Methods 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

[0003]

[0001] This application claims the priority of a Chinese patent application with an application number of 2023100868066 and an application title of "Method and Apparatus for Wireless Communication", which was filed with the China National Intellectual Property Administration on February 1st, 2023, and the entire content thereof is incorporated herein by reference.

[0002] This application relates to the technical field of communications, and more specifically, to a method and apparatus for wireless communication.

Background Art

[0003] A non-terrestrial network (NTN) system has high mobility. In the case of a system where the coverage of an NTN cell is stationary with respect to the ground (for example, a quasi-geostationary system), a terminal device in an idle state or a non-active state can perform cell reselection based on the downtime of the serving cell provided by the network device.

[0004] However, in a system where the NTN cell moves with the network device (for example, a quasi-geostationary cell), the change in the coverage of the serving cell may be disadvantageous for the terminal device to perform cell reselection.

Summary of the Invention

Problems to be Solved by the Invention

[0005] This application provides a method and apparatus for wireless communication. Hereinafter, each aspect according to the embodiments of this application will be described.

Means for Solving the Problems

[0006] In a first embodiment, a method for wireless communication is provided. The method includes the step of a terminal device performing cell reselection in an NTN cell based on first auxiliary information. The first auxiliary information is associated with information on one or more of the following: the distribution of TN cells in the NTN cell, subregions within the NTN cell related to the coverage angle of a network device corresponding to the NTN cell, and TN cells contained within the subregions within the NTN cell.

[0007] A second embodiment provides a method for wireless communication. The method includes the step of 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 information of one or more of the distribution of TN cells in the NTN cell, subregions in the NTN cell relating to the coverage angle of a network device corresponding to the NTN cell, and TN cells contained in the subregions in the NTN cell.

[0008] In a third embodiment, a device for wireless communication is provided. The device is a terminal device, which includes a reselection unit for performing cell reselection in an NTN cell based on first auxiliary information, the first auxiliary information being associated with information of one or more of the following: the distribution of TN cells in the NTN cell, subregions in the NTN cell related to the coverage angle of a network device corresponding to the NTN cell, and TN cells contained in the subregions in the NTN cell.

[0009] In a fourth embodiment, a device for wireless communication is provided. The device is a network device, which includes a transmitting unit for 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, and the first auxiliary information being associated with information of one or more of the distribution of TN cells in the NTN cell, subregions in the NTN cell relating to the coverage angle of a network device corresponding to the NTN cell, and TN cells contained in the subregions in the NTN cell.

[0010] In a fifth aspect, a communication device is provided. The communication device includes a memory and a processor, the memory being configured to store a program, and the processor being configured to call the program in the memory and execute the method according to the first or second aspect.

[0011] In the sixth aspect, an apparatus is provided. The apparatus includes a processor for calling a program from memory and performing the method described in the first or second aspect.

[0012] In the seventh embodiment, a chip is provided. The chip includes a processor that causes a device on which the chip is mounted to perform the method described in the first or second embodiment by calling a program from memory.

[0013] In the eighth aspect, a computer-readable storage medium is provided which stores a program that causes a computer to perform the method described in the first or second aspect.

[0014] In the ninth aspect, a computer program product is provided. The computer program product includes a program that causes a computer to perform the method described in the first or second aspect.

[0015] In the tenth aspect, a computer program is provided. The computer program causes a computer to perform the method described in the first or second aspect.

[0016] In the embodiments of the present invention, the terminal device can perform cell reselection in an NTN cell based on first auxiliary information. This first auxiliary information can be associated with one or more pieces of information, such as the distribution of TN cells within an NTN cell, subregions divided based on the coverage angle of the network device, and TN cells within those subregions. The first auxiliary information allows for a more accurate determination of the status of adjacent cells near the terminal device. When the terminal device performs cell reselection based on the first auxiliary information, unnecessary measurements can be reduced, thereby reducing power consumption. [Brief explanation of the drawing]

[0017] [Figure 1] This is a wireless communication system applicable to the embodiments of the present invention. [Figure 2] This is an NTN system applied to the embodiment of the present application. [Figure 3] This is another NTN system applicable to the embodiments of the present application. [Figure 4] This is a schematic diagram of a method for wireless communication according to an embodiment of the present invention. [Figure 5] This is a schematic diagram of the ground level of an NTN cell to which an embodiment of the present invention is applied. [Figure 6] This is a schematic diagram of the distribution of TN cells applied to the embodiment of the present application. [Figure 7] This is a schematic diagram of the distribution of another TN cell applied to the embodiment of the present invention. [Figure 8] This is a schematic diagram of the NTN cell division method according to an embodiment of the present invention. [Figure 9] This is a schematic diagram of another NTN cell division method according to an embodiment of the present application. [Figure 10] This is a schematic diagram of yet another NTN cell division method according to an embodiment of the present application. [Figure 11] This is a schematic diagram of the structure of a wireless communication device according to an embodiment of the present invention. [Figure 12] It is a structural schematic diagram of another device for wireless communication according to an embodiment of the present application. [Figure 13] It is a structural schematic diagram of a communication device according to an embodiment of the present application.

Embodiments for Carrying out 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. As is clear, the described embodiments are some of the embodiments of the present application, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative labor belong to the protection scope of the present application.

[0019] The embodiments of the present application can be applied to various communication systems. For example, the embodiments of the present application can be applied to a global system of mobile communication (GSM) system for mobile communication, a code division multiple access (CDMA) system, a wideband code division multiple access (WCDMA (registered trademark)) 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 system of the NR system, an LTE-based access to unlicensed spectrum (LTE-U) system on unlicensed spectrum, an NR-based access to unlicensed spectrum (NR-U) system on unlicensed spectrum, an NTN system, a universal mobile telecommunication system (UMTS), wireless local area networks (WLAN), wireless fidelity (WiFi), and a 5th-generation (5G) communication system. The embodiments of the present application can be applied to other communication systems such as future communication systems. The future communication system can be, for example, a 6th-generation (6G) mobile communication system or a satellite communication system, etc.

[0020] Conventional communication systems support a finite number of connections and are easy to implement. However, with the development of communication technology, 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 the following: device-to-device (D2D) communication, machine-to-machine (M2M) communication, machine-type communication (MTC), vehicle-to-vehicle (V2V) communication, and vehicle-to-everything / vehicle-to-infrastructure (V2X) communication. The embodiments of this application can also be applied to communication systems that support the above communication methods.

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

[0022] The communication system in the embodiment of the present application can be applied to the non-licensed spectrum. This non-licensed spectrum can also be considered a shared spectrum. Alternatively, the communication system in the embodiment of the present application can also be applied to the licensed spectrum. This licensed spectrum can also be considered a dedicated spectrum.

[0023] The embodiments of this application are applicable to terrestrial network (TN) systems and also to NTN systems. For example, the NTN system may include a 4G-based NTN system, an NR-based NTN system, an Internet of Things (IoT)-based NTN system, and a narrow-band Internet of Things (NB-IoT)-based NTN system.

[0024] The communication system may include one or more terminal devices. The terminal devices according to the embodiments of the present application may also be called user equipment (UE), access terminal, user unit, user 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. In some embodiments, the terminal device may be 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).

[0026] In some embodiments, a terminal device may refer to a device that provides voice and / or data connectivity to a user. For example, a terminal device may be a handheld device with wireless connectivity, an in-vehicle device, etc. Some specific examples of terminal devices may be a mobile phone, a tablet PC (Pad), a laptop computer, 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, balloon or satellite.

[0028] In addition to terminal devices, the communication system may further include one or more network devices. The network devices in the embodiments of the present application may be devices for communicating with terminal devices, and such network devices may also be called access network devices or radio access network devices. Such network devices may be, for example, base stations. The network devices in the embodiments of the present application may refer to radio access network (RAN) nodes (or devices) that provide terminal devices with access to a radio network. The term "base station" broadly covers, or may be replaced by, various names such as NodeB, evolved NodeB (eNB), next-generation NodeB (gNB), relay station, access point, transmitting and receiving point (TRP), transmitting point (TP), main 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, baseband unit (BBU), remote radio unit (RRU), active antenna unit (AAU), remote radio head (RRH), central unit (CU), distributed unit (DU), and positioning node. A base station may also be a macro base station, micro base station, relay node, donor node, or similar, or a combination thereof. A base station may further refer to a communication module, modem, or chip installed within the aforementioned device or apparatus.The base station may also be a mobile switching center, a device that performs base station functions in D2D, V2X, and M2M communications, a network-side device in a 6G network, or a device that performs base station functions in future communication systems. The base station can support networks with the same or different access technologies. The embodiments of this application do not limit the specific technologies employed in the network devices or the specific forms of the devices.

