window.

[0018] In the solution provided in this application embodiment, if the first network device generates SMTC configuration information based on the first delay, meaning the SMTC configuration information has already compensated for most of the delay, the terminal device can directly perform signal measurement within the first SMTC window obtained based on the SMTC configuration information when the delay difference is small (less than the third threshold), thereby reducing the computational load on the terminal device. However, when the transmission delay difference is large (greater than or equal to the third threshold), the start time of the first SMTC window is adjusted based on the transmission delay difference to ensure that the reference signal sent by the second network device falls within the adjusted SMTC window, thereby improving the success rate of reference signal reception and reducing measurement overhead. A small transmission delay difference indicates that the fluctuation range of the arrival time of the reference signal is small; a large transmission delay difference indicates that the fluctuation range of the arrival time of the reference signal is large, potentially exceeding the range of the SMTC window.

[0019] In some implementations, the method further includes: determining the wake-up time of the terminal device based on the start time of the third SMTC window and the measurement preparation time of the terminal device; and waking up the terminal device at the wake-up time. By waking up the terminal device in advance, it can be ensured that the terminal device can perform signal measurement within the third SMTC window, thereby improving the success rate of signal measurement.

[0020] In some implementations, the method further includes: receiving second information from the first network device, the second information indicating one or more of the following: a first time window, the first time window being a time range within which the terminal device performs signal measurements as determined by the first network device; a first time range, the first time range being a fluctuation range of the arrival time of a reference signal predicted by the first network device; and a first offset, indicating the range of magnitude within which the terminal device can adjust the SMTC window.

[0021] In the above scheme, the network device can also configure some additional information (such as the first time window, the first time range, and the first offset) to assist the terminal device in selecting the first SMTC window, thereby reducing the computational overhead and power consumption of the terminal device.

[0022] In some implementations, the SMTC configuration information includes the second information, and the SMTC configuration information is carried in a Radio Resource Management (RRC) connection release message.

[0023] In some implementations, the method further includes: receiving auxiliary information for the second network device from the first network device; and determining the first information based on the auxiliary information.

[0024] In some implementations, the method further includes: if the measurement result of the reference signal meets the reselection condition, then reselecting to reside in the second network device.

[0025] Secondly, a communication method is provided. This method can be executed by a first network device, or by a component (such as a circuit, chip, or chip system) configured in the first network device, or by a logic module or software capable of implementing all or part of the functions of the network device. This application does not limit this approach. The following description uses a first network device (such as an access network device) as an example.

[0026] The method includes: sending SMTC configuration information and auxiliary information of a second network device to a terminal device, wherein the second network device is a non-terrestrial network device; the SMTC configuration information is used to determine the position of the SMTC window; the auxiliary information is used to determine first information; the first information is used to determine a target time; the target time is the expiration time of the SMTC window; and a first SMTC window within the time period between the current time and the target time is used for the measurement of a reference signal; wherein the first information includes one or more of the following: Doppler frequency shift information for the second network device, transmission delay between the terminal device and the second network device, expiration time of the visibility window of the second network device, and validity period of the auxiliary information of the second network device.

[0027] In some implementations, the first SMTC window satisfies one or more of the following conditions: it is located within the DRX activation period of the terminal device; it at least partially overlaps with the DRX activation period of the terminal device; or it belongs to the first SMTC window after the current moment.

[0028] In some implementations, the method further includes: determining a first time delay between the terminal device and the second network device based on auxiliary information of the second network device and location information reported by the terminal device; and generating the SMTC configuration information based on the first time delay.

[0029] In some implementations, the method further includes: sending first indication information to the terminal device, the first indication information being used to indicate the first delay, the first delay being used by the terminal device to adjust the start time of the first SMTC window.

[0030] In some implementations, the method further includes: sending second information to the terminal device, the second information indicating one or more of the following: a first time window, the first time window being a time range within which the terminal device performs signal measurements as determined by the first network device; a first time range, the first time range being a fluctuation range of the arrival time of a reference signal predicted by the first network device; and a first offset, indicating the range of magnitude within which the terminal device can adjust the SMTC window.

[0031] In some implementations, the SMTC configuration information includes the second information, and the SMTC configuration information is carried in a Radio Resource Management (RRC) connection release message.

[0032] The second aspect is the implementation on the network device side, which corresponds to the first aspect. The explanations, supplements, and descriptions of the beneficial effects of the first aspect also apply to the second aspect, and will not be repeated here.

[0033] Thirdly, a communication device is provided, comprising a processing module and a transceiver module. The transceiver module is configured to receive SMTC configuration information from a first network device, the SMTC configuration information being used to determine the position of an SMTC window; the processing module is configured to determine a target time based on first information, the target time being the expiration time of the SMTC window, the first information including one or more of the following: Doppler frequency shift information for a second network device, transmission delay between the terminal device and the second network device, expiration time of the visibility window of the second network device, and validity period of auxiliary information of the second network device, wherein the second network device is a non-terrestrial network device; based on the SMTC configuration information, a first SMTC window is determined within a time period between the current time and the target time; and based on the first SMTC window, a reference signal transmitted by the second network device is measured.

[0034] Fourthly, a communication device is provided, comprising a transceiver module. This transceiver module is used to send SMTC configuration information and auxiliary information of a second network device (a non-terrestrial network device) to a terminal device. The SMTC configuration information is used to determine the position of an SMTC window, and the auxiliary information is used to determine first information. The first information is used to determine a target time, which is the expiration time of the SMTC window. A first SMTC window within the time interval between the current time and the target time is used for measuring a reference signal. The first information includes one or more of the following: Doppler frequency shift information for the second network device, transmission delay between the terminal device and the second network device, expiration time of the visibility window of the second network device, and validity period of the auxiliary information of the second network device. The communication device also includes a processing module for executing corresponding processing procedures.

[0035] The third and fourth aspects are the implementation on the device side, which correspond to the first and second aspects. The explanations, supplements, and descriptions of the beneficial effects of the first and second aspects also apply to the third and fourth aspects, and will not be repeated here.

[0036] Fifthly, a communication device is provided, including a processor. The processor is coupled to a memory and can be used to execute instructions or data in the memory to implement the method in any possible implementation of the first aspect described above. Optionally, the communication device further includes a memory. Optionally, the communication device further includes a communication interface, and the processor is coupled to the communication interface.

[0037] In one implementation, the communication interface may be a transceiver, or an input / output interface.

[0038] In another implementation, the communication device is a chip configured in a terminal device. When the communication device is a chip configured in a terminal device, the communication interface can be an input / output interface.

[0039] In a sixth aspect, a communication device is provided, including a processor. The processor is coupled to a memory and can be used to execute instructions or data in the memory to implement the method in any possible implementation of the second aspect described above. Optionally, the communication device further includes a memory. Optionally, the communication device further includes a communication interface, and the processor is coupled to the communication interface.

[0040] In one implementation, the communication interface may be a transceiver, or an input / output interface.

[0041] In another implementation, the communication device is a chip configured in an access network device. When the communication device is a chip configured in an access network device, the communication interface can be an input / output interface.

[0042] In a seventh aspect, a processor is provided, comprising: an input circuit, an output circuit, and a processing circuit. The processing circuit is configured to receive signals through the input circuit and transmit signals through the output circuit, causing the processor to execute a method in any possible implementation of any aspect.

[0043] In specific implementation, the processor can be one or more chips, the input circuit can be input pins, the output circuit can be output pins, and the processing circuit can be transistors, gate circuits, flip-flops, and various logic circuits. The input signal received by the input circuit can be received and input by, for example, but not limited to, a receiver, and the signal output by the output circuit can be, for example, but not limited to, output to and transmitted by a transmitter. Furthermore, the input circuit and the output circuit can be the same circuit, which is used as both the input circuit and the output circuit at different times. This application does not limit the specific implementation of the processor and various circuits.

[0044] Eighthly, a communication device is provided, including a processor and a memory. The processor is used to read instructions stored in the memory, receive signals via a receiver, and transmit signals via a transmitter to execute the method in any possible implementation of any of the preceding aspects.

[0045] Optionally, the processor may be one or more, and the memory may be one or more.

[0046] Ninthly, a computer program product is provided, the computer program product comprising: a computer program (also referred to as code or instructions) that, when the computer program is run, causes a computer to perform a method in any possible implementation of any of the above aspects.

[0047] In a tenth aspect, a computer-readable storage medium is provided that stores a computer program (also referred to as code or instructions) that, when run on a computer, causes the computer to perform the methods in any possible implementation of any of the preceding aspects.

[0048] Eleventhly, embodiments of this application provide a chip system including one or more processors for calling and executing instructions stored in memory, causing the methods in any of the above aspects or possible implementations to be executed. The chip system may be composed of chips or may include chips and other discrete devices.

[0049] The chip system may include input circuits or interfaces for transmitting information or data, and output circuits or interfaces for receiving information or data.

[0050] In a twelfth aspect, a communication system is provided, including the aforementioned terminal device and network device. Optionally, the communication system may further include other devices that communicate with the terminal device and / or network device. Attached Figure Description

[0051] Figure 1 This is a system architecture diagram of a wireless communication system to which embodiments of this application can be applied;

[0052] Figure 2 This is an architecture diagram of an NTN communication system applicable to embodiments of this application;

[0053] Figure 3 This is a schematic diagram of a DRX cycle;

[0054] Figure 4 This is a schematic diagram of an SMTC window;

[0055] Figure 5 A schematic flowchart illustrating a communication method provided in an embodiment of this application;

[0056] Figure 6 A schematic diagram of an effective SMTC window provided in an embodiment of this application;

[0057] Figure 7 A schematic diagram illustrating the determination of the first SMTC window based on the DRX activation period, provided for an embodiment of this application;

[0058] Figure 8 A schematic diagram illustrating another method for determining the first SMTC window based on the DRX activation period, provided for an embodiment of this application;

[0059] Figure 9 A schematic diagram illustrating another method for determining the first SMTC window based on the DRX activation period, provided as an embodiment of this application;

[0060] Figure 10 A schematic flowchart illustrating cell reselection by a terminal device, provided as an embodiment of this application;

[0061] Figure 11 A schematic flowchart illustrating cell redirection for a terminal device provided in an embodiment of this application;

[0062] Figure 12 A schematic block diagram of a communication device provided in an embodiment of this application;

[0063] Figure 13 This is a schematic diagram of the structure of a communication device provided in an embodiment of this application. Detailed Implementation

[0064] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

[0065] The technical solutions provided in this application can be applied to various communication systems, such as: Global System for Mobile Communications (GSM) systems, General Packet Radio Service (GPRS), Wireless Local Area Network (WLAN), Long Term Evolution (LTE) systems, LTE Frequency Division Duplex (FDD) systems, LTE Time Division Duplex (TDD) systems, sidelink communication systems, Universal Mobile Telecommunication System (UMTS), Worldwide Interoperability for Microwave Access (WiMAX) communication systems, non-terrestrial network (NTN) communication systems, 5th generation (5G) mobile communication systems, or new radio access technology (NR). 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. This application does not limit the scope of these applications.

