Method and apparatus for wireless communication

Abstract

The present application provides a method and apparatus for wireless communication, which helps to save the power consumption of a terminal device in a scenario of discontinuous network coverage. The method includes: the terminal device determines first time information; based on the first time information, the terminal device performs a transition from a first state to a second state; wherein the first time information is related to a first time period and / or a second time period, the first time period is the time period from the current moment to the starting moment when the terminal device enters a network coverage-free state, and the second time period is the duration of the network coverage-free state.

Description

Technical Field

[0001] This application relates to the field of communication technologies, and more particularly, to a method and apparatus for wireless communication. Background Art

[0002] With the operation of satellites in a non-terrestrial network (NTN), terminal devices may be in scenarios where there is no network coverage. Due to discontinuous network coverage, how terminal devices with high energy-saving requirements operate and how the network side configures are issues worthy of study. For example, in an NTN system based on the Internet of Things (IoT), when the IoT terminal device releases a radio resource control (RRC) connection or when it is woken up are problems that need to be solved. Summary of the Invention

[0003] This application provides a method and apparatus for wireless communication. The following introduces each aspect involved in the embodiments of this application.

[0004] In a first aspect, a method for wireless communication is provided, including: a terminal device determines first time information; based on the first time information, the terminal device performs a transition from a first state to a second state; wherein the first time information is related to a first time period and / or a second time period, the first time period is the time period from the current moment to the starting moment when the terminal device enters the no-network-coverage state, and the second time period is the duration of the no-network-coverage state.

[0005] In a second aspect, a method for wireless communication is provided, including: a network device determines first time information; based on the first time information, the network device instructs the terminal device to perform a transition from a first state to a second state; wherein the first time information is related to a first time period and / or a second time period, the first time period is the time period from the current moment to the starting moment when the terminal device enters the no-network-coverage state, and the second time period is the duration of the no-network-coverage state.

[0006] In a third aspect, a device for wireless communication is provided. The device is a terminal device, and the device includes: a determination unit for determining first time information; a first execution unit for performing a transition from a first state to a second state based on the first time information; wherein the first time information is related to a first time period and / or a second time period, the first time period is the time period from the current moment to the starting moment when the terminal device enters the no-network-coverage state, and the second time period is the duration of the no-network-coverage state.

[0007] Fourth aspect, a device for wireless communication is provided. The device is a network device and includes: a determination unit configured to determine first time information; an indication unit configured to, based on the first time information, instruct a terminal device to perform a transition from a first state to a second state; wherein the first time information is related to a first time period and / or a second time period, the first time period is a time period from the current moment to the starting moment when the terminal device enters a network coverage-free area, and the second time period is the duration of the network coverage-free period.

[0008] Fifth aspect, a communication device is provided, including a memory and a processor. The memory is configured to store a program, and the processor is configured to call the program in the memory to execute the method according to the first aspect or the second aspect.

[0009] Sixth aspect, a device is provided, including a processor configured to call a program from a memory to execute the method according to the first aspect or the second aspect.

[0010] Seventh aspect, a chip is provided, including a processor configured to call a program from a memory, such that a device installed with the chip executes the method according to the first aspect or the second aspect.

[0011] Eighth aspect, a computer-readable storage medium is provided, on which a program is stored, and the program causes a computer to execute the method according to the first aspect or the second aspect.

[0012] Ninth aspect, a computer program product is provided, including a program, and the program causes a computer to execute the method according to the first aspect or the second aspect.

[0013] Tenth aspect, a computer program is provided, and the computer program causes a computer to execute the method according to the first aspect or the second aspect.

[0014] In an embodiment of the present application, the terminal device can determine the first time information and perform a transition from the first state to the second state based on the first time information. Among them, the first time information includes the first time period from the moment when the terminal device currently has network coverage to the moment when it enters a network coverage-free area and the second time period of the continuous network coverage-free period. It can be seen that the terminal device can predict the time information of the network coverage-free area and perform a state transition in the case of discontinuous network coverage, thereby better saving power consumption. Description of the Drawings

[0015] Figure 1 is a wireless communication system to which an embodiment of the present application is applied.

[0016] Figure 2 is an NTN system to which an embodiment of the present application is applied.

[0017] Figure 3 is another NTN system to which the embodiments of the present application are applied.

[0018] Figure 4 is a schematic diagram of a possible scenario where the terminal device is in discontinuous coverage.

[0019] Figure 5 is a schematic diagram of an energy-saving configuration introduced by the Internet of Things.

[0020] Figure 6 is a schematic diagram of another energy-saving configuration introduced by the Internet of Things.

[0021] Figure 7 is a schematic flow diagram of a method for wireless communication provided by the embodiments of the present application.

[0022] Figure 8 is Figure 7 a schematic flow diagram of a possible implementation manner of the method shown

[0023] Figure 9 is a schematic flow diagram of another method for wireless communication provided by the embodiments of the present application.

[0024] Figure 10 is a schematic diagram of a possible configuration manner of the first configuration parameter.

[0025] Figure 11 is a schematic diagram of another possible configuration manner of the first configuration parameter.

[0026] Figure 12 is a schematic diagram of yet another possible configuration manner of the first configuration parameter.

[0027] Figure 13 is a schematic diagram of yet another possible configuration manner of the first configuration parameter.

[0028] Figure 14 is Figure 9 a schematic flow diagram of a possible implementation manner of the method shown.

[0029] Figure 15 is Figure 9 a schematic flow diagram of another possible implementation manner of the method shown.

[0030] Figure 16 is a schematic structural diagram of a device for wireless communication provided by the embodiments of the present application.

[0031] Figure 17 is a schematic structural diagram of another device for wireless communication provided by the embodiments of the present application.

[0032] Figure 18It is a schematic structural diagram of a communication device provided by an embodiment of the present application. Detailed implementation manners

[0033] Next, the technical solutions in the embodiments of the present application will be described with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some, rather than all, of the embodiments of the present application. For the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0034] 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, a code division multiple access (CDMA) system, a wideband code division multiple access (WCDMA) system, a general packet radio service (GPRS), a long term evolution (LTE) system, an advanced long term evolution (LTE-A) system, a new radio (NR) system, an evolved system of the NR system, an LTE-based access to unlicensed spectrum (LTE-U) system, an NR-based access to unlicensed spectrum (NR-U) system, an NTN system, a universal mobile telecommunication system (UMTS), a wireless local area networks (WLAN), a wireless fidelity (WiFi), a 5th-generation (5G) communication system. The embodiments of the present application can also be applied to other communication systems, such as future communication systems. Such future communication systems can be, for example, a 6th-generation (6G) mobile communication system, or a satellite communication system, etc.

[0035] Traditional communication systems support a limited number of connections and are easy to implement. However, with the development of communication technologies, communication systems can not only support traditional cellular communications, but also support one or more other types of communications. For example, a communication system can support one or more of the following communications: device to device (D2D) communication, machine to machine (M2M) communication, machine type communication (MTC), enhanced MTC (eMTC), vehicle to vehicle (V2V) communication, and vehicle to everything (V2X) communication, etc. Embodiments of the present application can also be applied to communication systems that support the above communication methods.

[0036] The communication system in the embodiments of the present application can be applied to a carrier aggregation (CA) scenario, can also be applied to a dual connectivity (DC) scenario, and can also be applied to a standalone (SA) networking scenario.

[0037] The communication system in the embodiments of the present application can be applied to unlicensed spectrum. This unlicensed spectrum can also be considered as shared spectrum. Alternatively, the communication system in the embodiments of the present application can also be applied to licensed spectrum. This licensed spectrum can also be considered as dedicated spectrum.

[0038] Embodiments of the present application can be applied to an NTN system. As an example, this NTN system can be a 4G-based NTN system, can be an NR-based NTN system, can also be an IoT-based NTN system or a narrow band internet of things (NB-IoT)-based NTN system.

[0039] The communication system can include one or more terminal devices. The terminal devices mentioned in the embodiments of the present application can also be referred to as user equipment (UE), access terminal, user unit, user station, mobile station, mobile station (MS), mobile terminal (MT), remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent, or user device, etc.

[0040] 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, cordless phone, session initiation protocol (SIP) phone, wireless local loop (WLL) station, personal digital assistant (PDA) device, handheld device with wireless communication function, computing device, or other processing device connected to a wireless modem, in-vehicle device, wearable device, terminal device in a next-generation communication system (such as an NR system), or terminal device in a future evolved public land mobile network (PLMN) network, etc.

[0041] In some embodiments, the terminal device may be a device that provides voice and / or data connectivity to a user. For example, the terminal device may be a handheld device, in-vehicle device, etc. with wireless connection function. As some specific examples, the terminal device may be a mobile phone, tablet (Pad), laptop, palm computer, mobile internet device (MID), wearable device, virtual reality (VR) device, augmented reality (AR) device, wireless terminal in industrial control, wireless terminal in self-driving, wireless terminal in remote medical surgery, wireless terminal in smart grid, wireless terminal in transportation safety, wireless terminal in smart city, wireless terminal in smart home, etc.