[0029] Base stations may be fixed or mobile. For example, a helicopter or 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 drone may be configured as a device for communicating with another base station.

[0030] In some deployments, the network device in the embodiments of the present invention refers to a CU or DU, or the network device may include both a CU and a DU. The gNB may further include an AAU.

[0031] As a non-limiting example, in the embodiments of the present application, the network device may have mobile characteristics; for example, the network device may be a mobile device. In some embodiments of the present application, the network device may be a satellite, a balloon station. In some embodiments of the present application, the network device may further be a base station installed at a location such as on land or in a body of water.

[0032] In embodiments of the present invention, a network device can provide services to a cell, and a terminal device communicates with the network device using the transmission resources (e.g., frequency domain resources, i.e., spectral resources) used by the cell, the cell may be a cell corresponding to a network device (e.g., a base station), the cell may belong to a macro base station, or to a base station corresponding to a small cell, the small cell here including metro cells, micro cells, pico cells, femto cells, etc., these small cells are characterized by a small coverage range and low transmission power and are applied to provide high-rate data transmission services.

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

[0034] Figure 1 illustrates one network device and two terminal devices. In some embodiments of the present application, the communication system 100 may include multiple network devices, and the coverage of each network device may include, but is not limited to, other terminal devices.

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

[0036] Satellite 210 is a spacecraft based on a space platform. 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. The Earth-based gateway 250 connects satellite 210 to a base station or core network, specifically determined based on the architecture selection.

[0037] The NTN architecture shown in Figure 2 is a bent-pipe transponder architecture. In this architecture, 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 for forwarding signals from feeder link 230 to service link 220, or as a repeater for forwarding signals from service link 220 to feeder link 230. In other words, the satellite 210 does not have base station functionality, and communication between terminal devices 240 and the base station in network 260 must be relayed using the satellite 210.

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

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

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

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

[0042] In the embodiments of this application, it should be understood that a device having communication functionality in a network / system can be called a communication device. Taking the communication system 100 shown in Figure 1 as an example, the communication device may include a network device 110 and a terminal device 120 having communication functionality, and the network device 110 and the terminal device 120 may be the specific devices described above, which will not be described in detail again here. The communication device may further include other devices in the communication system 100, such as a network controller and other network entities such as a mobility management entity, and is not limited to these in the embodiments of this application.

[0043] For the sake of understanding, some relevant technical knowledge relating to the embodiments of this application will be explained first. The following related technologies can be optionally combined with the technical solutions of the embodiments of this application as selectable means, and all of them fall within the scope of protection of the embodiments of this application. The embodiments of this application include at least some of the following:

[0044] With advancements in communication technology, communication systems (e.g., 5G) are opening up market potential for integrating satellite and terrestrial network infrastructure. For example, the 5G standard has made NTN, including its satellite segment, part of the 5G connectivity infrastructure of the well-known 3rd generation partnership project (3GPP®).

[0045] Communication satellites are classified according to their orbital height into low Earth orbit (LEO), medium Earth orbit (MEO), geostationary Earth orbit (GEO), and high elliptical orbit (HEO) satellites. Among these, LEO is an orbit centered on the Earth, with an altitude of 2,000 km or less, or a period of at least 11.25 times per day, and an eccentricity of less than 0.25. Most man-made objects in outer space are located in LEO orbits. LEO satellites orbit the Earth at high speed (mobile), but are in predictable or achievable orbits.

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

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

[0048] MEO (Metropolitan Orbital Oscillators): Typical altitudes are 5,000 km to 25,000 km, and orbital periods are 3 to 15 hours.

[0049] GEO: Its altitude is approximately 35,786 km, and its 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 types of NTN system architectures, using satellites as an example. The vented-pipe transponder architecture shown in Figure 2 corresponds to NTN transparent payloads, while the regenerative transponder architecture shown in Figure 3 corresponds to NTN regenerative payloads.

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

[0052] In the NTN system, both satellites and unmanned aerial vehicles (UAVs) have relatively high mobility. The cells that a satellite projects onto the ground may be fixed relative to the ground or may move with the satellite. Taking the serving cell corresponding to a LEO satellite as an example, the cells that the LEO satellite projects onto the ground are typically a quasi-Earth fixed cell and a quasi-Earth moving cell.

[0053] A cell stationary relative to the ground may refer to a serving cell whose covered geographical area is fixed. For example, different LEO satellites can cover the same area on the ground by adjusting the antenna's aiming angle, and if one LEO satellite can no longer cover that area, another LEO satellite will take over. Even in the case of satellites in geosynchronous orbit (GSO), the cell projected onto the ground may be a fixed cell.

[0054] A mobile cell may refer to a serving cell whose covered geographical area changes. For example, a cell projected onto the ground by an LEO satellite may move with the satellite. Generally, if the LEO satellite's antenna is perpendicular to the ground, the cell projected onto the ground by the LEO satellite is a mobile cell. Whether the LEO satellite acts as an independent base station or a relay base station, the mobile cell moves with the LEO satellite, and the relative distance between the LEO satellite and the terminal device is constantly changing. After a certain period, the LEO satellite's signal may no longer cover the terminal device, and if the network deployment is relatively well-established, 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 projected position of a satellite in a direction perpendicular to the ground may be called the satellite's nadir point, or it may be called the reference point or reference position. The trajectory of the satellite reference point on the ground is usually aligned with the satellite's orbit. In other words, the trajectory of the satellite reference point on the ground can be considered a projection of the satellite's orbit.

[0056] Satellite operation parameters can be represented by ephemeris data. Ephemeris data typically comes in two forms: orbital parameters and position, velocity, and time (PVT) parameters. Both orbital and PVT parameters can indicate the satellite's position relative to the ground. Terminal devices can use ephemeris data to determine the satellite's future trajectory and thereby determine whether measurement or handover is necessary.

[0057] When NTN network devices access the communication system, they need to distinguish between different types of radio access technology (RAT) corresponding to different types of satellite devices. For example, when NR satellites are accessed, devices in the 5G core network (5GC) 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, it is necessary to place serving cells corresponding to multiple RAT types in different tracking areas (TAs). In other words, cells for each NTN RAT type (e.g., NR(LEO), NR(MEO), NR(GEO), or NR(OTHERSAT)) need to be placed in TAs different from other NR satellite RAT types, and in TAs different from RAT types that support ground access. For each NTN RAT type, a non-overlapping tracking area or a core network (CN) registration area may be configured, and a clear mobility registration area (MRA) may be defined.

[0058] The NTN system may include quasi-earth-fixed systems and mobile unit systems. In the area of ​​enhanced cell measurement and reselection, different systems have different solutions. For example, in the case of time-based cell reselection in a quasi-earth-fixed system, a network device can provide terminal devices with a period of time during which its common cell will be out of service. All idle / inactive terminal devices within the cell can perform cell reselection before the cell outage time. For example, in the case of initiating location-based measurement in a quasi-earth-fixed system, a network device can provide terminal devices with a reference location and distance threshold for the serving cell. If the distance between the terminal device and the reference location of the current serving cell is greater than the distance threshold, the terminal device is required to perform an adjacent cell measurement.

[0059] Using the Rel-17 specification as an example, the specification specifies location-based measurement initiation rules and time-based measurement initiation rules for NTN quasi-earth-fixed cells. For location-based measurement initiation rules, a distance threshold and the serving cell's reference position (i.e., the cell center on the ground) are introduced. If the distance between the terminal device and the serving cell's reference position is less than the distance threshold and the conventional signal reception conditions are met, the terminal device does not need to perform priority-based adjacent cell measurement. These signal reception conditions may be reference signal received power (RSRP) conditions or reference signal received quality (RSRQ) conditions. Priority-based adjacent cell measurement refers to performing adjacent cell measurement based on frequencies within or between NR frequencies with equal or lower priority, or between RATs with lower priority. For time-based measurement initiation rules, the rules introduce a serving cell downtime, i.e., the time during which the cell stops covering the current area. If a cell downtime is set, the terminal device must begin measuring adjacent cells before the cell downtime, regardless of whether it meets the above location conditions or conventional RSRP / RSRQ conditions.