[0066] Figure 1 This is a schematic diagram of a communication system 100 used in an embodiment of this application. The communication system 100 may include network devices, such as... Figure 1 The network device 110 is shown. The communication system 100 may also include terminal devices, such as... Figure 1 The terminal device 120 shown. The network device 110 and the terminal device 120 can communicate via a wireless link.

[0067] Figure 1 An exemplary network device 110 and a terminal device 120 are shown. Optionally, the communication system 100 may also include multiple network devices and / or multiple terminal devices.

[0068] The network equipment in this application can be network-side equipment such as access network equipment and core network equipment. Access network equipment is sometimes also called access node. Access network equipment has wireless transceiver capabilities and is used to communicate with terminals. Access network equipment includes, but is not limited to, base stations, evolved NodeBs (eNodeBs), transmission reception points (TRPs) in the above-mentioned communication systems, next-generation NodeBs (gNBs) in 5G mobile communication systems, access network equipment or modules of access network equipment in open RAN (ORAN) systems, satellites in NTN communication systems, base stations in future mobile communication systems, or access nodes in WiFi systems. Access network equipment can also be modules or units that can implement some of the functions of a base station. Access network equipment can be macro base stations, micro base stations or indoor stations, relay nodes or donor nodes, or wireless controllers in cloud radioaccess network (CRAN) scenarios. Optionally, access network equipment can also be servers, wearable devices, or vehicle-mounted equipment, etc. For example, the access network equipment in vehicle-to-everything (V2X) technology can be a roadside unit (RSU). Multiple access network devices in a communication system can be base stations of the same type or different types. Base stations can communicate with terminals directly or via relay stations. Terminals can communicate with multiple base stations using different access technologies. The embodiments of this application do not limit the specific technology or device form used in the access network equipment. In this application, the access network equipment is referred to as a network device.

[0069] In this application, the means for implementing the functions of a network device can be a network device itself, or a means capable of supporting the network device in implementing those functions, such as a processor, circuit, chip, or chip system. This means can be installed in or connected to the network device. In the technical solutions provided in this application, the example of a network device being used to implement the functions of a network device is used to describe the technical solutions provided in this application.

[0070] The terminal device in this application can be a wireless terminal device capable of receiving network device scheduling and instruction information. The wireless terminal device can be a device providing voice and / or data connectivity to a user, a handheld device with wireless connectivity, or other processing devices connected to a wireless modem. For example, the terminal device can communicate with one or more core networks or the Internet via a radio access network (RAN). The terminal device can also be referred to as a terminal, user equipment (UE), mobile station, mobile terminal, etc. Terminal devices can be widely used in various scenarios, such as device-to-device (D2D), vehicle-to-everything (V2X) communication, machine-type communication (MTC), Internet of Things (IoT), ultra-reliable low-latency communication (URLLC), virtual reality, augmented reality, industrial control, autonomous driving, telemedicine, smart grids, smart furniture, smart offices, smart wearables, smart transportation, smart cities, or satellite communication, etc. The terminal can be a mobile phone, tablet computer, computer with wireless transceiver capabilities, wearable device, vehicle, aircraft (such as drone, helicopter, airplane), hot air balloon, ship, robot, robotic arm, or smart home device, etc. The embodiments of this application do not limit the form of the terminal device.

[0071] In this application, the apparatus for implementing the functions of a terminal device can be the terminal device itself, or any apparatus capable of supporting the terminal device in implementing those functions, such as a processor, circuit, chip, or chip system. This apparatus can be installed in or connected to the terminal device. In the technical solutions provided in this application, the example of a terminal device being used to implement the functions of a terminal device is used to describe the technical solutions provided in this application.

[0072] Access network devices and / or terminals can be fixed or mobile. They can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; on water; or in the air on aircraft, balloons, and satellites. This application does not limit the application scenarios of the access network devices and terminals. Access network devices and terminal devices can be deployed in the same or different scenarios; for example, both can be deployed on land; or the access network device can be deployed on land, and the terminal device on water, etc., and so on.

[0073] In practical applications, multiple network devices can collaborate to assist terminals in achieving wireless access, with different network devices each implementing a portion of the base station's functions. For example, network devices can be central units (CUs), distributed units (DUs), CUs (control planes, CPs), CUs (user planes, UPs), or radio units (RUs), etc. CUs and DUs can be set up separately or included in the same network element, such as a baseband unit (BBU). RUs can be included in radio frequency equipment or radio frequency units, such as remote radio units (RRUs), active antenna units (AAUs), or remote radio heads (RRHs).

[0074] In different systems, CU (or CU-CP and CU-UP), DU, or RU may have different names, but those skilled in the art will understand their meaning. For example, in an ORAN system, CU can also be called O-CU (Open CU), DU can also be called O-DU, CU-CP can also be called O-CU-CP, CU-UP can also be called O-CU-UP, and RU can also be called O-RU. Any of the units among CU (or CU-CP, CU-UP), DU, and RU in this application can be implemented through software modules, hardware modules, or a combination of software and hardware modules. CU (or CU-CP and CU-UP), DU, and RU can implement different protocol layer functions.

[0075] To facilitate understanding of the embodiments of this application, the terminology used in this application will be briefly explained first. Optionally, the explanation of some terms may also refer to the explanations in the 3rd Generation Partnership Project (3GPP) standard protocol.

[0076] 1. NTN communication system

[0077] To achieve ubiquitous communication services, 3GPP, in Release 17, designated satellite communication as an important supplement to terrestrial 5G cellular mobile communication networks, namely the NTN communication system. The NTN communication system is described below.

[0078] NTN communication systems provide communication services to users using non-terrestrial methods. These non-terrestrial methods may include, for example, satellite or unmanned aircraft system (UAS) platforms.

[0079] For terrestrial network communication, it's impossible to deploy communication equipment in scenarios like oceans, mountains, and deserts. Alternatively, considering the costs of setting up and operating communication equipment, terrestrial communication typically doesn't cover sparsely populated areas. Compared to terrestrial network (TN) communication, NTN has many advantages. First, NTN communication is not limited by user location. Theoretically, satellites can orbit the Earth, so every corner of the globe can be covered by satellite communication. Furthermore, the area covered by NTN equipment is far larger than that covered by terrestrial communication equipment. For example, a single satellite can cover a large ground area. Second, NTN communication has significant social value. NTN communication can achieve coverage at a lower cost; for example, satellite communication can reach remote mountainous areas or impoverished countries or regions at a lower cost. This allows people in these areas to enjoy advanced voice communication and mobile internet technologies, helping to narrow the digital divide with developed regions and promoting development in these areas. Third, NTN communication has a long communication distance without significantly increasing communication costs. Additionally, NTN communication is highly stable. For example, NTN communication is not limited by natural conditions and can be used even in the event of a natural disaster.

[0080] Based on their orbital altitude, communication satellites can be classified into low-earth orbit (LEO) satellites, medium-earth orbit (MEO) satellites, geostationary earthorbit (GEO) satellites, and highly elliptical orbit (HEO) satellites. Geostationary orbit satellites are also called geostationary orbit satellites.

[0081] To ensure satellite coverage and enhance the overall capacity of the satellite communication system, satellites can employ multi-beam coverage, meaning multiple beam footprints can form the satellite's coverage area. For example, a single satellite can generate dozens or even hundreds of beams to cover the ground. A single satellite beam can cover a ground area with a diameter of tens to hundreds of kilometers.

[0082] Figure 2 This is an architecture diagram of an NTN communication system provided in an embodiment of this application. See also... Figure 2 An NTN communication system may include a terrestrial NTN gateway, a satellite, and terminal equipment. The terrestrial NTN gateway may include a base station. The link between the satellite and the terminal equipment is a service link, and the link between the NTN gateway and the satellite is a feeder link. Depending on the satellite's method of processing wireless signals, the NTN communication system may include two scenarios: transparent forwarding and regenerative forwarding. Figure 2 This illustrates a communication scenario with transparent forwarding.

[0083] The gateway for a satellite may change depending on its location. Figure 2 For example, when the satellite is at position 2, the corresponding gateway is gateway 2, and the satellite can communicate with the terminal device through gateway 2; when the satellite moves to position 1, the corresponding gateway is gateway 1, and the satellite can communicate with the terminal device through gateway 1.

[0084] 2. Discontinuous reception (DRX)

[0085] To reduce terminal power consumption, some communication systems (such as LTE and NR systems) have introduced the DRX mechanism. This allows the terminal to enter a discontinuous reception state when there is no data reception, such as periodically entering sleep mode at certain times, thus saving power. A DRX cycle includes an "on duration" and an "opportunity for DRX," such as... Figure 3 As shown. During the active period, the terminal device monitors and receives downlink channels and signals. During the inactive period, the terminal device does not receive downlink channels and signals to reduce power consumption. The active period can also be called the wake-up period, and the inactive period can also be called the sleep period.

[0086] 3. Radio Resource Control (RRC) Status

[0087] Currently, the protocol defines three RRC states for terminal devices: RRC connected (RRC_CONNECTED) state, RRC idle (RRC-IDLE) state, and RRC inactive (RRC-INACTIVE) state.

[0088] Mobility management ensures that communication links between network devices and terminal devices are not interrupted due to the movement of terminal devices. Depending on the terminal device's state, mobility management can include RRC idle-state mobility management and RRC connected-state mobility management. In RRC idle state, mobility management mainly includes cell selection and cell reselection. In RRC connected state or RRC inactive state, mobility management mainly includes cell handover. Whether it's cell selection, cell reselection, or cell handover, it's all based on measurement results. Therefore, measurement is the foundation of mobility management.

[0089] Terminal devices can measure reference signals sent by network devices to obtain measurement results, which can be used for mobility management. For terminal devices in RRC connected or RRC inactive states, the terminal devices can report the measurement results to the network devices, which can then control the terminal devices to perform cell handover based on the measurement results. For terminal devices in RRC idle states, the terminal devices can perform cell selection or cell reselection based on the measurement results.