[0042] In some embodiments, the terminal device may be deployed on land. For example, the terminal device may be deployed indoors or outdoors. In some embodiments, the terminal device may be deployed on water, such as on a ship. In some embodiments, the terminal device may be deployed in the air, such as on an airplane, balloon, and satellite.

[0043] In addition to the terminal device, the communication system may further include one or more network devices. The network device in the embodiments of the present application may be a device for communicating with the terminal device, and this network device may also be referred to as an access network device or a radio access network device. This network device may be, for example, a base station. The network device in the embodiments of the present application may refer to a radio access network (RAN) node (or device) that connects the terminal device to the wireless network. The base station may generally cover various names as follows, or be replaced with the following names, such as: Node B, evolved Node B (eNB), next generation Node B (gNB), relay station, access point, transmitting and receiving point (TRP), transmitting point (TP), master station MeNB, secondary station SeNB, multi-mode radio (MSR) node, home base station, network controller, access node, wireless node, access point (AP), transmission node, transceiver node, base band unit (BBU), remote radio unit (RRU), active antenna unit (AAU), remote radio head (RRH), central unit (CU), distributed unit (DU), positioning node, etc. The base station may be a macro base station, a micro base station, a relay node, a donor node or the like, or a combination thereof. The base station may also refer to a communication module, a modem or a chip disposed in the foregoing device or apparatus. The base station may also be a mobile switching center and a device that undertakes the base station function in D2D, V2X, M2M communications, a network-side device in a 6G network, a device that undertakes the base station function in a future communication system, etc. The base station may support networks of the same or different access technologies. The embodiments of the present application do not limit the specific technologies and specific device forms adopted by the network device.

[0044] The base station may be fixed or mobile. For example, a helicopter or a drone may be configured to act as a mobile base station, and one or more cells may move according to the position of the mobile base station. In other examples, a helicopter or a drone may be configured to be a device for communicating with another base station.

[0045] In some deployments, the network device in the embodiments of the present application may refer to a CU or a DU, or the network device includes a CU and a DU. The gNB may further include an AAU.

[0046] By way of example and not limitation, in the embodiments of the present application, the network device may have mobility 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 or a balloon station. In some embodiments of the present application, the network device may also be a base station located at positions such as on land or in water areas.

[0047] In the embodiments of the present application, the network device may provide services for a cell. The terminal device communicates with the network device through the transmission resources used by the cell (for example, frequency domain resources, or in other words, spectrum resources). The cell may be the cell corresponding to the network device (such as a base station). The cell may belong to a macro base station or a base station corresponding to a small cell. Here, the small cells may include: metro cell, micro cell, pico cell, femto cell, etc. These small cells have the characteristics of small coverage range and low transmission power, and are suitable for providing high-rate data transmission services.

[0048] In a communication system, a PLMN may be composed of a group of base stations, a RAN, and a core network (CN). The base station is responsible for wireless communication with the terminal device. The RAN is responsible for transmitting the signal to the core network. The core network is responsible for processing and forwarding communication data.

[0049] In some embodiments, the PLMN selection order is generally as follows: registered public land mobile network (RPLMN) → home public land mobile network (HPLMN) → user controlled public land mobile network (UPLMN) → operator controlled public land mobile network (OPLMN). The RPLMN is the PLMN registered by the terminal device before the last shutdown or network disconnection, and is temporarily stored on the universal subscriber identity module (USIM) card. The operator corresponding to the HPLMN may have different number segments. Among them, the HPLMN is the PLMN corresponding to the international mobile subscriber identity (IMSI) of the user's USIM. The UPLMN is a list of PLMNs controlled by the user. This PLMN list and the corresponding access technology (ACT) are both stored in two dedicated files of the USIM card / subscriber identity module (SIM) card. The terminal device should be able to identify and read these files in the USIM card / SIM card, and then perform the PLMN selection operation, otherwise it cannot operate. When the operator burns the card, the PLMN that has signed a roaming agreement with the operator is written into the USIM card as the OPLMN, as a suggestion for the operator's user to select a network. The forbidden PLMN (FPLMN) is usually determined after the terminal device attempts to access a certain PLMN and is rejected. The terminal device will add the rejected PLMN to the FPLMN list.

[0050] In NB-IoT, the non-access stratum (NAS) usually selects the PLMN with the highest priority. The terminal device will preferentially search for this specified PLMN. If the terminal device finds the specified PLMN cell, it will immediately initiate a residence / registration. If the terminal device cannot find the specified PLMN, after searching all cells, it will find the PLMN with the second highest priority from them and attempt to reside / register.

[0051] Exemplarily, Figure 1 The schematic diagram of the architecture of a communication system provided by an embodiment of the present application. As Figure 1As shown, the communication system 100 may include a network device 110, which may be a device that communicates with a terminal device 120 (or referred to as a communication terminal, terminal). The network device 110 may provide communication coverage for a specific geographical area and may communicate with terminal devices located within that coverage area.

[0052] Figure 1 Exemplarily, one network device and two terminal devices are shown. In some embodiments of the present application, the communication system 100 may include multiple network devices and each network device's coverage area may include other numbers of terminal devices, which is not limited herein.

[0053] Exemplarily, Figure 2 is a schematic diagram of an architecture of the NTN system mentioned above. Figure 2 As shown, the NTN system 200 uses a satellite 210 as an aerial platform. As Figure 2 shown, the satellite radio access network includes a satellite 210, a service link 220, a feeder link 230, a terminal device 240, a gateway (GW) 250, and a network 260 including a base station and a core network.

[0054] The satellite 210 is a spacecraft based on a space platform. The service link 220 refers to the link between the satellite 210 and the terminal device 240. The feeder link 230 refers to the link between the gateway 250 and the satellite 210. The earth-based gateway 250 connects the satellite 210 to the base station or the core network, depending on the choice of the NTN architecture.

[0055] Figure 2 The shown NTN architecture is a bent-pipe transponder architecture. In this architecture, the base station is located on the earth behind the gateway 250 and the satellite 210 acts as a relay. The satellite 210 operates as a repeater that forwards the signals of the feeder link 230 to the service link 220, or forwards the signals of the service link 220 to the feeder link 230. That is, the satellite 210 does not have the function of a base station, and the communication between the terminal device 240 and the base station in the network 260 needs to be relayed by the satellite 210.

[0056] Exemplarily, Figure 3 is another schematic diagram of the NTN system. As Figure 3 shown, the satellite radio access network 300 includes a satellite 310, a service link 320, a feeder link 330, a terminal device 340, a gateway 350, and a network 360. Different from Figure 2 the above, there is a base station 312 on the satellite 310 and the network 360 behind the gateway 350 only includes the core network. Since the base station is deployed on the satellite, the PLMN only includes the core network part at this time.

[0057] Figure 3 The NTN architecture shown is a regenerative transponder architecture. In this architecture, the satellite 310 carries the base station 312 and can be directly connected to the terrestrial core network through a link. The satellite 310 has the function of a base station, and the terminal device 340 can communicate directly with the satellite 310. Therefore, the satellite 310 can be called a network device.

[0058] In Figure 2 and Figure 3 the communication system of the architecture shown may include multiple network devices, and the coverage range of each network device may include other numbers of terminal devices, which are not limited in the embodiments of the present application.

[0059] In the embodiments of the present application, Figures 1 to 3 the communication system shown may also include other network entities such as a mobility management entity (MME) and an access and mobility management function (AMF), which are not limited in the embodiments of the present application.

[0060] It should be understood that in the embodiments of the present application, a device with communication functions in the network / system may be called a communication device. Taking Figure 1 the communication system 100 shown as an example, the communication devices may include network devices 110 and terminal devices 120 with communication functions. The network devices 110 and terminal devices 120 may be the specific devices described above and will not be elaborated here; the communication devices may also include other devices in the communication system 100, such as other network entities like network controllers and mobility management entities, which are not limited in the embodiments of the present application.

[0061] For ease of understanding, some relevant technical knowledge involved in the embodiments of the present application will be introduced first. The following relevant technologies can be arbitrarily combined with the technical solutions of the embodiments of the present application as optional solutions, and they all fall within the protection scope of the embodiments of the present application. The embodiments of the present application include at least some of the following contents.

[0062] With the development of communication technologies, communication systems (e.g., 5G) will integrate the market potential of satellite and terrestrial network infrastructures. For example, the 5G standard makes NTN, including the satellite segment, a part of the recognized 5G connection infrastructure of the 3rd generation partnership project (3GPP).

[0063] NTN refers to a network or network segment that uses radio frequency (RF) resources on a satellite or unmanned aerial system (UAS) platform. Taking satellites as an example, communication satellites are classified into low earth orbit (LEO) satellites, medium earth orbit (MEO) satellites, geostationary earth orbit (GEO) satellites, high elliptical orbit (HEO) satellites, etc. according to different orbital altitudes. Among them, LEO is an earth-centered orbit with a height of 2000 kilometers or less, or at least 11.25 periods per day, and an eccentricity of less than 0.25. Most artificial objects in outer space are located in LEO. LEO satellites orbit the earth at high speed (mobility), but on a predictable or determinable orbit.

