Method and apparatus for wireless communication

Abstract

The present application provides a method and apparatus for wireless communication that contributes to a terminal device in an NTN cell performing cell reselection, the method including a step of the terminal device performing cell reselection in the NTN cell based on first auxiliary information, the first auxiliary information being associated with one or more of information on a distribution of TN cells in the NTN cell, a sub-area in the NTN cell related to a coverage angle of a network device corresponding to the NTN cell, and the TN cells included in the sub-area in the NTN cell.

Description

[Technical Field]

[0001] This application claims priority to a Chinese patent application bearing application number 2023100868066 and entitled "Method and Apparatus for Wireless Communication," filed with the China Patent Office on February 1, 2023, the entire contents of which are incorporated herein by reference.

[0002] TECHNICAL FIELD This application relates to the field of communications, and more particularly to methods and apparatus for wireless communications. [Background technology]

[0003] Non-terrestrial network (NTN) systems have high mobility. In systems where the coverage of NTN cells is stationary relative to the ground (e.g., semi-terrestrial fixed systems), terminal devices in idle or inactive states can perform cell reselection based on the outage time of the serving cell provided by the network device.

[0004] However, in systems where NTN cells move with the network device (e.g., quasi-terrestrial mobile cells), changes in the coverage of the serving cell may be detrimental to the performance of cell reselection by the terminal device. Summary of the Invention [Problem to be solved by the invention]

[0005] The present application provides a method and apparatus for wireless communication. Hereinafter, various aspects according to embodiments of the present application will be described. [Means for solving the problem]

[0006] In a first aspect, a method for wireless communication is provided, the method including: a terminal device performing cell reselection in an NTN cell based on first auxiliary information, the first auxiliary information being associated with one or more of information on a distribution of TN cells in the NTN cell, a sub-area in the NTN cell associated with a coverage angle of a network device corresponding to the NTN cell, and TN cells included in the sub-area in the NTN cell.

[0007] In a second aspect, a method for wireless communication is provided, the method comprising: a network device transmitting first auxiliary information to a terminal device, the first auxiliary information being used by the terminal device to perform cell reselection in an NTN cell, the first auxiliary information being associated with one or more of information on a distribution of TN cells in the NTN cell, a sub-area in the NTN cell related to a coverage angle of a network device corresponding to the NTN cell, and the TN cells included in the sub-area in the NTN cell.

[0008] In a third aspect, there is provided an apparatus for wireless communication, the apparatus being a terminal device, the terminal device including: a reselection unit for performing cell reselection in an NTN cell based on first auxiliary information, the first auxiliary information being associated with one or more of information of a distribution of TN cells in the NTN cell, a sub-area in the NTN cell related to a coverage angle of a network device corresponding to the NTN cell, and TN cells included in the sub-area in the NTN cell.

[0009] In a fourth aspect, there is provided an apparatus for wireless communication, the apparatus being a network device, the network device including: a transmitting unit for transmitting first auxiliary information to the terminal device, the first auxiliary information being used by the terminal device to perform cell reselection in an NTN cell, the first auxiliary information being associated with one or more pieces of information of a distribution of TN cells in the NTN cell, a sub-area in the NTN cell related to a coverage angle of a network device corresponding to the NTN cell, and the TN cells included in the sub-area in the NTN cell.

[0010] In a fifth aspect, there is provided a communications device, the communications device including a memory and a processor, the memory configured to store a program, and the processor configured to invoke the program in the memory to perform a method according to the first or second aspect.

[0011] In a sixth aspect, there is provided an apparatus, the apparatus comprising a processor for retrieving a program from a memory to perform a method according to the first or second aspect.

[0012] In a seventh aspect, there is provided a chip, the chip including a processor for calling a program from a memory to cause a device equipped with the chip to execute the method according to the first or second aspect.

[0013] In an eighth aspect, a computer-readable storage medium is provided, the computer-readable storage medium storing a program for causing a computer to perform the method according to the first or second aspect.

[0014] In a ninth aspect there is provided a computer program product, the computer program product comprising a program for causing a computer to carry out a method according to the first or second aspect.

[0015] In a tenth aspect there is provided a computer program which, when run on a computer, causes the computer to carry out a method according to the first or second aspect.

[0016] In an embodiment of the present application, a terminal device can perform cell reselection in an NTN cell based on first auxiliary information. The first auxiliary information can be associated with one or more pieces of information, such as the distribution of TN cells in the NTN cell, sub-regions divided based on the coverage angles of the network device, and TN cells in the sub-regions. The first auxiliary information can more accurately determine the status of neighboring cells near the terminal device. When the terminal device performs cell reselection based on the first auxiliary information, unnecessary measurements can be reduced, and power consumption can be reduced. [Brief explanation of the drawings]

[0017] [Figure 1] 1 illustrates a wireless communication system applied to an embodiment of the present application. [Figure 2] 1 is an NTN system applied to an embodiment of the present application. [Figure 3] 1 is another NTN system applied to an embodiment of the present application. [Figure 4] 1 is a schematic diagram of a method for wireless communication according to an embodiment of the present application; [Figure 5] FIG. 1 is a ground schematic diagram of an NTN cell to which an embodiment of the present application is applied. [Figure 6] FIG. 1 is a distribution schematic diagram of a TN cell applied to an example of the present application. [Figure 7] FIG. 10 is a distribution schematic diagram of another TN cell applied to an embodiment of the present application. [Figure 8] 1 is a schematic diagram of an NTN cell division method according to an embodiment of the present application. [Figure 9] FIG. 1 is a schematic diagram of another NTN cell division method according to an embodiment of the present application. [Figure 10] FIG. 10 is a schematic diagram of yet another NTN cell division method according to an embodiment of the present application. [Figure 11] 1 is a structural schematic diagram of a device for wireless communication according to an embodiment of the present application; [Figure 12] FIG. 2 is a structural schematic diagram of another device for wireless communication according to an embodiment of the present application; [Figure 13] 1 is a structural schematic diagram of a communication device according to an embodiment of the present application; DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, the technical solutions of the embodiments of the present application will be described with reference to the drawings of the embodiments of the present application, and it is obvious that the described embodiments are only some of the embodiments of the present application, and not all of the embodiments. All other embodiments that a person skilled in the art can obtain based on the embodiments of the present application without any creative work fall within the scope of protection of the present application.

[0019] Embodiments of the present application may be applied to various communication systems, such as a global system of mobile communications (GSM) system, a code division multiple access (CDMA) system, a wideband code division multiple access (WCDMA) system, a general packet radio service (GPRS), a long term evolution (LTE) system, an advanced long term evolution (LTE-A) system, a new radio (NR) system, an evolution of an NR system, an LTE-based access to unlicensed spectrum (LTE-U) system, an NR-based access to unlicensed spectrum (NR-U) system, an NTN system, a universal mobile telecommunication system (UMTS), a wireless local area network (WLAN), a wireless fidelity (WFI), a wireless local area network (WLAN), a wireless cellular ... The present invention may be applicable to wireless fidelity (WiFi) and fifth-generation (5G) communication systems. Embodiments of the present application may also be applicable to other communication systems, such as future communication systems. The future communication systems may be, for example, sixth-generation (6G) mobile communication systems or satellite communication systems.

[0020] Conventional communication systems support a limited number of connections and are easy to implement. However, with the development of communication technologies, communication systems can support not only conventional cellular communication but also one or more other types of communication. For example, a communication system can support one or more of device-to-device (D2D) communication, machine-to-machine (M2M) communication, machine-type communication (MTC), vehicle-to-vehicle (V2V) communication, and vehicle-to-everything (V2X) communication, etc., and embodiments of the present application can also be applied to communication systems supporting the above communication methods.

[0021] The communication system in the embodiments of the present application can be applied to a carrier aggregation (CA) scenario, a dual connectivity (DC) scenario, and a standalone (SA) networking scenario.

[0022] The communication system according to the embodiment of the present application may be applied to an unlicensed spectrum, which may also be considered a shared spectrum, or may be applied to a licensed spectrum, which may also be considered a dedicated spectrum.

[0023] Embodiments of the present application may be applied to terrestrial networks (TN) systems and NTN systems, which may include, for example, 4G-based NTN systems, NR-based NTN systems, internet of things (IoT)-based NTN systems, and narrowband internet of things (NB-IoT)-based NTN systems.

[0024] A communication system may include one or more terminal devices, which may also be referred to as user equipment (UE), access terminal, user unit, user station, mobile station, mobile station (MS), mobile terminal (MT), remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent, or user equipment.

[0025] In some embodiments, the terminal device may be a station (ST) in a WLAN, a cellular phone, a cordless phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA) device, a handheld device with wireless communication capabilities, a computing device or other processing device connected to a wireless modem, an in-vehicle device, a wearable device, a terminal device in a next generation communication system (e.g., an NR system) or a terminal device in a future public land mobile network (PLMN), etc.

[0026] In some embodiments, a terminal device may refer to a device that provides a user with voice and / or data connectivity. For example, the terminal device may be a handheld device with wireless connectivity, an in-vehicle device, etc. As some specific examples, the terminal device may be a mobile phone, a tablet PC (Pad), a laptop, a palmtop computer, a mobile internet device (MID), a wearable device, a virtual reality (VR) device, an augmented reality (AR) device, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical surgery, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, etc.

[0027] In some embodiments, the terminal device may be located on land, for example, the terminal device may be located indoors or outdoors, in some embodiments, the terminal device may be located on water, for example, on a steamship, in some embodiments, the terminal device may be located in the air, for example, on an airplane, a balloon, or a satellite.

[0028] In addition to the terminal device, the communication system may further include one or more network devices. The network device in the present embodiment may be a device for communicating with the terminal device, and the network device may also be referred to as an access network device or a radio access network device. The network device may be, for example, a base station. The network device in the present embodiment may refer to a radio access network (RAN) node (or device) that allows the terminal device to access the wireless network. The base station may broadly cover or be replaced with various names such as a Node B (Node B), evolved Node B (eNB), next generation Node B (gNB), relay station, access point, transmitting and receiving point (TRP), transmission point (TP), primary base station MeNB, secondary base station SeNB, multi-standard radio (MSR) node, home base station, network controller, access node, radio node, access point (AP), transmission node, transceiver node, base band unit (BBU), remote radio unit (RRU), active antenna unit (AAU), remote radio head (RRH), central unit (CU), distributed unit (DU), positioning node, etc. The base station may be a macro base station, a micro base station, a relay node, a donor node, or the like, or a combination thereof. A base station may also refer to a communication module, modem or chip installed within the aforementioned device or equipment.The base station may also be a mobile switching center and a device that performs the function of a base station in D2D, V2X, and M2M communications, a network side device in a 6G network, a device that performs the function of a base station in a future communication system, etc. The base station may support networks of the same or different access technologies. The embodiments of the present application do not limit the specific technologies adopted by the network devices and the specific device forms.

[0029] The base station may be fixed or mobile. For example, a helicopter or a drone may be configured as a mobile base station, and one or more cells may move based on the location of the mobile base station. In another example, a helicopter or a drone may be configured as a device for communicating with another base station.

[0030] In some deployments, the network device in the embodiments of this application may refer to a CU or a DU, or may include a CU and a DU. The gNB may further include an AAU.

