Communication method and apparatus

Abstract

Provided in the embodiments of the present application are a communication method and apparatus. The method is executed by a terminal device or a chip applied to the terminal device. The method comprises: receiving a first system message from a network device, wherein the first system message comprises a first condition, the first condition is used for a terminal device to determine whether to receive and / or read a second system message, and the second system message comprises ephemeris information configured by the network device; determining whether the first condition is met; and when the first condition is met, receiving and / or reading the second system message. In the embodiments of the present application, a terminal device can receive and / or read a second system message only when a first condition is met, that is, ephemeris information is received and / or read only when the first condition is met, thereby reducing invalid reading of the ephemeris information, and thus reducing the measurement power consumption of the terminal device.

Description

Communication method and device

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of the People's Republic of China on September 28, 2023, with application number 202311287397.2 and invention name "A Communication Method and Device", the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the field of communication technology, and in particular to a communication method and device. Background Art

[0004] When a terminal device reselects from a terrestrial network (TN) cell to a non-terrestrial network (NTN) cell, the terminal device needs to perform neighbor measurements on the NTN cell (i.e., NTN neighbor measurements). To improve the efficiency of the terminal device's cell reselection, the TN broadcasts ephemeris information to assist the terminal device in performing neighbor measurements on the NTN cell.

[0005] Currently, after the TN broadcasts the ephemeris information, the terminal device will continue to maintain the ephemeris information. That is, the terminal device will continue to receive and read system messages to update the ephemeris information, resulting in high measurement power consumption of the terminal device.

[0006] Summary of the Invention

[0007] Embodiments of the present application provide a communication method and apparatus for reducing measurement power consumption of a terminal device.

[0008] In a first aspect, an embodiment of the present application provides a communication method, which can be executed by a terminal device or a chip system that can implement the functions of the terminal device. The method includes: receiving a first system message from a network device, the first system message including a first condition, the first condition being used by the terminal device to determine whether to receive and / or read a second system message, the second system message including ephemeris information configured by the network device; determining whether the first condition is met; and receiving and / or reading the second system message if the first condition is met.

[0009] In an embodiment of the present application, the terminal device can receive and / or read the second system message only when the first condition is met, that is, the terminal device can receive and / or read the ephemeris information only when the first condition is met, thereby reducing invalid reading of the ephemeris information and reducing the measurement power consumption of the terminal device.

[0010] In an optional embodiment, the first condition includes one or more of the following: the signal quality of the serving cell of the terminal device is lower than or equal to a first threshold; the TN neighbor measurement condition is met; TN neighbor measurement is performed; the signal quality of the TN neighbor of the serving cell of the terminal device is lower than or equal to a second threshold; or the priority of the NTN neighbor of the serving cell of the terminal device is higher than the priority of the serving cell. In this embodiment, since the terminal device reads the ephemeris information in order to perform NTN neighbor measurement, if the terminal device does not need to perform NTN neighbor measurement, then the terminal device does not need to read the ephemeris information. Therefore, the first condition can limit the terminal device's reading of ephemeris information, thereby reducing invalid reading of ephemeris information and reducing the measurement power consumption of the terminal device.

[0011] In an optional embodiment, if the signal quality of the TN neighboring area of ​​the service cell of the terminal device is lower than or equal to the second threshold, the priority of the TN neighboring area is higher than the priority of the NTN neighboring area of ​​the service cell. In this embodiment, since the priority of NTN is lower than the priority of TN, the terminal device does not need to perform NTN neighboring area measurement when there is TN coverage around the terminal device. Therefore, the terminal device can read the second system message only when all TN neighboring areas with a higher priority than the NTN neighboring area have performed neighboring area measurement and the measured signal quality is lower than or equal to the second threshold, thereby reducing the invalid reading of ephemeris information and reducing the measurement power consumption of the terminal device.

[0012] In an optional embodiment, the first system message further includes a second condition; the method further includes: performing NTN neighbor cell measurement when the second condition is met, wherein the second condition includes that the signal quality of the TN neighbor cell of the terminal device's serving cell is lower than or equal to a second threshold. In this embodiment, since the priority of NTN is lower than that of TN, the terminal device does not need to perform NTN neighbor cell measurement when there is TN coverage around the terminal device. Therefore, the terminal device can perform NTN neighbor cell measurement only when the signal quality of the TN neighbor cell is lower than or equal to the second threshold, thereby enhancing the NTN neighbor cell measurement conditions, reducing invalid measurements of NTN neighbor cells, and reducing the measurement power consumption of the terminal device.

[0013] In an optional embodiment, the priority of the TN neighboring cell is higher than the priority of the NTN neighboring cell of the serving cell. In this embodiment, since the priority of NTN is lower than that of TN, the terminal device does not need to perform NTN neighboring cell measurement when there is TN coverage around the terminal device. Therefore, the terminal device can perform NTN neighboring cell measurement only when all TN neighboring cells with a higher priority than the NTN neighboring cell have been measured and the measured signal quality is lower than or equal to the second threshold. This enhances the NTN neighboring cell measurement conditions, reduces invalid measurements of NTN neighboring cells, and reduces the measurement power consumption of the terminal device.

[0014] In an optional embodiment, the method further includes: when the first condition is not met and the second condition is met, receiving and / or reading the second system message before performing the NTN neighbor measurement. In this embodiment, since the terminal device reads the ephemeris information in order to perform the NTN neighbor measurement, if the terminal device does not need to perform the NTN neighbor measurement, then the terminal device does not need to read the ephemeris information. Therefore, the terminal device can read the second system message before performing the NTN neighbor measurement, that is, the ephemeris information is read before performing the NTN neighbor measurement, thereby reducing invalid reading of the ephemeris information and reducing the measurement power consumption of the terminal device.

[0015] In an optional embodiment, the method further includes: if the first condition is not met and the first system message also includes first indication information, receiving and / or reading the second system message, where the first indication information is used to indicate that the second system message includes the ephemeris information. In this embodiment, the terminal device can read the second system message when the first system message indicates that the second system message includes the ephemeris information, thereby reducing ineffective reading of ephemeris information and thereby reducing measurement power consumption of the terminal device.

[0016] In an optional embodiment, the first threshold is equal to the third threshold, and the third threshold is the threshold corresponding to the TN neighboring cell measurement condition. In this embodiment, the first threshold can directly reuse the threshold corresponding to the TN neighboring cell measurement condition. Since the threshold corresponding to the TN neighboring cell measurement condition complies with the provisions of the existing protocol, it has better compatibility.

[0017] In an optional embodiment, the second threshold is higher than or equal to the third threshold, and the third threshold is the threshold corresponding to the TN neighbor measurement condition. In this embodiment, the second threshold can directly reuse the threshold corresponding to the TN neighbor measurement condition. Since the threshold corresponding to the TN neighbor measurement condition complies with the provisions of the existing protocol, it has better compatibility. Alternatively, the second threshold can be higher than the threshold corresponding to the TN neighbor measurement condition, and the threshold corresponding to the TN neighbor measurement condition is the same as the threshold corresponding to the unenhanced NTN neighbor measurement condition, making the terminal device ephemeris information reading condition easier to achieve than the unenhanced NTN neighbor measurement condition, so that the terminal device can read the ephemeris information before performing the NTN neighbor measurement, and then can use the ephemeris information to perform the NTN neighbor measurement.

[0018] In a second aspect, embodiments of the present application further provide a communication method, which can be executed by a network device or a chip system capable of implementing the functions of the network device. The method includes broadcasting a first system message and a second system message, wherein the first system message includes a first condition, the first condition being used by a terminal device to determine whether to receive and / or read the second system message, and the second system message includes ephemeris information configured by the network device.

[0019] In an optional embodiment, the first condition includes one or more of the following: the signal quality of the service cell of the terminal device is lower than or equal to a first threshold; the TN neighbor cell measurement condition is met; TN neighbor cell measurement is performed; the signal quality of the TN neighbor cell of the service cell of the terminal device is lower than or equal to a second threshold; or the priority of the NTN neighbor cell of the service cell of the terminal device is higher than the priority of the service cell.

[0020] In an optional implementation, if the signal quality of the TN neighboring cell of the serving cell of the terminal device is lower than or equal to the second threshold, the priority of the TN neighboring cell is higher than the priority of the NTN neighboring cell of the serving cell.