[0064] Satellites with different orbital altitudes have different orbital periods. Exemplarily, the typical height of LEO is 250 - 1500 kilometers, and the orbital period is 90 - 120 minutes. The typical height of MEO is 5000 - 25000 kilometers, and the orbital period is 3 - 15 hours. The height of GEO is about 35786 kilometers, and the orbital period is 24 hours.

[0065] As described above with satellites as an example Figure 2 and Figure 3 it can be seen that typical scenarios for a terminal device to access an NTN system involve an NTN transparent payload or an NTN regenerative payload. Among them, Figure 2 the shown bent-pipe transponder architecture corresponds to an NTN transparent payload, Figure 3 and the shown regenerative transponder architecture corresponds to an NTN regenerative payload.

[0066] In an NTN system, a communication device can infer the trajectory of a cell that a satellite can serve through the satellite ephemeris and epoch time. The satellite ephemeris contains information such as the position and velocity of the satellite at a specific epoch time. Among them, the epoch time is the reference time point of the satellite orbit parameters. The ephemeris also includes parameters such as the semi-major axis, eccentricity, inclination, and longitude of the ascending node of the satellite.

[0067] In some embodiments, a terminal device can use the satellite ephemeris and epoch time to solve the orbit of the satellite. For example, the terminal device can solve the orbit parameters of the satellite according to Kepler's law. Further, the position of the satellite at a future time point can be predicted using the orbit parameters and time information. Another example is that considering the movement of the satellite in orbit and the rotation of the earth, the parameters of the satellite can be calculated through a mathematical model.

[0068] As an example, for the elliptical orbit of a satellite, when the semi-major axis is a, the eccentricity is e, the inclination is i, the longitude of the ascending node is Ω, the argument of perigee is ω, and the mean anomaly is M, the mean anomaly corresponding to time t can be expressed as: M(t) = M0 + n * (t - t0);

[0069] where M(t) is the mean anomaly of the satellite, M0 is the mean anomaly corresponding to the epoch time t0, and n is the mean motion angular velocity.

[0070] The eccentric anomaly E can be obtained by solving Kepler's equation: E - e * sin(E) = M(t).

[0071] The true anomaly ν can be converted from the eccentric anomaly E according to the following formula:

[0072] After determining the true anomaly, the position of the satellite in the orbit can be calculated using the orbital parameters. That is, the position of the satellite is represented by the satellite's orbital equation. Among them, the distance r between the satellite and the earth's center can be calculated according to the following formula: r = a * (1 - e 2 ) / (1 + e * cos(v)).

[0073] Furthermore, the position (x, y, z) of the satellite in the rectangular coordinate system is calculated using the orbital parameters and the true anomaly:

[0074] x = r * (cos(Ω) * cos(ω + v) - sin(Ω) * sin(ω + v) * cos(i));

[0075] y = r * (sin(Ω) * cos(ω + v) + cos(Ω) * sin(ω + v) * cos(i));

[0076] z = r * sin(i) * sin(ω + v).

[0077] In the NTN system, multiple satellites can form a satellite constellation to provide services for terminal devices in NTN cells. In comparison, the satellites corresponding to earth mobile cells can provide services for less time than those corresponding to earth fixed cells. In an earth mobile cell, the coverage time of a satellite depends on the size of the satellite's footprint. The size of the satellite's footprint is related to the orbital altitude of the satellite. For example, the beam of a LEO satellite can reach 1000 kilometers, and the maximum coverage time is about 130 seconds.

[0078] However, even during the operation of a satellite constellation, ground terminal devices may still be in scenarios where there is no network coverage. That is, under the coverage of the NTN network, terminal devices may be in services with discontinuous coverage. The following provides an exemplary description of the discontinuous coverage scenario.

[0079] In some embodiments, due to the limited number of satellites in orbit, for a certain ground terminal device, the network service may be discontinuously covered. For example, for an earth mobile cell based on the Internet of Things, at a certain moment, there may be no satellite available to provide service for the terminal device. That is, the network providing service for this Internet of Things device is discontinuously covered.

[0080] In some embodiments, even if the terminal device is within the geographical coverage area of the satellite, the beam coverage range of the satellite may not include this terminal device. In this scenario, this terminal device may also be in an area with discontinuous coverage. For ease of understanding, the following takes a mobile cell as an example and combines Figure 4 an exemplary description of a discontinuous coverage scenario as shown.

[0081] In Figure 4 the NTN system shown, both terminal device 410 and terminal device 420 are within the geographical coverage area of satellite 430. Among them, terminal device 410 is near position 401 where satellite 430 is perpendicular to the ground, and terminal device 420 is near position 402. As Figure 4 can be seen, the beam center at apoch time of satellite 430 at epoch time t corresponds to ground position 402, and satellite 430 can provide service for terminal device 420. However, since the beam center is not perpendicular to the ground projection position 401 of satellite 430, satellite 430 cannot provide service for terminal device 410. Therefore, terminal device 410 is in a discontinuous coverage scenario.

[0082] The above analyzed the reasons for the discontinuous coverage of the NTN network by taking the Internet of Things as an example. Applications such as the Internet of Things and MTC are experiencing exponential growth and are expected to play a key role in future networks and systems. In these systems, the data transmission frequency of terminal devices is low, and there is no need to always maintain communication with network devices. For energy conservation, the network side can configure multiple energy-saving modes for terminal devices.

[0083] Exemplarily, NB-IoT can support three energy-saving modes, namely the power saving mode (PSM), the discontinuous reception (DRX) mode, and the extended discontinuous reception (eDRX) mode. In the PSM mode, the terminal device does not need to receive paging to detect whether there is a downlink service. Compared with the DRX mode, the terminal device in the eDRX mode will have a longer paging detection period.

[0084] Furthermore, the PSM and eDRX modes are adopted in NB-IoT to save the power consumption of the terminal device. Exemplarily, whether the terminal device uses PSM and eDRX depends on the capabilities of the terminal device and the configuration on the network side. In terms of capabilities, the network will not configure capabilities that the terminal device does not support. In terms of configuration, even if the terminal device supports the capability, the configuration can be different in different network situations.

[0085] Taking the PSM mode as an example, the working process of the energy-saving mode is introduced below. After the terminal device supporting the PSM mode stays in the idle state for a period of time, it will enter the PSM state. In the PSM state, the power amplifier (PA) of the terminal device stops working. That is to say, the radio frequency part of the terminal device stops working. In addition, the access stratum (AS) of the terminal device stops some related functions to reduce the power consumption of parts such as radio frequency and signaling processing, so as to achieve the purpose of low power consumption.

[0086] On the other hand, since the radio frequency part of the terminal device stops working, the terminal device cannot receive any paging and scheduling. For the network side, the terminal device is in an unreachable state at this time. In the unreachable state, data and text messages cannot reach the terminal device. However, the mark of the terminal device in the network is still in the registered state. Therefore, when the terminal device is woken up from the PSM state (unreachable state), it does not need to re-establish a public data network (PDN) connection, but can directly send data.

[0087] In the PSM mode, the state transition of the terminal device can be achieved through two timers. The two timers are the T3324 timer and the T3412 timer. For the convenience of understanding, the following combines Figure 5 and Figure 6 to exemplarily illustrate different energy-saving modes respectively. In Figure 5 and Figure 6 , the horizontal axis is time and the vertical axis is energy consumption.

[0088] ByFigure 5 It can be seen that the terminal device can send data with relatively high energy consumption in the active state, and mainly receive data with relatively low energy consumption in the idle state. After remaining in the idle state for a period of time, if it does not enter the active state again, the terminal device will directly enter the PSM state with lower energy consumption. The duration of the terminal device in the idle state is the duration of the T3324 timer.

[0089] Continue to refer to Figure 5 A complete tracking area update (TAU) cycle is the sum of the times of IDLE + PSM. The duration of a TAU cycle is defined as the duration of the T3412 timer. Therefore, T3412 is the TAU duration, and T3324 is the timer for entering the PSM state in the IDLE state.

[0090] Under certain specific access point networks (APNs), the terminal device can modify the T3412 and T3324 timers through standard commands specified by the 3rd generation partnership project (3GPP) protocol.

[0091] As an example, in NB-IoT, the terminal device can use attention (AT) commands (ATCommands) to communicate and configure with the NB-IoT module. AT commands are sent from the terminal device or data terminal to the terminal adapter or data circuit terminal. The terminal device controls the functions of the mobile station by sending AT commands and interacts based on various network services. The terminal device can send this command to the narrowband (NB) module. This module can carry the AT command in a reliable (confirmable, CON) or non-confirmable (NON) message sent to the NB-IoT platform.

[0092] As an example, the terminal device can modify the T3412 and T3324 timers through the command AT + CPSMS. Among them, CPSMS represents the control plane support for mobile terminated services. The AT + CPSMS command can be used to set the relevant parameters of PSM. In NB-IoT communication, AT + CPSMS is an AT command for controlling PSM.