[0031] By way of non-limiting example, in some embodiments of the present application, a network device may have mobile characteristics, e.g., the network device may be a mobile device. In some embodiments of the present application, the network device may be a satellite or balloon station. In some embodiments of the present application, the network device may also be a base station located at a location such as on land or in a body of water.

[0032] In an embodiment of the present application, a network device can provide a service to a cell, and a terminal device communicates with the network device through transmission resources (e.g., frequency domain resources, i.e., spectrum resources) used by the cell, and the cell may be a cell corresponding to the network device (e.g., a base station), and the cell may belong to a macro base station or a base station corresponding to a small cell, where the small cell may include a metro cell, a micro cell, a pico cell, a femto cell, etc., and these small cells are characterized by a small coverage range and low transmission power and are adapted to provide high-rate data transmission services.

[0033] For example, Figure 1 is a schematic diagram of a communication system architecture according to an embodiment of the present application. As shown in Figure 1, the communication system 100 may include a network device 110, which may be a device that communicates with terminal devices 120 (also referred to as communication terminals or terminals). The network device 110 may provide communication coverage in a specific geographic area and may communicate with terminal devices located within the coverage.

[0034] FIG. 1 exemplarily illustrates one network device and two terminal devices, and in some embodiments of the present application, the communication system 100 may include multiple network devices, and the coverage range of each network device may include other numbers of terminal devices, and this is not limited to the embodiments of the present application.

[0035] For example, Figure 2 is a schematic diagram of the architecture of the NTN system. The NTN system 200 shown in Figure 2 uses a satellite 210 as an airborne platform. As shown in Figure 2, the satellite radio access network includes the satellite 210, a service link 220, a feeder link 230, a terminal device 240, a gateway 250, and a network 260 including a base station and a core network.

[0036] Satellite 210 is a space-based vehicle. Service link 220 refers to the link between satellite 210 and terminal device 240. Feeder link 230 refers to the link between gateway 250 and satellite 210. Earth-based gateway 250 connects satellite 210 to a base station or core network, the specifics of which are determined based on the architecture choice.

[0037] The NTN architecture shown in Figure 2 is a bent-pipe transponder architecture, in which the base station is located on Earth behind the gateway 250, and the satellite 210 functions as a relay. The satellite 210 acts as a repeater to forward signals from the feeder link 230 to the service link 220, or vice versa. In other words, the satellite 210 does not have base station functionality, and communications between the terminal device 240 and the base stations in the network 260 must be relayed using the satellite 210.

[0038] For example, Figure 3 is a schematic diagram of another architecture of an NTN system. The NTN system 300 shown in Figure 3 also uses a satellite 310 as an airborne platform. The difference from Figure 2 is that a base station 312 is provided on the satellite 310, and the network 360 behind the gateway 350 only includes a core network.

[0039] The NTN architecture shown in Figure 3 is a regenerative transponder architecture. In this architecture, a satellite 310 carries a base station 312 and can be directly connected to an Earth-based core network by using a link. The satellite 310 has the functionality of a base station, and a terminal device 340 can communicate directly with the satellite 310. Therefore, the satellite 310 may be referred to as a network device.

[0040] The communication system of the architecture shown in Figures 2 and 3 may include multiple network devices, and the coverage range of each network device may include other numbers of terminal devices, and the embodiments of the present application are not limited thereto.

[0041] In the embodiments of the present application, the wireless communication systems shown in Figures 1 to 3 may further include other network entities such as a mobility management entity (MME), an access and mobility management function (AMF), etc., and the embodiments of the present application are not limited thereto.

[0042] It should be understood that in the embodiments of the present application, devices having a communication function in a network / system can be referred to as communication devices. Taking the communication system 100 shown in FIG. 1 as an example, the communication devices may include a network device 110 and a terminal device 120 having a communication function, and the network device 110 and the terminal device 120 may be the above-mentioned specific devices, and detailed descriptions will not be given again here. The communication devices may also include other devices in the communication system 100, such as other network entities such as a network controller, a mobility management entity, etc., and the embodiments of the present application are not limited thereto.

[0043] For ease of understanding, some related technical knowledge regarding the embodiments of the present application will be explained first. Hereinafter, the related technologies can be arbitrarily combined with the technical solutions of the embodiments of the present application as optional means, and they all fall within the protection scope of the embodiments of the present application. The embodiments of the present application include at least some of the following contents:

[0044] As communication technology develops, communication systems (e.g., 5G) have the market potential to integrate satellite and terrestrial network infrastructure. For example, 5G standards have made NTN, including the satellite segment, part of the 5G connectivity infrastructure of the well-known 3rd generation partnership project (3GPP®).

[0045] Communication satellites are classified by orbital height into low Earth orbit (LEO), medium Earth orbit (MEO), geostationary Earth orbit (GEO), and high elliptical orbit (HEO). LEO is an orbit centered on the Earth, with an altitude of 2,000 km or less, or at least 11.25 periods per day, and an eccentricity of less than 0.25. Most man-made objects in space are located in LEO. LEO satellites move around the Earth at high speed (mobility) but in a predictable or determinable orbit.

[0046] Satellites at different orbital altitudes have different orbital periods.

[0047] LEO: Typical altitudes are 250km to 1,500km, with orbital periods of 90 to 120 minutes.

[0048] MEO: Typical altitudes are 5,000km to 25,000km, with orbital periods of 3 hours to 15 hours.

[0049] GEO: Altitude is approximately 35,786 km, and the orbital period is 24 hours.

[0050] NTN refers to a network or network segment that uses radio frequency (RF) resources on a satellite or unmanned aerial system (UAS) platform. Typical NTN scenarios for accessing terminal devices involve NTN transparent payloads or NTN regenerative payloads. Figures 2 and 3 above show two NTN system architectures, taking satellites as examples. The bent-pipe transponder architecture shown in Figure 2 corresponds to the NTN transparent payload, while the regenerative transponder architecture shown in Figure 3 corresponds to the NTN regenerative payload.

[0051] In satellite-based NTN systems, the coverage range of a serving cell is generally large. The diameter of an NTN cell is at least 50 km. In some embodiments, an NTN cell can cover multiple cities where TN cells are deployed, as well as remote areas or ocean regions where TN cells are not deployed.

[0052] In the NTN system, both the satellite and the unmanned aerial vehicle system have relatively high mobility. The cells projected by the satellite onto the ground may be fixed relative to the ground or may move with the satellite. Taking the serving cell corresponding to the LEO satellite as an example, the cells projected by the LEO satellite onto the ground are usually fixed cells and moving cells.

[0053] A stationary cell relative to the Earth may refer to a serving cell whose geographic area it covers is fixed. For example, different LEO satellites can cover the same area on Earth by adjusting the pointing angles of their antennas, and if one LEO satellite is unable to cover that area, the other LEO satellite will take over. For satellites in geosynchronous orbit (GSO), the cell projected onto the Earth may also be a fixed cell.

[0054] A moving cell may refer to a serving cell whose covered geographical area changes. For example, the cell projected onto the ground by a LEO satellite may move along with the satellite. Generally, when the antenna of a LEO satellite is perpendicular to the ground, the cell projected onto the ground by the LEO satellite is a moving cell. Whether the LEO satellite is an independent base station or a relay base station, the moving cell moves along with the LEO satellite, and the relative distance between the LEO satellite and the terminal device is constantly changing. After a certain period of time, the signal from the LEO satellite may no longer cover the terminal device, and if the network deployment is relatively smooth, the next LEO satellite will cover the terminal device. Because the satellite system is spherical, the next LEO satellite may come from various angles.

[0055] The satellite's projected position in a direction perpendicular to the Earth's surface may be called the nadir, or may be called the reference position or reference point. The locus of the satellite reference position on the Earth's surface is usually aligned with the satellite's orbit. That is, the locus of the satellite reference point on the Earth's surface can be considered as a projection of the satellite's flight orbit.

[0056] The operational parameters of a satellite can be represented by ephemeris data. Ephemeris data usually comes in two forms: orbital parameters and position, velocity, and time (PVT) parameters. Either the orbital parameters or PVT parameters of a satellite can indicate the satellite's position coordinates relative to the Earth. A terminal device can determine the satellite's future operational trajectory using the ephemeris data, and thereby determine whether measurements or handovers are required.

[0057] When NTN network devices access the communication system, they must distinguish between the radio access technologies (RATs) corresponding to different types of satellite devices. For example, when accessing via NR satellites, 5G core network (5G core, 5GC) devices can distinguish between different NR satellite accesses by using different RAT type values. These RAT type values ​​include "NR(LEO)," "NR(MEO)," "NR(GEO)," and "NR(OTHERSAT)." To effectively implement mobility restrictions, serving cells corresponding to multiple RAT types must be deployed in tracking areas (TAs) for different RAT types. That is, cells for each NTN RAT type (e.g., NR(LEO), NR(MEO), NR(GEO), or NR(OTHERSAT)) must be deployed in TAs different from those for other NR satellite RAT types and RAT types supporting terrestrial access. For each NTN RAT type, a non-overlapping tracking area or core network (CN) registration area may be configured, and a distinct mobility registration area (MRA) may be defined.

[0058] The NTN system may include a quasi-terrestrial fixed system and a mobile unit system. Regarding the theme of cell measurement and reselection enhancement, different systems have different solutions. For example, in the case of time-based cell reselection in a quasi-terrestrial fixed system, the network device can provide the terminal device with the time when its common cell will stop serving. All idle / inactive terminal devices in the cell can perform cell reselection before the cell stop time. For example, in the case of location-based measurement initiation in a quasi-terrestrial fixed system, the network device can provide the reference position of the serving cell and a distance threshold for the terminal device. If the distance between the terminal device and the reference position of the current serving cell is greater than the distance threshold, the terminal device needs to perform neighbor cell measurements.

[0059] Taking the Rel-17 specification as an example, the specification specifies a location-based measurement initiation rule and a time-based measurement initiation rule for NTN quasi-terrestrial fixed cells. For the location-based measurement initiation rule, a distance threshold and a reference position of the serving cell (i.e., the terrestrial cell center) are introduced. If the distance between the terminal device and the reference position of the serving cell is less than the distance threshold and meets the conventional signal reception condition, the terminal device may not perform priority-based neighbor cell measurement. The signal reception condition may be a reference signal received power (RSRP) condition or a reference signal received quality (RSRQ) condition. Priority-based neighbor cell measurement refers to performing neighbor cell measurement based on NR intra- or inter-frequencies with equal or lower priority, or on an inter-RAT frequency with a lower priority. For the time-based measurement initiation rule, a cell outage time of the serving cell, i.e., the time when the cell stops covering the current area, is introduced. If a cell outage time is set, the terminal device must start measuring neighboring cells before the cell outage time, regardless of whether it meets the above location conditions or the conventional RSRP / RSRQ conditions.

[0060] However, the solutions described above that are applicable to semi-terrestrial fixed systems are not applicable to mobile unit systems.