[0090] The reference signal may include one or more of the following: SSB, channel-state-information reference signal (CSI-RS), and demodulation reference signal (DMRS). Measurement results may include one or more of the following: reference signal receiving power (RSRP), reference signal receiving quality (RSRQ), and signal-to-interference plus noise ratio (SINR).

[0091] 4. SMTC Configuration

[0092] For SSB measurements, due to equipment complexity and size limitations, terminal devices typically only have one RF module. To reduce measurement overhead, SMTC configuration is introduced. SMTC configuration defines the time window for SSB measurements performed by the terminal device. The terminal device only needs to perform SSB measurements within this time window to avoid measurement blindness and reduce power consumption.

[0093] Network devices can send SMTC configuration information to terminal devices. This SMTC configuration information may include the SMTC window period, SMTC window duration, and offset. Terminal devices can determine the start position, period, and duration of the SMTC window based on these three parameters, and measure the SSBs sent by the network device within the SMTC window. Network devices can generate SMTC configuration information based on a propagation delay of 0. Figure 4 This shows the position of a periodic SMTC window.

[0094] The period of the SMTC window can be 5, 10, 20, 40, 80 or 160 subframes, and the duration of the SMTC window can be 1, 2, 3, 4 or 5 subframes.

[0095] In terrestrial networks, the relative temporal positions of SSBs transmitted by the serving cell and neighboring cells are fixed. The propagation delay within the cell depends on the cell radius and the location of the terminal equipment. Because terrestrial network cells have small radii, the propagation delay is extremely small; even with a cell radius of 100km, the propagation delay is less than 0.5ms. From the perspective of the terminal equipment, the propagation delay variation is minimal, caused only by the movement of the terminal equipment, and traditional SMTC configurations are sufficient.

[0096] Currently, the LTE to NR NTN mobility project in 3GPP RAN2 Rel-19 mainly studies the lack of mobility management support between the LTE terrestrial network (TN) and NR NTN in RRC idle mode, aiming to achieve seamless connectivity for terminal devices from LTE TN to NR NTN. In idle mode, terminal devices can read system information blocks broadcast by network devices to obtain relevant cell selection configuration information and satellite-aided information. The terminal devices perform cell measurements based on the configuration information and determine the selected or reselected cell in the measurement report. Therefore, measurement is the first step in mobility management, and effective measurement is crucial for 5G NTN mobility management. Satellite-aided information can include one or more of the following: satellite ephemeris information, satellite clock, ephemeris validity period, and propagation delay compensation value. Ephemeris information includes satellite orbit information, velocity information, and position information. The ephemeris validity period is used to ensure effective use of the information. The propagation delay compensation value is used to adjust the timing during measurement.

[0097] However, in NTN communication systems, the propagation delay between terminal devices and satellites is very large. For example, the maximum two-way propagation delay for LEO satellites can reach 25.77ms (LEO satellite altitude 600km, transparent forwarding mode). Furthermore, the high-speed movement of satellites causes the propagation delay between terminal devices and serving cells, as well as between terminal devices and neighboring cells, to change over time. This propagation delay becomes even more complex and severe as satellite altitude increases and feeder link delays are considered. In addition, the rapid changes in the relative positions of the satellite and terminal devices lead to frequent changes in Doppler and visibility windows. Therefore, in most NTN network scenarios, it is difficult for the network side to customize SMTC according to the real-time location of the terminal devices. Current SMTC configuration technologies are prone to phase errors in NTN, resulting in measurement misalignment, repeated frequency sweeps, and high power consumption.

[0098] Currently, the 3GPP meeting has initially allowed terminal devices to adjust the offset based on the actual propagation delay. This means the terminal device can adjust the offset in the SMTC configuration according to the actual propagation delay and redetermine the starting position of the SMTC window based on this offset, ensuring that the arrival time of the SSB falls within the adjusted SMTC window. However, this approach is essentially a post-hoc compensation based on a single dimension (propagation delay). This approach has fundamental shortcomings in the complex dynamic environment of NTN, with the following two main defects.

[0099] (1) The multi-dimensional timeliness constraints were ignored. A successful SSB measurement depends not only on the signal's arrival time (determined by propagation delay), but also on the signal's resolvability (affected by Doppler shift) and availability (limited by the satellite visibility window). These three factors are independent and concurrent physical constraints, each with its own "failure point." For example, if only propagation delay is considered, the terminal device may perform a measurement at a time when the arrival time is accurate, but the Doppler shift exceeds the terminal device's processing capacity. The terminal device will not be able to correctly resolve the SSB, resulting in measurement failure and wasted power. Furthermore, if the SSB's arrival time exceeds the satellite's visibility window, meaning the satellite is not visible to the terminal device, the terminal device will also be unable to correctly receive the SSB, leading to measurement failure.

[0100] (2) Lack of forward-looking "optimal timing" decision-making ability. Current measurement methods passively "align" signals, rather than actively "predicting" which moment or time period in the future will be the best opportunity for measurement. For example, if the terminal device predicts that the satellite will fly out of the visible range in 100ms, a sensible decision is to perform the measurement before 100ms, rather than waiting for a more power-efficient method that aligns with the DRX cycle, but which would miss the satellite's measurement opportunity.

[0101] Therefore, this application aims to solve not only the problem of propagation delay compensation, but also a deeper, multi-dimensional dynamic constraint-based optimal decision-making problem unique to NTN scenarios. Specifically, it addresses how to unify multiple constraints with different physical properties and time scales unique to NTN, such as Doppler, propagation delay, and satellite visibility, under a single decision framework. This framework allows for the proactive calculation of the "most urgent and optimal" measurement timing, guiding the terminal equipment to dynamically adjust its SMTC configuration.

[0102] Based on this, embodiments of this application provide a communication method and a communication device. By determining the effective cutoff time of the SMTC window based on factors affecting the reception and resolution of the reference signal (one or more of transmission delay, Doppler shift, visibility window, and the validity period of auxiliary information), and determining a feasible first SMTC window before the cutoff time, signal measurement is performed based on the first SMTC window. Since the terminal device can theoretically successfully receive signals from the network device before the cutoff time, and the first SMTC window is located before the cutoff time, the terminal device can successfully receive the reference signal sent by the network device based on the first SMTC window, thereby improving the success rate of signal measurement and reducing the power consumption of the terminal device.

[0103] This application embodiment performs unified calculations on all time-varying factors affecting measurement, converting them all into a unified metric of "remaining time" or "latest moment," thereby finding the "shortest plank" that determines the validity of the current measurement opportunity. The purpose is to provide a decision-making basis for the validity of all potential SMTC windows, clearly defining the target time at which the measurement task must be completed. SMTC windows before the target time are potentially valid, while SMTC windows after the target time are invalid. The terminal device can ignore invalid SMTC windows, thereby avoiding invalid wake-ups.

[0104] The following is combined Figure 5 The wireless communication method provided in the embodiments of this application will be described in detail.

[0105] Figure 5 The method illustrated is described from the perspective of device interaction. The specific forms and quantities of the devices shown are merely examples and should not constitute any limitation on the implementation of the method provided in this application. The communication method of this application embodiment will be described in detail below using a network device (such as a first network device) and a terminal device as the execution subjects. The first network device can be a base station or an NTN gateway connected to a base station.

[0106] It should be understood that the terminal device in the embodiments of this application can be the terminal device itself, or a chip, chip system, or processor that supports the terminal device in implementing communication methods, or a logic module or software that can implement all or part of the terminal device. The network device in the embodiments of this application can be the network device itself, or a chip, chip system, or processor that supports the network device in implementing communication methods, or a logic module or software that can implement all or part of the network device.

[0107] See Figure 5 In step S510, the first network device sends SMTC configuration information to the terminal device. Correspondingly, the terminal device can receive SMTC configuration information from the first network device. In this embodiment, the terminal device is in RRC idle state. Of course, the terminal device can also be in RRC inactive state or RRC connected state. In RRC idle state, the terminal device can perform cell reselection or cell redirection based on measurement results. In RRC inactive state or RRC connected state, the terminal device can perform cell handover based on measurement results.

[0108] In some implementations, the first network device is a TN network device, such as a TN base station or an LTE TN base station. The terminal device can receive SMTC configuration information from the TN network device and measure the reference signal transmitted by the NTN network device based on the SMTC configuration information to access the NTN cell, thereby achieving a seamless TN-to-NTN connection. In other implementations, the first network device can be an NTN network device. The terminal device can receive SMTC configuration information from the NTN network device and measure the reference signal transmitted by the NTN network device based on the SMTC configuration information to access the NTN cell.

[0109] In some implementations, SMTC configuration information can be carried in system messages, such as system information block (SIB) 24. The first network device can broadcast SMTC configuration information through system messages. If the terminal device is in RRC idle state, it can obtain SMTC configuration information by receiving system messages broadcast by the first network device. SMTC configuration information corresponds to frequency points, where one frequency point can correspond to one SMTC configuration information. The first network device can broadcast multiple SMTC configuration information corresponding to multiple frequency points. The terminal device can select the SMTC configuration information corresponding to the frequency point of the cell being measured. SMTC configuration information can also be called SMTC baseline.

[0110] In some implementations, SMTC configuration information can be carried within an RRC connection release message. In a cell redirection scenario, before disconnecting from the terminal device, the first network device sends an RRC connection release message to the terminal device, and can then send SMTC configuration information to the terminal device via this message. In a cell redirection scenario, since the first network device specifies a cell to the terminal device, it can send SMTC configuration information corresponding to the frequency point of the specified cell when sending the SMTC configuration information.

[0111] If a terminal device obtains SMTC configuration information through both system messages and RRC connection release messages, it can prioritize using the SMTC configuration information from the RRC connection release message.

[0112] In some implementations, for terminal devices in RRC connected state, i.e., when the terminal device is connected to the first network device, the SMTC configuration information can be carried in any downlink message.

[0113] The SMTC configuration information may include the period, offset, and duration. The period is the duration of the SMTC window, the duration is the duration of the SMTC window, and the offset can be used to determine the start time of the SMTC window. The period can be in units of subframes, and the size of the period can be 5, 10, 20, 40, 80, or 160 subframes. The duration can also be in units of subframes, and the duration can be 1, 2, 3, 4, or 5 subframes. Of course, the duration and period can also be in units of milliseconds (ms), but this embodiment does not specifically limit this.