[0060] However, the solutions applicable to the above-mentioned quasi-earth-fixed systems cannot be applied to mobile unit systems.

[0061] In a mobile unit system, NTN cell coverage moves with the network devices. Even if terminal devices are fixed, their relative positions to the network devices change. In other words, in a mobile unit system, both the positions of terminal devices and serving cells can change. Taking a mobile cell of a low Earth orbit (LEO) satellite as an example, a typical LEO satellite has a speed of 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, all idle / inactive terminal devices in the cell need to be allocated in 6.61 seconds. This means that all terminal devices in the cell need to re-select another cell to stay in, and new terminal devices also stay in that cell. In the above solution, the information that the network device provides to the terminal device to trigger cell measurement / re-selection may be inaccurate and contribute little to the terminal device performing adjacent cell measurement or cell re-selection.

[0062] As mentioned above, NTN cells typically offer a much larger coverage area than TN cells. Because NTN cell coverage is sufficiently large, a single NTN unit can cover areas in both the ocean and terrestrial regions. Generally, more TN cells are deployed in terrestrial areas. For example, within an NTN cell serviced by a satellite, many terrestrial TN cells may be available.

[0063] Considering the characteristics of NTN, in the mobility management domain, network-side devices are very likely to assign a higher priority to frequency measurement of TN cells than to NTN. When an NTN cell contains multiple TN cells, it is necessary to consider how terminal devices in the common area of ​​the TN cell and NTN cell, and terminal devices only within the NTN cell area, can effectively perform cell reselection between TN cells and NTN cells. In other words, terminal devices staying within an NTN cell may be located in an area without TN coverage. In an area without TN network coverage, terminal devices do not need to perform adjacent cell measurements to adjacent cells of the TN cell.

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

[0065] To address some of the above problems, an embodiment of the present invention proposes a method for wireless communication. In this method, a terminal device is instructed to perform cell reselection by first auxiliary information. An idle or inactive terminal device performs measurements for cell reselection only when it receives the first auxiliary information, thereby reducing unnecessary measurements and contributing to a reduction in the power consumption of the terminal device during NTN cell movement. For ease of understanding, the main technical solutions of the embodiment of the present invention will be described in detail with reference to Figure 4.

[0066] Figure 4 is constructed from the perspective of the interaction between the terminal device and the network device. The terminal device determines the opportunity to trigger cell reselection through communication with the network device.

[0067] The terminal device may be any of the aforementioned terminal devices that communicate with network devices within an NTN cell, or it may be a terminal device that communicates within other ground 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 located in the common area of ​​an NTN cell and a TN cell. In some embodiments, the terminal device may be a communication device located only within the NTN cell area.

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

[0069] The network device may be a communication device that provides network services to the NTN cell where the terminal device is located. For example, the network device may be a satellite that functions as a standalone base station, or an unmanned aerial vehicle (UAV) system used as a relay base station.

[0070] An NTN cell may be a serving cell whose coverage is stationary relative to the ground, such as a quasi-earth fixed cell. Alternatively, an NTN cell may be a serving cell whose coverage moves with network devices, such as a quasi-earth mobile cell. This is not a limitation.

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

[0072] The first auxiliary information is used to instruct the terminal device to perform cell reselection. In order to effectively perform cell reselection, the terminal device needs to determine the distribution of multiple types of networks and the distribution of TN cells within the NTN cell. The first auxiliary information instructs the terminal device how to perform cell reselection by being associated with one or more pieces of information. The information associated with the first auxiliary information may be the distribution of TN cells within the NTN cell, a sub-region within the NTN cell, or TN cells contained within a sub-region within the NTN cell.

[0073] In some embodiments, the first auxiliary information is associated with the distribution of TN cells within an NTN cell and instructs the terminal device to perform cell reselection. This cell reselection is typically NTN-TN cell reselection. In a possible implementation, the first auxiliary information may indicate, by the distribution of TN cells, whether or not there are TN cells adjacent to the terminal device. The terminal device can then decide whether or not to perform measurements related to cell reselection based on this information.

[0074] As a possible implementation, the distribution of TN cells may include multiple types of information. This information may be the position coordinates of TN cells within an NTN cell, the position coordinates of TN cells relative to the center of an NTN cell, the coverage of TN cells, or the boundary line 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 decide whether or not to reselect cells based on the surrounding TN cell situation.

[0075] For example, a terminal device may determine the position of a TN cell based on its position coordinates or its relative position coordinates with respect to the center of the TN cell. The terminal device can then determine, based on its own position information, whether or not there are any TN cells nearby that can be used for cell reselection.

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

[0077] For example, a terminal device may determine its distance from a TN cell based on the boundary line between the coverage of TN cells and NTN cells. The terminal device can then decide when to perform cell reselection based on how its distance from the TN cell changes.

[0078] In some embodiments, the first auxiliary information is associated with a subregion within an NTN cell and instructs the terminal device to perform cell reselection. After the terminal device receives the auxiliary information, it may calculate which subregion it belongs to based on its location and the received auxiliary information. Appropriate subregion division can help the terminal device perform cell reselection. To perform cell reselection more effectively, the subregions within the NTN may be associated with the coverage angle of the network device. For example, when dividing subregions based on the coverage angle of the network device, the terminal device may determine the distance from the edge of the NTN cell by the subregion it occupies, and thereby determine cell reselection. If the terminal device is about to move out of the coverage range of an NTN cell, it is necessary to trigger a measurement for cell reselection beforehand. The NTN cell division method will be described in detail later with reference to Figure 8.

[0079] As a possible implementation, the system may notify terminal devices via broadcast / system information (e.g., SIB) that an NTN cell will be divided into multiple sub-regions. The sub-regions may be further divided into multiple virtual regions. Terminal devices can determine which sub-region they are located in based on the sub-region division and decide whether or not to perform cell reselection based on the network conditions within that sub-region.

[0080] In some embodiments, the first auxiliary information is associated with TN cells contained within a sub-region of an NTN cell and instructs the terminal device to perform cell reselection. The sub-region division method containing the TN cells may vary and is not limited here. For example, an NTN cell may divide the sub-region based on the coverage angle described above. Alternatively, for example, an NTN cell may divide the sub-region according to a grid pattern. Several types of cell division methods will be specifically described later with reference to Figures 8 to 10.

[0081] As a possible implementation, sub-regions within an NTN cell may correspond to the frequency information of TN cells within that sub-region. By using TN frequency information corresponding to the sub-region where the terminal device is located as auxiliary information, it is possible to support the terminal device in performing more accurate TN measurements. Furthermore, if the divided sub-regions have a high degree of agreement with the architecture of the terrestrial network, the terminal device can understand the frequency distribution of TN within each sub-region.

[0082] In a possible implementation, a TN cell included in a sub-region may further include a frequency information group of the TN cell corresponding to the sub-region. If an NTN cell includes multiple sub-regions, each of the multiple sub-regions corresponds to a frequency information group of one TN cell. One or more frequencies within a frequency information group each have a corresponding priority, which the terminal device can use to perform cell reselection. That is, the terminal device obtains frequency list information for the sub-region in which it is located, and the TN frequency table within each region has a priority array, for example, based on TN frequency information from different regions, the priority of a TN frequency point in the NTN sub-region in which the terminal device is located is higher than the priority of a frequency point in another NTN sub-region. For TN frequencies with a higher reselection priority, the terminal device performs relevant measurements according to a defined detection threshold.

[0083] As a possible implementation, a terminal device may obtain a list of TN frequencies in the region it is located in through first auxiliary information and perform measurements accordingly. To distinguish them, different identifiers may be used for frequency groups of NTN cells and TN cells.