[0021] In an optional embodiment, the first system message also includes a second condition, and the second condition is used for the terminal device to perform NTN neighbor cell measurement. The second condition includes that the signal quality of the TN neighbor cell of the service cell of the terminal device is lower than or equal to a second threshold.

[0022] In an optional implementation, the priority of the TN neighboring cell is higher than the priority of the NTN neighboring cell of the serving cell.

[0023] In an optional implementation, the first threshold is equal to the third threshold, and the third threshold is a threshold corresponding to the TN neighboring cell measurement condition.

[0024] In an optional implementation, the second threshold is higher than or equal to a third threshold, and the third threshold is a threshold corresponding to a TN neighboring cell measurement condition.

[0025] Regarding the technical effects brought about by the second aspect or some optional implementation methods, reference may be made to the introduction to the technical effects of the first aspect or corresponding implementation methods.

[0026] In a third aspect, embodiments of the present application provide a communication device comprising a processor and a memory; the memory is configured to store computer instructions, and when the device is running, the processor executes the computer instructions stored in the memory to cause the device to perform any of the implementation methods described in aspects 1 to 2 above. The memory can be volatile or non-volatile memory, such as a cache memory in a semiconductor chip.

[0027] In a fourth aspect, embodiments of the present application provide a communications device, which may be a terminal device or a network device, or a chip for a terminal device or a network device. The device has the function of implementing any of the implementation methods of the first to second aspects described above. The function may be implemented by hardware, or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above-described functions.

[0028] In a fifth aspect, an embodiment of the present application provides a communication device, comprising a unit or means for executing each step of any implementation method in the above-mentioned first to second aspects.

[0029] In a sixth aspect, an embodiment of the present application provides a communication device, comprising a processor and an interface circuit, wherein the processor is configured to communicate with other devices via the interface circuit and execute any of the implementation methods described in the first to second aspects above. The processor may be one or more processors.

[0030] In a seventh aspect, an embodiment of the present application provides a communication device, comprising a processor coupled to a memory, the processor configured to call a program stored in the memory to execute any of the implementation methods described in aspects 1 to 2 above. The memory may be located within or outside the device. The processor may also be one or more processors.

[0031] In an eighth aspect, an embodiment of the present application further provides a computer-readable storage medium, wherein instructions are stored in the computer-readable storage medium, which, when executed on a communication device, enables any implementation method in the above-mentioned first to second aspects to be executed.

[0032] In the ninth aspect, an embodiment of the present application further provides a computer program product, which includes a computer program or instructions. When the computer program or instructions are run by a communication device, any implementation method in the above-mentioned first to second aspects is executed.

[0033] In the tenth aspect, an embodiment of the present application further provides a chip system, comprising: a processor for executing any implementation method in the above-mentioned first to second aspects. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] FIG1 is a schematic diagram of an NTN system provided in an embodiment of the present application;

[0035] FIG2 is a schematic diagram of another NTN system provided in an embodiment of the present application;

[0036] FIG3 is a schematic diagram of the structure of an access network device provided in an embodiment of the present application;

[0037] FIG4 is a flow chart of a communication method provided in an embodiment of the present application;

[0038] FIG5 is a schematic diagram of the structure of a communication device provided in an embodiment of the present application;

[0039] FIG6 is a schematic diagram of the structure of a communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0040] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0041] The communication method provided in the embodiments of this application can be applied to an NTN system. The NTN system can utilize non-terrestrial network devices such as drones, high altitude platform stations (HAPS), and satellites to form a network and provide services such as data transmission and voice communication to terminal devices. Furthermore, the NTN system may also include other non-terrestrial network devices, which are not limited in this application.

[0042] The NTN system can also support various mobile communication systems, such as: new radio (NR) system, long term evolution (LTE) system or other communication systems such as future communication systems, and the specific ones are not limited here.

[0043] Taking satellites as an example of non-terrestrial network equipment in the NTN system, satellites can be categorized by their altitude, i.e., the height of their orbit, into geostationary Earth orbit (GEO), medium Earth orbit (MEO), and low-Earth orbit (LEO). GEO is a geostationary Earth orbit, in which satellites remain stationary relative to Earth. The GEO orbital altitude is typically 35,786 kilometers (km). LEO and MEO are collectively referred to as non-geostationary orbits (NGSO). Satellites in these orbits move at high speeds relative to Earth. LEO's orbital altitude is typically 160 to 2000 km, while MEO's is 2000 to 35,786 km. NGSOs can be further categorized into earth moving cells and geostationary cells (quasi-Earth fixed cells), depending on whether the satellite's beam moves with it. For earth moving cells, the cell moves relative to the ground, and the satellite's beam pointing follows the satellite's movement. For earth fixed cells or quasi-Earth fixed cells, the cell remains fixed relative to the ground for a certain period of time, and the satellite antenna can use its beamforming capability to point the beam to a fixed area on the ground for a certain period of time.

[0044] In an NTN system, NTN equipment can operate in two modes: transparent and regenerative. Based on the operating mode of the NTN equipment, the NTN system architecture can be categorized into two types: a transparent forwarding architecture, in which NTN equipment can act as relays or amplifiers, performing RF filtering and amplification, and regenerating physical layer signals. NTN equipment can be responsible for Layer 1 (L1) relaying, performing physical layer forwarding, and is invisible to higher layers. A regenerative architecture, in which NTN equipment performs the processing functions of access network equipment. For example, satellites operating in regenerative mode can be categorized as regenerative satellites without inter-satellite links (ISLs) between satellites; regenerative satellites with ISLs, in which satellites have interfaces for direct data exchange, where the ISLs are Xn ports; or regenerative satellites with the processing functions of distributed units (DUs) of access network equipment, in which case the satellites act as DUs.

[0045] For example, Figure 1 shows a schematic diagram of an NTN system applicable to embodiments of the present application. This NTN system can be a transparent forwarding architecture. In the system shown in Figure 1, a terminal device can communicate with the 5G core network (CN) through the access network, and then connect to the data network (DN) through the 5G CN. Satellites and NTN gateways can serve as relay devices between terminal devices and base stations or as remote radio units (RRUs) of base stations.

[0046] For example, Figure 2 shows a schematic diagram of another NTN system applicable to embodiments of the present application. This NTN system can be a regenerative architecture. In the system shown in Figure 2, satellites can serve as base stations, forming an access network with NTN gateways. These base stations communicate with 5G CNs through the NTN gateways, and can then connect to DNs through the 5G CNs. Furthermore, satellites can provide wireless access services to terminal devices. Figure 2 exemplifies a regenerative satellite architecture without intersatellite links.

[0047] It should be noted that Figures 1 and 2 only illustrate one satellite and one NTN gateway. In actual use, an architecture with multiple satellites and / or multiple NTN gateways may be adopted as needed. Each satellite may provide services to one or more terminal devices, each NTN gateway may correspond to one or more satellites, and each satellite may correspond to one or more NTN gateways, although this embodiment of the present application does not specifically limit this.

[0048] It should be noted that FIG. 1 and FIG. 2 are merely examples of the NTN system. The NTN system may also include other specific systems, which is not limited in this application.

[0049] The devices involved in the embodiments of the present application include terminal devices and network devices, and the network devices include, for example, terrestrial network devices (such as access network devices) and non-terrestrial network devices (such as satellites).

[0050] A terminal device, also known as user equipment (UE), mobile station (MS), or mobile terminal (MT), refers to a device that provides voice and / or data connectivity to users. For example, a terminal device can be a handheld device or vehicle-mounted device with wireless connectivity. Currently, some examples of terminal devices include: mobile phones, tablets, laptops, PDAs, mobile internet devices (MIDs), wearable devices, virtual reality (VR) devices, augmented reality (AR) devices, wireless terminals in industrial control, wireless terminals in self-driving cars, wireless terminals in remote medical surgery, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, and wireless terminals in smart homes.

[0051] Access network equipment may refer to a radio access network (RAN) node (or device), such as a base station, that connects a terminal device to a wireless network. Examples of RAN nodes include: evolved Node B (gNB), transmission reception point (TRP), evolved Node B (eNB), radio network controller (RNC), Node B (NB), base station controller (BSC), base transceiver station (BTS), home evolved Node B (HNB), base band unit (BBU), or wireless fidelity (Wi-Fi) access point (AP).