[0061] In a mobile unit system, the coverage of an NTN cell moves along with the network device. Even if the terminal device is fixed, the relative position between the terminal device and the network device changes. That is, in a mobile unit system, the positions of both the terminal device and the serving cell may change. Taking a mobile cell of a low-earth orbit (LEO) satellite as an example, the speed of a typical LEO satellite is 7.56 km / s. As the LEO satellite moves, its footprint slides across the Earth. Considering that the diameter of an NTN cell is at least 50 km, it takes 6.61 seconds for all idle / inactive terminal devices in the cell to be allocated. That is, all terminal devices in the cell must reselect another visiting cell, and new terminal devices will also visit the cell. In the above solution, the information provided by the network device to the terminal device for triggering cell measurement / reselection may be inaccurate, and it does little to contribute to the terminal device's neighbor cell measurement or cell reselection.

[0062] As mentioned above, NTN cells typically provide a much larger coverage area than TN cells. The coverage area of ​​an NTN cell is large enough that one NTN unit may cover both maritime and land areas. Generally, more TN cells are installed in land areas. For example, within a satellite-served NTN cell, many land TN cells may be available.

[0063] Considering the characteristics of NTN, in the mobility management area, it is highly likely that network side devices will assign a higher priority to frequency measurements of TN cells than NTN cells. When an NTN cell contains multiple TN cells, it is necessary to consider how to efficiently perform cell reselection between TN cells and NTN cells for terminal devices in the common area of ​​the TN cell and the NTN cell, and for terminal devices only in the NTN cell area. That is, terminal devices staying in NTN cells may be located in areas without TN coverage. In areas without TN network coverage, terminal devices do not need to perform neighbor cell measurements on neighbor cells of TN cells.

[0064] Furthermore, considering the states of terminal devices in the common area and NTN cell area, auxiliary information is needed to assist the terminal device in making measurements for cell reselection in order to effectively perform cell reselection. For example, for a terminal device in a radio resource control (RRC) idle state (RRC_IDLE) or an RRC inactive state (RRC_INACTIVE), the mobility of the NTN cell and NTN-TN must be taken into account in order for the terminal device to perform cell reselection, and measurements for cell reselection increase the power consumption of the terminal device. That is, a terminal device in an idle state has not established an RRC connection with a network device, and in the case of a moving cell, the terminal device cannot yet determine whether it is within the coverage range of the network device. Therefore, a terminal device in an idle state may need to periodically receive broadcast information or system information to measure its relative position with the serving cell, and these measurements increase the power consumption of the terminal device.

[0065] To solve some of the above problems, an embodiment of the present application proposes a method for wireless communication, in which a terminal device is instructed to perform cell reselection by first assistance information. A terminal device in an idle or inactive state performs measurements for cell reselection only when it receives the first assistance information, thereby reducing unnecessary measurements and contributing to reducing power consumption of the terminal device when moving between NTN cells. For ease of understanding, the main technical solution of the embodiment of the present application will be described in detail with reference to Figure 4.

[0066] Figure 4 is constructed in terms of the interaction between the terminal device and the network device: the terminal device determines, by communication with the network device, the opportunity to trigger cell reselection.

[0067] The terminal device may be any of the terminal devices described above that communicate with network devices in an NTN cell, or may be a terminal device that communicates in other land mobile cells. In some embodiments, the terminal device may be a communication device with low mobility in NB-IoT. In some embodiments, the terminal device may be a communication device that is within a common area of ​​an NTN cell and a TN cell. In some embodiments, the terminal device may be a communication device that is only within the NTN cell area.

[0068] In some embodiments, the terminal device may be a communication device in an idle or inactive state in an NTN cell. The terminal device may receive broadcast information or system information transmitted from the network device. In some embodiments, the terminal device may be a communication device in an active state. The terminal device may receive broadcast information or system information transmitted from the network device and may also receive dedicated signaling transmitted from the network device. The dedicated signaling facilitates reducing consumption of common resources.

[0069] The network device may be a communications device that is provided by the NTN cell in which the terminal device is located, for example, a satellite that functions as a standalone base station, or an unmanned aerial vehicle (UAV) system used as a relay base station.

[0070] The NTN cell may be a serving cell whose coverage is stationary relative to the earth, such as a quasi-earth fixed cell, or a serving cell whose coverage moves with the network device, such as a quasi-earth mobile cell, but is not limited thereto.

[0071] Referring to FIG. 4, in step S410, the terminal device receives first auxiliary information sent from the network device.

[0072] The first auxiliary information is used to instruct a terminal device to perform cell reselection. To effectively perform cell reselection, the terminal device needs to determine the distribution of multiple types of networks and the distribution of TN cells in the NTN cell. The first auxiliary information is associated with one or more pieces of information to instruct the terminal device how to perform cell reselection. The information associated with the first auxiliary information may be the distribution of TN cells in the NTN cell, a sub-area in the NTN cell, or a TN cell included in a sub-area in the NTN cell.

[0073] In some embodiments, the first auxiliary information is associated with a distribution of TN cells within an NTN cell and instructs the terminal device to perform cell reselection, typically NTN-TN cell reselection. In a possible implementation, the first auxiliary information may indicate whether there are TN cells adjacent to the terminal device according to the distribution of TN cells. The terminal device can then use this information to determine whether to perform measurements related to cell reselection.

[0074] In a possible implementation, the distribution of TN cells may include multiple types of information, such as the location coordinates of TN cells within NTN cells, the location coordinates of TN cells relative to the center of NTN cells, the coverage of TN cells, and the boundary between the coverage of TN cells and the coverage of NTN cells. Based on one or more of the above information, the terminal device can determine whether to perform cell reselection based on the conditions of surrounding TN cells.

[0075] For example, the terminal device may determine the location of the TN cell based on the location coordinates of the TN cell or the relative location coordinates with the center of the NTN cell. The terminal device can determine whether there is a TN cell available for cell reselection in the surrounding area based on its own location information.

[0076] For example, the terminal device may determine the coverage range of the TN cell based on the location coordinates and coverage of the TN cell. The terminal device can determine when to perform cell reselection based on the coverage range of the TN cell and its own movement information.

[0077] For example, the terminal device may determine the distance from the TN cell based on the boundary between the coverage of the TN cell and the coverage of the NTN cell. The terminal device can determine when to perform cell reselection based on the change in the distance from the TN cell.

[0078] In some embodiments, the first aiding information is associated with a sub-area within the NTN cell and instructs the terminal device to perform cell reselection. After the terminal device receives the aiding information, the terminal device may calculate which sub-area it belongs to based on its location information and the received aiding information. Appropriate sub-area division may help the terminal device perform cell reselection. To perform cell reselection more efficiently, the sub-area within the NTN may be associated with the coverage angle of the network device. For example, when dividing the sub-area based on the coverage angle of the network device, the terminal device may determine the distance from the edge of the NTN cell depending on the sub-area in which it is located and thereby determine cell reselection. If the terminal device intends to leave the coverage range of the NTN cell, it needs to trigger measurements for cell reselection in advance. The NTN cell division method will be described in detail later with reference to FIG. 8.

[0079] In a possible implementation, the system may notify the terminal device by broadcast / system information (e.g., SIB) that the NTN cell is divided into multiple sub-areas. The sub-areas may be further divided into multiple virtual areas. The terminal device can determine the sub-area in which it is located based on the sub-area division and determine whether to perform cell reselection based on the network conditions in the sub-area in which it is located.

[0080] In some embodiments, the first auxiliary information is associated with a TN cell included in a sub-area within the NTN cell and instructs the terminal device to perform cell reselection. The sub-area including the TN cell may be divided in various ways, and is not limited thereto. For example, the NTN cell may divide the sub-area based on the coverage angle. Also, for example, the NTN cell may divide the sub-area according to a grid pattern. Various cell division methods will be described later with reference to Figures 8 to 10.

[0081] In a possible implementation, the sub-areas within the NTN cell may correspond to the frequency information of the TN cells within the sub-area. Using the TN frequency information corresponding to the sub-area where the terminal device is located as auxiliary information can help the terminal device perform more accurate TN measurement. Furthermore, if the divided sub-areas have a high degree of correspondence with the architecture of the terrestrial network, the terminal device can understand the frequency distribution of TN within each sub-area.

[0082] In a possible implementation, the TN cell included in the sub-region may further include a frequency information group of the TN cell corresponding to the sub-region. When the NTN cell includes multiple sub-regions, each sub-region among the multiple sub-regions corresponds to a frequency information group of one TN cell. One or more frequencies in the frequency information group have corresponding priorities, which can be used by the terminal device to perform cell reselection. That is, the terminal device obtains frequency list information of the sub-region in which it is located, and the TN frequency table in each region has a priority arrangement. For example, based on the TN frequency information of different regions, the priority of the TN frequency point in the NTN sub-region in which the terminal device is located is higher than the priority of the frequency point in other NTN sub-regions. For TN frequencies with higher reselection priorities, the terminal device performs related measurements according to a defined detection threshold.

[0083] In a possible implementation, the terminal device may obtain the TN frequency list of the area where it is located through the first auxiliary information and perform measurements accordingly. For distinction, the frequency groups of NTN cells and TN cells may adopt different identifiers.

[0084] For ease of understanding, the frequency information groups of the TN cells corresponding to the sub-areas of the NTN cells will be described below with reference to the NTN cell division of the example shown in Figure 5. Figure 5 is a ground schematic diagram of the NTN cell to which the embodiments of the present application are applied.

[0085] Referring to Figure 5, the NTN cell 500 is divided into three sub-areas, namely, sub-area NTN1, sub-area NTN2, and sub-area NTN3. As shown in Figure 5, sub-area NTN1 has one TN cell and the corresponding frequency is fa. Sub-area NTN2 has four TN cells and the corresponding frequencies are fa, fb, and fc, respectively. Sub-area NTN3 has one TN cell and the corresponding frequency is fd. Therefore, the frequency information groups corresponding to the sub-areas in the NTN cell 500 can be expressed as follows:

[0086] Area 1: Frequency information group {fa}; Area 2: Frequency information group {fa,fb,fc}; Area 3: Frequency information group {fd}.

[0087] When a terminal device acquires that it is in a certain sub-area, for example, in the area NTN2, it acquires that there are TN cells in the area and the frequency information group {fa, fb, fc} of the TN. However, the terminal device may not know the distance from these TN areas to its own location, and the network device can inform the terminal device of the coordinate position of each TN cell in the sub-area or the position of the boundary between the coverage of the TN cell and the coverage of the NTN cell, as described above.

[0088] Returning to step S410 shown in FIG. 4, in some embodiments, the information associated with or included in the first auxiliary information may further include frequency information of the TN cell, and reference positions and distance thresholds of neighboring cells of the TN cell. The frequency information of the TN cell may be frequency information of all TN cells within the NTN cell. The reference positions and distance thresholds of neighboring cells of the TN cell may be used by the terminal device to perform cell reselection in the TN cell, or to perform measurements for cell reselection on neighboring cells if handover of the TN cell fails.

[0089] In the case of a near-terrestrial mobile cell, the coverage of the NTN cell changes as the network device moves. The network device needs to periodically update one or more pieces of information associated with or included in the first assistance information. For example, the network device can provide a list of TN frequencies in its coverage at different times by broadcasting.

[0090] In some embodiments, the first assistance information may be carried by one or more of broadcast information, system information, and dedicated signaling. That is, the network device may transmit the first assistance information to the terminal device by one or more of the above information. Dedicated signaling may reduce consumption of common resources.