[0093] Figure 6Schematically introduced the relevant parameters in the eDRX mode. In the traditional DRX mode, the minimum interval is 2.56 seconds (DRX cycle). For the Internet of Things where data is not frequently sent, such a time interval is too frequent. To further reduce the power consumption caused by listening for paging, the NB-IoT introduced the eDRX technology of enhanced discontinuous reception. In each eDRX cycle, there is a paging time window (PTW). During the PTW, the terminal device will listen for the paging messages sent by the network side and make a response.

[0094] It should be noted that the terminal device can only listen for the paging channel according to the DRX cycle within the PTW to receive downlink services. Since the DRX cycle is short, it can be considered that the terminal does not sleep within the PTW and is always reachable. The time outside the PTW is in the sleep state, does not listen for the paging channel, and cannot receive downlink services. Therefore, the PTW window period is a state of eDRX. Once the PTW window has passed, the device enters the silent state and can only receive paging until the next periodic PTW.

[0095] As Figure 6 can be seen, the terminal device intermittently listens for paging according to the eDRX cycle in the idle state, reducing power consumption. Specifically, after a PTW, the terminal device will enter the silent state and wait until the eDRX cycle is completed before entering the PTW again to listen for paging. When the paging falls outside the PTW, the terminal device cannot respond to the paging and needs to wait until the paging cached by the network side is sent again and falls within the PTW before it can successfully respond. Thus, it can be seen that the sleep time of the terminal device in the eDRX mode is relatively long.

[0096] During the communication process, the network side (core network) can configure the parameters of various energy-saving modes for the terminal device. Exemplarily, the network side can configure the relevant parameters of eDRX for the terminal device through the AMF or MME.

[0097] As an example, the terminal device can first negotiate with the MME to obtain terminal device-specific eDRX, and then calculate the paging hyper-frame (PH) to obtain the hyper-system frame number (H-SFN) of the paging message. Then, the terminal device can obtain the possible system frame number (SFN) range where its paging message is located through the calculation of the paging time window (PTW). Among them, PTW is terminal device-specific and can be determined by PH, the start position (PTW_start) and the end position (PTW_end) within PH. Finally, the terminal device can obtain the subframe where the paging message is located through the paging frame (PF) and the paging occasion (PO).

[0098] Meanwhile, the core network can also configure a suitable eDRX period for the terminal device. The position of PH, PTW_start, and PTW_end are mainly determined by the eDRX period, the PTW length, and the identity (ID) of the terminal device. Exemplarily, PH, PTW_start, and PTW_end can be determined according to the following formulas:

[0099] H-SFN mod TeDRX,H = (UE_ID_H mod TeDRX,H);

[0100] Among them, UE_ID_H is determined as follows: If monitoring the paging radio network temporary identifier (P-RNTI) on the physical downlink control channel (PDCCH) or the MTC physical downlink control channel (MTC PDCCH, MPDCCH), then the ID is the highest significant 10 bits of the hash function; if monitoring P-RNTI on the narrow band physical downlink control channel (NPDCCH), then the ID is the highest significant 12 bits of the hash function.

[0101] TeDRX,H is the eDRX period of the terminal device in the hyper-frame. Generally, TeDRX,H = 1, 2,..., 256 hyper-frames. For NB-IoT, TeDRX,H = 2,..., 1024 hyper-frames. TeDRX,H is configured by the upper layer. 1 hyper-frame = the time of 1024 SFNs, that is, 10.24s. Therefore, the available time range of the eDRX period is 20.48 seconds to 2.9127 hours.

[0102] PTW_start represents the first radio frame of PH. PTW_start is the SFN that satisfies the following equation:

[0103] SFN = 256 * ieDRX, where ieDRX = floor(UE_ID_H / TeDRX,H) mod 4.

[0104] PTW_end is the last radio frame of PTW. PTW_end is the SFN that satisfies the following equation:

[0105] SFN = (PTW_start + L * 100 - 1) mod 1024, where L is the paging time window length (seconds) configured by the upper layer.

[0106] As described above in conjunction with Figure 5 and Figure 6 introduced various energy-saving modes and the related parameters of the eDRX mode. From Figure 5 and Figure 6 it can be seen that the energy consumption of the terminal device in the idle state and the PSM state is relatively low, so energy saving can be achieved.

[0107] As can be seen from the foregoing, in the NTN coverage scenario, network discontinuous coverage may occur. When the Internet of Things and MTC are under NTN coverage, the time window without network coverage may be misaligned with the window in which the terminal device is in an unreachable state, resulting in an impact on energy saving and communication quality. Therefore, how the terminal devices of the Internet of Things work in the case of discontinuous coverage is a problem worthy of study.

[0108] Furthermore, as can be seen from the foregoing, the DRX, eDRX, and PSM configurations of the terminal device are configured by the core network for the terminal device. However, when the terminal device is in the NTN, receiving signals from the base station via the satellite belongs to the process of the access network, and the core network may not know the coverage of the access network, and thus will not actively consider configuring the eDRX configuration and PSM configuration that match the communication scenario of discontinuous satellite signal coverage for the terminal device. This is also a problem worthy of study.

[0109] Exemplarily, when the terminal device attempts to establish a connection with the satellite, the remaining time of satellite coverage may be too short, resulting in the inability to complete the connection establishment. Exemplarily, when the terminal device is about to lose network coverage, it may be in the wake-up or idle state, and the power consumption of the terminal device attempting to send data or receive a paging may be wasted. Therefore, the terminal devices in the Internet of Things or MTC applications need to consider the scenario of discontinuous coverage to better save power and ensure communication quality.

[0110] It should be noted that the problem mentioned above that the energy-saving configuration of the Internet of Things may be affected by the discontinuous coverage of the NTN system is only an example. The embodiments of the present application can be applied to any type of scenario where the relevant configuration of the terminal device is affected due to discontinuous network coverage.

[0111] Based on this, the embodiments of the present application propose a method for wireless communication. Through this method, the terminal device can predict the first time information when entering the network coverage-free area, and thus perform state transitions of different states based on the first time information to save power consumption or successfully establish communication with the satellite. For the sake of easy understanding, the method proposed by the embodiments of the present application will be described in detail below in combination with Figure 7 to illustrate the method proposed by the embodiments of the present application in detail.

[0112] Refer to Figure 7 , in step S710, the terminal device determines the first time information.

[0113] The terminal device is any type of terminal device described above, which is not limited herein.

[0114] In some embodiments, the terminal device is a device that communicates through a satellite in the NTN system. Exemplarily, when the base station is deployed on the satellite, the terminal device directly communicates with the base station on the satellite. Exemplarily, when the satellite is used as a relay, the terminal device communicates with the network device on the ground through the satellite.

[0115] As an example, the terminal device is currently located within the service area of the first satellite in the NTN. The current moment can be the moment when the terminal device is in any state. Exemplarily, the terminal device can be in the RRC active state at the current moment. Exemplarily, the terminal device can be in the RRC idle state at the current moment. Exemplarily, the terminal device can be in the PSM state at the current moment.

[0116] The first satellite can be the satellite that provides services to the terminal device at the current moment, that is, the current satellite. That is to say, at the current moment, the terminal device has already established a connection with the first satellite, or the terminal device can establish a connection with the first satellite. Exemplarily, the terminal device is located within the geographical coverage area of the first satellite. Exemplarily, the terminal device is located within the signal coverage area of the first satellite at the current moment.

[0117] As an example, at the current moment, the terminal device is in a scenario with network coverage.

[0118] In some embodiments, the terminal device is a communication device with a relatively low service transmission rate or less data transmission. For example, the terminal device is a communication device in NB-IoT. Another example is that the terminal device is a communication device in an MTC application.

[0119] In some embodiments, the terminal device is a device that supports energy saving or low - power consumption configurations. That is to say, the terminal device can achieve energy saving during operation through parameters configured by the network device or the core network. For example, the terminal device has the ability to support DRX configuration or eDRX configuration. Also, for example, the terminal device has the ability to support PSM configuration.

[0120] The first time information refers to the time parameter related to the scenario where the network coverage of the terminal device is discontinuous. In some embodiments, the first time information refers to the relevant time parameter when the terminal device enters the scenario without network coverage from the scenario with network coverage. In some embodiments, the first time information refers to the relevant time parameter when the terminal device enters the scenario with network coverage from the scenario without network coverage.

[0121] As an example, the terminal device entering the scenario without network coverage can also indicate that the terminal device is in the scenario of discontinuous network coverage. Discontinuous network coverage can also be referred to as discontinuous cell coverage. That is to say, the terminal device is within the coverage area of a cell at some moments and may not be within the coverage area of any cell at other moments.

[0122] As an example, when the terminal device is in cell coverage, the cell can indicate whether it supports discontinuous coverage through the system information block (SIB) and provide the necessary information for discontinuous coverage prediction.