[0052] In one network architecture, access network equipment may include centralized unit (CU) nodes, distributed unit (DU) nodes, or both CU and DU nodes. RAN equipment including CU and DU nodes splits the protocol layers of the gNB in ​​the NR system, centrally controlling some protocol layer functions within the CU and distributing some or all of the remaining protocol layer functions within the DU, which is then centrally controlled by the CU, as shown in Figure 3. Furthermore, the CU can be divided into a control plane (CU-CP) and a user plane (CU-UP). The CU-CP is responsible for control plane functions, primarily including radio resource control (RRC) and the control plane's corresponding packet data convergence protocol (PDCP) (i.e., PDCP-C). PDCP-C is primarily responsible for encryption, decryption, integrity protection, and data transmission of control plane data. The CU-UP is responsible for user plane functions, primarily including the service data adaptation protocol (SDAP) and the user plane's corresponding PDCP (i.e., PDCP-U). SDAP is primarily responsible for processing core network data and mapping flows to bearers. The PDCP-U is primarily responsible for data plane encryption and decryption, integrity protection, header compression, sequence number maintenance, and data transmission. The CU-CP and CU-UP are connected via the E1 interface. The CU-CP represents the gNB's connection to the core network via the NG interface and to the DU via the F1 interface control plane (i.e., F1-C). The CU-UP connects to the DU via the F1 interface user plane (i.e., F1-U). Alternatively, the PDCP-C may also reside in the CU-UP.

[0053] It is understandable that in different systems, CU (including CU-CP or CU-UP) or DU may have different names, but those skilled in the art can understand their meanings. For example, in an open radio access network (O-RAN) system, CU may also be referred to as O-CU (open CU), DU may also be referred to as O-DU, CU-CP may also be referred to as O-CU-CP, and CU-UP may also be referred to as O-CU-UP. For the convenience of description, this application uses CU, CU-CP, CU-UP and DU as examples for description.

[0054] In the embodiments of the present application, the communication device for implementing the functions of a network device or a terminal device may be the network device or the terminal device itself, or may be a device capable of supporting the network device or the terminal device to implement the functions, such as a chip system, which may be installed in the network device or the terminal device. In the technical solutions provided in the embodiments of the present application, the technical solutions provided in the embodiments of the present application are described by taking the case where the device for implementing the functions of a network device is a network device, and the case where the device for implementing the functions of a terminal device is a terminal device as an example.

[0055] In the embodiments of the present application, the number of nouns, unless otherwise specified, means "singular noun or plural noun", that is, "one or more". "At least one" means one or more, and "plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. For example, A / B means: A or B. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single items or plural items.

[0056] In the embodiments of this application, ordinal numbers such as "first" and "second" are used to distinguish multiple objects and are not used to limit the size, content, sequence, timing, priority, or importance of the multiple objects. For example, the first system message and the second system message can be the same system message or different system messages, and such names do not indicate a difference in priority or importance between the two system messages.

[0057] The above briefly introduces the communication system applicable to the embodiments of the present application. The following introduces the relevant technical solutions involved in the embodiments of the present application.

[0058] 1) System Information (SI)

[0059] SI consists of a master information block (MIB) and multiple system information blocks (SIBs). System information can be further divided into minimum SI and other SI. Minimum SI includes basic information required for initial access and information for obtaining any other SI.

[0060] The minimum SI includes MIB and SIB1. Among them, MIB contains cell barring status information and configuration information required for further receiving system messages, such as control resource set (CORSET) #0 configuration. MIB is broadcast periodically through the broadcast channel (BCH). SIB1 contains scheduling information of other SIBs and basic information required for initial access. SIB1 is also called remaining minimum system information (RMSI). SIB1 is broadcast periodically through the downlink shared channel (DL-SCH) or sent to terminal devices in the RRC connected state (RRC_CONNECTED) through dedicated signaling.

[0061] Other SI includes all SIBs that are not broadcast in the minimum SI. These SIBs can be broadcast periodically on DL-SCH, on-demand on DL-SCH, that is, a terminal device in RRC idle state (RRC_IDLE), RRC inactive state (RRC_INACTIVE) or RRC_CONNECTED sends a request to the network side, or sent in a dedicated manner on DL-SCH to a terminal device in RRC_CONNECTED.

[0062] The SIBs related to cell reselection include: SIB2, SIB3 and SIB4. Among them, SIB2 contains cell reselection information, which is mainly related to the serving cell; SIB3 contains the serving frequency and co-frequency neighboring cell information related to cell reselection (including cell reselection parameters common to the frequency and cell-specific reselection parameters); SIB4 contains information about other NR frequencies and inter-frequency neighboring cells related to cell reselection (including cell reselection parameters common to the frequency and cell-specific reselection parameters), which can also be used for NR idle / inactive state measurements;

[0063] The SIB currently carrying ephemeris information is SIB19 (NR NTN) or SIB31 (Internet of Things (IoT) NTN). SIB19 contains the information required for cell access in the NTN system, primarily including ephemeris information for the serving cell's satellite, ephemeris information for neighboring cells, the serving cell's reference position, range threshold, remaining service time, and other parameters. The satellite's ephemeris information includes orbital parameters, or parameters such as the satellite's position calculated based on the orbital parameters. It is understood that the satellite's ephemeris information can be used to calculate, predict, depict, or track the satellite's flight time, position, speed, and other states.

[0064] 2) Cell reselection

[0065] The terminal device selects a cell with better signal quality to reside in through neighboring cell measurement. The terminal device considers two parameters when initiating neighboring cell measurement: cell priority and the signal quality of the current serving cell. Specifically, if the neighboring cell priority is higher than the current serving cell priority, the measurement is initiated unconditionally. If the neighboring cell priority is lower than or equal to the current serving cell priority, the terminal device measures the signal quality of the current serving cell and compares it with the quality standard issued by the network. If the signal quality of the terminal device's current serving cell is above the threshold, the neighboring cell measurement is not initiated; otherwise, the neighboring cell measurement is initiated.

[0066] Terminal devices can obtain neighboring cell information and priority information from the system message of the current serving cell. Neighboring cell information and priority information are generally configured by the network side and sent to terminal devices through cell broadcast. The value range of the cell reselection priority parameter (CellReselectionPriority) is (0-7). The larger the value of this parameter, the higher the reselection priority of all cells on the corresponding carrier frequency. NR also configures a cell reselection sub-priority parameter (CellReselectionSubPriority) for each carrier frequency, with a value of 0.2, 0.4, 0.6 or 0.8.

[0067] For example, if the neighboring cell priority is higher than the serving cell priority, the neighboring cell measurement is started unconditionally.

[0068] Neighboring cell priority equals serving cell priority: If the neighboring cell and serving cell are co-frequency cells, and the serving cell's cell selection received signal strength value (Srxlev) is lower than or equal to the threshold SIntraSearchP, and the serving cell's cell selection received signal quality value (Squal) is lower than or equal to the threshold SIntraSearchQ, the terminal device performs neighboring cell intra-frequency measurement. If the neighboring cell and serving cell are inter-frequency cells, and the serving cell's Srxlev is lower than or equal to the threshold SnonIntraSearchP, and the serving cell's Squal is lower than or equal to the threshold SnonIntraSearchQ, the terminal device performs neighboring cell inter-frequency measurement.

[0069] The neighboring cell priority is lower than the serving cell priority: if the serving cell's Srxlev is lower than or equal to the threshold SnonIntraSearchP, and the serving cell's Squal is lower than or equal to the threshold SnonIntraSearchQ, the terminal device performs neighboring cell inter-frequency measurement or neighboring cell inter-system (inter-RAT) measurement.

[0070] 3) NTN-TN neighboring cell measurement

[0071] For the scenario where the terminal device reselects from an NTN cell to a TN cell, the terminal device needs to perform neighbor measurements on the TN cell (i.e., TN neighbor measurements). For example, in order to improve the efficiency of cell reselection or measurement of the terminal device, NTN will broadcast TN coverage information. After receiving the TN coverage information, the terminal device can determine whether to perform neighbor measurements on the TN cell based on the TN coverage information. If there is no TN coverage at the current location of the terminal device, the terminal device does not perform TN neighbor measurements, thereby reducing the measurement power consumption of the terminal device. For the scenario where the terminal device reselects from a TN cell to an NTN cell, the terminal device needs to perform neighbor measurements on the NTN cell (i.e., NTN neighbor measurements). For example, in order to improve the efficiency of cell reselection or measurement of the terminal device, TN will broadcast the ephemeris information of the NTN cell to assist the terminal device in performing neighbor measurements on the NTN cell. In addition, since the priority of NTN is lower than that of TN, the terminal device does not need to perform neighbor measurements on the NTN cell when there is TN coverage around the terminal device.