[0091] The first auxiliary information can help the terminal device avoid performing unnecessary measurements in TN cells. To reduce unnecessary measurements, the most straightforward solution is to broadcast the location information of TN cells, so that the terminal device knows whether it needs to start measurements. By identifying NTN and TN cells in the broadcast information of the network device, the terminal device can know whether the cell to start measurements is an NTN or TN cell.

[0092] In step S420, the terminal device performs cell reselection in the NTN cell based on the first auxiliary information.

[0093] The cell reselection may be a cell handover. When a terminal device performs cell reselection in an NTN cell, it may refer to an NTN-NTN handover or an NTN-TN handover. That is, the cell after the terminal device performs cell reselection in an NTN cell may be an NTN cell or a TN cell, and is not limited thereto.

[0094] The NTN and TN deployed in a network may be deployed in different / the same PLMN. In some embodiments, when the NTN and TN are in the same PLMN, a terminal device in an inactive state can retain communication parameters of the terminal device in the inactive state and the current cell when performing cell reselection. The communication parameters may include protocol data unit (PDU) sessions and data radio bearers (DRBs) established by the terminal device. For example, when a terminal device in an RRC_INACTIVE state is in a scenario where the NTN and TN overlap, the terminal device retains the existing PDU sessions and established DRBs when performing TN reselection and switches to RRC_CONNECTED or RRC_IDLE. That is, a terminal device in an RRC_INACTIVE state served by an NTN cell reselects to be served from the NTN cell to a TN cell before RRC state switching while maintaining the communication parameters, and then performs state switching. A UE in an RRC_INACTIVE state served by a TN cell similarly maintains the communication parameters when reselecting to be served by the NTN cell.

[0095] In some embodiments, when a terminal device in an inactive state performs cell reselection, it triggers a mobility registration area update process. For example, when a terminal device in an RRC_INACTIVE state reselects from an NTN cell to a TN cell or from a TN cell to an NTN cell, the terminal device needs to trigger a mobility registration area update process, thereby notifying the AMF that it has entered a new TA or MRA. Note that a terminal device in a connected state also supports selection from an NTN cell to a TN cell.

[0096] In some embodiments, measurements corresponding to cell reselection may be performed to determine multiple detection parameters based on a defined detection threshold, which may include one or some or all of a detection time period, a distance, a detection energy (e.g., RSRP), and a detection count.

[0097] When performing cell reselection, the terminal device performs handover between different types of networks based on the tracking areas corresponding to the cells. In some embodiments, the network side device defines tracking areas based on multiple RATs corresponding to the types of NTN satellites. In scenarios where the NTN cell and the TN cell overlap, mobility management can be performed by clearly defining the TA or MRA of the NTN cell and the TN cell.

[0098] In some embodiments, the terminal device may perform cell reselection based on network frequency priority. In an NTN cell, priorities for different frequencies of the TN system or inter-system frequencies may be derived from the system information block (SIB) and may be derived from different systems during RRC release and inter-system reselection. If reselection priorities are not configured in the SIB inter-frequency, no measurements are performed for cell reselection. If frequency priorities are configured using dedicated signaling, the terminal device ignores all priorities derived from the SIB. For example, dedicated signaling configures frequency priorities for the NTN region.

[0099] In a possible implementation, if the system information / dedicated signaling configures the reselection priority for NTN and TN, this corresponds to introducing a loose measurement period for TN frequencies whose reselection priority is higher than the reselection priority of the current NTN cell. That is, a long period can be configured for measurements in TN / NTN cells, regardless of whether the terminal device is currently in the NTN cell or the TN cell. For example, if the terminal device is in a TN cell, a long period is configured for measurements in the NTN cell. This allows to reduce the power consumption of terminal devices that perform cell reselection between NTN and TN.

[0100] In a possible implementation, if the reselection priority of a frequency corresponding to a TN cell is higher than the reselection priority of a frequency corresponding to an NTN cell, the terminal device may perform measurements for cell reselection based on the priorities of different frequencies in the inter-frequency list and / or inter-RAT frequency list. For example, as specified in specification TS 38.133, the terminal device can perform measurements with a higher priority between NR frequencies or between RATs. The inter-frequency list (NR NTN or TN) and the inter-RAT frequency list (IoT NTN or TN) are extensible, thereby adding a TN / NTN indication.

[0101] As can be seen from Figure 4, the terminal device may perform cell reselection based on the first assistance information, which may help reduce unnecessary measurements in TN cells, thereby facilitating a reduction in power consumption. The coverage of the TN cells associated with the first assistance information may help the terminal device perform NTN-TN and TN-NTN. For quasi-terrestrial fixed cells and quasi-terrestrial mobile cells, the coverage of the TN cells may be described in various ways.

[0102] In some embodiments, the coverage of a TN cell may be determined based on the relative distance and / or angular range of the TN cell relative to the center of the NTN cell, where the reference direction of the angular range may be the movement trajectory of the network device or a reference axis associated with the geographical area of ​​the NTN cell.

[0103] In one possible implementation, if the line connecting the center of a TN cell and the center of an NTN cell forms an acute angle with the reference direction, the TN cell may be represented by that angle and distance range. That is, if the angle β1 of the TN cell with respect to the reference direction is less than 90 degrees and the distance between the TN cell and the center of the NTN cell is between DL1 and DL2, the coverage of the TN cell is represented by β1, DL1, and DL2.

[0104] As another possible implementation, if the line connecting the center of the TN cell and the NTN cell forms a right angle or an obtuse angle with the reference direction, the TN cell may be represented by multiple angles and distance ranges. That is, if the angle β2 of the TN cell with respect to the reference direction is 90 degrees or more and the distance between the TN cell and the center of the NTN cell is between DL1 and DL2, the coverage of the TN cell is represented by 90 degrees, β2, DL1, and DL2.

[0105] For ease of understanding, different distribution representations of TN cells will be described below with reference to Figures 6 and 7. Figure 6 is a schematic diagram of TN cells located in an acute angle region, and Figure 7 is a schematic diagram of TN cells located in an obtuse angle region.

[0106] Referring to FIG. 6, in the figure, when β1<90°, that is, the angle range relative to the reference direction is less than 90°, the coverage of the TN cell is represented by the angle β1 and two distance values ​​DL1 and DL2.

[0107] Referring to FIG. 7, when the angle range relative to the reference direction is equal to or greater than 90 degrees, the coverage of a TN cell is represented by two angles β1 and β2 and two distance values ​​DL1 and DL2.

[0108] In some embodiments, the coverage of a TN cell may be represented by the sub-area in which the TN cell is located. The TN cell in the NTN cell shown in FIG. 5 is used as an example. The outermost TN cell in the NTN cell is represented by sub-area NTN3. The distribution of TN cells shown in FIG. 6 is used as an example. In FIG. 6, NTN1, NTN2, and NTN3 represent three sub-areas in the NTN cell. In FIG. 6, the three TN cells located at distances DL1 to DL2 from the center of the NTN cell are respectively represented by NTN2, and the one TN cell whose distance from the center of the NTN cell is greater than DL2 is represented by NTN3. Other types of sub-area divisions will be described in detail later with reference to FIGS. 8 to 11.

[0109] The above has described how a terminal device performs cell reselection based on the first auxiliary information with reference to Figures 4 to 7. The first auxiliary information is used to determine when the terminal device starts measurements for cell reselection. However, when specifically starting measurements, the terminal device further performs cell reselection based on distance information, time information, and boundary information of TN cells and priorities of TN cells, thereby effectively performing measurements related to cell reselection.

[0110] In some embodiments, in addition to the first assistance information, the terminal device further performs cell reselection based on one or more measurement-related information, which may be, for example, a distance reselection threshold set by the terminal device, a first time threshold set by the terminal device, a distance relaxation amount set by the terminal device, a time relaxation amount set by the terminal device, a second time threshold for the terminal device to stay in a sub-region, a boundary threshold for the sub-region in which the terminal device is located, and a priority of a frequency corresponding to a TN cell.

[0111] In a possible implementation, after determining the coordinate position of the TN cell, the terminal device sets a distance reselection threshold Dtarget and a first time threshold Ttarget1. The distance reselection threshold is used to determine whether to perform cell reselection based on the distance between the terminal device and the TN cell. The sub-area in which the terminal device is located may be referred to as a first sub-area. When performing cell reselection, the terminal device preferentially considers the TN cell in the first sub-area. For example, if the first distance between the terminal device and the TN cell in the first sub-area is less than the distance reselection threshold, the terminal device performs cell reselection.

[0112] The first distance may be determined based on the position coordinates of the TN cell relative to the center of the NTN cell and / or the position coordinates of the TN cell. That is, the terminal device may directly acquire the position coordinates of the TN cell, or may calculate the position of the TN cell based on the relative position coordinates. For example, the terminal device derives the absolute distance between the terminal device and the TN cell from the acquired relative position coordinates of the TN cell in the first sub-area. If the absolute distance is less than the distance reselection threshold, the terminal device initiates reselection measurement.

[0113] In a possible implementation, the network device does not inform the terminal device of the coordinate location of the TN cell, and therefore the terminal device only sets a first time threshold Ttarget1. If the terminal device does not find the above measures within the first time threshold and the UE does not find a suitable cell after the reselection time period T-target1 is exceeded, the UE stays in the NTN area.

[0114] In a possible implementation, regardless of the number of TN cell-related information received by the terminal device, the terminal device sets a second time threshold Ttarget2. The second time threshold is a delay threshold for the terminal device to stay in a specific sub-area. For example, when the time the terminal device stays in the first sub-area exceeds the second time threshold, the terminal device performs cell reselection. The time threshold for the terminal device to stay in each sub-area may be constant or may vary. The second time threshold is set based on the size of the sub-area or the number of TN cells in the sub-area.

[0115] In a possible implementation, the terminal device further sets a boundary threshold Mtarget for the sub-area in which the terminal device is located, and if the distance between the terminal device and the boundary of the sub-area is less than the boundary threshold, the terminal device considers measurements of TN cells in the sub-areas on both sides of the boundary.

[0116] In a possible implementation, the terminal device introduces relaxation measurements through relaxation quantities, thereby reducing measurements and power consumption. The relaxation quantities may include a time relaxation quantity and a distance relaxation quantity. Relaxation measurements based on the time relaxation quantity are time measurement relaxation. Relaxation measurements based on the distance relaxation quantity are distance measurement relaxation.

[0117] In a possible implementation, the terminal device further performs cell reselection based on the priority of the frequency corresponding to the TN cell. The priority-based cell reselection has been described above, and a repeated description will be omitted here.

[0118] The above-mentioned first time threshold may be referred to as a time period threshold, and is used to limit the time period during which the terminal device performs cell reselection.

[0119] In some embodiments, the terminal device determines whether to perform cell reselection based on the plurality of measurement-related information. For example, if the delay of the terminal device's stay in the first sub-area exceeds a second time threshold and / or the distance between the terminal device and the nearest TN cell is within a reselection distance threshold, the terminal device performs reselection measurements and initiates cell reselection. Also, for example, if the terminal device acquires location coordinates of a TN cell in the first sub-area and the distance between the terminal device and the TN cell is within a reselection distance threshold, the terminal device initiates reselection measurements regardless of whether the second time threshold has elapsed.