[0123] In some embodiments, the first time information includes the time when the terminal device can be out of network coverage, so it can also be called out - of - coverage indication information. In some embodiments, the first time information can be used for the terminal device to release the RRC connection, so it can also be called release - assisting information. In some embodiments, the first time information is related to the unreachable state of the terminal device, so it can also be called unreachable information.

[0124] The first time information is related to the first time period and / or the second time period. As an example, the first time information can include the first time period and / or the second time period. As an example, the first time information can be used to determine the first time period and / or the second time period.

[0125] As an example, the first time period or the second time period can include one or more time parameters of this time period. These time parameters can include the start time (starting moment), end time (ending moment), and duration of the time period.

[0126] As an example, the first time information can include at least one of the following: the duration of no network coverage, the time (moment) of entering the scenario without network coverage, and the time (moment) of returning to network coverage.

[0127] In some embodiments, the first time information may indicate the time parameters of a first time period. The first time period is the time period from the current moment to the starting moment when the terminal device enters an area without network coverage. That is to say, after the first time period, the terminal device will lose network coverage. If the terminal device can predict the time of coverage loss, the terminal device can check whether the remaining time of the current cell coverage is long enough to accommodate connection establishment, so as to ensure that the terminal device can successfully establish communication with the network device. In addition, for a terminal device that is about to lose coverage, it can also make preparations in advance to further save power consumption.

[0128] As an example, the first time period may indicate the starting moment when the terminal device leaves the satellite signal coverage area. This starting moment is also the critical time when the terminal device is at the edge of the satellite signal coverage. This starting moment is the starting moment when the terminal device enters an area without network coverage.

[0129] As an example, the first time period is the time period when the terminal device reaches the edge of the current cell.

[0130] As an example, before the terminal device reaches the edge of the current cell, it will switch to other serving cells. The first time period is the time period from the current position of the terminal device to the edge of other cells where cell switching no longer occurs.

[0131] As an example, before the terminal device reaches the edge of the current cell, it does not perform satellite switching. The first time period is the time period from the current position to the edge of the current cell.

[0132] In some embodiments, the first time information may indicate the time parameters of a second time period. The second time period is the duration of the area without network coverage. That is to say, after the second time period, the terminal device will enter a scenario with network coverage. The second time period may also be referred to as an uncovered gap or an unavailable period. If the terminal device can determine the duration of the area without network coverage, according to this duration, the terminal device can be woken up in time when entering the network coverage to ensure communication.

[0133] As an example, the starting moment of the second time period is the starting moment when the terminal device enters the area without network coverage. The ending moment of the second time period is the moment when the terminal device enters the area with network coverage from the area without network coverage.

[0134] In some embodiments, due to the periodic operation of the satellite constellation, the first time period and the second time period when the terminal device enters the area without network coverage are also periodic. When the terminal device enters the area without network coverage, it may enter a state where the network is unreachable, such as PSM. Therefore, the first cycle for the terminal device to be woken up can be determined according to the periodically occurring first time period and second time period.

[0135] As an example, the first period can be used to determine the timing when the terminal device is awakened from the sleep state / silent state / PSM state.

[0136] As an example, according to the first time period and the second time period, the entry time when the terminal device re-enters the satellite signal coverage area can be determined. According to this entry time, the terminal device can send a request message for waking up the terminal device to the core network or the network device at a configured interval, that is, determine the first period when the terminal device is awakened in the recommended information.

[0137] In some embodiments, the first time information can indicate the time parameters of the first time period and the second time period. The terminal device can determine the network coverage duration and the non-network coverage duration in the discontinuous coverage according to the first time information, so as to recommend reasonable configuration parameters to the network device or the core network to match the discontinuous coverage scenario.

[0138] As an example, the terminal device can determine the recommended configuration parameters according to the first time information, that is, the recommended information.

[0139] The terminal device can determine the first time information according to multiple pieces of information. The terminal device can predict when the discontinuous coverage will start based on this time, so as to determine when to release the RRC connection to avoid triggering a radio link failure (RLF). Further, the terminal device can synchronize the first time information with the network device to release the terminal device to the RRC_IDLE state in a timely manner.

[0140] In some embodiments, the terminal device can make a prediction based on one or more pieces of information to determine the first time information. The one or more pieces of information can also be referred to as the necessary information for predicting discontinuous coverage. Exemplarily, the first time information can be related to one or more of the following: the location information of the terminal device; the relative position information between the terminal device and the first satellite; and the relevant information of multiple satellites related to the terminal device. Among them, the multiple satellites include the first satellite.

[0141] As an example, the first time information can be determined according to one or more of the above-mentioned pieces of information.

[0142] In some embodiments, the terminal device can estimate the first time information according to its own location information. The location information of the terminal device can be determined according to the global navigation satellite system (GNSS). Exemplarily, the location information of the terminal device can include the location change information of the terminal device. The location change information is, for example, the movement information of the terminal device.

[0143] As an example, when the terminal device is currently in the RRC active state, it can determine the edge change of the serving cell based on the communication with the satellite. The terminal device can estimate the time when it reaches the cell edge based on its own location information, so as to determine the first time period.

[0144] In some embodiments, the first time information can be determined according to the relative position information between the terminal device and the first satellite. The relative position information can include the elevation angle of the terminal device relative to the first satellite, and / or the distance between the terminal device and the edge of the service area of the first satellite.

[0145] As an example, in the case of discontinuous coverage of IoT NTN, the elevation angle value or the elevation angle change rate of the terminal device relative to the first satellite can be used by the terminal device to determine whether it will enter discontinuous coverage. For example, when the elevation angle of the terminal device relative to the first satellite < 5 degrees, the terminal device can determine that it will soon leave the service area of the first satellite.

[0146] As an example, the terminal device can determine whether it will leave the coverage range of the first satellite according to the distance between it and the edge of the service area. For example, when the reference position of the terminal device to the cell edge is less than a certain set value, the terminal device will soon enter discontinuous coverage.

[0147] In some embodiments, the first time information can be related to the location information of the terminal device and the ephemeris information / position information of the first satellite. Exemplarily, the terminal device can obtain the ephemeris information of the first satellite according to the ephemeris table. The terminal device can determine the remaining duration of the terminal device within the coverage range of the first satellite according to its own location and ephemeris information, so as to determine the first time information according to this duration. Based on this first time information, the terminal device can determine the duration during which the terminal device can be woken up in the recommended information.

[0148] As an example, for a ground fixed cell served by a non-geostationary orbit (NGSO) satellite, the network can provide the cell stop time. Optionally, the terminal device can estimate the time when it reaches the cell edge according to the service time (T-service) of the service. Optionally, the terminal device can estimate the satellite parameters according to the GNSS positioning information and estimate the first time information.

[0149] As an example, for the case of a mobile cell, the network cannot provide the stop time. Therefore, the terminal device can predict the duration of the cell service based on the reference position of the first satellite in the broadcast. For example, the terminal device can predict the cell service time according to the satellite position (x, y, z) calculation formula mentioned above.

[0150] In some embodiments, the first time information may be determined based on the relevant information of multiple satellites related to the terminal device. The multiple satellites related to the terminal device may refer to the satellites that are currently or may soon provide services to the terminal device. Exemplarily, the multiple satellites include a first satellite that currently provides services to the terminal device. Exemplarily, the multiple satellites further include one or more satellites other than the first satellite. The one or more satellites may be any one or any number of satellites that may soon provide services to the terminal device.

[0151] As an example, the multiple satellites may be some or all of the satellites in the satellite constellation related to the terminal device.

[0152] As an example, in a mobile cell, the serving cell is usually the area served by one or more satellites. The serving cell may be the serving cell where the terminal device is located. The multiple satellites may include the satellites that serve the serving cell.

[0153] In some embodiments, the relevant information of the multiple satellites may include at least one of the ephemeris information of the multiple satellites, the position information of the multiple satellites, the beam information of the multiple satellites, and the time information for the multiple satellites to provide services to the terminal device. Since the multiple satellites include the first satellite, the relevant information of the multiple satellites also includes the relevant information of the first satellite.

[0154] In some embodiments, the relevant information of the multiple satellites may be carried in the SIB. The network device may broadcast the SIB to facilitate the terminal device to receive the relevant information of the multiple satellites. For example, the network device may indicate the support for discontinuous coverage by broadcasting the SIB32 of the first satellite information (such as ephemeris and beam information) or other information blocks. An exemplary description will be given later with SIB32 as an example.

[0155] As an example, the relevant information of the multiple satellites may be carried in one or more of the following information: SIB3, SIB31, SIB32.

[0156] As an example, the relevant information of the first satellite may be carried in the auxiliary information. When the terminal device is in the NTN network, the auxiliary information may include information related to the network coverage of the satellite, such as the ephemeris information of the satellite. The terminal device can predict whether it will lose the network coverage of the satellite or whether it is in the network coverage of the satellite based on the auxiliary information, so as to determine the relevant time information for losing the network coverage.