[0084] For ease of understanding, the frequency information groups of TN cells corresponding to sub-regions of NTN cells will be explained below by referring to the NTN cell division example shown in Figure 5. Figure 5 is a schematic ground diagram of an NTN cell to which the embodiment of this application applies.

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

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

[0087] If a terminal device determines that it is located within a specific sub-region, for example, in region NTN2, it will also determine that there are TN cells in that region and the frequency information group {fa, fb, fc} of those TN cells. However, the terminal device may not know the distance from these TN regions to its own location, and the network device can, as described above, inform the terminal device of the coordinate location of each TN cell within the sub-region or the location of the boundary line between the coverage of TN cells and the coverage of NTN cells.

[0088] Returning to step S410 shown in Figure 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 adjacent 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 adjacent 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 adjacent cells if the handover of the TN cell fails.

[0089] In the case of quasi-earth mobile cells, NTN cell coverage changes as network devices move. Network devices need to periodically update one or more pieces of information associated with or included in the primary auxiliary information. For example, a network device can provide a list of TN frequencies in coverage at different times by broadcast.

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

[0091] The first auxiliary information can help terminal devices avoid performing unnecessary measurements in TN cells. The most direct solution to reduce unnecessary measurements is to broadcast the location information of TN cells so that terminal devices know whether or not they need to start measuring. By identifying NTN and TN cells in the broadcast information of network devices, terminal devices can know whether the cell in which they start measuring is an NTN or a TN cell.

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

[0093] Cell reselection may also be a cell handover. A terminal device performing cell reselection in an NTN cell may refer to either an NTN-NTN handover or an NTN-TN handover. In other words, the cell after a terminal device performs cell reselection in an NTN cell may be an NTN cell or a TN cell; the distinction is not limited here.

[0094] NTN and TN deployed in a network may be deployed in different or the same PLMN. In some embodiments, when NTN and TN are in the same PLMN, an inactive terminal device can retain its communication parameters with the current cell when performing cell reselection. These communication parameters may include protocol data unit (PDU) sessions and data radio bearers (DRBs) configured by the terminal device. For example, if a terminal device in the RRC_INACTIVE state is in a scenario where NTN and TN overlap, the terminal device will retain its existing PDU session and configured DRB when performing TN reselection and switch to RRC_CONNECTED or RRC_IDLE. In other words, an RRC_INACTIVE terminal device served by an NTN cell will reselect to be served from an NTN cell to a TN cell while maintaining its communication parameters before the RRC state switch, and then perform the state switch. Similarly, an RRC_INACTIVE UE served by a TN cell will retain its communication parameters when reselecting to be served by an NTN cell.

[0095] In some embodiments, when an inactive terminal device performs a cell reselection, it triggers a mobility registration area update process. For example, if a terminal device in the RRC_INACTIVE state reselects from an NTN cell to a TN cell or from a TN cell to an NTN cell, the terminal device must trigger a mobility registration area update process to notify the AMF that it has entered a new TA or MRA. Note that it is also supported for connected terminal devices to select from an NTN cell to a TN cell.

[0096] In some embodiments, the measurement corresponding to cell reselection may be performed to determine several detection parameters based on a defined detection threshold. For example, the defined detection threshold may include one or some or all of the following: detection time period, distance, detection energy (e.g., RSRP), and number of detections.

[0097] When a terminal device performs cell reselection, it performs a handover to a different type of network based on the tracking area corresponding to the cell. In some embodiments, the network-side device defines the tracking area based on multiple types of RATs corresponding to the type of NTN satellite. For scenarios where NTN cells and TN cells 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, terminal devices may perform cell reselection based on network frequency priority. In an NTN cell, the priority of different frequencies within the TN system, or between systems, may originate from the system information block (SIB), and may originate from different systems during RRC release and inter-system reselection. If no reselection priority is set for the SIB inter-frequency, no measurement is performed for cell reselection. If frequency priority is set using dedicated signaling, the terminal device ignores all priorities originating from the SIB. For example, dedicated signaling sets frequency priority in the NTN domain.

[0099] One possible implementation is that when system information / dedicated signaling sets the re-selection priority between NTN and TN, this is equivalent to introducing a gradual measurement time at TN frequencies where the re-selection priority is higher than the current NTN cell re-selection priority. In other words, a long period can be set for measurements in TN / NTN cells, regardless of whether the terminal device is currently in an NTN or TN cell. For example, if the terminal device is in a TN cell, a long period is set for measurements in NTN cells. This reduces the power consumption of the terminal device performing cell re-selection between NTN and TN.

[0100] As a possible implementation, if the reselection priority of the frequency corresponding to a TN cell is higher than the reselection priority of the frequency corresponding to an NTN cell, the terminal device may perform measurements for cell reselection based on the priority 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 higher priority measurements 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 expandable to add TN / NTN indications.

[0101] As can be seen in Figure 4, terminal devices can facilitate the reduction of unnecessary measurements in TN cells by performing cell reselection based on the first auxiliary information, thereby promoting a reduction in power consumption. The coverage of TN cells associated with the first auxiliary information can help terminal devices perform NTN-TN and TN-NTN. In the case of quasi-earth stationary cells and quasi-earth mobile cells, the coverage of TN cells can be explained in various ways.

[0102] In some embodiments, TN cell coverage may be determined based on a relative distance range and / or angular range of the TN cells with respect to the center of the NTN cell. The reference direction of the angular range may be the motion 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 centers of a TN cell and an NTN cell forms an acute angle with respect to the reference direction, the TN cell may be represented by the 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 centers of the TN cell and the NTN cell is in DL1 to DL2, the coverage of the TN cell is represented by β1, DL1, and DL2.

[0104] In another possible implementation, if the line connecting the centers of the TN cell and the NTN cell forms a right or obtuse angle with respect to 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 greater, and the distance between the centers of the TN cell and the NTN cell is DL1 to DL2, then the coverage of the TN cell is represented by 90 degrees, β2, DL1, and DL2.

[0105] For ease of understanding, the different representations of TN cell distributions will be explained below with reference to Figures 6 and 7. Figure 6 is a schematic diagram in which TN cells are located in the acute-angle region, and Figure 7 is a schematic diagram in which TN cells are located in the obtuse-angle region.

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

[0107] Referring to Figure 7, when the angular range with respect to the reference direction is 90 degrees or more, the coverage of the 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-regions in which the TN cell is located. For example, consider the TN cells within an NTN cell shown in Figure 5. The outermost TN cell within the NTN cell is represented by sub-region NTN3. For example, consider the distribution of TN cells shown in Figure 6. In Figure 6, NTN1, NTN2, and NTN3 represent three sub-regions within the NTN cell. In Figure 6, the three TN cells located at a distance of DL1 to DL2 from the center of the NTN cell are each represented by NTN2, while the single TN cell located at a distance greater than DL2 from the center of the NTN cell is represented by NTN3. Several other types of sub-region divisions will be described in detail later with reference to Figures 8 to 11.

[0109] The above describes 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 begins measuring cell reselection. However, when the measurement is actually started, the terminal device further performs cell reselection based on the distance, time, and boundary information of the TN cells, as well as the priority of the TN cells, thereby effectively performing the relevant measurements of cell reselection.

[0110] In some embodiments, in addition to the first auxiliary information, the terminal device performs cell reselection based on one or more additional measurement-related pieces of information. The measurement-related information 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 where the terminal device is located, and a frequency priority corresponding to the TN cell.

[0111] In a possible implementation, once the coordinate position of a TN cell is determined, the terminal device sets a distance reselection threshold Dtarget and a first time threshold Ttarget1. The distance reselection threshold is used to determine whether or not to perform cell reselection based on the distance between the terminal device and the TN cell. The sub-region where the terminal device is located may be called the first sub-region. When performing cell reselection, the terminal device prioritizes TN cells within the first sub-region. For example, if the first distance between the terminal device and a TN cell in the first sub-region 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 obtain the position coordinates of the TN cell, or it may calculate the position of the TN cell based on relative position coordinates. For example, the terminal device derives the absolute distance between the terminal device and the TN cell from the obtained relative position coordinates of the TN cell in the first sub-region. If the absolute distance is less than the distance reselection threshold, the terminal device starts a reselection measurement.