[0120] In some embodiments, measurement relaxation involves a relaxation amount, which may also be referred to as a slack amount. In the measurement relaxation state, the terminal device still follows the RSRP-based frequency measurement rules of an existing serving cell of the same or lower priority.

[0121] In a possible implementation, if the time required for the terminal device to perform cell reselection based on the distance reselection threshold or the second time threshold exceeds the first time threshold, but the terminal device cannot find a suitable cell, the first time threshold is relaxed. For example, the terminal device may stay in the first sub-area and relax the first time threshold based on a time relaxation amount. The relaxation amount is Toffset, and the first time threshold corresponding to the time measurement relaxation is Ttarget1+Toffset. Therefore, the time period for the lower reselection is Ttarget1+Toffset, and the terminal device is in the time measurement relaxation of the TN cell.

[0122] In a possible implementation, when the terminal device performs cell reselection based on the distance reselection threshold or the second time threshold, if it cannot find a suitable cell that satisfies the condition of being less than the distance reselection threshold, it may relax the distance reselection threshold. For example, when the terminal device stays in the first sub-area, the distance reselection threshold may be relaxed based on a distance relaxation amount. The relaxation amount is Doffset, and the distance reselection threshold corresponding to the distance measurement relaxation is Dtarget+Doffset. Therefore, the distance threshold for the next reselection is Dtarget+Doffset, and at this time, the terminal device is in the distance measurement relaxation of the TN cell.

[0123] In some embodiments, when in measurement relaxation, the terminal device may determine whether to terminate the measurement relaxation based on one or more pieces of information.

[0124] In one possible implementation, the terminal device may determine whether to terminate measurement relaxation based on whether the sub-area in which the terminal device is located changes. For example, when the terminal device moves from one sub-area to another, the terminal device can determine the sub-area in which the terminal device is located and determine the priority of the TN frequency of the area in which the terminal device is located. In this sub-area, the terminal device performs cell reselection based on a newly set time threshold, a newly set distance threshold, or a newly set boundary threshold. Therefore, measurement relaxation needs to be suspended.

[0125] In another possible implementation, the terminal device may determine whether to terminate the measurement relaxation based on whether the distance, time, or boundary measured by the terminal device reaches the corresponding threshold. For example, if the terminal device reaches the distance threshold, boundary threshold, and time threshold after newly setting these thresholds, the terminal device terminates the relaxation measurement.

[0126] In yet another possible implementation, the terminal device may determine whether to terminate the measurement relaxation based on whether a synchronization signal block (SSB) is detected in frequency detection. For example, if the terminal device detects an SSB in the frequency, the terminal device terminates the relaxation measurement.

[0127] In some embodiments, when a terminal device moves relative to a network device corresponding to an NTN cell and the terminal device's residence time in a first sub-area exceeds a second time threshold, measurements for cell reselection performed by the terminal device are determined based on a boundary threshold. If the distance between the terminal device and the boundary of the first sub-area is less than the boundary threshold corresponding to the first sub-area, the terminal device performs measurements for cell reselection based on the priorities of frequencies corresponding to the first sub-area and the second sub-area, where the second sub-area is the sub-area the terminal device is attempting to reach. If the distance between the terminal device and the boundary of the first sub-area is greater than the boundary threshold corresponding to the first sub-area, the terminal device performs measurements for cell reselection on the frequency corresponding to the first sub-area. That is, if the delay of the terminal device's residence in the first sub-area exceeds the second time threshold and the distance between the terminal device and the boundary of the sub-area is less than the boundary threshold, both the first sub-area and the second sub-area to be reached are involved in the measurements performed by the terminal device. The terminal device may perform measurements based on the priorities of frequencies corresponding to the two sub-areas. If the delay of the terminal device staying in the first sub-area exceeds a second time threshold and the distance between the terminal device and the boundary of the sub-area is greater than a boundary threshold, the terminal device starts measurement, and only the frequency point list within the first sub-area is involved in the measurement.

[0128] In some embodiments, if the distance between the terminal device and the nearest TN station is within a distance reselection threshold, the terminal device enables reselection measurements and initiates cell reselection, or if the delay of the terminal device's stay in the first sub-region does not exceed a second time threshold, regardless of the terminal device's distance from the boundary, the terminal device does not initiate cell reselection measurements.

[0129] The above describes how a terminal device performs cell reselection based on a set threshold. Both the first assistance information and the threshold refer to sub-areas within the NTN cell. As mentioned above, proper division into sub-areas can help the terminal device to perform measurements and / or cell reselection.

[0130] To align with the coverage division of terrestrial TN cellular networks, the present embodiment proposes a method for dividing NTN cells based on the coverage angle of a network device. The current coverage of a network device can be determined through the azimuth angle of the network device's antenna. In this coverage area, the included angle formed by the line connecting the network device to the coverage location and the perpendicular line of the network device to the ground is the coverage angle of the network device. That is, the coverage angle corresponding to a terminal device can be determined based on the ratio of the distance between the terminal device and the network device to the height of the network device above the ground. The coverage angle may also be called the offset angle. Terminal devices at different locations correspond to different coverage angles. At the edge position of the NTN cell, the coverage angle is the azimuth angle of the antenna. Therefore, the coverage angle of the network device is less than or equal to the azimuth angle of the antenna.

[0131] In some embodiments, dividing the NTN cell based on coverage angles involves determining the coverage angles of the corresponding sub-regions based on the azimuth angle of the antenna. The coverage angles may or may not be an arithmetic progression. For example, if the azimuth angle of the antenna is 60 degrees, the coverage angles corresponding to the sub-regions may be 15 degrees, 30 degrees, 45 degrees, and 60 degrees, respectively. That is, the NTN cell is divided into four sub-regions based on the azimuth angle, and one boundary of each sub-region is determined by the coverage angles corresponding to the four sub-regions. For example, at the cell edge, the satellite coverage angle is αmax, which can be divided into α1, α2, α3...αi, where α1<α2<α3...<αi<αmax.

[0132] In a possible implementation, the sub-areas into which the NTN is divided may be multiple circular or ring-shaped areas centered on the projection position of the network device in a direction perpendicular to the ground. If the NTN cell includes N sub-areas (N is a natural number greater than 1), the N coverage angles corresponding to the boundaries of the N sub-areas away from the center are determined by the following condition: 0<αi<αi+1≦αN where αi is the coverage angle corresponding to the boundary away from the center of the i-th subregion among the N subregions, i is a natural number ranging from 1 to N-1, and αN is the azimuth angle of the antenna.

[0133] In a possible implementation, the sub-regions into which an NTN cell is divided may or may not equally divide the coverage of the NTN cell. For example, if an NTN cell includes N sub-regions, the NTN cell may be equally divided into the N sub-regions. That is, the areas of the N sub-regions may be equal. Also, for example, the areas corresponding to the N sub-regions may be partially equal or unequal.

[0134] In some embodiments, a sub-region within the NTN cell can be determined based on a projected position of the network device in a direction perpendicular to the ground. The projected position may be referred to as a first position. The NTN can determine a boundary of the sub-region based on the coverage angle, where the boundary of the sub-region includes a curve centered on the first position. The first position can be determined based on coordinates of the network device. For example, the terminal device can determine orbital parameters or PVT parameters of the network device based on ephemeris data corresponding to the network device, and these parameters can determine the coordinates of the network device's projection onto the ground. Based on the first position and the coverage angle, location information for multiple sub-regions of the NTN cell can be determined.

[0135] In some embodiments, when an NTN cell is divided based on coverage angles, other information may also be considered. That is, the virtual sub-areas in the NTN cell may be determined based on one or more other related information. The other related information may be the coordinates of a network device, the geographical environment of the NTN cell's coverage, the distribution of TN cells in the NTN cell's coverage, signal interaction limitations of the NTN cell, measurement requirements and / or handover requirements of a terminal device, or auxiliary information provided by a terminal device. For example, when an NTN cell is divided into N sub-areas, the value of N may be increased based on the other related information, thereby increasing the number of sub-areas and dividing the NTN cell more finely.

[0136] In a possible implementation, the sub-areas within the NTN cell are adapted to the coordinates of the network device and the coverage situation of the TN. For example, if the coordinates indicate that the network device is in a densely populated area or there are many TN cells within the NTN cell, the number of sub-areas can be increased. Increasing the number of sub-areas allows for more accurate transition from the NTN cell to the TN cell.

[0137] In a possible implementation, the sub-areas within an NTN cell are adapted to the geographical environment of the coverage. For example, if the main coverage of an NTN cell is ocean or desert, the number of sub-areas may be reduced. Since there are fewer TN cells in the area, the probability of handover to a TN cell is small.

[0138] In a possible implementation, the sub-areas within the NTN cell may be determined based on the signal interaction limitations of the NTN cell. For example, if there are many TN cells within the NTN cell, and there are many sub-areas, the terminal device will need to perform many signal interactions with the network device to meet the requirements for measurement or handover between different sub-areas. If the network device is a satellite, the transmission delay will be relatively large, and the number of sub-areas can be reduced to reduce the interaction.

[0139] In a possible implementation, the sub-areas within the NTN cell may be determined based on the measurement and / or handover requirements of the terminal device. For example, to reduce power consumption, if the terminal device has high measurement or handover accuracy requirements, the number of sub-areas may be increased, thereby reducing the variance in subsequent measurement and handover decisions.

[0140] In a possible implementation, the sub-regions within the NTN cell may be further determined based on other auxiliary information provided by the terminal device. For example, the terminal device may provide the network device with information about its surrounding environment or location information determined in other ways. The network device may determine the number of sub-regions based on auxiliary information provided by multiple terminal devices.

[0141] As described above, in order to determine the division method of NTN cells and the number of sub-areas, in addition to the coverage angle and position of the network device, the ground conditions of the NTN cell coverage, the distribution of TN cells in the coverage, communication requirements and auxiliary information provided by the terminal device can be taken into consideration, so that the division of NTN cells can be more accurate and the division can be more adapted to the geographical area of ​​coverage.

[0142] Hereinafter, the NTN cell division method according to the embodiment of the present invention will be specifically described with reference to FIG.

[0143] Referring to Figure 8, the projection position of the network device in a direction perpendicular to the ground is a first position 810, and the azimuth angle of the antenna is the maximum azimuth angle αmax of the network device. Based on the azimuth angle, the NTN cell is divided into three sub-areas, NTN1, NTN2, and NTN3. As shown in Figure 8, the boundaries of the three sub-areas are centered at the first position 810. Specifically, the boundary curve 820 of the sub-area NTN1 is a circle centered at the first position 810. The boundaries of the sub-area NTN2 are curves 820 and 830, respectively, and the curve 830 is also a circle centered at the first position 810. Similarly, the boundaries of the sub-area NTN3 are curves 830 and 840, respectively, and the curve 840 is also a circle centered at the first position 810.

[0144] As shown in Figure 8, the coverage angles of the network devices corresponding to the boundaries of multiple sub-areas are less than or equal to the azimuth angle of the antenna. The coverage angle corresponding to the boundary curve 820 of sub-area NTN1 is α1, which is less than αmax. The coverage angles corresponding to the two boundaries of sub-area NTN2 are α1 and α2, respectively, which are both less than αmax. The coverage angle corresponding to the inner boundary curve 830 of sub-area NTN3 is α2, and the coverage angle corresponding to the outer boundary curve 840 is equal to αmax.