[0157] As an example, the relevant information of satellites other than the first satellite among multiple satellites can also be sent through RRC signaling. For example, after receiving the first time information, the first satellite can notify the terminal device through RRC dedicated signaling whether there are other moving satellites around. If there are other satellites, the terminal device is further notified of the ephemeris parameters of the other satellites.

[0158] Optionally, the first time information can be determined according to the ephemeris information or position information of multiple satellites. The ephemeris information of multiple satellites can be used to determine the position information of multiple satellites. For example, the position information of a satellite can be determined according to the ephemeris table and the epoch time.

[0159] As an example, when the relevant information of multiple satellites includes the position information of multiple satellites, the terminal device can estimate the trajectory of the serving cell on the earth by predicting this position information.

[0160] As an example, by obtaining the position information of multiple satellites or any one of the multiple satellites, the trajectories of the satellites at different times can be depicted. The terminal device can predict the time to enter the satellite coverage and the time to leave the satellite coverage according to the trajectory parameters.

[0161] As an example, the terminal device can predict the time when other satellites will cover itself and the time point when it will leave the current serving satellite (the first satellite) through the satellite and ephemeris parameters of other movable satellites sent by the first satellite.

[0162] As an example, the orbit of any one of the multiple satellites may have slight changes. To ensure the accuracy of the prediction, the terminal device can regularly update the prediction results.

[0163] Optionally, the first time information can be determined according to the beam information of the satellite, so as to more accurately predict the remaining duration of the terminal device within the satellite coverage. For the scenario of a mobile cell, if the terminal device only predicts according to the ephemeris information of the satellite, there may be a large deviation. For example, since Figure 4 the beam center of the satellite is not perpendicular to the satellite position, relying only on the ephemeris table may not be sufficient for the terminal device to determine whether it will be within the satellite coverage at a given time. That is to say, the discontinuous coverage predicted only according to the ephemeris information may be incorrect. To improve the accuracy, the necessary information for predicting discontinuous coverage can include the ephemeris tables and beam information of multiple satellites.

[0164] As an example, when the SIB contains the beam information of any one of multiple satellites, it may indicate that the cell supports discontinuous coverage. That is to say, the information in the SIB can implicitly indicate whether the cell indicates discontinuous coverage. For example, when the SIB32 contains the beam information of the serving satellite, the SIB32 can indicate that the cell of the serving satellite supports discontinuous coverage. Based on the beam information in the SIB, the terminal device can more accurately predict how long it can stay within the coverage area of the first satellite. Combining with the position information of the terminal device and the satellite, the terminal device can generally know when it will enter discontinuous coverage. For another example, when the SIB32 does not contain beam information, it means that it is not supported.

[0165] As an example, when the SIB includes the beam information of any one of multiple satellites, the terminal device sends the first time information.

[0166] Optionally, the first time information can be determined according to the time information provided by multiple satellites for the terminal device. The time information provided by multiple satellites can be determined according to the ephemeris information and beam information of multiple satellites. Exemplarily, the service durations of multiple satellites can be used to determine the first time period and / or the second time period.

[0167] As an example, the first duration is the remaining duration of the service provided by the first satellite. That is to say, the first duration is the duration between the current moment and the moment when the terminal device leaves the service area of the first satellite. The second duration represents the time information of other multiple satellites covering the terminal device. There will be multiple starting moments for other multiple satellites to cover the terminal device. There are multiple durations between the current moment and multiple starting moments, and the minimum value of multiple durations is the second duration. That is to say, the second duration is the minimum value of one or more durations between the current moment and one or more moments when one or more satellites start to provide services for the terminal device. The first time period can be determined according to the first duration and the second duration.

[0168] For example, when the first duration is greater than or equal to the second duration, the duration of the first time period is greater than the first duration.

[0169] For another example, when the first duration is less than the second duration, the duration of the first time period is equal to the first duration.

[0170] For another example, when the terminal device does not perform satellite handover before leaving the service area of the first satellite, the duration of the first time period is the first duration.

[0171] The first-time information can be carried in various types of information. Optionally, the first-time information can be carried in one or more of the following types of information: auxiliary information of the terminal device, downlink channel quality report (DCQR), access stratum release assistance indication (AS RAI).

[0172] In some embodiments, the terminal device can report the first-time information to the first satellite via RRC dedicated signaling. The RRC dedicated signaling can include the auxiliary information of the terminal device.

[0173] In some embodiments, the first-time information can be carried in a newly added information field. For example, an information field for sending the first-time information can be added based on the DCQR. Another example is that a corresponding information field for sending the first-time information can be added based on the AS RAI.

[0174] As an example, the terminal device can send an AS RAI command carrying the first-time information to the NB module. When the module sends a CON or NON message to NB-IoT, it carries the AS RAI, thereby achieving the transmission of the first-time information.

[0175] Continue to refer to Figure 7 , in step S720, based on the first-time information, the terminal device performs a transition from the first state to the second state.

[0176] The first state can be the state of the terminal device at the current moment or at other moments, which is not limited herein.

[0177] The second state can be any state different from the first state. In some embodiments, the first state and the second state can be any two of the RRC active state, the RRC idle state, and the PSM state. That is to say, the state transition performed by the terminal device can include the transition between any two of the RRC active state, the RRC idle state, and the PSM state.

[0178] As an example, the first state is the RRC active state and the second state is the RRC idle state.

[0179] As an example, the first state is the PSM state and the second state is the wake-up state. The PSM state can also be referred to as the unreachable state.

[0180] As an example, the first state is the RRC idle state or the PSM state, and the second state is the RRC active state.

[0181] When the terminal device performs a transition from the first state to the second state, the terminal device can transition from the first state to the second state according to the transition timing, or can determine whether to transition from the first state to the second state. That is to say, the terminal device can not perform the state transition.

[0182] Based on the first time information, it can mean that the terminal device directly performs the state transition according to the first time information, or it can mean that the network device sends a transition indication based on the first time information, and the terminal device performs the state transition according to the transition indication sent by the network device. As can be seen from the foregoing, the first time information can indicate a period when the terminal device is unreachable. Both the network device-centered and the terminal device-centered processes can be used to determine and coordinate the period when the terminal device is unreachable. These two methods are not mutually exclusive, they can serve different use cases, and can coexist in the same network. The method embodiments of state transition centered on the terminal device and the network device will be introduced separately later.

[0183] In some embodiments, when the first state is the RRC idle state or the PSM state, the first time information can be used by the terminal device to determine whether to establish a connection. As an example, the first time information further includes a third time period during which the first serving cell provides services to the terminal device, and the duration of the third time period is used by the terminal device to determine whether to establish an RRC connection with the first serving cell.

[0184] For example, when the first serving cell is a cell that provides services for the current first satellite, the third time period represents the remaining duration during which the first satellite can provide services to the terminal device. If the remaining duration is not sufficient to establish a connection, the terminal device may not establish a connection with the first satellite. If the remaining duration is sufficient to establish a connection, the terminal device may establish an RRC connection with the first satellite in the case of having a service requirement to ensure communication.

[0185] Another example is that when the first serving cell can be a cell that provides services for other satellites when the terminal device switches to other satellites. Similarly, the third time period can also represent the remaining duration during which other satellites provide services to the terminal device, which will not be elaborated here.

[0186] As an example, when the terminal device does not perform a handover before reaching the edge of the current serving cell, the third time period is the first time period.

[0187] As an example, when the duration of the third time period is less than or equal to the first threshold, the terminal device does not establish an RRC connection to avoid connection failure and reduce the power consumption caused by establishing a connection.

[0188] In the process of state transition centered around the terminal device, the terminal device can determine the first time information related to no network coverage based on various information and send the first time information to the network device. Although the network device may have more accurate coverage data than the terminal device, the network device usually cannot know its location as accurately as the terminal device. In addition, in some cases in NB IoT, the terminal device may not send a location report to the network device (e.g., eNB), which means that the terminal device's estimation of being in no network coverage will be more accurate than that of the network device. Further, if the terminal device predicts the first time information, even if it loses the signal in the RRC connected state, since it knows that it is about to enter no network coverage, it does not have to go through the power - expensive RLF declaration process.

[0189] In some embodiments, after the terminal device determines the first time information, the terminal device can send the first time information to the network device. After receiving the first time information, the network device can send the first indication information to the terminal device. The first indication information can indicate whether the terminal device transitions from the first state to the second state, or can also indicate the transition timing for the terminal device to perform the state transition.

[0190] As an example, the first indication information includes the transition timing for the terminal device to transition from the RRC active state to the RRC idle state. For example, the first indication information can indicate this transition timing by configuring a transition timer for the terminal device to avoid the terminal device making an autonomous transition.

[0191] As an example, the terminal device notifies the network device of the in - reachable period of the terminal device and / or the indication of leaving or entering the coverage area (the first time information). Further, when the terminal device is in the RRC connected (RRC_CONNECTED) state, the network device or the terminal device can configure the terminal device to report this indication through a first timer. The first timer is, for example, an out - of - coverage timer.