[0113] In a possible implementation, the network device does not notify the terminal device of the coordinate location of the TN cell; therefore, the terminal device only sets the first time threshold Ttarget1. If the terminal device fails to find the above measure within the first time threshold, and the UE cannot find a suitable cell even after exceeding the reselection time period T-target1, the UE remains within the NTN area.

[0114] As a possible implementation, regardless of the amount of TN cell-related information the terminal device receives, the terminal device sets a second time threshold Ttarget2. The second time threshold is the delay threshold for the terminal device to stay in a particular sub-region. For example, if the time the terminal device spends in the first sub-region exceeds the second time threshold, the terminal device performs cell reselection. The time threshold for the terminal device to stay in each sub-region is constant or variable. The second time threshold is set based on the size of the sub-region or the number of TN cells within the sub-region.

[0115] As a possible implementation, the terminal device further sets a boundary threshold Mtarget. This boundary threshold is for the sub-region in which the terminal device is located. If the distance between the terminal device and the boundary of the sub-region is less than the boundary threshold, the terminal device considers measuring TN cells in the sub-region on both sides of the boundary.

[0116] As a possible implementation, terminal devices introduce relaxation measurements through relaxation quantities, thereby reducing measurements and power consumption. Relaxation quantities may include time relaxation quantities and distance relaxation quantities. Relaxation measurements based on time relaxation quantities are time-measurement relaxations. Relaxation measurements based on distance relaxation quantities are distance-measurement relaxations.

[0117] As a possible implementation, the terminal device further performs cell reselection based on the frequency priority corresponding to the TN cell. Cell reselection based on priority has been described above, and a redundant explanation will be omitted here.

[0118] The first time threshold mentioned above may also be called the time period threshold, and is used to limit the time period over which the terminal device performs cell reselection.

[0119] In some embodiments, the terminal device decides whether or not to perform cell reselection based on the above-mentioned measurement-related information. For example, if the delay in the terminal device's stay in the first sub-region exceeds the second time threshold and / or the distance between the terminal device and the nearest TN cell is within the distance reselection threshold, the terminal device performs a reselection measurement and starts cell reselection. Alternatively, for example, if the terminal device obtains the position coordinates of a TN cell in the first sub-region and the distance between the terminal device and the TN cell is within the reselection distance threshold, the terminal device starts a reselection measurement regardless of whether the second time threshold has elapsed.

[0120] In some embodiments, measurement relaxation is involved through a relaxation amount, which may also be called a loosening amount. In the measurement relaxation state, the terminal device still adheres to frequency measurement rules based on the RSRP of existing serving cells of the same or lower priority.

[0121] One possible implementation is to relax the first time threshold if the time it takes 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. For example, the terminal device may remain in the first sub-region and relax the first time threshold based on a time relaxation amount, Toffset, and the first time threshold corresponding to the time-measure relaxation is Ttarget1+Toffset. Therefore, the time period of the next reselection is Ttarget1+Toffset, and at this time, the terminal device is in a time-measure relaxation state for the TN cell.

[0122] As a possible implementation, when a terminal device performs cell reselection based on a distance reselection threshold or a second time threshold, if it cannot find a suitable cell that satisfies the condition of being below the distance reselection threshold, the distance reselection threshold may be relaxed. For example, the terminal device may remain within the first sub-region, and 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 point, the terminal device is in a distance measurement relaxation state for TN cells.

[0123] In some embodiments, when measurement relaxation is in progress, the terminal device may decide whether or not to terminate the measurement relaxation based on one or more pieces of information.

[0124] One possible implementation is that the terminal device may decide whether to terminate the measurement relaxation based on whether the sub-region in which the terminal device is located changes. For example, when the terminal device moves from one sub-region to another, the terminal device can determine the sub-region in which it is located and determine the priority of the TN frequencies in that region. In this sub-region, 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, the measurement relaxation needs to be paused.

[0125] In another possible implementation, the terminal device may decide 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, the terminal device may set new distance thresholds, boundary thresholds, and time thresholds, and then terminate the relaxation measurement when these thresholds are reached.

[0126] In yet another possible implementation, the terminal device may decide whether to terminate the measurement relaxation based on whether or not it has detected a synchronization signal block (SSB) in the 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 to a network device corresponding to an NTN cell, and the time the terminal device stays in the first sub-region exceeds a second time threshold, the cell reselection measurement performed by the terminal device is determined based on a boundary threshold. If the distance between the terminal device and the boundary of the first sub-region is less than the boundary threshold corresponding to the first sub-region, the terminal device performs the cell reselection measurement based on the frequency priority corresponding to the first and second sub-regions, where the second sub-region is the sub-region the terminal device is trying to reach. If the distance between the terminal device and the boundary of the first sub-region is greater than the boundary threshold corresponding to the first sub-region, the terminal device performs the cell reselection measurement for the frequency corresponding to the first sub-region. In other words, if the delay in the terminal device's stay in the first sub-region exceeds the second time threshold, and the distance between the terminal device and the boundary of the sub-region is less than the boundary threshold, both the first sub-region and the second sub-region being tried to reach are involved in the measurement performed by the terminal device. The terminal device may also perform the measurement based on the frequency priority corresponding to the two sub-regions. If the delay in the terminal device's stay in the first sub-region exceeds the second time threshold, and the distance between the terminal device and the boundary of the sub-region is greater than the boundary threshold, the terminal device starts the measurement, and the region being measured is limited to the frequency point list within the first sub-region.

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

[0129] The above explains how terminal devices perform cell reselection based on configured thresholds. Both the first auxiliary information and the thresholds refer to sub-regions within NTN cells. As mentioned above, appropriate division into sub-regions can help terminal devices perform measurement and / or cell reselection.

[0130] To ensure coverage division and consistency with terrestrial TN cellular networks, embodiments of the present invention propose a method for dividing NTN cells based on the coverage angle of network devices. The current coverage of a network device can be determined through the azimuth angle of the network device's antenna. In this coverage, the angle formed by the line connecting the network device and the coverage location and the perpendicular of the network device to the ground is the coverage angle of the network device. In other words, 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 relative to 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 locations of an NTN cell, the coverage angle is the azimuth angle of the antenna. Therefore, the coverage angle of a network device is less than or equal to the azimuth angle of the antenna.

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

[0132] As a possible implementation, the multiple sub-regions into which NTN is divided may be multiple circular or ring-shaped regions centered on the projection position of the network device in a direction perpendicular to the ground. If an NTN cell contains N sub-regions (where N is a natural number greater than 1), the N coverage angles corresponding to the boundaries of the N sub-regions away from the center are given by the condition: 0 < αi < αi + 1 ≤ αN The following conditions are met, where αi is the coverage angle corresponding to the boundary of the i-th sub-region out of N sub-regions, i is a natural number in the range of 1 to N-1, and αN is the azimuth angle of the antenna.

[0133] As a possible implementation, the multiple 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 contains N sub-regions, the NTN cell may be divided equally into 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 or may not be partially equal.

[0134] In some embodiments, sub-regions within an NTN cell can be determined based on the projected position of a network device in a direction perpendicular to the ground. This projected position may be referred to as the first position. NTN can determine the boundaries of the sub-regions based on the coverage angle, and the boundaries of the sub-regions include a curve centered on the first position. The first position can be determined based on the coordinates of a network device. For example, a terminal device can determine the 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, the positional information of multiple sub-regions of an NTN cell can be determined.

[0135] In some embodiments, when an NTN cell is divided based on coverage angle, several other pieces of information may be considered. That is, multiple virtual sub-regions in an NTN cell may be determined based on one or more other relevant pieces of information. These other relevant pieces of information may include the coordinates of network devices, the geographical environment of the NTN cell coverage, the distribution of TN cells in the NTN cell coverage, limitations on signal interaction of NTN cells, measurement requirements and / or handover requirements of terminal devices, or auxiliary information provided by terminal devices. For example, when dividing an NTN cell into N sub-regions, the number of sub-regions can be increased and the NTN cell can be divided more finely by increasing the value of N based on the above other relevant pieces of information.