[0072] Currently, after the TN broadcasts the NTN cell's ephemeris information, the terminal device will continuously maintain the NTN cell's ephemeris information. That is, the terminal device will continuously read system messages to update the NTN cell's ephemeris information. However, since the terminal device reads the NTN cell's ephemeris information in order to perform neighboring cell measurements on the NTN cell, if the terminal device does not need to perform neighboring cell measurements on the NTN cell, then the terminal device does not need to read the NTN cell's ephemeris information. Therefore, the terminal device unconditionally reads the NTN cell's ephemeris information, which only increases the terminal device's measurement power consumption.

[0073] 4) Advance Neighborhood Measurement

[0074] Narrow band Internet of things (NB-IoT) introduces a connection-state neighbor measurement technology, which can carry out neighbor measurements in advance when the quality of the wireless link of the current serving cell deteriorates, so that the RRC connection can be quickly reestablished when the terminal device detects a radio link failure. Specifically, the terminal device is configured to perform neighbor measurements in advance based on the signal quality of the current serving cell, or the distance between the terminal device and the reference position of the current serving cell, or the remaining service time of the current serving cell (or the time when the current serving cell stops providing services to the covered area). Exemplarily, the process of early neighbor measurement is as follows:

[0075] When the terminal device changes from RRC_IDLE or RRC_INACTVE to RRC_CONNECTED, the terminal device can perform the following operations:

[0076] If SIB3 carries the configuration information of advance measurement (such as neighCellMeasCriteria), the terminal device sets the reference value (NRSRPRef) of the narrowband reference signal receiving power (NRSRP) to the latest serving cell measurement result, which can be used for cell selection or reselection. Among them, neighCellMeasCriteria contains two parameters: s-MeasureDeltaP and t-MeasureDeltaP, s-MeasureDeltaP indicates the change threshold of the NRSRP of the serving cell for the terminal device in RRC_CONNECTED to trigger neighbor measurement, and t-MeasureDeltaP indicates the duration of the neighbor measurement for the terminal device in RRC_CONNECTED.

[0077] Alternatively, if the system message SIB3 carries neighCellMeasCriteria and the relaxed measurement conditions are not met, the terminal device starts timer T326 and sets the length of timer T326 to t-MeasureDeltaP. The relaxed measurement conditions refer to conditions under which the terminal device may not perform neighboring area measurements, for example, if the terminal device is in the center of the cell, the terminal device may not perform neighboring area measurements, or if the terminal device is moving at a low speed, the terminal device may not perform neighboring area measurements or reduce neighboring area measurements. Timer T326 is used to control the measurement time of advance measurement. If timer T326 times out, the terminal device stops advance measurement.

[0078] When the terminal device is in RRC_CONNECTED, the terminal device can perform the following operations:

[0079] If SIB3 carries neighCellMeasCriteria and the difference between NRSRPRef and the first difference is higher than s-MeasureDeltaP, the terminal device can set NRSRPRef equal to the first difference, where the first difference is the difference between NRSRP and the transmit power offset (nrs-PowerOffsetNonAnchor), or the terminal device can start or restart timer T326 and set its length to t-MeasureDeltaP.

[0080] Alternatively, if SIB3 does not carry neighCellMeasCriteria or if timer T326 is running, the terminal device can perform neighbor cell intra-frequency measurement when the first difference is lower than the threshold s-MeasureIntra, and perform neighbor cell inter-frequency measurement when the first difference is lower than the threshold s-MeasureInter.

[0081] Alternatively, if SIB3 carries the service stop time (t-service) of the serving cell, the terminal device may perform neighboring cell same-frequency measurement or neighboring cell different-frequency measurement before the service stop time expires. The specific time when the neighboring cell measurement is performed is up to the terminal device to implement. Alternatively, the terminal device may carry the neighboring cell service start time (or also called the neighboring cell coverage start time, such as t-ServiceStartNeigh) in SIB3, and perform neighboring cell same-frequency measurement or neighboring cell different-frequency measurement on or after the arrival of t-ServiceStartNeigh. The specific time when the neighboring cell measurement is performed is up to the terminal device to implement.

[0082] Alternatively, if SIB3 carries the reference location (referenceLocation) and distance threshold (distanceThresh) of the serving cell, the terminal device may perform neighboring cell measurement when the distance between the terminal device and the reference location of the serving cell is lower than the distance threshold.

[0083] However, since the above neighbor cell measurement conditions only consider the signal quality of the current serving cell, the distance between the terminal device and the reference location of the current serving cell, or the remaining service time of the current serving cell, the priority of TN and NTN are not taken into account. If a TN neighbor cell exists, the terminal device does not need to perform neighbor cell measurement on the NTN cell. Unconditionally performing neighbor cell measurement on the NTN cell will only increase invalid neighbor cell measurements of the terminal device, thereby increasing the measurement power consumption of the terminal device.

[0084] 5) Reading ephemeris information

[0085] For NB-IoT, the ephemeris information of the satellite of the serving cell is carried in SIB31, for example, in SystemInformationBlockType31 (or for NB-IOT, the system message is SystemInformationBlockType31-NB). The ephemeris information of the satellite of the neighboring cell is carried in the newly defined SIB. For a terminal device in RRC_CONNECTED, the process of reading the ephemeris information of the serving cell is as follows: When the terminal device obtains the ephemeris information of the serving cell, the terminal device starts timer T317, for example, according to the reference start time (e.g., epoch time) of the validity period of the ephemeris information of the satellite specified in SystemInformationBlockType31, and the duration of timer T317 is the validity period of the ephemeris information of the satellite specified in SystemInformationBlockType31 (e.g., ul-syncValidityDuration). If timer T317 times out, the terminal device determines that the ephemeris information of the serving cell is expired. At this time, the terminal device can start timer T318 to obtain SIB31 and / or a new SIB carrying the ephemeris information of the neighboring cell. After the terminal device obtains the ephemeris information of the serving cell, it will stop timer T318. After stopping timer T318, the terminal device will no longer read the ephemeris information of the neighboring cell. However, when the terminal device stops timer T318, the ephemeris information of the neighboring cell may not have been obtained. If timer T318 times out, for NB-IOT terminal devices that have not activated access side security and do not support transmission optimization through the control plane, the terminal device enters RRC_IDLE. Otherwise, the terminal device initiates RRC reestablishment.

[0086] In order to solve the above-mentioned problem of high measurement power consumption of the terminal device due to unconditional reading of ephemeris information and unconditional neighboring cell measurement of the NTN cell, the embodiment of the present application provides the following embodiment 1 solution, which is described in detail below.

[0087] Example 1

[0088] The present application provides a communication method to reduce the measurement power consumption of a terminal device. This method can be applied to scenarios where a terminal device reselects from a TN cell to an NTN cell and performs NTN neighbor measurements. Alternatively, this method can be applied to scenarios where a terminal device in the RRC_CONNECTED state in NB-IoT performs NTN neighbor measurements in advance to quickly initiate RRC connection reestablishment.

[0089] As shown in Figure 4, a flow chart of a communication method provided in an embodiment of the present application is provided. In the following description, the method is performed by a network device (or a chip applied to a network device) and a terminal device (or a chip applied to a terminal device) as an example. The method includes:

[0090] S401: The network device broadcasts a first system message and a second system message. Correspondingly, the terminal device receives the first system message from the network device.

[0091] Among them, the first system message may include a first condition (also known as an ephemeris information reception and / or reading condition), and the first condition may be used for the terminal device to receive and / or read the second system message, and the second system information may include the ephemeris information configured by the network device, and the ephemeris information is the ephemeris information of the NTN neighboring cell of the service cell. Optionally, the first system message may be SIB1, SIB2, SIB3, SIB4 or other system messages, and the second system message may be SIB19, SIB31 or other system messages. Optionally, the network device is a network device corresponding to a TN cell, which can be understood as the network device providing TN services for the terminal device, or the service cell of the terminal device is a TN cell. It can be understood that the terminal device in the implementation of this application is currently residing in or accessing a cell under the network device.