[0114] The start time of the SMTC window can be determined based on the following formula:

[0115] (1)

[0116] in, Indicates the start time of the SMTC window. Here, P is the SMTC phase reference zero, P is the period of the SMTC window, and k is the period index, where k is an integer. This is the offset. The phase reference zero point can be determined based on the offset.

[0117] In some implementations, SMTC configuration information can be shared by multiple network devices. A first network device can generate SMTC configuration information based on the transmission times of reference signals from multiple second network devices, ensuring that the reference signals transmitted by the multiple network devices fall within the SMTC window. The terminal device, based on this SMTC configuration information, determines the SMTC window and receives the reference signals transmitted by the multiple network devices within the SMTC window; that is, the SMTC window can cover the reference signals transmitted by the multiple network devices.

[0118] In step S520, the terminal device determines the target time based on the first information. The target time is the cutoff time of the valid SMTC window. The valid SMTC window can be understood as the time when the terminal device can receive and parse the reference signal within the window. Therefore, the cutoff time of the valid SMTC window can also be understood as the latest time when the terminal device can receive or parse the reference signal. Thus, the cutoff time can also be replaced by the latest time.

[0119] In some implementations, the SMTC window may also be called a time window, measurement window, or SMTC measurement window, etc., and these different terms can be used interchangeably.

[0120] The first information may include one or more of the following: Doppler frequency shift between the terminal device and the second network device, transmission delay between the terminal device and the second network device, the cutoff time of the visibility window of the second network device, and the validity period of the auxiliary information of the second network device. The second network device may be a non-terrestrial network device, also known as an NTN network device. For example, the second network device may be a satellite, or it may be a future mobile network device.

[0121] In some implementations, the terminal device can determine the target time separately for each network device. The target times for different network devices can be the same or different. Taking satellite 1 as the second network device, the target time is the cutoff time at which the terminal device can receive and / or parse the reference signal from satellite 1. Taking satellite 2 as the second network device, the target time is the cutoff time at which the terminal device can receive and / or parse the reference signal from satellite 2.

[0122] In step S530, the terminal device determines a first SMTC window within the time period between the current time and the target time based on the SMTC configuration information. That is, the first SMTC window is located before the target time. The time period between the current time and the target time is the valid time period. The terminal device can determine multiple periodic SMTC windows based on the SMTC configuration information. Some of these SMTC windows are located before the target time, and some are located after the target time. The terminal device can select one SMTC window from the SMTC windows located before the target time as the first SMTC window.

[0123] Figure 6 The correspondence between the SMTC window and the target time is shown. Figure 6 For example, SMTC windows 2 and 3 are located between the current time and the target time, and are valid windows; SMTC window 4 is located after the target time, and is an invalid window. The first SMTC window is one of SMTC windows 2 and SMTC window 3.

[0124] In step S540, the terminal device measures the reference signal sent by the second network device based on the first SMTC window. This reference signal is the SSB. Of course, the reference signal can also be CSI-RS, etc. For example, if the terminal device is in the RRC idle state, the reference signal is the SSB. Similarly, if the terminal device is in the RRC inactive state or the RRC connected state, the reference signal can be either the SSB or CSI-RS.

[0125] The terminal device can directly measure the reference signal within the first SMTC window, or it can adjust the first SMTC window based on the latency with the second network device and measure the reference signal within the adjusted SMTC window. This embodiment does not specifically limit the specific implementation. A detailed description will follow.

[0126] In some implementations, assuming the current time is t0, the terminal device can calculate and predict the shortest remaining measurable time between the terminal device and the second network device based on satellite-assisted information and the terminal device's location, thereby obtaining the target time.

[0127] The following section describes the scheme for the terminal device to determine the target time based on the first information. The terminal device can calculate the target time in real time or periodically; this application does not specifically limit this.

[0128] In some implementations, the terminal device can calculate a shortest measurable remaining time based on each piece of information in the first information, and select the minimum value of each remaining time to obtain the target time.

[0129] In some implementations, the terminal device can determine the first moment when the Doppler frequency shift reaches a first threshold based on Doppler frequency shift information for the second network device. The first threshold is the upper limit of the Doppler frequency shift that the terminal device can accept, and the first threshold is related to the processing capability of the terminal device. If the Doppler frequency shift exceeds the terminal device's acceptable upper limit, the measurement or tracking cost increases, and the terminal device needs to perform measurement or reselection as soon as possible.

[0130] Doppler shift is a carrier frequency offset caused by a significant relative velocity between the second network device and the terminal device. This Doppler shift may change over time. Doppler shift information can include the offset and / or the rate of change. The offset refers to the frequency shift of the carrier center at the current moment, and the rate of change refers to the speed at which this offset changes over time.

[0131] The SMTC configuration information defines the measurement information such as the period, start point, and duration of the reference signal measured by the terminal device. To reliably acquire and evaluate these reference signals within the SMTC window, the receiving frequency of the reference signal must be within the acquisition or tracking capabilities of the terminal device's receiver and algorithm. Therefore, the magnitude of the Doppler frequency shift directly affects the success rate of reference signal acquisition and tracking. Thus, the first moment can be determined based on the terminal device's acceptable upper limit for Doppler frequency shift. In other words, after the first moment, the Doppler frequency shift will exceed the terminal device's processing capabilities, and the terminal device will be unable to correctly resolve the reference signal. Therefore, the terminal device needs to complete the measurement of the reference signal as quickly as possible before the first moment.

[0132] In some implementations, the terminal device can predict how long after the Doppler frequency shift will exceed the processing capacity limit of the terminal device's receiver or algorithm, based on the current Doppler frequency shift and its rate of change. The calculation formula can be as follows:

[0133] (2)

[0134] in, This represents the Doppler frequency shift at time t. Indicates the carrier frequency. Represents the speed of light. Let be the speed of movement at time t. Indicates the distance traveled. Represents the acceleration at time t. This represents the rate of change of the Doppler frequency shift at time t. Indicates the first moment, Indicates the current moment. Indicates time Doppler shift, This represents the first threshold.

[0135] In some implementations, the terminal device can determine the second moment when the transmission delay reaches a second threshold based on the transmission delay between the terminal device and the second network device. The second threshold is the upper limit of the transmission delay acceptable to the terminal device, and it is related to the processing capability of the terminal device. If the transmission delay exceeds the terminal device's acceptable upper limit, the measurement or tracking cost increases, and the terminal device needs to perform measurement or reselection as soon as possible.

[0136] Transmission delay reflects the round-trip propagation delay between the terminal device and the second network device. The SMTC configuration information only specifies the measurement window and does not guarantee the exact location of the reference signal within the measurement window. Therefore, the terminal device can use the transmission delay to estimate the downlink arrival time of the reference signal, thus aligning the start time and duration of the SMTC window with the actual arrival time of the signal. Furthermore, the rate of change of transmission delay reflects the drift speed of the reference signal's arrival time, allowing the terminal device to decide whether to perform the measurement earlier or extend the window.

[0137] The second threshold can be understood as a tolerance, which refers to the range of error in the arrival time of the reference signal that the terminal device can tolerate under the current timing reference. When the transmission delay exceeds the second threshold, the acquisition window will not align, leading to detection failure or measurement distortion. Therefore, a second time point can be determined based on the second threshold. In other words, after the second time point, the transmission delay will exceed the processing capacity of the terminal device, and the terminal device will be unable to correctly resolve the reference signal. Therefore, the terminal device needs to complete the measurement of the reference signal as soon as possible before the second time point.

[0138] In some implementations, the terminal device can predict how long it will take for the signal to actually arrive outside the tolerance range of the current capture window, based on the current transmission delay and its rate of change. The calculation formula can be as follows:

[0139] (3)

[0140] in, Indicates the second moment. This represents the upper limit of tolerable transmission delay (i.e., the second threshold). Indicates time Transmission delay, Indicates time The rate of change of transmission delay, Indicates the current moment.

[0141] In some implementations, the terminal device can determine a third time point, which is the cutoff time of the visibility window of the second network device. The cutoff time of the visibility window is also called the end time of the visibility window.

[0142] Taking a satellite as the second network device as an example, because satellites move at high speeds, terminal devices can only measure and receive reference signals within the satellite's beam coverage area. If outside the satellite's visibility window, factors such as satellite beam leaving the field, low elevation angle, insufficient link budget, or obstruction may result in the reference signal being invisible or of poor quality, making it difficult to obtain effective measurement results. The satellite's visibility window indicates that within this window, the satellite is visible to the terminal device, and the terminal device can receive messages transmitted by the satellite.

[0143] The visibility window's cutoff time can be predicted locally using an elevation angle occlusion model based on auxiliary information from the second network device and the terminal device's positioning information. The terminal device's positioning information can be Global Navigation Satellite System (GNSS) positioning information. The auxiliary information from the second network device can be obtained through system messages (such as SIB33).

[0144] (4)

[0145] in, Indicates the third moment. Indicates the end time of the visibility window.

[0146] In some implementations, the terminal device can determine the fourth time based on the validity period of the auxiliary information, with the fourth time being the end time of the validity period. The validity period of the auxiliary information can refer to the validity period of the ephemeris information.

[0147] In some implementations, the first network device can send auxiliary information from the second network device to the terminal device (see...). Figure 5 (Step S505 in the above). For example, the first network device can send auxiliary information of the second network device to the terminal device via a system message (such as SIB33). In some implementations, the first network device can obtain the auxiliary information of the second network device by receiving a broadcast message from the second network device.

[0148] This auxiliary information is only valid for a limited period, which is called the validity period. After this period, the ephemeris, sweep plan, or reference clock may have been updated, and the visibility window, Doppler shift, and transmission delay predictions determined based on the previous auxiliary information will be inaccurate or distorted.

[0149] (5)

[0150] in, Indicates the fourth moment, Indicates the end date of the validity period.

[0151] In some implementations, the terminal device can determine the target time based on one or more of the first time, second time, third time, and fourth time.

[0152] As an example, the terminal device can determine the target time as the minimum value among the first, second, third, and fourth time points, using the following formula:

[0153] (6)

[0154] in, The target time, also known as the most urgent event time, represents the deadline by which the terminal device must complete a valid measurement. Based on this, the solution in this application embodiment can achieve the transformation from multi-dimensional constraints to one-dimensional decision-making.

[0155] In this way, it can be ensured that before the target time, the Doppler frequency shift and transmission delay will not exceed the tolerance range of the terminal device, the second network device is visible to the terminal device, and the auxiliary information of the second network device is still valid. The first SMTC window determined before the target time can ensure that the terminal device can receive and parse the reference signal from the second network device within the first SMTC window, thereby reducing the number of invalid measurements and reducing the power consumption of the terminal device.