[0136] One possible implementation is that sub-regions within an NTN cell are adapted to the coordinates of network devices and the coverage status of TN. For example, if the coordinates indicate that the network device is in a densely populated area, or if there are many TN cells within the NTN cell, the number of sub-regions can be increased. Increasing the number of sub-regions allows for more accurate transitions between NTN cells and TN cells.

[0137] As a possible implementation, sub-regions within an NTN cell are adapted to the geographical environment of the coverage. For example, if the primary coverage of an NTN cell is ocean or desert, the number of sub-regions may be reduced. Because there are fewer TN cells in that region, the probability of handover to a TN cell is low.

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

[0139] As a possible implementation, sub-regions within an NTN cell may be determined based on the measurement and / or handover requirements of the terminal devices. For example, if accuracy requirements for measuring or handover of terminal devices are high in order to reduce power consumption, the number of sub-regions may be increased to reduce variability in subsequent measurement and handover decisions.

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

[0141] As described above, in order to determine the NTN cell division method and the number of sub-regions, in addition to the coverage angle and location of network devices, the ground conditions of the NTN cell coverage, the distribution of TN cells in the coverage, communication requirements, and auxiliary information provided by terminal devices may be considered. This will result in more precise NTN cell division and allow the division to be more adapted to the geographical area of ​​the coverage.

[0142] The NTN cell division method according to the embodiment of the present invention will be specifically described below with reference to Figure 8.

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

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

[0145] The coverage angle corresponding to a terminal device within a sub-region is within the range of the coverage angle corresponding to the boundary of that sub-region. For example, the coverage angle corresponding to a terminal device within sub-region NTN1 is α1 or less.

[0146] The concentric circle division method shown in Figure 8 is merely an example, and it should be understood that other division methods based on coverage angles can also be applied to this invention. For example, multiple elliptical sub-regions can be determined based on the coverage angles of network devices in multiple directions.

[0147] The NTN cell division scheme, as explained with reference to Figure 8, can be applied to quasi-earth fixed cells and quasi-earth mobile cells. The relative positional changes between terminal devices and network devices differ depending on the cell type. This will be explained in detail later.

[0148] The NTN cell division method shown in Figure 8 can be better unified with the coverage division of the terrestrial TN cellular network. This division allows the NTN network to better integrate with the terrestrial cellular system and reduces blind spots in measurements. In addition to division based on azimuth angle, NTN cells with antennas may be divided in several other ways, which will be briefly explained below with reference to Figures 9 and 10.

[0149] As mentioned above, NTN cells may be divided by other methods. Figures 9 and 10 show two possible divisions.

[0150] Referring to Figure 9, the NTN cell is divided into eight sub-regions by four intersecting diameters. These 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-regions a, b, and e each contain a TN cell.

[0151] Referring to Figure 10, the NTN cell is divided into nine sub-regions by a grid pattern. These nine sub-regions 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 Figure 9, sub-region f and sub-region h each contain TN cells.

[0152] If TN cells exist in the subregions shown in Figures 9 and 10, they can be indicated by predetermined instruction information. For example, in the instruction information, a bit corresponding to a subregion containing a TN cell is set to 1, and otherwise it is set to 0. The division rules and numbering rules may be pre-configured in the terminal device. In this way, the network device can indicate the location of a TN cell by providing only a few bits to the terminal device. As a possible implementation, the network device may notify the terminal device of the instruction message by broadcast, SIB message, or RRC message. Upon receiving the instruction information, the terminal device can calculate the approximate range of the TN cell based on the reference position and radius of the TN cell.

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

[0154] In the case of quasi-earth-fixed cells, the coverage of an NTN cell can be divided into multiple sub-regions. For example, the coverage of an NTN cell in a quasi-earth-fixed cell may be divided into n equally divided sub-regions according to the method shown in Figure 8, or it may be divided into several unequal sub-regions based on the distribution of TN cells.

[0155] In the case of a quasi-earth-fixed cell, the coverage of the NTN cell does not change, but the relative distance of the network device to the terminal device does. After a certain period of time, the signal of the current network device may no longer 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. Conversely, 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 outside the coverage of the first network device. The terminal device can communicate with a second network device that services the area instead of the first network device. In other words, in the case of a quasi-earth-fixed cell, if the terminal device is stationary, the terminal device is always within the same sub-area. However, the network device that provides service to the terminal device changes.

[0156] In the case of quasi-global mobile cells, NTN cell coverage changes as network devices move. After cell partitioning is performed on the NTN cell, the sub-region where terminal devices are located changes as network devices move. When terminal devices are stationary, the sub-region where terminal devices are located changes. Terminal devices determine the sub-region where they are located and subsequent changes based on messages sent from network devices (e.g., the first message mentioned above). When terminal devices are in motion, terminal devices need to periodically receive messages from network devices to determine the sub-regions where they are currently and later located, thereby determining whether to trigger adjacent cell measurements and related measurements and calculations.

[0157] In some embodiments, the network device may provide the terminal device with the antenna beam angle at the cell center and the cell radius through broadcast information / system information / dedicated signaling. The beam angle at the cell center allows for the determination of the direction of sub-satellite points and the distance of service links. The network device may further provide the terminal device with NTN cell divisions, and the sub-regions into which the NTN is divided may differ based on geographical location and different antenna azimuth angles. The terminal device can calculate the coordinates of the reference position at the cell center based on the network device's antenna azimuth angle and movement speed. The terminal device may also need to calculate the cell edge through the cell radius or threshold.

[0158] In some embodiments, a time threshold T may be set when the network device moves. After each time T has elapsed, the network device may provide reference information to the terminal device. The network device may provide the moving cell with updated ephemeris parameters or with timestamped ephemeris parameters. The network device may also provide the moving cell with multiple reference positions and their time information or moving speed. After determining the time it takes for the terminal device to reach the edge of the cell, the terminal device knows when to begin cell measurement and cell reselection.

[0159] The method embodiments of the present application have been described in detail above with reference to Figures 4 to 10. The apparatus embodiments of the present application will now be described in detail below with reference to Figures 11 to 13. Since the description of the apparatus embodiments corresponds to the description of the method embodiments, it should be understood that for parts not described in detail, the above-mentioned method embodiments can be referenced.

[0160] Figure 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 of the terminal devices described above. The apparatus 1100 shown in Figure 11 includes a reselection unit 1110.

[0161] The reselection unit 1110 is configured to perform cell reselection in an NTN cell based on first auxiliary information, the first auxiliary information being associated with information on one or more subregions within the NTN cell related to the distribution of TN cells within the NTN cell, and the coverage angles of network devices corresponding to the NTN cells, where the subregions are related to the NTN cell, or the coverage angles of network devices corresponding to TN cells contained within a subregion within the NTN cell.

[0162] Selectively, the first auxiliary information further includes one or more of the following: a frequency information group of TN cells corresponding to a subregion within an NTN cell; the position coordinates of a TN cell; the position coordinates of a TN cell relative to the center of an NTN cell; frequency information of a TN cell; reference position and distance threshold of adjacent cells to a TN cell; coverage of a TN cell; and the boundary line between the coverage of a TN cell and the coverage of an NTN cell.

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

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

[0165] Selectively, the method for representing TN cell coverage is related to the angle of the TN cell with respect to the reference direction. 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 DL1 to DL2, the TN cell coverage is represented by β1, DL1, and DL2. Alternatively, 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 DL1 to DL2, the TN cell coverage is represented by 90 degrees, β2, DL1, and DL2.

[0166] Selectable, an NTN cell contains multiple sub-regions, each of which corresponds to one frequency information group, and one or more frequencies within the frequency information group have corresponding priorities, which are used by terminal devices to perform cell reselection.

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

[0168] Selectively, the first auxiliary information is carried by one or more of the following: broadcast information, system information, and dedicated signaling.

[0169] Selectively, the terminal device performs cell reselection based on one or more of the following pieces of information: 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's stay in a sub-region, a boundary threshold for the sub-region where the terminal device is located, and the frequency priority corresponding to the TN cell within the NTN cell.

[0170] Selectively, the terminal device is located within a first subregion of the NTN cell, and the reselection unit 1110 is further configured to perform cell reselection if the first distance between the terminal device and the TN cell within the first subregion is less than a distance reselection threshold.