[0092] Exemplarily, the network device may broadcast a second system message. The second system message may include satellite-related information. The satellite-related information may include NTN configuration information (NTN-Config). The NTN configuration information includes parameters required for the terminal device to access the satellite, such as ephemeris information, common timing advance (TA), scheduling offset (K_offset), uplink synchronization time validity period, or ephemeris information validity period reference start time. The satellite-related information may also include one or more of the following: the out-of-service time of the serving cell, which indicates when the cell provided by the NTN quasi-earth fixed system stops serving the area currently covered by it; the reference position of the serving cell, which indicates the reference position of the cell provided by the NTN quasi-earth fixed system, and is used to start the location-based measurement in RRC_IDLE and RRC_INACTIVE; the distance threshold, which indicates the distance threshold from the reference position of the serving cell, and is used to start the location-based measurement in RRC_IDLE and RRC_INACTIVE; NTN neighbor cell configuration information (NTN-NeighCellConfig), which includes the configuration information of the satellite of the neighbor cell, the frequency information of the neighbor cell, and the cell identifier of the neighbor cell.

[0093] In one possible implementation, the first condition may include one or more of the following:

[0094] The signal quality of the serving cell is lower than or equal to a first threshold. The signal quality of the serving cell may be a reference signal received power (RSRP) of the serving cell, a reference signal received quality (RSRQ) of the serving cell, or a value determined based on the RSRP of the serving cell and the RSRQ of the serving cell, such as Srxlev of the serving cell and Squal of the serving cell;

[0095] Neighboring cell measurement conditions are met, where the neighboring cell measurement conditions may include high-priority neighboring cell measurement conditions, equal-priority neighboring cell measurement conditions, and low-priority neighboring cell measurement conditions. For example, the neighboring cell measurement conditions may include one or more of the following: the priority of the neighboring cell is higher than the priority of the serving cell, and the terminal device unconditionally starts the neighboring cell measurement; the priority of the neighboring cell is equal to the priority of the serving cell, if the neighboring cell and the serving cell are co-frequency cells, the Srxlev of the serving cell is lower than or equal to the threshold SIntraSearchP and the Squal of the serving cell is lower than or equal to the threshold SIntraSearchQ, then the terminal device starts the neighboring cell co-frequency measurement; if the neighboring cell and the serving cell are inter-frequency cells, the Srxlev of the serving cell is lower than or equal to the threshold SnonIntraSearchP and the Squal of the serving cell is lower than or equal to the threshold SnonIntraSearchQ, then the terminal device starts the neighboring cell inter-frequency measurement; the priority of the neighboring cell is lower than the priority of the serving cell, if the Srxlev of the serving cell is lower than or equal to the threshold SnonIntraSearchP and the Squal of the serving cell is lower than or equal to the threshold SnonIntraSearchQ, then the terminal device starts the neighboring cell inter-frequency measurement or the neighboring cell inter-system measurement;

[0096] TN neighbor cell measurement conditions are met. Among them, the TN neighbor cell measurement conditions may include one or more of the following: the priority of the TN neighbor cell is higher than the priority of the serving cell, and the terminal device unconditionally starts the TN neighbor cell measurement; the priority of the TN neighbor cell is equal to the priority of the serving cell, if the TN neighbor cell and the serving cell are co-frequency cells, the Srxlev of the serving cell is lower than or equal to the threshold SIntraSearchP and the Squal of the serving cell is lower than or equal to the threshold SIntraSearchQ, then the terminal device starts the TN neighbor cell co-frequency measurement; if the TN neighbor cell and the serving cell are inter-frequency cells, the Srxlev of the serving cell is lower than or equal to the threshold SnonIntraSearchP and the Squal of the serving cell is lower than or equal to the threshold SnonIntraSearchQ, then the terminal device starts the TN neighbor cell inter-frequency measurement; the priority of the TN neighbor cell is lower than the priority of the serving cell, if the Srxlev of the serving cell is lower than or equal to the threshold SnonIntraSearchP and the Squal of the serving cell is lower than or equal to the threshold SnonIntraSearchQ, then the terminal device starts the TN neighbor cell inter-frequency measurement or the neighbor cell inter-system measurement;

[0097] Conduct TN neighboring cell measurements;

[0098] The signal quality of the TN neighboring cells of the serving cell is lower than or equal to the second threshold. Optionally, the priority of the TN neighboring cells of the serving cell is higher than the priority of the NTN neighboring cells of the serving cell. The signal quality of the TN neighboring cells of the serving cell may be the RSRP of the TN neighboring cells of the serving cell, the RSRQ of the TN neighboring cells of the serving cell, or a value determined based on the RSRP of the TN neighboring cells of the serving cell and the RSRQ of the TN neighboring cells of the serving cell, such as the Srxlev of the TN neighboring cells of the serving cell and the Squal of the TN neighboring cells of the serving cell;

[0099] Or, the priority of the NTN neighboring cell of the serving cell is higher than the priority of the serving cell.

[0100] In one possible implementation, the first threshold may be equal to the third threshold, and the second threshold may be greater than or equal to the third threshold. The third threshold may be a threshold corresponding to the aforementioned TN neighboring cell measurement condition. For example, the first threshold may be equal to the threshold SnonIntraSearchP and the threshold SnonIntraSearchQ, or may be the threshold SIntraSearchP and the threshold SIntraSearchQ. For another example, the second threshold may be greater than or less than the threshold SIntraSearchP and the threshold SIntraSearchQ, or may be greater than or less than the threshold SnonIntraSearchP and the threshold SnonIntraSearchQ.

[0101] S402: The terminal device determines whether a first condition is met, and receives and / or reads a second system message if the first condition is met.

[0102] Reading the second system message may be understood as reading the ephemeris information in the second system message.

[0103] Exemplarily, the first condition includes that the signal quality of the serving cell is lower than or equal to a first threshold, and the terminal device may receive and / or read the second system message when the signal quality of the serving cell is lower than or equal to the first threshold. Otherwise, the terminal device does not need to receive and / or read the second system message.

[0104] Alternatively, the above-mentioned first condition includes the above-mentioned TN neighbor area measurement condition or performs TN neighbor area measurement, and the terminal device may receive and / or read the second system message when the above-mentioned TN neighbor area measurement condition is met or TN neighbor area measurement is performed. Otherwise, the terminal device does not need to receive and / or read the second system message. For example, because the terminal device will conditionally start TN neighbor area measurement when the priority of the TN neighbor area is higher than the priority of the serving cell, and the terminal device will not unconditionally start TN neighbor area measurement when the priority of the TN neighbor area is equal to or lower than the priority of the serving cell. Therefore, the terminal device may not perform TN neighbor area measurement immediately after the priority of the TN neighbor area is equal to or lower than the priority of the serving cell and the above-mentioned TN neighbor area measurement condition is met, but may first receive and / or read the second system message. It can be understood that the terminal device receives and / or reads the second system message after the above-mentioned TN neighbor area measurement condition is met. Alternatively, the terminal device may also perform TN neighbor area measurement after meeting the above-mentioned TN neighbor area measurement condition, and receive and / or read the second system message at the same time.

[0105] Alternatively, the above-mentioned first condition includes that the signal quality of the TN neighboring area of ​​the serving cell is lower than or equal to the second threshold. Optionally, when the priority of the TN neighboring area of ​​the serving cell is higher than the priority of the NTN neighboring area of ​​the serving cell, the terminal device can receive and / or read the second system message when the signal quality of the TN neighboring area of ​​the serving cell is lower than or equal to the second threshold, and the priority of the TN neighboring area of ​​the serving cell is higher than the priority of the NTN neighboring area of ​​the serving cell. Otherwise, the terminal device does not need to receive and / or read the second system message. It can be understood that the terminal device can read the second system message when all TN neighboring areas with a priority higher than the NTN neighboring area have performed neighboring area measurements and the measured signal quality is lower than or equal to the second threshold. Alternatively, it can also be understood that the terminal device receives and / or reads the second system message when it determines that NTN neighboring area measurements are required. Alternatively, the terminal device can receive and / or read the second system message when the priority of the NTN neighboring area of ​​the serving cell is higher than the priority of the serving cell.