[0156] As another example, the terminal device can determine the target time based on a portion of the first, second, third, and fourth time points.

[0157] In some embodiments, the terminal device can use any one of the first, second, third, and fourth moments as the target moment to reduce the computational complexity of the terminal device. For example, if the visibility window has a significant impact on the reception of the reference signal, while other factors have a smaller impact, such as if the terminal device has strong processing capabilities and can handle reference signals with large time delays or large Doppler shifts, then the terminal device can consider only the visibility window and ignore other factors, i.e., use the third moment as the target moment. In this case, the terminal device does not need to calculate the first, second, and fourth moments, thereby reducing the computational complexity of the terminal device.

[0158] For example, if the Doppler frequency shift has a significant impact on the reception of the reference signal, while other factors have a smaller impact, such as the terminal device being insensitive to time delay and the second network device having a large coverage area that is always visible to the terminal device or visible for a long period of time, then the terminal device can only consider the magnitude of the Doppler frequency shift and ignore other factors, that is, take the first moment as the target moment. In this case, the terminal device does not need to calculate the second, third, and fourth moments, thereby reducing the computational complexity of the terminal device.

[0159] For example, if transmission delay has a significant impact on the reception of the reference signal, while other factors have a smaller impact—such as a terminal device with strong processing capabilities capable of handling reference signals with large delays, and a second network device with a large coverage area that is always visible to the terminal device or visible for a long period of time—then the terminal device can only consider transmission delay and ignore other factors, i.e., take the second moment as the target moment. In this case, the terminal device does not need to calculate the first, third, and fourth moments, thereby reducing the computational complexity of the terminal device.

[0160] In other embodiments, the terminal device can determine the target time based on any two of the first, second, third, and fourth times. For example, the terminal device can determine the target time based on the first and second times, where the target time is the smaller of the first and second times. Alternatively, the terminal device can determine the target time based on the first and third times, where the target time is the smaller of the first and third times. Alternatively, the terminal device can determine the target time based on the first and fourth times, where the target time is the smaller of the first and fourth times. Alternatively, the terminal device can determine the target time based on the second and third times, where the target time is the smaller of the second and fourth times. Alternatively, the terminal device can determine the target time based on the second and fourth times, where the target time is the smaller of the second and fourth times. Alternatively, the terminal device can determine the target time based on the third and fourth times, where the target time is the smaller of the third and fourth times.

[0161] In some other embodiments, the terminal device can determine the target time based on any three of the first, second, third, and fourth times. For example, the terminal device can determine the target time based on the first, second, and third times, where the target time is the minimum value among the first, second, and third times. Alternatively, the terminal device can determine the target time based on the first, second, and fourth times, where the target time is the minimum value among the first, second, and fourth times. Alternatively, the terminal device can determine the target time based on the second, third, and fourth times, where the target time is the minimum value among the second, third, and fourth times. Alternatively, the terminal device can determine the target time based on the first, third, and fourth times, where the target time is the minimum value among the first, third, and fourth times.

[0162] The above section introduced how to determine the target time. The following section introduces how to select the first SMTC window.

[0163] In some implementations, the first SMTC window can be any SMTC window located between the current time and the target time.

[0164] In some implementations, the first SMTC window satisfies one or more of the following conditions: it is located within the DRX activation period of the terminal device, at least partially overlaps with the DRX activation period of the terminal device, and is the first SMTC window after the current time. Specifically, "the SMTC window is located within the DRX activation period" means that the time period in which the SMTC window is located belongs to the DRX activation period; "the SMTC window at least partially overlaps with the DRX activation period" means that a portion of the time period of the SMTC window belongs to the DRX activation period; and "the first SMTC window after the current time" is the SMTC window closest to the current time.

[0165] In some implementations, the terminal device can determine the first SMTC window based on power consumption and access latency requirements. For example, if the terminal device has high power consumption requirements, it can preferentially select an SMTC window that overlaps with or at least partially overlaps with the DRX activation period as the first SMTC window; this strategy for selecting the first SMTC window can be called a power-priority strategy. Conversely, if the terminal device has high access latency requirements, it can select the first SMTC window after the current time as the first SMTC window; this strategy can be called a latency-priority strategy.

[0166] As an example, to minimize the power consumption of the terminal device, the terminal device can select an SMTC window located within the DRX active period as the first SMTC window. This avoids waking the terminal device during the DRX inactive period, and allows the terminal device to complete reference signal measurement and paging processing during the DRX active period, thereby reducing the terminal device's power consumption. For example, let's take... Figure 7 For example, the SMTC window between the current time and the target time includes SMTC window 3, SMTC window 4 and SMTC window 5, but only SMTC window 4 is in the DRX active period, so SMTC window 4 can be used as the first SMTC window.

[0167] As another example, the first SMTC window is an SMTC window that at least partially overlaps with the DRX activation period. For instance, if there is no SMTC window within the DRX activation period between the current time and the target time, the terminal device can select an SMTC window that partially overlaps with the DRX activation period as the first SMTC window, which can reduce the power consumption of the terminal device to some extent. Figure 8 For example, the SMTC window between the current time and the target time includes SMTC window 2 and SMTC window 3. SMTC window 3 partially overlaps with the DRX activation period, while SMTC window 2 is located in the DRX inactive period. Therefore, SMTC window 3 can be used as the first SMTC window.

[0168] For example, for power-sensitive devices such as IoT devices, power consumption is the primary consideration for terminal devices. Therefore, terminal devices can... Within the window, an SMTC window that overlaps or partially overlaps with the DRX activation period is selected as the first SMTC window. If a suitable SMTC window exists, two tasks can be completed with a single wake-up. If no suitable SMTC window exists, any SMTC window between the current time and the target time can be used as the first SMTC window. For example, the terminal device can use the first SMTC window after the current time as the first SMTC window to reduce the access latency of the terminal device.

[0169] As another example, the first SMTC window is the first SMTC window after the current time. For instance, if the terminal device has high requirements for access latency and wants to access the network device for data transmission as soon as possible, the terminal device can use the first SMTC window after the current time as the first SMTC window.

[0170] In this implementation, the terminal device needs to complete the measurement as quickly as possible and select a candidate cell for access to reduce the latency of accessing the NTN cell. Therefore, the terminal device needs to... Select the SMTC window that is closest to the current time and is feasible as the first SMTC window.

[0171] In some implementations, the terminal device can first select the first SMTC window based on a power consumption priority strategy. If there is no SMTC window that meets the conditions, then the first SMTC window can be selected based on a latency priority strategy.

[0172] As an example, if a second SMTC window exists within the time interval between the current time and the target time, the terminal device can designate the second SMTC window as the first SMTC window. The second SMTC window is located within the DRX activation period or at least partially overlaps with the DRX activation period. Furthermore, if both an SMTC window within the DRX activation period and an SMTC window partially overlapping with the DRX activation period exist within the time interval between the current time and the target time, the terminal device can preferentially select the SMTC window within the DRX activation period as the first SMTC window. If no SMTC window within the DRX activation period exists within the time interval between the current time and the target time, and only an SMTC window partially overlapping with the DRX activation period exists, the terminal device can designate the SMTC window partially overlapping with the DRX activation period as the first SMTC window.

[0173] If no second SMTC window exists within the time interval between the current time and the target time, the terminal device can use the first SMTC window after the current time as the first SMTC window to ensure the terminal device's access latency. For example, let's consider... Figure 9 For example, the SMTC window between the current time and the target time includes SMTC window 3 and SMTC window 4. However, both SMTC window 3 and SMTC window 4 are in the DRX inactive period. Therefore, the first SMTC window after the current time (i.e. SMTC window 3) can be used as the first SMTC window.

[0174] After determining the first SMTC window, the terminal device can directly measure the reference signal sent by the second network device within the first SMTC window. Alternatively, the terminal device can adjust the start time of the first SMTC window based on the transmission delay to ensure that the arrival time of the reference signal falls within the adjusted first SMTC window, thereby improving the success rate of reference signal reception. 3GPP specifies that terminal devices are allowed to adjust the offset based on satellite identity (ID) or actual propagation delay. Therefore, after obtaining the first SMTC window, the offset of the first SMTC window can be adjusted to adjust the start time of the first SMTC window, ensuring that the predicted reference signal falls within the adjusted SMTC window.

[0175] As an example, the terminal device can adjust the start time of the first SMTC window based on the transmission delay between the terminal device and the second network device to obtain a third SMTC window, and measure the reference signal sent by the second network device within the third SMTC window.

[0176] Terminal devices can adjust the offset in the SMTC configuration information based on transmission latency. Adjusting the offset allows for adjustment of the start time of the SMTC window. The formula for adjusting the offset is as follows:

[0177] (7)

[0178] in, This indicates the adjusted offset. This represents the base offset in the SMTC configuration information; T represents the transmission delay. This represents the quantization alignment function, which converts a continuous time value into a discrete value conforming to the SMTC offset format. This represents the thresholding and truncation function, which ensures that the final adjustment amount will not exceed the preset range. This indicates the maximum allowable fine-tuning range, meaning the adjustment offset cannot exceed [ ]. The interval in which ] is located.

[0179] The calculated offset Substituting into the above formula (1), we can obtain the adjusted start time of SMTC.

[0180] In some implementations, if the first network device generates SMTC configuration information based on a transmission delay of 0, the terminal device can adjust the start time of the first SMTC window based on a second delay to obtain a third SMTC window. The second delay is the transmission delay between the terminal device and the second network device at the current time. If the first network device generates SMTC configuration information based on a first delay, the terminal device can determine the difference between the first and second delays and adjust the start time of the first SMTC window based on this difference to obtain a third SMTC window. The first network device can indicate the first delay to the terminal device. For example, the first network device can send first indication information to the terminal device, which indicates the first delay used by the terminal device to adjust the start time of the first SMTC window. The first indication information can be carried in an RRC connection release message.

[0181] The first delay is the transmission delay between the terminal device and the second network device, determined by the first network device before the current time. For example, the first network device can determine the first delay based on auxiliary information from the second network device (such as ephemeris information) and the location information reported by the terminal device; the first delay can also be called an estimate of the transmission delay. Due to the movement of the second network device and / or the terminal device, the distance between the second network device and the terminal device is constantly changing. Therefore, there is a certain difference between the second delay and the first delay, and the terminal device can adjust the start time of the first SMTC window based on this difference.