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

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

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

[0174] Selectively, the terminal device is located within a first sub-region of the NTN cell, and the re-selection unit 1110 is further configured to perform cell re-selection if the time the terminal device stays in the first sub-region exceeds a second time threshold.

[0175] Selectively, the time it takes for the reselection unit 1110 to perform cell reselection based on a distance reselection threshold or a second time threshold exceeds the first time threshold, and the measurement unit is further configured to enter a time measurement relaxation based on a time relaxation amount if the terminal device does not find a cell for handover within the first time threshold.

[0176] Selectable options include Ttarget1 as the first time threshold set by the terminal device, Toffset as the time relaxation amount, and Ttarget1+Toffset as the first time threshold corresponding to time measurement relaxation.

[0177] Optionally, the terminal device may terminate distance measurement relaxation or time measurement relaxation based on one or more pieces of information, including whether the sub-region in which the terminal device is located changes, whether the distance, time, or boundary measured by the terminal device reaches the corresponding threshold, and whether the terminal device has detected a synchronization signal block in frequency detection.

[0178] Selectively, the terminal device moves relative to a network device corresponding to an NTN cell, and if the time the terminal device stays in the first sub-region exceeds a second time threshold, the measurement unit further performs a measurement for cell reselection based on the frequency priority of the first and second sub-regions, provided that the distance between the terminal device and the boundary of the first sub-region is less than the boundary threshold corresponding to the first sub-region, wherein the second sub-region is the sub-region the terminal device is attempting to reach, and if the distance between the terminal device and the boundary of the first sub-region is greater than the boundary threshold corresponding to the first sub-region, the measurement unit performs a measurement for cell reselection for the frequency corresponding to the first sub-region.

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

[0180] Selectively, communication parameters include the protocol data unit session and the data radio bearer set by the terminal device.

[0181] If the terminal device is in an inactive state and cell re-selection is performed, it will trigger the mobility registration area update process.

[0182] Selectively, the boundaries of sub-regions within an NTN cell correspond to the coverage angle of the network device corresponding to the NTN cell, the projection position of the network device in the direction perpendicular to the ground is the first position, and the boundaries of the sub-regions include a curve with the first position as its center.

[0183] Selectively, an NTN cell contains N sub-regions, where N is a natural number greater than 1, and the N coverage angles corresponding to the boundaries of the N sub-regions away from the first position are given by the following conditions: 0 < αi < αi + 1 ≤ αN The following conditions are met, where αi is the coverage angle corresponding to the boundary of the i-th sub-region out of N sub-regions, away from the first position, i is a natural number in the range of 1 to N-1, and αN is the azimuth angle of the antenna.

[0184] Selectively, an NTN cell contains N sub-regions, where N is a natural number greater than 1, and the N sub-regions either equally or unequally divide the coverage of the NTN cell.

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

[0186] Figure 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 Figure 12 includes a transmitting unit 1210.

[0187] The transmission unit 1210 can be used to transmit first auxiliary information to a terminal device, which is configured to enable the terminal device to perform cell reselection in an NTN cell. The first auxiliary information is associated with information on the distribution of TN cells within an NTN cell, subregions within an NTN cell related to the coverage angle of a network device corresponding to an NTN cell, and one or more TN cells contained within a subregion within an NTN cell.

[0188] Selectively, the first auxiliary information further includes one or more of the following: a frequency information group of TN cells corresponding to a subregion within an NTN cell; the position coordinates of a TN cell; the position coordinates of a TN cell relative to the center of an NTN cell; frequency information of a TN cell; reference position and distance threshold of adjacent cells to a TN cell; coverage of a TN cell; and the boundary line between the coverage of a TN cell and the coverage of an NTN cell.

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

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

[0191] Selectable methods for representing TN cell coverage are related to the angle of the TN cell relative to the reference direction. 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 DL1 to DL2, the TN cell coverage is represented by β1, DL1, and DL2. 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 DL1 to DL2, the TN cell coverage is represented by 90 degrees, β2, DL1, and DL2.

[0192] Selectable, an NTN cell contains multiple sub-regions, each of which corresponds to one frequency information group, and one or more frequencies within the frequency information group have corresponding priorities, which are used by terminal devices to perform cell reselection.

[0193] Selectively, the first auxiliary information is carried by one or more of the following: broadcast information, system information, and dedicated signaling.

[0194] Selectively, the boundaries of sub-regions within an NTN cell correspond to the coverage angle of the network device, the projected position of the network device in a direction perpendicular to the ground is the first position, and the boundaries of the sub-regions include a curve with the first position as its center.

[0195] Selectively, an NTN cell contains N sub-regions, where N is a natural number greater than 1, and the N coverage angles corresponding to the boundaries of the N sub-regions away from the first position are given by the following conditions: 0 < αi < αi + 1 ≤ αN The following conditions are met, where αi is the coverage angle corresponding to the boundary of the i-th sub-region out of N sub-regions, away from the first position, i is a natural number in the range of 1 to N-1, and αN is the azimuth angle of the antenna.

[0196] Selectively, an NTN cell contains N sub-regions, where N is a natural number greater than 1, and the N sub-regions either equally or unequally divide the coverage of the NTN cell.

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

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

[0199] The apparatus 1300 may include one or more processors 1310. The processors 1310 can support the apparatus 1300 in implementing the methods described in the above embodiment of the method. The processors 1310 may be general-purpose processors or dedicated processors. 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, etc. The general-purpose processor may be a microprocessor, or the processor may be any conventional processor, etc.

[0200] The device 1300 may further include one or more memories 1320. A program is stored in the memory 1320, which can be executed by the processor 1310, causing the processor 1310 to perform the method described in the above embodiment of the method. The memory 1320 may be independent of the processor 1310 or may be integrated with the processor 1310.

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

[0202] Embodiments of the present application further provide a computer-readable storage medium for storing a program. The computer-readable storage medium can be applied to a terminal or 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 network device in each embodiment of the present application.

[0203] In some embodiments, the computer-readable storage medium may be any available medium that a computer can read, or a data storage device such as a server or data center that integrates one or more available media. The available media may be magnetic media (e.g., floppy disks, hard disks, tapes), optical media (e.g., digital video discs (DVDs)), or semiconductor media (e.g., solid-state disks (SSDs)).

[0204] Embodiments of the present application further provide a computer program product, which includes a program, which can be applied to a terminal or network device according to an embodiment of the present application, and which causes a computer to perform the method executed by the terminal or network device in each embodiment of the present application.

[0205] In the above embodiments, all or part of the embodiments may be implemented by software, hardware, firmware, or any combination thereof. If implemented by software, all or part of the embodiments may be implemented in the form of a computer program product. The computer program product includes one or more computer instructions. Loading and executing the computer program instructions into a computer generates all or part of the procedures or functions described in the embodiments of this application. The computer may be a general-purpose computer, a dedicated 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 by wire (e.g., coaxial cable, fiber optic cable, digital subscriber line (DSL)) or wirelessly (e.g., infrared, radio, microwave, etc.).

[0206] Embodiments of the present application further provide a computer program which can be applied to a terminal or network device according to an embodiment of the present application, and which causes a computer to execute the method performed by the terminal or network device in 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 solely to interpret the specific embodiments of this application and are not intended to limit this application. The terms “first,” “second,” “third,” and “fourth,” etc., in the specification, claims, and drawings of this application are used to distinguish different subjects, not to describe a specific order. Furthermore, the terms “include,” “have,” and any variations thereof are intended to cover non-exclusive inclusion.

[0208] In the embodiments of the present application, the “instruction” referred to may be direct instruction, indirect instruction, or indicate a related relationship. For example, A instructing B may mean that A directly instructs B, for example, that B can be obtained by A; or A indirectly instructs B, for example, that A instructs C, that B can be obtained by C; or it may indicate a related relationship between A and B.

[0209] In the embodiments of this application, the term "correspondence" may indicate a direct or indirect correspondence between the two, a related relationship between the two, or a relationship such as instruction and instruction, setting and setting.

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

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

[0212] In the embodiments of this application, the term "and / or" simply describes the relationship between related objects and indicates that there are three types of relationships. For example, A and / or B includes the cases where only A exists, where A and B exist simultaneously, and where only B exists. In this specification, the symbol " / " generally indicates that the preceding and following related objects are in an "or" relationship.