[0106] Alternatively, the first condition includes the neighboring cell measurement condition, and the terminal device may receive and / or read the second system message when the neighboring cell measurement condition is met. Otherwise, the terminal device does not need to receive and / or read the second system message.

[0107] According to the above scheme, the terminal device can read the ephemeris information only when the signal quality of the serving cell is lower than or equal to the first threshold, or meets the TN neighbor measurement conditions, or meets the neighbor measurement conditions, or performs TN neighbor measurement, or the signal quality of the TN neighbor of the serving cell is lower than or equal to the second threshold, or the priority of the NTN neighbor of the serving cell is higher than the priority of the serving cell, thereby reducing invalid reading of ephemeris information and reducing the measurement power consumption of the terminal device.

[0108] In a possible implementation, the first system message may include the first condition and the second condition (also known as the enhanced NTN neighbor measurement condition), or the first system message may not include the first condition but only include the second condition.

[0109] The second condition may include that the signal quality of the TN neighboring cell of the serving cell is lower than or equal to the second threshold. Optionally, the priority of the TN neighboring cell of the serving cell is higher than the priority of the NTN neighboring cell of the serving cell.

[0110] The unenhanced NTN neighbor measurement conditions are the same as the above-mentioned TN neighbor measurement conditions. For example, the unenhanced NTN neighbor measurement conditions may include one or more of the following: the priority of the NTN neighbor is higher than the priority of the serving cell, and the terminal device unconditionally starts the NTN neighbor measurement; the priority of the NTN neighbor is equal to the priority of the serving cell. If the NTN neighbor and the serving cell are co-frequency cells, the Srxlev of the serving cell is lower than or equal to the threshold SIntraSearchP and the Squal of the serving cell is lower than or equal to the threshold SIntraSearchQ, then the terminal device starts the NTN neighbor co-frequency measurement. If the NTN If the neighboring cell and the serving cell are inter-frequency cells, the Srxlev of the serving cell is lower than or equal to the threshold SnonIntraSearchP and the Squal of the serving cell is lower than or equal to the threshold SnonIntraSearchQ, the terminal device starts the NTN neighboring cell inter-frequency measurement; the priority of the NTN neighboring cell is lower than the priority of the serving cell. If the Srxlev of the serving cell is lower than or equal to the threshold SnonIntraSearchP and the Squal of the serving cell is lower than or equal to the threshold SnonIntraSearchQ, the terminal device starts the NTN neighboring cell inter-frequency measurement or the neighboring cell inter-system measurement.

[0111] The terminal device can perform NTN neighbor cell measurement when the second condition is met. It can be understood that the terminal device can perform NTN neighbor cell measurement when all TN neighbor cells with a higher priority than the NTN neighbor cell have been measured and the measured signal quality is lower than or equal to the second threshold. Optionally, the terminal device can perform NTN neighbor cell measurement when the unenhanced NTN neighbor cell measurement condition is met.

[0112] For example, the priority of the TN neighboring cell is higher than the priority of the serving cell:

[0113] The terminal device unconditionally starts TN neighbor cell measurement and obtains the Srxlev and Squal of the TN neighbor cell. If the Srxlev of the TN neighbor cell is lower than or equal to the threshold SIntraSearchP, and the Squal of the TN neighbor cell is lower than or equal to the threshold SIntraSearchQ, or if the Srxlev of the TN neighbor cell is lower than or equal to the threshold SnonIntraSearchP, and the Squal of the TN neighbor cell is lower than or equal to the threshold SnonIntraSearchQ, the terminal device performs NTN neighbor cell measurement.

[0114] The priority of a TN neighbor cell is equal to the priority of the serving cell:

[0115] If the TN neighbor cell and the serving cell are co-frequency cells, the serving cell's Srxlev is lower than or equal to the threshold SIntraSearchP, and the serving cell's Squal is lower than or equal to the threshold SIntraSearchQ, the terminal device initiates TN neighbor cell co-frequency measurement to obtain the TN neighbor cell's Srxlev and TN neighbor cell's Squal. If the TN neighbor cell's Srxlev is lower than or equal to the threshold SIntraSearchP, and the TN neighbor cell's Squal is lower than or equal to the threshold SIntraSearchQ, the terminal device performs NTN neighbor cell measurement.

[0116] If the TN neighbor cell and the serving cell are inter-frequency cells, the Srxlev of the serving cell is lower than or equal to the threshold SnonIntraSearchP, and the Squal of the serving cell is lower than or equal to the threshold SnonIntraSearchQ, the terminal device initiates TN neighbor cell inter-frequency measurement to obtain the Srxlev and Squal of the TN neighbor cell. If the Srxlev of the TN neighbor cell is lower than or equal to the threshold SnonIntraSearchP, and the Squal of the TN neighbor cell is lower than or equal to the threshold SnonIntraSearchQ, the terminal device performs NTN neighbor cell measurement.

[0117] The priority of the TN neighbor cell is lower than that of the serving cell:

[0118] If the Srxlev of the serving cell is lower than or equal to the threshold SnonIntraSearchP and the Squal of the serving cell is lower than or equal to the threshold SnonIntraSearchQ, the terminal device initiates TN neighbor cell inter-frequency measurement or neighbor cell inter-system measurement to obtain the Srxlev and Squal of the TN neighbor cell. If the Srxlev of the TN neighbor cell is lower than or equal to the threshold SnonIntraSearchP and the Squal of the TN neighbor cell is lower than or equal to the threshold SnonIntraSearchQ, the terminal device performs NTN neighbor cell measurement.

[0119] In one possible implementation, the terminal device may receive and / or read the second system message before performing the NTN neighbor cell measurement if the first condition is not met but the second condition is met. Otherwise, the terminal device does not need to receive and / or read the second system message.

[0120] In one possible implementation, the terminal device may receive and / or read the second system message if the first condition is not met and the first system message also includes first indication information. Otherwise, the terminal device does not need to receive and / or read the second system message. The first indication information is used to indicate that the second system message includes ephemeris information.

[0121] Exemplarily, when the terminal device changes from RRC_IDLE or RRC_INACTVE to RRC_CONNECTED, the terminal device may perform the following operations:

[0122] If SIB3 carries neighCellMeasCriteria, the terminal device sets NRSRPRef to the latest serving cell measurement result, which can be used for cell selection or reselection.

[0123] Alternatively, if the system message SIB3 carries neighCellMeasCriteria and the relaxed measurement condition is not met, the terminal device starts timer T326 and sets the length of timer T326 to t-MeasureDeltaP.

[0124] When the terminal device is in the RRC_CONNECTED state, the terminal device can perform the following operations:

[0125] If SIB3 carries neighCellMeasCriteria and the difference between NRSRPRef and the first difference is higher than s-MeasureDeltaP, the terminal device can set NRSRPRef equal to the first difference, where the first difference is the difference between NRSRP and nrs-PowerOffsetNonAnchor, or the terminal device can start or restart timer T326 and set its length to t-MeasureDeltaP.

[0126] Alternatively, if SIB3 does not carry neighCellMeasCriteria or if timer T326 is running, the terminal device can perform neighbor cell intra-frequency measurement when the first difference is lower than the threshold s-MeasureIntra, and perform TN neighbor cell inter-frequency measurement when the first difference is lower than the threshold s-MeasureInter.

[0127] Furthermore, if the signal quality of the TN neighboring area of ​​the serving cell is lower than or equal to the second threshold, the terminal device may perform NTN neighboring area measurement, and optionally, the priority of the TN neighboring area of ​​the serving cell is higher than the priority of the NTN neighboring area of ​​the serving cell. It can be understood that the terminal device may perform NTN neighboring area measurement if the enhanced NTN neighboring area measurement condition is met. The enhanced NTN neighboring area measurement condition includes that the signal quality of the TN neighboring area of ​​the serving cell is lower than or equal to the second threshold, and optionally, the priority of the TN neighboring area of ​​the serving cell is higher than the priority of the NTN neighboring area of ​​the serving cell.