[0182] Terminal devices can adjust the offset in the SMTC configuration information based on the difference in transmission delay. Adjusting the offset allows for adjustment of the start time of the SMTC window. The formula for adjusting the offset is as follows:

[0183] (8)

[0184] in, This indicates the adjusted offset. This represents the base offset in the SMTC configuration information; This represents the difference in transmission delay; This represents the quantization alignment function, which converts a continuous time value into a discrete value conforming to the SMTC offset format. This represents the thresholding and truncation function, which ensures that the final adjustment amount will not exceed the preset range. This indicates the maximum allowable fine-tuning range, meaning the adjustment offset cannot exceed [ ]. The interval in which ] is located.

[0185] The calculated offset Substituting into the above formula (1), we can obtain the adjusted start time of SMTC.

[0186] In some implementations, the terminal device can determine whether the start time of the first SMTC window needs to be adjusted based on the magnitude of the difference. For example, if the difference is large, such as greater than or equal to a third threshold, failure to adjust the start time of the first SMTC window may result in the arrival time of the reference signal being outside the first SMTC window. In this case, the terminal device adjusts the start time of the first SMTC window based on the difference to obtain the third SMTC window.

[0187] For example, if the difference is small, such as less than the third threshold, then even without adjusting the start time of the first SMTC window, the arrival time of the reference signal can still fall within the first SMTC window. In this case, the terminal device does not need to adjust the start time of the first SMTC window and can directly measure the reference signal sent by the second network device within the first SMTC window. For ease of description, the first SMTC window that does not require adjustment of the start time will also be referred to as the third SMTC window below; that is, the third SMTC window is the SMTC window for the terminal device to measure the reference signal.

[0188] In summary, the terminal device can accurately determine the effective timing for reference signal measurement based on its own location information and the auxiliary information from the second network device, and adjust the SMTC basic configuration sent by the network side according to the real-time propagation delay, so that the SMTC window can accurately cover at least one reference signal measurement.

[0189] After obtaining the third SMTC window, the terminal device can determine its wake-up time based on the start time of the third SMTC window and its measurement preparation time, and wake up the terminal device at that wake-up time to ensure that it can perform signal measurements within the third SMTC window. The calculation formula is as follows:

[0190] (9)

[0191] in, Indicates the wake-up time of the terminal device. This indicates the measurement preparation time of the terminal equipment. This indicates the start time of the third SMTC window. Measurement preparation time is related to the capabilities of the terminal equipment.

[0192] If the wake-up time is outside the DRX activation period or in the DRX inactive period, the terminal device can be woken up at the wake-up time, so that the terminal device is in a wake-up state after the wake-up time.

[0193] In some implementations, the first network device may also send second information to the terminal device, the second information indicating one or more of the following: a first time window, a first time range, and a first offset.

[0194] The first time window is the time range within which the terminal device performs signal measurements, as determined by the first network device. This first time window can also be called the predicted window. It represents the optimal measurement time range, meaning the link quality between the terminal device and the second network device is relatively good within this timeframe. Within the first time window, the relative positions of the terminal device and the second network device meet preset conditions, such as the terminal device not only being within the coverage area of ​​the second network device but also being located close to the center of that coverage area. The first network device can determine the first time window based on the ephemeris information of the second network device and the location information of the terminal device.

[0195] For example, when the elevation angle of the second network device is greater than 50 degrees, the terminal device is within the coverage area of ​​the second network device. However, the communication quality between the terminal device and the second network device is better only when the elevation angle of the second network device is greater than 80 degrees. Therefore, the first network device can calculate the time range corresponding to the elevation angle being greater than 80 degrees, and this time range is the first time window.

[0196] The terminal device can determine the first SMTC window within the first time window, meaning the first SMTC window is located within the first time window. For ease of description, the time period between the current time and the target time will be referred to as the second time window. The terminal device can determine the first SMTC window based on the first and second time windows, such that the first SMTC window is located in the overlapping area of ​​the first and second time windows. Within this overlapping area, the terminal device can select the first SMTC window based on the power priority strategy and / or delay priority strategy described above. For simplicity, this will not be elaborated further here.

[0197] The first time range is the fluctuation range of the arrival time of the reference signal predicted by the first network device. This first time range can be called the SSB Time Uncertainty. In some implementations, the first network device can predict the transmission delay between the second network device and the terminal device, and generate SMTC configuration information based on this delay. However, the transmission delay may change; that is, the arrival time of the reference signal may fluctuate, possibly being delayed or advanced, and may not necessarily fall within the SMTC window configured by the first network device. Therefore, the first network device can indicate the first time range to the terminal device, allowing the terminal device to adjust the position of the SMTC window based on the first time range. Alternatively, if the first network device generates SMTC configuration information based on a transmission delay of 0, but due to the transmission delay between the terminal device and the second network device, the arrival time of the reference signal may fluctuate, such as being delayed. Therefore, the first network device can indicate the first time range to the terminal device, allowing the terminal device to adjust the position of the SMTC window based on the first time range.

[0198] The first network device can determine a first time range based on the ephemeris information of the second network device and the location information of the terminal device. The first time range is related to the transmission delay between the terminal device and the second network device.

[0199] The terminal device can adjust the start time of the first SMTC window according to the above formula based on the first time range to obtain the third SMTC window.

[0200] The first offset indicates the range within which the terminal device can adjust the SMTC window. For example, the first network device can authorize the terminal device to adjust the offset in the SMTC configuration information within a certain range using the first offset. The first offset can be called the maximum offset adjustment (offsetAdjustMax). When the terminal device adjusts the start time of the first SMTC window based on the transmission delay, it cannot exceed the adjustment range corresponding to the first offset. The first offset can be, for example, the one mentioned above. The terminal device can adjust the offset within a certain range. ].

[0201] In some implementations, the first message is an RRC connection release message. The first network device can use this message to indicate the redirected cell to the terminal device; the redirected cell can include one or more cells. For example, the network device can use the RRC connection release message to configure the priority of the redirected cell to the terminal device; the priority of the redirected cell can include the priority order of multiple cells. As can be seen from the above, during the redirection process, the first network device indicates the redirected cell to the terminal device, meaning the cell or network device that the terminal device needs to measure is clearly defined. Therefore, the first network device can indicate the second information corresponding to these network devices to the terminal device.

[0202] In some implementations, the first network device can determine the second information based on the ephemeris information of the second network device and the location information of the terminal device. For example, during a cell redirection process, before disconnection, the terminal device can report its location information to the first network device. The first network device can then obtain the ephemeris information of the second network device and determine the second information corresponding to the second network device based on the location information reported by the terminal device and the ephemeris information of the second network device.

[0203] In some implementations, the second information can be carried in a newly added field of the RRC connection release message. During the cell redirection process, the first network device can configure the second information to the terminal device via the RRC connection release message.

[0204] In some implementations, the RRC connection release message includes SMTC configuration information, and the second information can be carried in a newly added field of the SMTC configuration information, that is, the SMTC configuration information includes the second information.

[0205] In some implementations, the first network device can configure the second information separately for each network device. For example, if the redirection cell indicated by the first network device to the terminal device includes cells corresponding to multiple network devices, the first network device can also configure multiple pieces of second information corresponding to each of the multiple network devices to the terminal device.

[0206] In some implementations, the terminal device can measure the reference signal sent by the second network device within the third SMTC window, obtain the measurement result, and determine whether the second network device meets the reselection conditions based on the measurement result. If the second network device meets the reselection conditions, the terminal device can camp on the cell corresponding to the second network device. The measurement result can include one or more of the following: RSRP, RSRQ, SINR. The reselection conditions can be called reselection criteria or reselection rules. In this scenario, the terminal device is in RRC idle state.

[0207] In some implementations, if the terminal device is in an RRC inactive state or an RRC connected state, the terminal device can measure the reference signal sent by the second network device in the third SMTC window, obtain the measurement result, and report the measurement result to the first network device. The first network device can determine the handover decision based on the measurement result.

[0208] The above solution can be applied to cell reselection scenarios, cell redirection scenarios, and cell handover scenarios. The following section will combine... Figures 10-11 This section introduces the implementation process of cell reselection and cell redirection. It should be noted that any content not described in detail below can be found in the preceding text.

[0209] Figure 10 This is a schematic flowchart illustrating a cell reselection process performed by a terminal device according to an embodiment of this application. The terminal device obtains information via cell broadcast during the RRC idle state.

[0210] In step S1010, the LTE TN base station broadcasts the master information block (MIB) and SIB1. Correspondingly, the terminal device receives the MIB and SIB1 from the LTE TN. The MIB and SIB1 include the scheduling of system information (SI). The terminal device can determine the scheduling information of other SIBs based on the MIB and SIB1.

[0211] In step S1020, the LTE TN base station broadcasts SIB3, SIB4 and SIB5. Correspondingly, the terminal device receives SIB3, SIB4 and SIB5 from the LTE TN base station. These SIB messages include the reselection parameters and a list of candidate cells.

[0212] In step S1030, the terminal device determines the reselection conditions and the candidate cell list based on the received SIB message.

[0213] In step S1040, the LTE TN base station broadcasts SIB24 and SIB33, and correspondingly, the terminal device receives SIB24 and SIB33 from the LTE TN base station. SIB24 includes SMTC configuration information for the NR-NTN frequency point, and SIB33 includes NTN auxiliary information, which is also called satellite auxiliary information.

[0214] In step S1050, the terminal device performs prediction calculations based on the SMTC configuration information and NTN auxiliary information, and adjusts the offset in the SMTC configuration information.

[0215] The terminal device can predict the visibility window and arrival time of each candidate satellite based on satellite-aided information, and calculate the target time. And in Select the first SMTC window within the time window.

[0216] The terminal equipment can determine the effective time window for measurement based on the scheme described above, such as its own GNSS location information and NTN auxiliary information. ], and in Within the time window, select the first SMTC window and adjust the start time of the first SMTC window according to the transmission delay, or adjust the offset in the SMTC configuration information based on the delay to obtain the adjusted SMTC window.

[0217] In step S1060, the terminal device measures the NR NTN base station within the adjusted SMTC window. If the base station meets the reselection rules, the terminal device performs cell reselection and camps on the NTN cell.

[0218] By employing the above approach, the terminal device can clearly define the effective SMTC window period, significantly reducing unnecessary measurement attempts and RF on-time, which helps lower the power consumption of the terminal device. Furthermore, this approach allows the terminal device to obtain accurate measurement timing, resulting in a higher hit rate for reselection and faster service establishment, which is particularly beneficial for weak coverage or high-speed LEO scenarios.