[0145] The coverage angle corresponding to the terminal device in the sub-region is within the coverage angle range corresponding to the sub-region boundary, for example, the coverage angle corresponding to the terminal device in the sub-region NTN1 is less than or equal to α1.

[0146] It should be understood that the concentric circle division scheme shown in Figure 8 is merely an example, and that division schemes based on other coverage angles are also applicable to the present application. For example, multiple elliptical sub-regions can be determined based on the coverage angles of the network device in multiple directions.

[0147] The NTN cell division method described with reference to Figure 8 can be applied to quasi-earth fixed cells and quasi-earth mobile cells. The relative position change between the terminal device and the network device varies depending on the cell type, as will be explained in detail later.

[0148] The NTN cell division scheme shown in Figure 8 can be more closely integrated with the coverage division of terrestrial TN cellular networks. This division allows the NTN network to better integrate with terrestrial cellular systems and reduce measurement blind spots. In addition to division based on azimuth, NTN cells with antennas can be divided in several other ways, which will be briefly described below with reference to Figures 9 and 10.

[0149] As mentioned above, the NTN cell may be divided in other ways. Figures 9 and 10 show two possible divisions.

[0150] Referring to Figure 9, the NTN cell is divided into eight equal sub-regions by four intersecting diameters. The eight sub-regions are sub-region a, sub-region b, sub-region c, sub-region d, sub-region e, sub-region f, sub-region g, and sub-region h. As shown in Figure 8, sub-region a, sub-region b, and sub-region e each contain a TN cell.

[0151] 10, the NTN cell is divided into nine sub-regions by a grid pattern, which are sub-region a, sub-region b, sub-region c, sub-region d, sub-region e, sub-region f, sub-region g, sub-region h, and sub-region i. As shown in FIG. 9, sub-region f and sub-region h each contain a TN cell.

[0152] If a TN cell exists in a sub-area in Figures 9 and 10, it can be indicated by predetermined indication information. For example, in the indication information, a bit corresponding to the sub-area including the TN cell is set to 1, and otherwise set to 0. The division rule and numbering rule may be pre-configured in the terminal device. In this way, the network device can indicate the location of the TN cell by simply providing a few bits to the terminal device. As a possible implementation form, the network device may notify the terminal device of the indication message by broadcast, an SIB message, or an RRC message. Upon receiving the indication information, the terminal device can calculate the approximate range of the TN cell based on the reference position and radius of the NTN cell.

[0153] The NTN cell division method described above with reference to FIG. 8 can be applied to quasi-earth fixed cells and quasi-earth mobile cells.

[0154] For a quasi-earth fixed cell, the coverage of the NTN cell can be divided into multiple sub-areas. For example, the coverage of the NTN cell of a quasi-earth fixed cell can be divided into n equal sub-areas according to the scheme shown in Figure 8, or it can be divided into several unequal sub-areas based on the distribution of the TN cells.

[0155] In the case of a quasi-terrestrial fixed cell, the coverage of the NTN cell does not change, but the relative distance of the network device to the terminal device changes. After a certain period of time, the signal of the current network device may not be able to cover the terminal device. For example, if the service link distance L is less than the maximum service link distance Lmax and the coverage angle of the first network device corresponding to the terminal device is less than αmax, the terminal device is within the coverage range of the first network device. Alternatively, if the service link distance is greater than the maximum distance or the coverage angle of the first network device corresponding to the terminal device is greater than αmax, the terminal device is already out of the coverage range of the first network device. The terminal device can communicate with a second network device serving the area instead of the first network device. That is, in the case of a quasi-terrestrial fixed cell, when the terminal device is stationary, the terminal device is always in the same sub-area. However, the network device serving the terminal device changes.

[0156] In the case of a quasi-terrestrial mobile cell, the coverage of the NTN cell changes as the network device moves. After cell division is performed on the NTN cell, the sub-area in which the terminal device is located changes as the network device moves. When the terminal device is stationary, the sub-area in which the terminal device is located changes. The terminal device determines the sub-area in which the terminal device is located and subsequent changes based on a message (e.g., the first message described above) sent from the network device. When the terminal device is in a mobile state, the terminal device periodically receives a message from the network device and needs to determine the sub-area in which the terminal device is currently and later located, thereby determining whether to trigger neighbor cell measurements and related measurements and calculations.

[0157] In some embodiments, the network device may provide the terminal device with the antenna beam angle of the cell center and the radius of the cell through broadcast information / system information / dedicated signaling. The beam angle of the cell center can determine the direction of the sub-satellite point and the distance of the service link. The network device may also provide the terminal device with NTN cell division, and the sub-regions into which the NTN is divided may vary based on the geographical location and different azimuth angles of the antenna. The terminal device can calculate the coordinates of the reference position of the cell center based on the antenna azimuth angle and moving speed of the network device. The terminal device may also need to calculate the cell edge through the radius or threshold of the cell.

[0158] In some embodiments, when the network device moves, a time threshold T may be set. Every time the time T passes, the network device may provide reference information to the terminal device. The network device may provide updated ephemeris parameters or time-stamped ephemeris parameters to the moving cell each time. The network device may also provide multiple reference positions and their time information or moving speed to the moving cell. After determining the time when the terminal device will reach the edge of the cell, the terminal device knows when to start cell measurements and cell reselection.

[0159] Above, a method embodiment of the present application has been described in detail with reference to Figures 4 to 10. Hereinafter, an apparatus embodiment of the present application will be described in detail with reference to Figures 11 to 13. Since the description of the apparatus embodiment corresponds to the description of the method embodiment, it should be understood that reference can be made to the above method embodiment for parts not described in detail.

[0160] 11 is a schematic block diagram of an apparatus for wireless communication according to one embodiment of the present application. The apparatus 1100 may be any terminal device described above. The apparatus 1100 shown in FIG. 11 includes a reselection unit 1110.

[0161] The reselection unit 1110 is configured to perform cell reselection in the NTN cell based on first auxiliary information, where the first auxiliary information is associated with one or more pieces of information: a distribution of TN cells in the NTN cell; a sub-area in the NTN cell related to a coverage angle of a network device corresponding to the NTN cell; where the sub-area is related to the NTN cell or the coverage angle of a network device corresponding to a TN cell included in the sub-area in the NTN cell.

[0162] Optionally, the first auxiliary information further includes one or more pieces of information: a frequency information group of a TN cell corresponding to a sub-area within the NTN cell; a location coordinate of the TN cell; a location coordinate of the TN cell relative to the center of the NTN cell; frequency information of the TN cell; a reference location and distance threshold of an adjacent cell of the TN cell; a coverage of the TN cell; and a boundary line between the coverage of the TN cell and the coverage of the NTN cell.

[0163] Optionally, the coverage of the TN cell is determined based on the relative distance range and / or angular range of the TN cell relative to the center of the NTN cell, the angular range being determined based on a reference direction.

[0164] Optionally, the reference direction is determined based on the movement trajectory of the network device corresponding to the NTN cell.

[0165] Optionally, the manner of representing the coverage of a TN cell is related to the angle of the TN cell relative to a reference direction, and if the angle β1 of the TN cell relative to the reference direction is less than 90 degrees and the distance between the TN cell and the center of the NTN cell is between DL1 and DL2, the coverage of the TN cell is represented by β1, DL1 and DL2, or if the angle β2 of the TN cell relative to the reference direction is 90 degrees or more and the distance between the TN cell and the center of the NTN cell is between DL1 and DL2, the coverage of the TN cell is represented by 90 degrees, β2, DL1 and DL2.

[0166] Optionally, the NTN cell includes multiple sub-areas, each sub-area among the multiple sub-areas corresponds to one frequency information group, and one or more frequencies in the frequency information group have corresponding priorities, which are used by the terminal device to perform cell reselection.

[0167] Optionally, the apparatus 1100 further includes a measurement unit configured to perform measurements for cell reselection according to priorities of different frequencies in the frequency list and / or frequency list of radio access technologies when a reselection priority of a frequency corresponding to a TN cell is higher than a reselection priority of a frequency corresponding to an NTN cell.

[0168] Optionally, the first auxiliary information is carried in one or more of broadcast information, system information, and dedicated signaling.

[0169] Optionally, the terminal device further performs cell reselection based on one or more information of a distance reselection threshold set by the terminal device, a first time threshold set by the terminal device, a distance relaxation amount set by the terminal device, a time relaxation amount set by the terminal device, a second time threshold for the terminal device to stay in the sub-region, a boundary threshold for the sub-region in which the terminal device is located, and a priority of a frequency corresponding to a TN cell within the NTN cell.

[0170] Optionally, the terminal device is located within a first sub-area of ​​the NTN cell, and the reselection unit 1110 is further configured to perform cell reselection when a first distance between the terminal device and the TN cell in the first sub-area is less than a distance reselection threshold.

[0171] Optionally, the first distance is determined based on the position coordinates of the TN cell and / or the relative position coordinates of the center of the TN cell and the NTN cell.

[0172] Optionally, the measurement unit is further used to enter distance measurement relaxation based on the distance relaxation amount when the terminal device cannot find a cell for handover through cell reselection.

[0173] Optionally, the distance reselection threshold set by the terminal device is Dtarget, the distance relaxation amount is Doffset, and the distance reselection threshold corresponding to the distance measurement relaxation is Dtarget+Doffset.

[0174] Optionally, the terminal device is located within a first sub-area of ​​the NTN cell, and the reselection unit 1110 is further configured to perform cell reselection when the time that the terminal device stays in the first sub-area exceeds a second time threshold.

[0175] Optionally, the time at which the reselection unit 1110 performs cell reselection based on the distance reselection threshold or the second time threshold exceeds the first time threshold, and the measurement unit is further configured to enter time measurement relaxation based on a time relaxation amount if the terminal device cannot find a cell for handover within the first time threshold.

[0176] Optionally, the first time threshold set by the terminal device is Ttarget1, the time relaxation amount is Toffset, and the first time threshold corresponding to the time measurement relaxation is Ttarget1+Toffset.

[0177] Optionally, the terminal device terminates distance measurement relaxation or time measurement relaxation based on one or more of the following information: whether the sub-region in which the terminal device is located changes; whether the distance, time, or boundary measured by the terminal device reaches a corresponding threshold; and whether the terminal device detects a synchronization signal block in frequency detection.

[0178] Optionally, when the terminal device moves relative to the network device corresponding to the NTN cell, and the time the terminal device stays in the first sub-area exceeds a second time threshold, the measurement unit is further configured to perform measurements for cell reselection based on priorities of frequencies corresponding to the first sub-area and the second sub-area when a distance between the terminal device and a boundary of the first sub-area is less than a boundary threshold corresponding to the first sub-area, wherein the second sub-area is a sub-area that the terminal device attempts to reach, and when a distance between the terminal device and the boundary of the first sub-area is greater than the boundary threshold corresponding to the first sub-area, perform measurements for cell reselection on the frequency corresponding to the first sub-area.

[0179] Optionally, the NTN cell and the TN cell within the NTN cell are located in the same PLMN, and the terminal device is in an inactive state, and the reselection unit is further configured to retain communication parameters of the terminal device and the current cell when performing cell reselection.