[0192] Exemplarily, the value of the first timer can be configured by the network device or can be configured by the terminal device itself.

[0193] Exemplarily, when the value of the first timer is configured to zero, the terminal device can immediately release the RRC connection and enter the RRC idle state.

[0194] Exemplarily, the configuration or sending information of the first time information can introduce a new indication from an uplink dedicated control channel (UL DCCH) message or can use the existing ASRAI.

[0195] As an example, when the terminal device sends the first time information to the network device, the terminal device may start a first timer.

[0196] As an example, after receiving the first time information, the network device may also start a first timer.

[0197] As an example, after predicting when the discontinuous coverage will start, the terminal device may send the first time information to the network device. The terminal device or the network device may start a first timer. When the first timer expires, the terminal device may perform an action to leave the RRC connection according to the behavior of the network device and enter the RRC idle state. Among them, the reason for the RRC release may be marked as "other".

[0198] Exemplarily, when the first timer is running, the terminal device may send the first time information to the network device. Before leaving the first satellite service area, the network device is still providing services to the terminal device. Any uplink / downlink transmission between the terminal device and the network device may continue. Additionally, during this period, the network device may also choose to reconfigure the terminal device to disable or stop the first timer.

[0199] In some embodiments, the terminal device may also autonomously enter the RRC idle state. Optionally, the terminal device may determine the transition timing for the state transition according to the first timer, rather than according to the indication of the network device.

[0200] As an example, the first timer may be set in the terminal device. The terminal device may start the first timer when sending the first time information. When the first timer expires, the terminal device autonomously performs an action to leave the RRC connection and enters the RRC idle state. The reason for the RRC release may also be marked as "other".

[0201] As an example, when the terminal device releases the RRC connection based on the first timer, the reason for the RRC release may be marked as a new reason. When about to enter a scenario without network coverage, the network device may send an RRC Release message to the terminal device with the new reason.

[0202] As an example, the first timer may be used for the terminal device to determine the transition timing from the RRC active state to the RRC idle state.

[0203] As an example, the terminal device may also send second indication information to the network device. The second indication information may indicate that the RRC idle state is the preferred state. The second indication information may also be used by the terminal device to determine the transition timing from the RRC active state to the RRC idle state according to the first timer. When the first timer expires, the terminal device may transition from the RRC active state to the RRC idle state. That is to say, if the first timer expires, regardless of whether the first indication information from the network device is received, the terminal device may directly perform the state transition.

[0204] As an example, since the terminal device knows its own coverage situation, it may indicate to the network that "RRC_IDLE" is the preferred RRC state when starting the first timer. If no indication of RRC release is received when the first timer expires, the terminal device autonomously enters RRC_IDLE.

[0205] Whether the transition timing is determined according to the indication of the network device or autonomously determined by the terminal device, the transition timing is related to one or more of the following information: the service type of the terminal device, the service priority of the terminal device, and the downlink data of the network device. This will be described in detail later in combination with the state transition process centered on the network device.

[0206] In some embodiments, when the terminal device determines that it is about to enter a network coverage - free scenario, the first time information may also indicate an instruction for the terminal device to leave the RRC connection. The network device may determine based on this information that it is time to release the terminal device. Releasing the terminal device means transitioning the terminal device from the RRC active state to the RRC idle state.

[0207] As an example, if the network device deems it necessary, it may prevent the terminal device from autonomously entering the idle state through the release timer configuration.

[0208] In some embodiments, when the terminal device predicts the arrival of an uncovered gap, it may autonomously release an existing RRC connection. If due to discontinuous coverage, the terminal device does not have enough time to complete the RRC re - establishment process, the terminal device may determine the timing to transition to the RRC idle state according to the situation triggering RLF. Exemplarily, when the actual time for the terminal device to enter the network coverage - free scenario is earlier than the time indicated by the first time information, the terminal device may enter the network coverage - free scenario in advance. In this scenario, the terminal device may not be aware that it has entered the network coverage - free scenario, but instead initiate an RRC re - establishment request due to signal loss, resulting in RLF.

[0209] As an example, the terminal device can directly transition to the RRC idle state after triggering RLF. That is to say, when the terminal device predicts that it is about to enter a network coverage - free scenario, once RLF is triggered, it directly releases the RRC connection with the network (NW).

[0210] As an example, when the number of times the terminal device triggers RLF is greater than a threshold value, it transitions to the RRC idle state. For example, when RLF is triggered N times, the terminal device transitions from the RRC active state to the RRC idle state. Here, N is a natural number greater than or equal to 1.

[0211] In some embodiments, to avoid mismatches in the RRC connection state, the terminal device may trigger a request to release the RRC connection before the actual RLF event. By triggering this request, the terminal device can notify the network of the RRC connection release. This method may cause the RRC connection to be released earlier than the actual RLF situation, thus affecting data transmission. If early release is to be avoided, the terminal device can implicitly release on RLF, that is, release the RRC connection when RLF is triggered. However, the network should be aware of the behavior of the terminal device so that it can decide on the locally released UE context based on the data transmission state and the latest reported radio conditions.

[0212] In some embodiments, when the terminal device knows that network coverage is about to start and the remaining time in the current cell is not sufficient to complete a new connection establishment process, the decision on whether to trigger re - establishment or enter the RRC idle state can also be made based on the implementation of the terminal device.

[0213] The previous text introduced the process of state transition centered around the terminal device. Next, the process of state transition centered around the network device is introduced. In this process, the network device can detect the activity level of the terminal device's services to determine the timing of the terminal device's state transition. It should be understood that the terminal device can also determine the timing of state transition according to the service type by itself, which will not be elaborated here.

[0214] In some embodiments, the network device can be any of the base stations described above or a network - side device other than the communication device corresponding to the core network. Exemplarily, when the base station is set on a satellite, the network device can refer to the satellite. Exemplarily, when the base station is set on the ground and the satellite is only used for relaying, the network device can include the satellite and the base station.

[0215] As an example, the network device includes a first satellite, and the terminal device is located within the service area of the first satellite at the current moment.

[0216] In the network device-centric conversion process, the terminal device maintains an RRC connection with the network device. The network device can understand the service status of the terminal device based on the communication with the terminal device, thereby indicating the state conversion of the terminal device. Furthermore, the terminal device will also send the first time information to the network device, so as to avoid possible state mismatch between the terminal device and the network device as much as possible.

[0217] In some embodiments, the network device may also determine the first time information by detecting the service activity of the terminal device, etc. That is, the network device may receive the first time information sent by the terminal device, or may determine the first time information by itself. The network device may instruct the terminal device to perform a transition from the first state to the second state based on the first time information.

[0218] In some embodiments, when the terminal device notifies the network device of the first time information of leaving the coverage area, the network device can determine whether to immediately allow the terminal device to release the RRC connection and enter the RRC idle state. In other words, the network device can determine the switching timing.

[0219] As can be seen from the foregoing, the timing of the conversion may be related to the service type and service priority of the terminal device and the downlink data of the network device.

[0220] As an example, the network device may set an activity factor function related to the service type and / or service priority of the terminal device to determine the transition timing. Exemplarily, the network device may detect the activity level of the terminal device service and configure the transition timing for the terminal device supporting DRX to perform state transition. Exemplarily, the activity factor function may be a first factor δ(x, y). Wherein, x may be related to the service type, y may be related to the service priority, and 0<δ(x, y)≤1.

[0221] As an example, the network device can configure the conversion timing according to the transmission requirements of the downlink data to avoid the loss of downlink data. Exemplarily, in order to avoid the loss of the sent downlink data, the network device can instruct the terminal device to enter the RRC idle state in advance. Since the network device knows the timing when the terminal device enters the idle state, if the network device still has downlink data to send, the downlink data can be stored and buffered, and then sent when the terminal device is connected again. The situation in which the terminal device is connected again is, for example, when a new satellite covers the terminal device, or when the terminal device switches to other satellites, or when the terminal device receives a wake-up signal.

[0222] Exemplarily, the fourth time period between the conversion timing and the current moment is the product of the first time period and the second factor, where the second factor is greater than 0 and less than 1. The second factor is, for example, α. When the first time period is the first duration, the first time period can be expressed as T1. The network device can instruct the terminal device to enter the RRC idle state after the α*T1 (1>α>0) time period.

[0223] It can be seen from Figure 7 that after predicting the first time information, the terminal device can perform a state transition autonomously or according to the instruction of the network device. Generally, when the terminal device is in the connected mode, it knows the discontinuity of the coverage, so the terminal device can decide to release the RRC connection instead of triggering a re-establishment process, thereby reducing power consumption.

[0224] As can be seen from the foregoing, before the terminal device leaves the service area of the first satellite, the terminal device may receive the ephemeris information and / or beam information of other satellites. The terminal device can determine whether to perform a satellite handover. By performing a satellite handover, the time when the terminal device enters an area without network coverage can be delayed. Further, the terminal device can perform a state transition after performing a satellite handover. As an example, the terminal device can determine whether to perform a satellite handover or a state transition according to the first duration and the second duration introduced above.