[0128] Optionally, the terminal device may receive and / or read the second system message when one or more of the following conditions are met: the signal quality of the serving cell is less than or equal to the first threshold; a neighboring cell measurement condition is met; a TN neighboring cell measurement condition is met; a TN neighboring cell measurement is performed; an NTN neighboring cell measurement condition is met; or an NTN neighboring cell measurement is performed. Otherwise, the terminal device does not need to receive and / or read the second system message. The terminal device may then perform NTN neighboring cell measurements based on the ephemeris information read from the second system message. The NTN neighboring cell measurement condition may be the enhanced NTN neighboring cell measurement condition described above, or the non-enhanced NTN neighboring cell measurement condition described above.

[0129] Alternatively, if SIB3 carries the service outage time of the serving cell, the terminal device may perform neighboring cell same-frequency measurement or neighboring cell different-frequency measurement before the service outage time expires. The specific time when the neighboring cell measurement is performed is up to the terminal device to implement. Alternatively, the terminal device may perform neighboring cell same-frequency measurement or neighboring cell different-frequency measurement when t-ServiceStartNeigh arrives or after SIB3 carries t-ServiceStartNeigh. The specific time when the neighboring cell measurement is performed is up to the terminal device to implement.

[0130] Alternatively, if SIB3 carries the reference position and distance threshold of the serving cell, the terminal device may perform neighboring cell measurement when the distance between the terminal device and the reference position of the serving cell is lower than the distance threshold.

[0131] According to the above solution, the terminal device can perform neighbor cell measurement on the NTN cell only when the signal quality of the TN neighbor cell of the serving cell is lower than or equal to the second threshold, thereby reducing invalid measurements of the NTN neighbor cell and reducing the measurement power consumption of the terminal device.

[0132] In order to solve the above-mentioned problem that the terminal device stops timer T318 because it obtains the ephemeris information of the serving cell, resulting in the ephemeris information of the neighboring cell not being obtained, the present application implements the solution of the following embodiment 2, which can be implemented in combination with the above-mentioned embodiment 1, and is described in detail below.

[0133] Example 2

[0134] In this embodiment 2, the terminal device may postpone stopping timer T318. Specifically, if timer T317 times out, the terminal device may start timer T318 and obtain SIB31. Furthermore, if the ephemeris information of the neighboring cell expires, the terminal device may obtain a new SIB carrying the ephemeris information of the neighboring cell. The terminal device may stop timer T318 if it successfully obtains SIB31 and a new SIB carrying the ephemeris information of the neighboring cell. Optionally, timer T317 may correspond to the ephemeris information of the serving cell (i.e., the ephemeris information of the serving cell expires when timer T317 times out), or timer T317 may correspond to the ephemeris information of the neighboring cell (i.e., the ephemeris information of the neighboring cell expires when timer T317 times out). When timer T318 stops or times out, the terminal device no longer reads SIB31 and the new SIB carrying the ephemeris information of the neighboring cell.

[0135] Alternatively, the terminal device may define a new timer T318x. Timer T318x may correspond to the time for obtaining the ephemeris information of the neighboring cell, while timer T318 may correspond to the time for obtaining the ephemeris information of the serving cell. The terminal device may continue to read the ephemeris information of the neighboring cell if timer T318 stops or times out, and may stop timer T318x if the ephemeris information of the neighboring cell is successfully obtained.

[0136] Specifically, if timer T317 times out, the terminal device may start timer T318 and obtain SIB31. Further, if the ephemeris information of the neighboring cell expires, the terminal device may obtain a new SIB carrying the ephemeris information of the neighboring cell. The terminal device may stop timer T318 if SIB31 is successfully obtained. If the ephemeris information of the neighboring cell expires or the terminal device has not yet obtained a new SIB carrying the ephemeris information of the neighboring cell, the terminal device may start timer T318x, and then the terminal device may stop timer T318x if the ephemeris information of the neighboring cell is successfully obtained. Optionally, timer T317 may correspond to the ephemeris information of the serving cell (i.e., the ephemeris information of the serving cell expires when timer T317 times out), or timer T317 may correspond to the ephemeris information of the neighboring cell (i.e., the ephemeris information of the neighboring cell expires when timer T317 times out). When timer T318 stops or times out, for NB-IoT devices that have not activated access side security and do not support control plane transmission optimization, the terminal device enters RRC_IDLE. Otherwise, the terminal device initiates RRC reestablishment. When T318x stops or times out, the terminal device no longer reads the new SIB carrying the ephemeris information of the neighboring cells.

[0137] Alternatively, the terminal device may define a new timer, T318y. Timer T318y may correspond to the time for obtaining the ephemeris information of the neighboring cell, while timer T318 may correspond to the time for obtaining the ephemeris information of the serving cell. The terminal device may stop timer T318y if the ephemeris information of the neighboring cell is successfully obtained.

[0138] Specifically, if timer T317 times out, the terminal device may start timer T318 and obtain SIB31. Further, if the ephemeris information of the neighboring cell expires, the terminal device may start timer T318y and obtain a new SIB carrying the ephemeris information of the neighboring cell. The terminal device may stop timer T318 if SIB31 is successfully obtained. At this time, although the terminal device stops obtaining SIB 31, it may continue to obtain the ephemeris information of the neighboring cell. The terminal device may stop timer T318y if the ephemeris information of the neighboring cell is successfully obtained. At this time, although the terminal device stops obtaining the new SIB carrying the ephemeris information of the neighboring cell, it may continue to obtain SIB31. Optionally, timer T317 may correspond to the ephemeris information of the serving cell (i.e., the ephemeris information of the serving cell expires when timer T317 times out), or timer T317 may correspond to the ephemeris information of the neighboring cell (i.e., the ephemeris information of the neighboring cell expires when timer T317 times out). When timer T318 stops or times out, for NB-IoT devices that have not activated access side security and do not support control plane transmission optimization, the terminal device enters RRC_IDLE. Otherwise, the terminal device initiates RRC reestablishment. When timer T318y stops or times out, the terminal device can no longer read the new SIB carrying the ephemeris information of the neighboring cells.

[0139] According to the above solution, the terminal device can postpone stopping timer T318 or newly define a new timer to control the reading of the ephemeris information of the neighboring cell, thereby ensuring that the terminal device successfully obtains the ephemeris information of the neighboring cell.

[0140] In the embodiments of the present application, the network device or terminal device may perform some or all of the steps in the embodiments of the present application. These steps or operations are merely examples, and the embodiments of the present application may also perform other operations or variations of various operations. In addition, the various steps may be performed in a different order than those presented in the embodiments of the present application, and it is possible that not all of the operations in the embodiments of the present application need to be performed.

[0141] To implement the functions in the above embodiments, the network device or terminal device includes hardware structures and / or software modules that perform the corresponding functions. Those skilled in the art should readily appreciate that, in conjunction with the units and method steps of the various examples described in the embodiments disclosed in this application, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in hardware or in a manner driven by computer software depends on the specific application scenario and design constraints of the technical solution.

[0142] Figures 5 and 6 are schematic diagrams of the structures of possible communication devices provided in embodiments of the present application. These communication devices can be used to implement the functions of the network device or terminal device in the above method embodiments, thereby also achieving the beneficial effects of the above method embodiments. In the embodiments of the present application, the communication device can be a network device or terminal device, or a module (such as a chip) applied to the network device or terminal device.

[0143] The communication device 500 shown in Figure 5 includes a processing unit 510 and a communication unit 520. The communication device 500 is used to implement the functions of the network device or terminal device in the above method embodiment.

[0144] When the communication device 500 is used to implement the functions of the terminal device in the above embodiment:

[0145] a communication unit, configured to receive a first system message from a network device, the first system message including a first condition, the first condition being used by the terminal device to determine whether to receive and / or read a second system message, the second system message including ephemeris information configured by the network device;

[0146] The processing unit is configured to determine whether the first condition is met; and if the first condition is met, receive and / or read the second system message.

[0147] When the communication device 500 is used to implement the functions of the network device in the above embodiment:

[0148] A communication unit is configured to broadcast a first system message and a second system message, wherein the first system message includes a first condition, the first condition is used by a terminal device to determine whether to receive and / or read the second system message, and the second system message includes ephemeris information configured by the network device.

[0149] For a more detailed description of the processing unit 510 and the communication unit 520, reference can be made to the relevant description in the above method embodiment, which will not be repeated here.