[0180] Optionally, the communication parameters include a protocol data unit session and a data radio bearer established by the terminal device.

[0181] Optionally, when the terminal device is in an inactive state and performs a cell reselection, it triggers a mobility registration area update process.

[0182] Optionally, the boundary of a sub-area within the NTN cell corresponds to a coverage angle of a network device corresponding to the NTN cell, the projected position of the network device in a direction perpendicular to the ground is a first position, and the boundary of the sub-area includes a curve with the first position as its center.

[0183] Optionally, the NTN cell includes N sub-regions, where N is a natural number greater than 1, and N coverage angles respectively corresponding to boundaries of the N sub-regions away from the first location satisfy the condition: 0<αi<αi+1≦αN where αi is the coverage angle corresponding to the boundary of the i-th sub-region among the N sub-regions away from the first position, i is a natural number ranging from 1 to N-1, and αN is the azimuth angle of the antenna.

[0184] Optionally, an NTN cell includes N sub-regions, where N is a natural number greater than 1, and the N sub-regions may or may not equally divide the coverage of the NTN cell.

[0185] Optionally, the sub-area within the NTN cell is further determined based on one or more of the following information: coordinates of the network device corresponding to the NTN cell, the geographical environment of the NTN cell's coverage, the distribution of TN cells in the NTN cell's coverage, signal interaction limitations of the NTN cell, measurement requirements and / or handover requirements of the terminal device, and auxiliary information provided by the terminal device.

[0186] 12 is a schematic block diagram of an apparatus for wireless communication according to another embodiment of the present application. The apparatus 1200 may be any of the network devices described above. The apparatus 1200 shown in FIG. 12 includes a transmitting unit 1210.

[0187] The transmitting unit 1210 can be used to transmit first auxiliary information to a terminal device, where the first auxiliary information is configured to cause the terminal device to perform cell reselection in an NTN cell, and the first auxiliary information is associated with one or more pieces of information: a distribution of TN cells in the NTN cell; a sub-area in the NTN cell related to a coverage angle of a network device corresponding to the NTN cell; and a TN cell included in the sub-area in the NTN cell.

[0188] Optionally, the first auxiliary information further includes one or more pieces of information: a frequency information group of a TN cell corresponding to a sub-area within the NTN cell; a location coordinate of the TN cell; a location coordinate of the TN cell relative to the center of the NTN cell; frequency information of the TN cell; a reference location and distance threshold of an adjacent cell of the TN cell; a coverage of the TN cell; and a boundary line between the coverage of the TN cell and the coverage of the NTN cell.

[0189] Optionally, the coverage of the TN cell is determined based on the relative distance range and / or angular range of the TN cell relative to the center of the NTN cell, the angular range being determined based on a reference direction.

[0190] Optionally, the reference direction is determined based on the movement trajectory of the network device corresponding to the NTN cell.

[0191] Optionally, the method of representing the coverage of a TN cell is related to the angle of the TN cell relative to a reference direction, and if the angle β1 of the TN cell relative to the reference direction is less than 90 degrees and the distance between the TN cell and the center of the NTN cell is between DL1 and DL2, the coverage of the TN cell is represented by β1, DL1 and DL2, and if the angle β2 of the TN cell relative to the reference direction is 90 degrees or more and the distance between the TN cell and the center of the NTN cell is between DL1 and DL2, the coverage of the TN cell is represented by 90 degrees, β2, DL1 and DL2.

[0192] Optionally, the NTN cell includes multiple sub-areas, each sub-area among the multiple sub-areas corresponds to one frequency information group, and one or more frequencies in the frequency information group have corresponding priorities, which are used by the terminal device to perform cell reselection.

[0193] Optionally, the first auxiliary information is carried in one or more of broadcast information, system information, and dedicated signaling.

[0194] Optionally, the boundary of a sub-area within the NTN cell corresponds to a coverage angle of the network device, the projected position of the network device in a direction perpendicular to the ground is a first position, and the boundary of the sub-area includes a curve with the first position as its center.

[0195] Optionally, the NTN cell includes N sub-regions, where N is a natural number greater than 1, and N coverage angles respectively corresponding to boundaries of the N sub-regions away from the first location satisfy the condition: 0<αi<αi+1≦αN where αi is the coverage angle corresponding to the boundary of the i-th sub-region among the N sub-regions away from the first position, i is a natural number ranging from 1 to N-1, and αN is the azimuth angle of the antenna.

[0196] Optionally, an NTN cell includes N sub-regions, where N is a natural number greater than 1, and the N sub-regions may or may not equally divide the coverage of the NTN cell.

[0197] Optionally, the sub-area within the NTN cell is further determined based on one or more of the following information: coordinates of the network device, the geographical environment of the NTN cell coverage, the distribution of TN cells in the NTN cell coverage, signal interaction limitations of the NTN cell, measurement requirements and / or handover requirements of the terminal device, and auxiliary information provided by the terminal device.

[0198] FIG. 13 shows a structural diagram of a communication device according to an embodiment of the present application. The dashed lines in FIG. 13 indicate that the unit or module is optional. The device 1300 can be used to implement the method described in the above method embodiment. The device 1300 can be a chip, a terminal device, or a network device.

[0199] The device 1300 may include one or more processors 1310. The processor 1310 can support the device 1300 in implementing the methods described in the method embodiments above. The processor 1310 may be a general-purpose processor or a special-purpose processor. For example, the processor may be a central processing unit (CPU). Alternatively, the processor may be another general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component, or the like. A general-purpose processor may be a microprocessor, or the processor may be any conventional processor, or the like.

[0200] The device 1300 may further include one or more memories 1320. The memories 1320 may store programs that, when executed by the processor 1310, cause the processor 1310 to perform the methods described in the method embodiments above. The memory 1320 may be separate from the processor 1310 or may be integrated into the processor 1310.

[0201] The apparatus 1300 may further include a transceiver 1330. The processor 1310 may communicate with other devices or chips via the transceiver 1330. For example, the processor 1310 may transmit and receive data to and from other devices or chips via the transceiver 1330.

[0202] An embodiment of the present application further provides a computer-readable storage medium for storing a program, which can be applied to a terminal or a network device according to the embodiment of the present application, and the program can cause a computer to execute the method performed by the terminal or the network device according to each embodiment of the present application.

[0203] In some embodiments, the computer-readable storage medium may be any available medium that can be read by a computer, or a data storage device that integrates one or more available media, such as a server, a data center, etc. The available medium may be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a digital versatile disk (DVD)), or a semiconductor medium (e.g., a solid state disk (SSD)).

[0204] An embodiment of the present application further provides a computer program product, the computer program product including a program, which is applicable to a terminal or a network device according to an embodiment of the present application, and the program causes a computer to execute the method performed by the terminal or the network device according to each embodiment of the present application.

[0205] The above embodiments may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented in software, all or in part may be implemented in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded into and executed by a computer, the computer generates all or some of the procedures or functions described in the embodiments of the present application. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wire (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, radio, microwave, etc.).

[0206] The embodiments of the present application further provide a computer program, which is applicable to a terminal or a network device according to the embodiments of the present application, and causes a computer to execute the method executed by the terminal or the network device according to each embodiment of the present application.

[0207] In this application, the terms "system" and "network" may be used interchangeably. Furthermore, the terms used in this application are used only to interpret specific embodiments of the present application and are not intended to limit the present application. The terms "first," "second," "third," "fourth," etc. in the specification, claims, and drawings of this application are used to distinguish between different objects, not to describe a particular order. Furthermore, the terms "include," "have," and any variations thereof are intended to cover a non-exclusive inclusion.

[0208] In the embodiments of the present application, the "indication" referred to may be a direct indication or an indirect indication, or may represent an association relationship. For example, when A indicates B, it may mean that A directly indicates B, e.g., that B can be obtained by A, or that A indirectly indicates B, e.g., that A indicates C, e.g., that B can be obtained by C, or may represent an association relationship between A and B.

[0209] In the embodiments of the present application, the term "correspondence" may indicate that there is a direct or indirect correspondence relationship between the two, or that there is an association relationship between the two, or a relationship such as a directing and a directed, or a setting and a set.

[0210] In the embodiments of the present application, the "protocol" may refer to a standard protocol in the communications field, and may include, for example, an LTE protocol, an NR protocol, and related protocols applied to future communications systems, but is not limited thereto in the present application.

[0211] In the embodiments of the present application, determining B based on A does not mean determining B based only on A, but B may be determined based on A and / or other information.

[0212] In the examples of the present application, the term "and / or" simply describes the relationship between related objects and indicates that three types of relationships exist, for example, A and / or B includes three cases: the presence of only A, the simultaneous presence of A and B, and the presence of only B. In addition, in this specification, the symbol " / " generally indicates that the related objects before and after it are in an "or" relationship.

[0213] It should be understood that in some embodiments of the present application, the disclosed systems, devices, and methods can be implemented in other forms. For example, the device embodiments described above are merely exemplary, and the division of the units is merely a logical function division. In actual implementation, other division schemes may be adopted, for example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not implemented. Furthermore, the shown or discussed mutual couplings or direct couplings or communication connections may be indirect couplings or communication connections via some interfaces, devices, or units, and may be in electrical, mechanical, or other forms.

[0214] 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, i.e., they may be located in one place or distributed across multiple network units. Some or all of the units can be selected based on actual needs to achieve the objectives of the means of this embodiment.

[0215] Furthermore, each functional unit in each embodiment of the present application may be integrated into one processing unit, each unit may exist physically separately, or two or more units may be integrated into one unit.

[0216] Although specific embodiments of the present application have been described above, the scope of protection of the present application is not limited thereto, and all modifications and substitutions that can be easily conceived by those skilled in the art without departing from the technical scope disclosed in the present application fall within the scope of protection of the present application. Therefore, the scope of protection of the present application should be in accordance with the scope of protection of the claims.

Claims

1. 1. A method for wireless communication, comprising: The terminal device performs cell reselection in a non-terrestrial network (NTN) cell based on first auxiliary information, distribution of terrestrial network TN cells within said NTN cells; a sub-area within the NTN cell associated with a coverage angle of a network device corresponding to the NTN cell; and The method is characterized in that the information is associated with one or more of the TN cells included in a sub-area within the NTN cell.

2. The first auxiliary information is a frequency information group of a TN cell corresponding to a sub-area within the NTN cell; the location coordinates of the TN cell; the position coordinates of the TN cell relative to the center of the NTN cell; Frequency information of the TN cell; the reference position and distance threshold of the neighboring cells of the TN cell; the coverage of the TN cell, and 2. The method of claim 1, further comprising one or more pieces of information of a boundary line between the coverage of the TN cell and the coverage of the NTN cell.

3. 3. The method of claim 2, wherein the coverage of the TN cell is determined based on a relative distance range and / or angle range between the center of the TN cell and the center of the NTN cell, and the angle range is determined based on a reference direction.

4. The method of claim 3 , wherein the reference direction is determined based on a movement trajectory of a network device corresponding to the NTN cell.