[0213] In some embodiments relating to this application, it should be understood that the disclosed systems, apparatus and methods can be implemented in other forms. For example, the apparatus embodiments described above are merely illustrative, and for instance, the division of the units is merely one logic function division. In actual implementation, other division schemes may be employed, for example, multiple units or components may be combined or integrated into another system, or some features may be ignored or omitted. Furthermore, the mutual coupling, direct coupling or communication connection described or considered may also be an indirect coupling or communication connection via several interfaces, apparatus or units, and may be in the form of electrical, mechanical or other means.

[0214] The units described as separation members may or may not be physically separated, and the members referred to as units may or may not be physical units; that is, they may be located in one place or distributed among multiple network units. Based on actual needs, some or all of the units can be selected 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 a single processing unit, each unit may exist physically separately, and two or more units may be integrated into a single unit.

[0216] Although specific embodiments of the present application have been described above, the scope of protection of this application is not limited thereto. Any modifications or substitutions that a person skilled in the art could easily conceive without departing from the technical scope disclosed herein fall within the scope of protection of this application. Therefore, the scope of protection of this application should be the same as the scope of protection of the claims described above.

Claims

1. A method for wireless communication, The process includes the step of a terminal device performing cell reselection in a non-terrestrial network (NTN) cell based on first auxiliary information, wherein the first auxiliary information is: A sub-region within the NTN cell related to the coverage angle of the network device corresponding to the NTN cell, or A terrestrial network (TN) cell included in the sub-region within the NTN cell, Associated with one or more of the following pieces of information, A method for performing cell reselection, wherein the terminal device is located in a first sub-region of the NTN cell, and the first distance between the terminal device and the TN cell in the first sub-region is less than a distance reselection threshold, at least in part.

2. The above first auxiliary information is, The frequency information group of the TN cell corresponding to the sub-region within the NTN cell, The position coordinates of the aforementioned TN cell, The position coordinates of the TN cell relative to the center of the NTN cell, The frequency information of the aforementioned TN cell, The reference position and distance threshold of adjacent cells of the aforementioned TN cell, The coverage of the aforementioned TN cell, or The method according to claim 1, further comprising one or more pieces of information regarding the boundary line between the coverage of the TN cell and the coverage of the NTN cell.

3. The method according to claim 2, wherein the coverage of the TN cell is determined based on at least one of a distance range or an angular range of the TN cell with respect to the center of the NTN cell, and the angular range is determined based on a reference direction.

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

5. The coverage of the TN cell is related to the angle of the TN cell with respect to the reference direction. The angle β of the TN cell with respect to the aforementioned reference direction １ When the angle is less than 90 degrees, the distance between the center of the TN cell and the center of the NTN cell is DL １ ~DL ２ If it is located, the coverage of the TN cell is β １ DL １ and DL ２ It is determined by, or The angle β of the TN cell with respect to the reference direction ２ is 90 degrees or more, and the distance between the center of the TN cell and the center of the NTN cell is DL １ to DL ２ In the case where it is, the coverage of the TN cell is 90 degrees, β ２ , DL １ and DL ２ The method according to claim 3, determined by

6. The method according to claim 2, wherein the NTN cell includes a plurality of sub-regions, each of which sub-regions corresponds to a frequency information group, and one or more frequencies within the frequency information group each have a corresponding priority, the priority being used by the terminal device to perform the cell reselection.

7. The method according to claim 6, further comprising the step of the terminal device performing the cell reselection measurement based on the priority of different frequencies in the frequency list or the frequency list of the radio access technology if the reselection priority of the frequency corresponding to the TN cell is higher than the reselection priority of the frequency corresponding to the NTN cell.

8. The method according to claim 1, wherein the first auxiliary information is transported by one or more of the following: broadcast information, system information, or dedicated signaling.

9. The aforementioned terminal device is The first time threshold set by the terminal device, The distance relaxation amount set by the terminal device, The time relaxation amount set by the aforementioned terminal device, The second time threshold for the terminal device to remain in the sub-region, The boundary threshold of the sub-region where the terminal device is located, or The method according to claim 1, which performs cell reselection based on one or more pieces of information regarding the frequency priority corresponding to the TN cell within the NTN cell.

10. The method according to claim 1, wherein the first distance is determined based on the position coordinates of the TN cell or the position coordinates of the TN cell with respect to the center of the NTN cell.

11. The method according to claim 1, further comprising the step that if the terminal device cannot find a cell for handover by the cell reselection, the terminal device enters distance measurement relaxation based on a distance relaxation amount set by the terminal device.

12. The distance reselection threshold set by the terminal device is D ｔａｒｇｅｔ The distance relaxation amount is D ｏｆｆｓｅｔ The distance reselection threshold corresponding to the aforementioned distance measurement relaxation is D ｔａｒｇｅｔ +D ｏｆｆｓｅｔ The method according to claim 11.

13. The method according to claim 9, further comprising the step of the terminal device performing the cell reselection if the time the terminal device stays in the first sub-region exceeds the second time threshold.

14. The time it takes for the terminal device to perform cell reselection based on the distance reselection threshold or the second time threshold exceeds the first time threshold, and the method The method according to claim 9, further comprising the step that if the terminal device cannot find a cell for handover within the first time threshold, the terminal device enters a time measurement relaxation based on the time relaxation amount.

15. The first time threshold set by the terminal device is T ｔａｒｇｅｔ１ The aforementioned time relaxation amount is T ｏｆｆｓｅｔ The first time threshold corresponding to the relaxation of time measurement is T ｔａｒｇｅｔ１ +T ｏｆｆｓｅｔ The method according to claim 14.

16. A method for wireless communication, The network device includes the step of transmitting first auxiliary information to a terminal device, wherein the first auxiliary information includes information for performing cell reselection in a non-terrestrial network (NTN) cell, and the first auxiliary information is A sub-region within the NTN cell related to the coverage angle of the network device corresponding to the NTN cell, or A terrestrial network (TN) cell included in the sub-region within the NTN cell, Associated with one or more of the following pieces of information, A method for performing cell reselection, wherein the terminal device is located in a first sub-region of the NTN cell, and the first distance between the terminal device and the TN cell in the first sub-region is less than a distance reselection threshold, at least in part.

17. The above first auxiliary information is, The frequency information group of the TN cell corresponding to the sub-region within the NTN cell, The position coordinates of the aforementioned TN cell, The position coordinates of the TN cell relative to the center of the NTN cell, The frequency information of the aforementioned TN cell, The reference position and distance threshold of adjacent cells of the aforementioned TN cell, The coverage of the aforementioned TN cell, or The method according to claim 16, comprising information on one or more boundaries between the coverage of the TN cell and the coverage of the NTN cell.

18. The method according to claim 17, wherein the coverage of the TN cell is determined based on at least one of a distance range or an angular range of the TN cell with respect to the center of the NTN cell, and the angular range is determined based on a reference direction.

19. It is a device, At least one processor, The system includes one or more non-temporary computer-readable storage media coupled to the at least one processor and storing programming instructions executed by the at least one processor, and when the programming instructions are executed, The device is instructed to perform a cell reselection operation in a non-terrestrial network (NTN) cell based on the first auxiliary information, and the first auxiliary information is, A sub-region within the NTN cell related to the coverage angle of the network device corresponding to the NTN cell, or Associated with information of one or more terrestrial network (TN) cells included in the sub-region within the NTN cell, The apparatus is located within a first sub-region of the NTN cell and performs cell reselection in at least partially in response to the fact that a first distance between the apparatus and the TN cell within the first sub-region is less than a distance reselection threshold.

20. The above first auxiliary information is, A frequency information group of a TN cell corresponding to a sub-region within the aforementioned NTN cell, The position coordinates of the aforementioned TN cell, The position coordinates of the TN cell relative to the center of the NTN cell, The frequency information of the aforementioned TN cell, The reference position and distance threshold of adjacent cells of the aforementioned TN cell, The coverage of the aforementioned TN cell, or The apparatus according to claim 19, further comprising one or more pieces of information regarding the boundary line between the coverage of the TN cell and the coverage of the NTN cell.

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