[0150] The communication device 600 shown in Figure 6 includes a processor 610 and an interface circuit 620. The processor 610 and the interface circuit 620 are coupled to each other. The interface circuit 620 can be a transceiver or an input / output interface. For example, the communication device 600 can also include a memory 630 for storing instructions executed by the processor 610, or storing input data required by the processor 610 to execute instructions, or storing data generated after the processor 610 executes instructions.

[0151] When the communication device 600 is used to implement the above method embodiment, the processor 610 is used to implement the functions of the above processing unit 510 , and the interface circuit 620 is used to implement the functions of the above communication unit 520 .

[0152] When the communication device is a chip used in a terminal device, the chip of the terminal device implements the functions of the terminal device in the above method embodiments. The chip of the terminal device receives information from other modules in the terminal device (such as a radio frequency module or antenna), and the information is sent by the network device to the terminal device; or the chip of the terminal device sends information to other modules in the terminal device (such as a radio frequency module or antenna), and the information is sent by the terminal device to the network device.

[0153] When the above-mentioned communication device is a module applied to a network device, the module of the network device implements the functions of the network device in the above-mentioned method embodiment. The module of the network device receives information from other modules in the network device (such as a radio frequency module or an antenna), and the information is sent by the terminal device to the network device; or, the module of the network device sends information to other modules in the network device (such as a radio frequency module or an antenna), and the information is sent by the network device to the terminal device. The module of the network device here can be a chip of the network device, or it can be a DU or other module. The DU here can be a DU under the open radio access network (O-RAN) architecture.

[0154] The processor in the embodiments of the present application may be a central processing unit (CPU), or may be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. The general-purpose processor may be a microprocessor or any conventional processor.

[0155] The method steps in the embodiments of the present application can be implemented by hardware or by a processor executing software instructions. The software instructions can be composed of corresponding software modules, and the software modules can be stored in a random access memory, a flash memory, a read-only memory, a programmable read-only memory, an erasable programmable read-only memory, an electrically erasable programmable read-only memory, a register, a hard disk, a mobile hard disk, a compact disc read-only memory (CD-ROM) or any other form of storage medium well known in the art. An exemplary storage medium is coupled to the processor so that the processor can read information from the storage medium and can write information to the storage medium. Of course, the storage medium can also be an integral part of the processor. The processor and the storage medium can be located in an ASIC. In addition, the ASIC can be located in a network device or a terminal device. Of course, the processor and the storage medium can also be present in a network device or a terminal device as discrete components.

[0156] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean 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 the present application.

[0157] Those skilled in the art will appreciate that the various illustrative logical blocks and steps described in conjunction with the embodiments disclosed herein can be implemented using electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0158] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0159] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed can be through some interface, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0160] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0161] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the part that essentially contributes to the technical solution of the present application or the part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes a number of instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a RAM, a magnetic disk or an optical disk.

[0162] Obviously, those skilled in the art may make various changes and modifications to the present application without departing from the scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include these modifications and variations.

Claims

1. A communication method, characterized in that: The method is performed by a terminal device or a chip applied to the terminal device, and includes: Receiving a first system message from a network device, the first system message including a first condition, the first condition being used by the terminal device to determine whether to receive and / or read a second system message, the second system message including ephemeris information configured by the network device; determining whether the first condition is met; When the first condition is met, the second system message is received and / or read.

2. The method according to claim 1, characterized in that The first condition includes one or more of the following: The signal quality of the serving cell of the terminal device is lower than or equal to the first threshold; Meet the ground network TN neighboring area measurement conditions; Conduct TN neighboring cell measurements; The signal quality of the TN neighboring cell of the serving cell of the terminal device is lower than or equal to the second threshold; or, The priority of the non-terrestrial network NTN neighboring cell of the service cell of the terminal equipment is higher than the priority of the service cell.

3. The method according to claim 2, characterized in that If the signal quality of the TN neighboring cell of the service cell of the terminal device is lower than or equal to the second threshold, the priority of the TN neighboring cell is higher than the priority of the NTN neighboring cell of the service cell.

4. The method according to any one of claims 1 to 3, characterized in that: The first system message further includes a second condition; and the method further includes: When the second condition is met, NTN neighbor cell measurement is performed, and the second condition includes that the signal quality of the TN neighbor cell of the service cell of the terminal device is lower than or equal to the second threshold.

5. The method according to claim 4, characterized in that The priority of the TN neighboring cell is higher than the priority of the NTN neighboring cell of the serving cell.

6. The method according to claim 4 or 5, characterized in that The method further comprises: When the first condition is not met but the second condition is met, the second system message is received and / or read before performing the NTN neighbor cell measurement.

7. The method according to claim 4 or 5, characterized in that The method further comprises: In a case where the first condition is not met and the first system message further includes first indication information, the second system message is received and / or read, where the first indication information is used to indicate that the second system message includes the ephemeris information.

8. The method according to claim 2, characterized in that The first threshold is equal to the third threshold, and the third threshold is a threshold corresponding to the TN neighboring cell measurement condition.

9. The method according to any one of claims 2 to 4, characterized in that: The second threshold is higher than or equal to the third threshold, and the third threshold is a threshold corresponding to the TN neighboring cell measurement condition.

10. A communication method, characterized in that: The method is performed by a network device or a chip applied to the network device, and includes: A first system message and a second system message are broadcasted, wherein the first system message includes a first condition, and the first condition is used for a terminal device to determine whether to receive and / or read the second system message, and the second system message includes ephemeris information configured by the network device.

11. The method according to claim 10, characterized in that The first condition includes one or more of the following: The signal quality of the serving cell of the terminal device is lower than or equal to the first threshold; Meet the TN neighboring cell measurement conditions; Conduct TN neighboring cell measurements; The signal quality of the TN neighboring cell of the serving cell of the terminal device is lower than or equal to the second threshold; or, The priority of the NTN neighboring cell of the service cell of the terminal device is higher than the priority of the service cell.

12. The method according to claim 11, characterized in that If the signal quality of the TN neighboring cell of the service cell of the terminal device is lower than or equal to the second threshold, the priority of the TN neighboring cell is higher than the priority of the NTN neighboring cell of the service cell.

13. The method according to any one of claims 10-11, characterized in that: The first system message also includes a second condition, which is used by the terminal device to perform NTN neighbor cell measurement. The second condition includes that the signal quality of the TN neighbor cell of the service cell of the terminal device is lower than or equal to a second threshold.

14. The method according to claim 13, characterized in that The priority of the TN neighboring cell is higher than the priority of the NTN neighboring cell of the serving cell.

15. The method according to claim 11, characterized in that The first threshold is equal to the third threshold, and the third threshold is a threshold corresponding to the TN neighboring cell measurement condition.

16. The method according to any one of claims 11 to 13, characterized in that: The second threshold is higher than or equal to the third threshold, and the third threshold is a threshold corresponding to the TN neighboring cell measurement condition.

17. A communication device, characterized in that: The method comprises a module for executing the method as claimed in any one of claims 1 to 9, or a module for executing the method as claimed in any one of claims 10 to 16.

18. A communication device, characterized in that: The invention comprises a processor and an interface circuit, wherein the interface circuit is used to receive signals from other communication devices outside the communication device and transmit them to the processor or send signals from the processor to other communication devices outside the communication device, and the processor implements the method as described in any one of claims 1 to 9 or the method as described in any one of claims 10 to 16 through a logic circuit or by executing code instructions.

19. A communication device, characterized in that: include: Memory for storing computer programs; A processor, configured to call and run the computer program from the memory to implement the method according to any one of claims 1 to 9, or to implement the method according to any one of claims 10 to 16.

20. A chip system, characterized in that: include: Memory for storing computer programs; A processor, configured to call and run the computer program from the memory, so that a device equipped with the chip system executes the method as claimed in any one of claims 1 to 9, or executes the method as claimed in any one of claims 10 to 16.

21. A computer program product, characterized in that The invention comprises a computer program, which, when executed by a communication device, implements the method according to any one of claims 1 to 16.

22. A computer-readable storage medium, characterized in that: The storage medium stores a computer program or an instruction, and when the computer program or the instruction is executed by the communication device, the method according to any one of claims 1 to 16 is implemented.

23. A communication system, characterized in that: include: A terminal device, configured to execute the method according to any one of claims 1 to 9; A network device, configured to execute the method according to any one of claims 10 to 16.

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