5. The method of expressing the coverage of the TN cell is related to the angle of the TN cell relative to the reference direction; When the angle β1 of the TN cell with respect to the reference direction is less than 90 degrees and the distance between the TN cell and the center of the NTN cell is between DL1 and DL2, the coverage of the TN cell is represented by β1, DL1, and DL2; The method of claim 3, characterized in that if the angle β2 of the TN cell relative to the reference direction is greater than or equal to 90 degrees and the distance between the TN cell and the center of the NTN cell is between DL1 and DL2, the coverage of the TN cell is represented by 90 degrees, β2, DL1 and DL2.

6. 3. The method of claim 2, wherein an NTN cell includes a plurality of sub-areas, each sub-area among the plurality of sub-areas corresponds to one of the frequency information groups, and one or more frequencies in the frequency information group have corresponding priorities, and the priorities are used by the terminal device to perform the cell reselection.

7. 7. The method of claim 6, further comprising: if a reselection priority of a frequency corresponding to the TN cell is higher than a reselection priority of a frequency corresponding to the NTN cell, the terminal device performs measurements for the cell reselection according to priorities of different frequencies in a frequency list and / or a frequency list of radio access technologies.

8. The method according to any one of claims 1 to 7, characterized in that the first auxiliary information is carried in one or more of the following information: broadcast information, system information, and dedicated signaling.

9. The terminal device further comprises: a distance reselection threshold set by the terminal device; a first time threshold set by the terminal device; a distance relaxation amount set by the terminal device; a time relaxation amount set by the terminal device; a second time threshold for the terminal device to stay in the sub-region; a boundary threshold of the sub-region in which the terminal device is located; and The method according to any one of claims 1 to 8, characterized in that the cell reselection is performed based on one or more pieces of information of the priority of frequencies corresponding to TN cells in the NTN cell.

10. The terminal device is located within a first sub-area of ​​the NTN cell, and the method comprises:

10. The method of claim 9, further comprising: if a first distance between the terminal device and a TN cell in the first sub-area is less than the distance reselection threshold, the terminal device performs the cell reselection.

11. The method according to claim 10, wherein the first distance is determined based on the position coordinates of the TN cell and / or the relative position coordinates of the center of the TN cell and the NTN cell.

12. 11. The method of claim 10, further comprising: if the terminal device cannot find a cell for handover by the cell reselection, the terminal device enters distance measurement relaxation based on the distance relaxation amount.

13. 13. The method of claim 12, wherein the distance reselection threshold set by the terminal device is Dtarget, the distance relaxation amount is Doffset, and the distance reselection threshold corresponding to the distance measurement relaxation is Dtarget+Doffset.

14. The terminal device is located within a first sub-area of ​​the NTN cell, and the method comprises:

10. The method of claim 9, further comprising: when a time during which the terminal device stays in the first sub-region exceeds the second time threshold, the terminal device performs the cell reselection.

15. a time at which the terminal device performs cell reselection based on the distance reselection threshold or the second time threshold exceeds the first time threshold, and the method further comprises:

10. The method of claim 9, further comprising: if the terminal device cannot find a cell for handover within the first time threshold, the terminal device enters time measurement relaxation based on the time relaxation amount.

16. 16. The method of claim 15, wherein the first time threshold set by the terminal device is Ttarget1, the time relaxation amount is Toffset, and the first time threshold corresponding to the time measurement relaxation is Ttarget1+Toffset.

17. The terminal device whether the sub-region in which the terminal device is located changes; Whether the distance, time or boundary measured by the terminal device reaches a corresponding threshold; and 16. The method according to claim 12 or 15, characterized in that the distance measurement relaxation or the time measurement relaxation is terminated based on one or more pieces of information, such as whether the terminal device has detected a synchronization signal block in frequency detection.

18. The terminal device and the network device corresponding to the NTN cell move relatively, and when the time that the terminal device stays in the first sub-area exceeds the second time threshold, the method includes: When the distance between the terminal device and the boundary of the first sub-area is less than a boundary threshold corresponding to the first sub-area, the terminal device performs measurements for the cell reselection based on frequency priorities corresponding to the first sub-area and a second sub-area, where the second sub-area is a sub-area that the terminal device intends to reach; 10. The method of claim 9, further comprising: when a distance between the terminal device and a boundary of the first sub-region is greater than a boundary threshold corresponding to the first sub-region, the terminal device performs measurements for the cell reselection on a frequency corresponding to the first sub-region.

19. The NTN cell and a TN cell within the NTN cell are located in the same public land mobile network (PLMN), the terminal device is in an inactive state, and the method includes:

19. The method according to any one of claims 1 to 18, further comprising the step of maintaining communication parameters of the terminal device and a current cell when the terminal device performs the cell reselection.

20. 20. The method of claim 19, wherein the communication parameters include a protocol data unit session and a data radio bearer established by the terminal device.

21. the terminal device is in an inactive state, and the method includes:

21. The method according to any one of claims 1 to 20, further comprising the step of triggering a mobility registration area update process when the terminal device performs the cell reselection.

22. A method according to any one of claims 1 to 21, characterized in that the boundary of a sub-area within the NTN cell corresponds to the coverage angle of a network device corresponding to the NTN cell, the projection position of the network device in a direction perpendicular to the ground is a first position, and the boundary of the sub-area includes a curve with the first position as its center.

23. The NTN cell includes N sub-areas, where N is a natural number greater than 1, and N coverage angles respectively corresponding to boundaries of the N sub-areas away from the first location are determined by the following condition: 0<αi<αi+1≦αN where αi is a coverage angle corresponding to a boundary of an ith subregion of the N subregions away from the first location, i is a natural number ranging from 1 to N−1, and αN is an azimuth angle of the antenna.

24. 23. The method of claim 22, wherein the NTN cell includes N sub-areas, where N is a natural number greater than 1, and the N sub-areas may or may not equally divide the coverage of the NTN cell.

25. The sub-region within the NTN cell further comprises: the coordinates of a network device corresponding to said NTN cell; the geographical environment of the NTN cell coverage; a distribution of TN cells in the coverage of the NTN cells; Limiting signal interactions of the NTN cells; Measurement and / or handover requirements of the terminal device, and 23. The method of claim 22, wherein the determination is based on one or more pieces of auxiliary information provided by the terminal device.

26. 1. A method for wireless communication, comprising: The network device includes a step of transmitting first auxiliary information to a terminal device, the first auxiliary information being used by the terminal device to perform cell reselection in a non-terrestrial network (NTN) cell, and the first auxiliary information includes: distribution of terrestrial network TN cells within said NTN cells; a sub-area within the NTN cell associated with a coverage angle of a network device corresponding to the NTN cell; and The method is characterized in that the information is associated with one or more of the TN cells included in a sub-area within the NTN cell.

27. The first auxiliary information is a frequency information group of a TN cell corresponding to a sub-area within the NTN cell; the location coordinates of the TN cell; the position coordinates of the TN cell relative to the center of the NTN cell; Frequency information of the TN cell; the reference position and distance threshold of the neighboring cells of the TN cell; the coverage of the TN cell, and 27. The method of claim 26, further comprising one or more of the following information: a boundary line between the coverage of the TN cell and the coverage of the NTN cell.

28. 28. The method of claim 27, wherein the coverage of the TN cell is determined based on a relative distance range and / or angle range between the center of the TN cell and the center of the NTN cell, and the angle range is determined based on a reference direction.

29. 29. The method of claim 28, wherein the reference direction is determined based on a movement trajectory of a network device corresponding to the NTN cell.

30. The method of expressing the coverage of the TN cell is related to the angle of the TN cell relative to the reference direction; When the angle β1 of the TN cell with respect to the reference direction is less than 90 degrees and the distance between the TN cell and the center of the NTN cell is between DL1 and DL2, the coverage of the TN cell is represented by β1, DL1, and DL2; 29. The method of claim 28, wherein if the angle β2 of the TN cell relative to the reference direction is greater than or equal to 90 degrees and the distance between the TN cell and the center of the NTN cell is between DL1 and DL2, the coverage of the TN cell is represented by 90 degrees, β2, DL1 and DL2.

31. 28. The method of claim 27, wherein an NTN cell includes a plurality of sub-areas, each sub-area among the plurality of sub-areas corresponds to one of the frequency information groups, and one or more frequencies in the frequency information group have corresponding priorities, and the priorities are used by the terminal device to perform the cell reselection.

32. The method according to any one of claims 26 to 31, characterized in that the first auxiliary information is borne in one or more of the following information: broadcast information, system information, and dedicated signaling.

33. 33. The method of claim 26, wherein the boundary of a sub-area within the NTN cell corresponds to a coverage angle of the network device, the projection position of the network device in a direction perpendicular to the ground is a first position, and the boundary of the sub-area includes a curve with the first position as its center.

34. The NTN cell includes N sub-areas, where N is a natural number greater than 1, and N coverage angles respectively corresponding to boundaries of the N sub-areas away from the first location are determined by the following condition: 0<αi<αi+1≦αN where αi is a coverage angle corresponding to a boundary of an ith subregion of the N subregions away from the first location, i is a natural number ranging from 1 to N−1, and αN is an azimuth angle of the antenna.

35. 34. The method of claim 33, wherein the NTN cell includes N sub-areas, where N is a natural number greater than 1, and the N sub-areas may or may not equally divide the coverage of the NTN cell.

36. The sub-region within the NTN cell further comprises: the coordinates of the network device; the geographical environment of the NTN cell coverage; a distribution of TN cells in the coverage of the NTN cells; Limiting signal interactions of the NTN cells; Measurement and / or handover requirements of the terminal device, and 34. The method of claim 33, wherein the determination is based on one or more pieces of auxiliary information provided by the terminal device.

37. 1. An apparatus for wireless communication, the apparatus being a terminal device, the terminal device comprising: a reselection unit for performing cell reselection in a non-terrestrial network NTN cell based on first auxiliary information, the first auxiliary information comprising: distribution of terrestrial network TN cells within said NTN cells; a sub-area within the NTN cell associated with a coverage angle of a network device corresponding to the NTN cell; and An apparatus characterized in that it is associated with information of one or more of the TN cells included in a sub-area within the NTN cell.

38. 1. A wireless communication device, the device being a network device, the network device comprising: A transmitting unit for transmitting first auxiliary information to the terminal device, the first auxiliary information being used by the terminal device to perform cell reselection in a non-terrestrial network (NTN) cell, the first auxiliary information including: distribution of terrestrial network TN cells within said NTN cells; a sub-area within the NTN cell associated with a coverage angle of a network device corresponding to the NTN cell; and An apparatus characterized in that it is associated with information of one or more of the TN cells included in a sub-area within the NTN cell.

39. A communication device comprising: a memory; and a processor, wherein the memory is used to store a program; and the processor is used to call the program in the memory and execute the method of any one of claims 1 to 36.

40. A communication device, characterized in that it comprises a processor for calling a program from a memory to perform the method of any one of claims 1 to 36.

41. A chip comprising a processor that causes a device equipped with the chip to execute the method according to any one of claims 1 to 36 by calling a program from a memory.

42. A computer-readable storage medium having stored thereon a program for causing a computer to execute the method according to any one of claims 1 to 36.

43. A computer program product, characterized in that a computer-readable storage medium contains a program that causes a computer to carry out the method according to any one of claims 1 to 36.

44. A computer program, characterized in that it causes a computer to carry out the method according to any one of claims 1 to 36.

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