[0219] Figure 11 This is a schematic flowchart illustrating a cell redirection driven by a network device, provided as an embodiment of this application. A terminal device can be redirected to a cell specified by the network device under its control. The scheme includes two processes: coarse-grained prediction and enhanced SMTC issuance on the network side, and fine-grained adjustment based on precise location on the terminal side.

[0220] In step S1110, the LTE TN base station obtains satellite auxiliary information of the target frequency point, which is the frequency point used by the NTN base station, and configures pre-aligned SMTC configuration information according to the positioning information reported by the terminal device.

[0221] During this phase, LTE TN base stations can perform coarse-grained predictions and distribute enhanced SMTC configuration information.

[0222] 3GPP specifies that network devices can configure redirection priorities via RRC connection release messages when disconnecting RRC connections, instructing terminal devices to redirect to a designated NTN cell. Therefore, when a network device instructs a terminal device to redirect to an NTN cell via an RRC connection release message, the network device (base station or its connected NTN gateway) utilizes its powerful computing capabilities and global perspective, based on satellite ephemeris information and an understanding of the approximate location of the terminal device, to pre-calculate a propagation delay estimate for the terminal device. Based on this estimate, the network device generates a pre-aligned SMTC configuration. The offset in this SMTC configuration has already compensated for most of the propagation delay.

[0223] In step S1120, the LTE TN base station sends an RRC connection release message to the terminal device. This RRC connection release message includes SMTC configuration information and redirection information, with the redirection information including a priority list of redirected cells. Additionally, an IE field can be added to this RRC connection release message to indicate the first time window, first time range, and first offset mentioned above. The RRC connection release message may also include a latency estimate. .

[0224] In step S1130, the terminal device saves the redirection information, releases resources, and enters the RRC idle state.

[0225] In step S1140, the terminal device obtains the system messages of the NTN cell on the target frequency point, such as MIB and / or SIB1, according to the redirection information.

[0226] In step S1150, the terminal device uses SMTC configuration information and NTN auxiliary information to perform prediction calculations and fine-tunes the offset in the SMTC configuration information. The terminal device can determine the first SMTC window according to the scheme described above, such as determining the target time based on the NTN auxiliary information, selecting the first SMTC window within the time period before the target time based on the SMTC configuration information, and considering the transmission delay and delay estimate at the current time. The difference between the values ​​is used to adjust the start time of the first SMTC window, or in other words, the offset in the SMTC configuration information is adjusted based on the difference to obtain the adjusted SMTC window.

[0227] Specifically, the terminal device uses the SMTC configuration information as a baseline, combines the latest GNSS location information and auxiliary information, calculates the real-time transmission delay T, and obtains the delay correction amount due to position deviation. The terminal device uses this correction amount. Within the network's permitted [ Within the range, the offset is finely adjusted to compensate for the small time deviation caused by the difference between the location of the terminal device and the terminal location predicted by the network. The specific formula is as shown in formula (8) above.

[0228] In step S1160, the terminal device performs SSB measurement within the adjusted SMTC window. If the NTN cell meets the reselection conditions, it camps on that NTN cell.

[0229] Before performing the measurement, the terminal device will still calculate the effective time window as described above as a safety check, that is, calculate the target time, select the first SMTC window according to the strategy described above, and adjust the start time of the first SMTC window to avoid invalid measurements and reduce the power consumption of the terminal device.

[0230] The above solution can move the calculation of measurement timing to the network side, with only minor adjustments required on the terminal device side. This results in a higher success rate for the first round of measurements and faster access. When there are satellite candidates or significant uncertainties, the network can unify its strategies, improve interoperability consistency, and reduce the power consumption of terminal devices, thus saving power.

[0231] The differences between the above solution and related technologies mainly include the following three points, which will be introduced separately below.

[0232] (1) The core of the related technology is “compensation”, that is, under the premise that the measurement window has been roughly determined, the arrival time of the signal is “corrected” according to the measured transmission delay. Its essence is a kind of post-event, one-dimensional alignment.

[0233] The key feature of this application's embodiment is "prediction," which proactively and forward-lookingly predicts the optimal measurement opportunity within a future period, determined by multiple physical factors. This involves setting a deadline for the measurement to be completed and then finding a suitable measurement time within that deadline. Furthermore, the terminal device can autonomously decide based on its own status, selecting an SMTC window within the effective time window.

[0234] (2) The relevant technologies only consider the propagation delay factor and ignore other factors in the NTN scenario that may also lead to measurement failure.

[0235] The solution proposed in this application presents a unified decision-making framework based on the "most pressing event time." It unifies four physical constraints of different natures and time scales—propagation delay, Doppler shift, satellite visibility, and the validity period of auxiliary information—into a single dimension of "remaining time" for comparison. By taking the minimum value among these constraints, the true bottleneck determining the success or failure of the measurement can be identified, resulting in a comprehensive and accurate decision-making process—a systematic approach completely lacking in related technologies.

[0236] (3) The relevant technologies are usually statically configured on the network side or fine-tuned by the terminal device based on the propagation delay. In essence, they are all one-way instructions or corrections.

[0237] The solutions in this application propose different adaptive implementation paths for general cell reselection scenarios and dedicated scenarios involving network indication redirection. Particularly for network-driven redirection scenarios, the solution explicitly proposes a two-stage collaborative mechanism of "network coarse adjustment + terminal fine adjustment." The network utilizes its global perspective to provide the terminal device with a more accurate "enhanced SMTC baseline," while the terminal device uses its precise local location for the final "fine calibration." To support this advanced functionality, the solution also proposes a specific approach to add IE fields (such as predictedWindow, ssbTimeUncertainty, offsetAdjustMax) to the RRC connection release message, making the solution more complete.

[0238] It should be understood that Figures 1 to 11 The flowcharts or scene diagrams shown are for illustrative purposes only and are not intended to limit the embodiments of this application to the examples illustrated. In fact, those skilled in the art can interpret the embodiments based on... Figures 1 to 11 The examples in the document can be transformed into equivalent ways to obtain more implementations.

[0239] The above text combined Figures 1 to 11 This document describes in detail the communication method provided in the embodiments of this application. The following will combine... Figures 12 to 13 The device embodiments of this application are described in detail below. It should be understood that the communication device of this application embodiment can execute the various communication methods of the foregoing embodiments of this application, that is, the specific working processes of the various products below can be referred to the corresponding processes in the foregoing method embodiments.

[0240] In the embodiments described above, the terminal device may execute some or all of the steps in each embodiment; the network device may execute some or all of the steps in each embodiment. These steps or operations are merely examples, and the embodiments of this application may also perform other operations or variations thereof. Furthermore, the steps may be executed in different orders as presented in the embodiments, and it is not necessary to execute all the operations in the embodiments of this application. Moreover, the sequence number of each step does not imply the order of execution; the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0241] Figure 12 This is a schematic block diagram of a communication device provided in an embodiment of this application. Figure 12As shown, the communication device 1200 may include a communication module 1220. The communication module 1220 can implement corresponding communication functions, which can be internal communication functions of the communication device 1200 or communication functions between the communication device 1200 and other devices. Optionally, the communication module 1220 may also be referred to as a communication interface or transceiver module. Optionally, the communication device 1200 further includes a processing module 1210. The processing module 1210 can implement corresponding processing functions.

[0242] Optionally, the communication device 1200 further includes a storage module, which can be used to store instructions and / or data; the processing module 1210 can read the instructions and / or data in the storage module so that the communication device 1200 can implement the aforementioned method embodiments.

[0243] In one possible design, the communication device 1200 may correspond to the terminal device in the above method embodiments, or a component (such as a circuit, chip, or chip system) configured in the terminal device. The communication device 1200 may be used to execute the steps or processes performed by the terminal device in any of the above method embodiments.

[0244] For example, in some implementations, the communication module 1220 is configured to: receive SMTC configuration information from a first network device, the SMTC configuration information being used to determine the position of an SMTC window; and the processing module 1210 is configured to: determine a target time based on first information, the target time being the expiration time of the SMTC window, the first information including one or more of the following: Doppler frequency shift information for a second network device, transmission delay between the terminal device and the second network device, expiration time of the visibility window of the second network device, and validity period of auxiliary information of the second network device, wherein the second network device is a non-terrestrial network device; determine a first SMTC window within the time period between the current time and the target time based on the SMTC configuration information; and measure a reference signal transmitted by the second network device based on the first SMTC window.

[0245] The above are merely examples; for detailed steps or procedures, please refer to the descriptions in the foregoing embodiments.

[0246] In one possible design, the communication device 1200 may correspond to a network device (such as the first network device) in the above method embodiments, or a component (such as a circuit, chip, or chip system) configured in a network device. The communication device 1200 can be used to perform the steps or processes performed by the network device in any of the above method embodiments.

[0247] For example, the communication module 1220 is used to: send SMTC configuration information and auxiliary information of a second network device to a terminal device, wherein the second network device is a non-terrestrial network device; the SMTC configuration information is used to determine the position of the SMTC window; the auxiliary information is used to determine first information; the first information is used to determine a target time; the target time is the expiration time of the SMTC window; and a first SMTC window within the time period between the current time and the target time is used for the measurement of a reference signal; wherein the first information includes one or more of the following: Doppler frequency shift information for the second network device, transmission delay between the terminal device and the second network device, expiration time of the visibility window of the second network device, and validity period of the auxiliary information of the second network device.

[0248] The above are merely examples; for detailed steps or procedures, please refer to the descriptions in the foregoing embodiments.

[0249] Figure 13 This is another schematic block diagram of the communication device 1300 provided in the embodiments of this application. The communication device 1300 may be a chip, chip system, or processor, etc., in a terminal device or network device that implements the above-described methods. The communication device 1300 can be used to implement the methods described in the above-described method embodiments; for details, please refer to the descriptions in the above-described method embodiments.

[0250] like Figure 13 As shown, the communication device 1300 may include one or more processors 1310, which may also be referred to as processing units or processing modules, and can implement certain control functions. The processor 1310 may be a general-purpose processor or a dedicated processor, such as a baseband processor or a central processing unit. The baseband processor can be used to process communication protocols and communication data, while the central processing unit can be used to control the communication device 1300 (e.g., a base station, baseband chip, user, user chip), execute software programs, and process data from the software programs.

[0251] In an alternative design, the processor 1310 may also store instructions and / or data that can be executed by the processor 1310 to cause the communication device 1300 to perform the methods described in the above method embodiments.

[0252] In another alternative design, the communication device 1300 may include a communication interface 1320 for implementing receiving and transmitting functions. For example, the communication interface 1320 may be a transceiver circuit, interface, interface circuit, or transceiver. The transceiver circuit, interface, interface circuit, or transceiver for implementing receiving and transmitting functions may be separate or integrated. The aforementioned transceiver circuit, interface, interface circuit, or transceiver may be used for reading and writing code / data, or it may be used for transmitting or relaying signals.

[0253] Optionally, the communication device 1300 may include one or more memories 1330, which may store instructions that can be executed on the processor 1310, causing the communication device 1300 to perform the methods described in the above method embodiments. Optionally, the memories 1330 may also store data. Optionally, the processor 1310 may also store instructions and / or data. The processor 1310 and the memories 1330 may be provided separately or integrated together.

[0254] It should be understood that, in one possible design, the steps in the method embodiments provided in this application can be implemented by integrated logic circuits in the processor's hardware or by instructions in software form. The steps of the methods disclosed in the embodiments of this application can be directly implemented by a hardware processor, or implemented by a combination of hardware and software modules in the processor. The software modules can reside in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. 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. To avoid repetition, detailed descriptions are not provided here.

[0255] In one implementation, the communication device 1300 may correspond to the terminal device in the above method embodiments and may be used to execute the various steps and / or processes executed by the terminal device in the above method embodiments. The processor 1310 may be used to execute instructions stored in the memory 1330, and when the processor 1310 executes the instructions stored in the memory, the processor 1310 is used to execute the various steps and / or processes of the above method embodiments corresponding to the terminal device.

[0256] In another implementation, the communication device 1300 may correspond to the network device in the above method embodiments and may be used to execute the various steps and / or processes executed by the network device in the above method embodiments. The processor 1310 may be used to execute instructions stored in the memory 1330, and when the processor 1310 executes the instructions stored in the memory, the processor 1310 is used to execute the various steps and / or processes of the above method embodiments corresponding to the network device.

[0257] It should be understood that the aforementioned processing device can be one or more chips. For example, the processing device can be a field-programmable gate array (FPGA), an application-specific integrated circuit (ASIC), a system-on-chip (SoC), a central processor unit (CPU), a network processor (NP), a digital signal processor (DSP), a microcontroller unit (MCU), a programmable logic device (PLD), or other integrated chips.

[0258] It is understood that 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.

[0259] According to the method provided in the embodiments of this application, this application also provides a chip system, which includes one or more processors for calling and executing instructions stored in memory, thereby causing the method described in the embodiments of this application to be executed. The chip system may be composed of chips or may include chips and other discrete devices.

[0260] The chip system may include input circuits or interfaces for transmitting information or data, and output circuits or interfaces for receiving information or data.

[0261] According to the method provided in the embodiments of this application, this application also provides a communication system, which includes the aforementioned network device and terminal device.

[0262] According to the method provided in the embodiments of this application, this application also provides a computer program product, which includes: computer program code, which, when run on a computer, causes the computer to execute the various steps or processes executed by the network device or terminal device in any of the foregoing method embodiments.

[0263] According to the method provided in the embodiments of this application, this application also provides a computer-readable storage medium storing program code, which, when run on a computer, causes the computer to execute the various steps or processes executed by the network device or terminal device in any of the foregoing method embodiments.

[0264] The computer-readable storage medium may be the aforementioned volatile memory or non-volatile memory, or it may include both volatile memory and non-volatile memory.

[0265] In the embodiments of this application, the terms and English abbreviations are exemplary examples given for ease of description and should not be construed as limiting the application in any way. This application does not preclude the possibility of defining other terms that can achieve the same or similar functions in existing or future agreements.

[0266] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product. The computer program product includes one or more computer instructions. When these computer 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.

[0267] 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.

[0268] It should be understood that in the various embodiments of this application, the sequence number of each process does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0269] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A communication method characterized by comprising: The method is applied to a terminal device, and includes: receiving synchronization signal or physical broadcast channel block (SSB) measurement timing configuration (SMTC) configuration information from a first network device, the SMTC configuration information being used to determine a location of an SMTC window; determining a target time based on first information, the target time being a cutoff time at which the SMTC window is valid, the first information including one or more of the following: Doppler shift information for a second network device, a transmission delay between the terminal device and the second network device, a cutoff time of a visibility window of the second network device, a validity period of assistance information of the second network device, the second network device being a non-terrestrial network device; determining a first SMTC window within a time period between a current time and the target time based on the SMTC configuration information; performing measurement on a reference signal transmitted by the second network device based on the first SMTC window.

2. The method of claim 1, wherein, The determination of the target time based on the first information includes: determining a first time at which the Doppler shift reaches a first threshold based on the Doppler shift information for the second network device; determining a second time at which the transmission delay reaches a second threshold based on the transmission delay between the terminal device and the second network device; determining a third time, the third time being the cutoff time of the visibility window of the second network device; determining a fourth time based on the validity period of the assistance information, the fourth time being an ending time of the validity period; determining the minimum value among the first time, the second time, the third time, and the fourth time as the target time.

3. The method according to claim 1 or 2, characterized in that, The first SMTC window satisfies one or more of the following conditions: located within a discontinuous reception (DRX) active period of the terminal device; at least partially overlapping with the DRX active period of the terminal device; belonging to a first SMTC window after the current time.

4. The method of claim 3, wherein, The determination of the first SMTC window includes: if there is a second SMTC window within the time period between the current time and the target time, determining the second SMTC window as the first SMTC window; if there is no second SMTC window within the time period between the current time and the target time, determining a first SMTC window after the current time as the first SMTC window; wherein the second SMTC window is located within the DRX active period or at least partially overlaps with the DRX active period.

5. The method according to claim 1 or 2, characterized in that, The measurement on the reference signal transmitted by the second network device based on the first SMTC window includes: adjusting a start time of the first SMTC window based on the transmission delay between the terminal device and the second network device to obtain a third SMTC window; performing measurement on the reference signal transmitted by the second network device within the third SMTC window.

6. The method of claim 5, wherein, The SMTC configuration information is configuration information matching a first delay, the first delay being a transmission delay between the terminal device and the second network device determined by the first network device before the current time. The starting moment of the first SMTC window is adjusted based on the transmission delay between the terminal device and the second network device, to obtain a third SMTC window, including: determining a difference between the first delay and a second delay, the second delay being a transmission delay between the terminal device and the second network device at a current moment; adjusting the starting moment of the first SMTC window based on the difference, to obtain the third SMTC window.

7. The method of claim 6, wherein, The starting moment of the first SMTC window is adjusted based on the difference, to obtain the third SMTC window, including: if the difference is greater than or equal to a third threshold, adjusting the starting moment of the first SMTC window based on the difference, to obtain the third SMTC window; The reference signal sent by the second network device is measured based on the first SMTC window, including: if the difference is less than the third threshold, measuring the reference signal sent by the second network device within the first SMTC window.

8. The method according to claim 6 or 7, characterized in that, The method further includes: determining a wake-up moment of the terminal device based on the starting moment of the third SMTC window and a measurement preparation time of the terminal device; waking up the terminal device at the wake-up moment.

9. The method of claim 1 or 2, wherein, The method further includes: receiving second information from the first network device, the second information being used to indicate one or more of the following information: a first time window, the first time window being a time range in which the terminal device performs signal measurement determined by the first network device; a first time range, the first time range being a fluctuation range of an arrival moment of a reference signal predicted by the first network device; a first offset, used to indicate a range of an amplitude by which the terminal device can adjust an SMTC window.

10. The method of claim 9, wherein, The SMTC configuration information includes the second information, and the SMTC configuration information is carried in a radio resource management (RRC) connection release message.

11. The method of claim 1 or 2, wherein, The method further includes: receiving assistance information for the second network device from the first network device; determining the first information based on the assistance information.

12. The method of claim 1 or 2, wherein, The method further includes: if a measurement result of the reference signal meets a reselection condition, camping on the second network device through reselection.

13. A method of communication, comprising: The method is applied to a first network device, including: sending, to a terminal device, synchronization signal or physical broadcast channel block (SSB) measurement timing configuration (SMTC) configuration information and assistance information of a second network device, the second network device being a non-terrestrial network device, the SMTC configuration information being used to determine a position of an SMTC window, and the assistance information being used to determine first information, the first information being used to determine a target moment, the target moment being a cutoff moment at which the SMTC window is valid, and a first SMTC window in a time period between a current moment and the target moment being used for measurement of a reference signal; The first information includes one or more of the following information: Doppler shift information for the second network device, a transmission delay between the terminal device and the second network device, a cutoff time of a visibility window of the second network device, and a validity period of assistance information of the second network device.

14. The method of claim 13, wherein, The first SMTC window satisfies one or more of the following conditions: The first SMTC window is located in a discontinuous reception (DRX) active period of the terminal device. The first SMTC window at least partially overlaps with the DRX active period of the terminal device. The first SMTC window is the first SMTC window after the current time.

15. The method according to claim 13 or 14, characterized in that, The method further includes: determining a first delay between the terminal device and the second network device based on the assistance information of the second network device and the location information reported by the terminal device; and generating the SMTC configuration information based on the first delay.

16. The method of claim 15, wherein, The method further includes: sending, to the terminal device, first indication information used to indicate the first delay, the first delay being used by the terminal device to adjust a start time of the first SMTC window.

17. The method of claim 13 or 14, wherein, The method further includes: sending, to the terminal device, second information used to indicate one or more of the following information: a first time window, the first time window being a time range in which the terminal device performs signal measurement as determined by the first network device; a first time range, the first time range being a fluctuation range of a reference signal arrival time predicted by the first network device; and a first offset, the first offset being used to indicate a range of adjustment of the SMTC window by the terminal device.

18. The method of claim 17, wherein, The SMTC configuration information includes the second information, and the SMTC configuration information is carried in a radio resource management (RRC) connection release message.

19. A communications device, characterized by The apparatus includes at least one processor coupled with a memory, the memory storing programs or instructions, and the processor executes the programs or instructions to cause the apparatus to perform the method of any one of claims 1-12 or any one of claims 13-18.

20. A computer readable storage medium having stored thereon a computer program or instructions, characterized in that, The computer programs or instructions, when executed, cause a computer to perform the method of any one of claims 1-12 or any one of claims 13-18.

21. A communication system, characterized by The communication apparatus includes the apparatus of claim 19.

22. A chip system, characterized by The chip system includes one or more processors configured to invoke and run instructions stored in a memory, such that the method of any one of claims 1-12 or any one of claims 13-18 is executed.

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