[0225] In some embodiments, the terminal device can determine the timing of performing a state transition according to the relevant information of multiple satellites. The relevant information of multiple satellites can be used to determine the first duration and the second duration. For the sake of easy understanding, the following combines Figure 8 to exemplarily illustrate the process of the terminal device performing a state transition based on the first duration and the second duration. This process includes multiple steps.

[0226] Step S1, the network device can broadcast the ephemeris table and beam information of the first satellite.

[0227] Step S2, the terminal device predicts the first duration of leaving the first satellite according to its own location information and the broadcast information.

[0228] Step S3, the first satellite notifies the ephemeris parameters of one or more surrounding satellites through RRC dedicated signaling based on the first duration.

[0229] Step S4, the terminal device predicts multiple durations of these satellites from the current moment to the coverage start moment according to the received ephemeris parameters of one or more satellites. The minimum value of the multiple durations is the second duration. The satellite corresponding to the second duration is the second satellite. Further, the terminal device can also predict the time when one or more satellites' coverage leaves itself to determine the durations of the first time period and the second time period.

[0230] In step S5, the terminal device can determine how to handle the scenario of no network coverage based on the magnitude relationship between the first duration and the second duration.

[0231] Exemplarily, when the first duration is greater than or equal to the second duration, the terminal device performs a handover from the first satellite to the second satellite corresponding to the second duration according to the first condition; when the first duration is less than the second duration, the terminal device transitions from the RRC active state to the RRC idle state.

[0232] As an example, the first condition is related to the handover condition for the terminal device to perform satellite handover and / or the service requirements of the terminal device. The handover conditions for performing satellite handover include factors affecting handover such as signal measurement results.

[0233] As an example, if the first duration is greater than or equal to the second duration, the terminal device can first hand over from the first satellite (source satellite) to the second satellite (target satellite) when the handover condition is met. After the satellite handover is successful, the terminal device can choose whether to enter the RRC idle state within the service area of the second satellite according to the current state of the service.

[0234] As an example, if the first duration is greater than or equal to the second duration and the handover condition is not met, the first satellite can send a handover command to the terminal device to reduce the power consumption of the terminal device caused by continuously performing measurements and sending measurement reports. The terminal device can determine whether to perform a handover from the first satellite to the second satellite according to the first condition.

[0235] Exemplarily, the first condition can be whether the terminal device has service requirements. If the terminal device has service requirements, the terminal device performs a handover from the first satellite to the second satellite. If the terminal device has no service requirements, it can transition from the RRC active state to the RRC idle state. For example, the terminal device can indicate an instruction to leave the RRC connection to the network device, so that the network device believes that the terminal device can be released. Similarly, if the network needs, it can also release the timer configuration to prevent the terminal device from autonomously entering the idle state.

[0236] As an example, if the first duration is less than the second duration, the terminal device can autonomously or according to the indication of the network device transition from the RRC active state to the RRC idle state. When the terminal device leaves or is about to leave the coverage of the first satellite, the terminal device can send the first time information to the network device based on prediction. This information helps the network device effectively utilize resources. If the network device does not expect further uplink and downlink data transmission from the terminal device, the terminal device is released to the RRC idle state.

[0237] Figure 8 The method in is executed by the terminal device. In step S810, the terminal device determines the first duration and the second duration.

[0238] In step S820, it is determined whether the first duration is less than the second duration. If so, step S830 is executed; otherwise, step S840 is executed.

[0239] In step S830, a transition is made from the RRC active state to the RRC idle state. The terminal device can execute this autonomously or according to an indication.

[0240] In step S840, satellite handover is performed according to the first condition.

[0241] As described above in connection with Figure 7 and Figure 8 method embodiments for dealing with discontinuous coverage centered on the terminal device and the network device are respectively introduced. Through these method embodiments, the terminal device can determine the timing to release the RRC connection or be woken up based on the first time information to match the time without network coverage, thereby saving power consumption or ensuring the success rate of communication establishment in the case of discontinuous coverage.

[0242] As can be seen from the foregoing, generally only the terminal device and the access network know the coverage situation of the terminal device, and the core network may not know this coverage situation. However, in Internet of Things or MTC applications, the DRX cycle / eDRX cycle and PSM state of the terminal device in the idle state need to be configured by the core network. Therefore, in the scenario of discontinuous coverage, how to reasonably match the coverage situation of the terminal device with the configuration of the core network is also an issue that needs to be considered.

[0243] To solve the above problems, an embodiment of the present application proposes another method for wireless communication. Through this method, the first time information determined by the terminal device can be used by the core network to determine a first configuration parameter, and this first configuration parameter is used to instruct the terminal device to perform a state transition. It can be seen that the core network takes into account the time information without network coverage when making a configuration, so that a more reasonable energy-saving mode can be configured.

[0244] For ease of understanding, the following specifically describes another method for wireless communication according to an embodiment of the present application in connection with Figure 9 The method shown in Figure 9 is related to the method shown in Figure 7 For the sake of brevity, Figure 7 the term explanations given in

[0245] Figure 9 is written from the perspective of the interaction among the terminal device, the network device, and the core network. The terminal device is currently located within the service area of the first satellite in the NTN. The communication device corresponding to the core network can be a network element or entity in the core network.

[0246] Exemplarily, the communication device corresponding to the core network may include an MME or an AMF. The AMF / MME may determine configuration parameters of modes such as DRX, eDRX, or PSM when the terminal device is in an unreachable state.

[0247] Exemplarily, when the base station is deployed on a satellite, the ground device only includes the core network. In this scenario, the PLMN is the core network.

[0248] See Figure 9 , in step S910, the terminal device sends first time information. The first time information is the first time information determined by the terminal device in Figure 7 . The first time information is related to the first time period and / or the second time period, which will not be elaborated here. It should be understood that the second time period may be the duration of the network coverage loss period or the unavailable period, or may also represent the duration of the terminal device being unreachable.

[0249] From Figure 9 , it can be seen that the terminal device sends the first time information to the network device. In step S920, the network device forwards the first time information to the core network. Regardless of whether the base station is deployed on the first satellite, the network device includes the first satellite that receives the first time information.

[0250] In some embodiments, the base station is deployed on the first satellite and the core network is deployed on the ground. The terminal device sends the first time information to the base station on the first satellite, and the base station forwards the first time information to the core network on the ground.

[0251] In some embodiments, both the base station and the core network are located on the ground. The terminal device sends the first time information to the first satellite, and the first satellite forwards the first time information to the base station or the core network on the ground. The communication device corresponding to the core network communicates with the terminal device through the first satellite.

[0252] As an example, when the terminal device predicts and estimates the first time information, the terminal device may report the time parameters of the first time period and the second time period. After receiving it, the network device may send it to the AMF / MME through a NAS message.

[0253] As an example, the network device may also estimate and predict the first time information of the terminal device based on the location information of the terminal device and the information of other adjacent satellites in the vicinity.

[0254] In step S925, the core network determines the first configuration parameter.

[0255] In some embodiments, the first time information is used by the core network to determine the first configuration parameters of the terminal device. That is, the core network can determine the configuration parameters of the terminal device according to the first time information, namely the first configuration parameters. When the core network configures the parameters of the eDRX configuration and / or PSM configuration for the terminal device according to the first time information, it can ensure that the terminal device is woken up when it is within the satellite signal coverage range, so as to successfully receive signals from the satellite. As an example, when the MME provides timers (such as periodic TAU timers, eDRX mode and PSM mode configurations) to the terminal device, the duration of the unavailable period (no network coverage or the terminal device is unreachable) related to the first time information and the start time of the unavailable period can be considered.

[0256] As an example, the core network can set a caching timer according to the second time period in the first time information. For example, after receiving the first time information, the PLMN can set a corresponding timer T2 according to the predicted and estimated second time period of the terminal device. During the timer T2, if the terminal device needs to be paged, the PLMN will store this information. After the second time period has passed, the PLMN will then send the cached data to the NTN network, and the NTN network will also forward the corresponding information to the terminal device.

[0257] As an example, the duration of the caching timer is set to be greater than one or more DRX cycles or eDRX cycles to avoid the network device paging the terminal device when it is outside the satellite coverage range, resulting in waste of resources.

[0258] As an example, the core network can determine the first mode of the terminal device. The configuration parameters of the first mode are the first configuration parameters.

[0259] In some embodiments, the first mode is any one or more energy-saving modes configured by the core network for the terminal device to perform reasonable energy-saving configuration in the case of discontinuous network coverage and save the power consumption of the terminal device.

[0260] The first mode may include one or more of the following: DRX mode, eDRX mode, and PSM mode. As an example, the first mode may be any one of the above three modes. As an example, the first mode may include the above three modes or any two of the above three modes. For example, in the Internet of Things, the first mode includes eDRX mode and PSM mode.

[0261] In some embodiments, the first mode may be determined according to the recommendation of the terminal device. Exemplarily, the terminal device may indicate its recommended mode in the first time information, or may carry the parameter information of the recommended mode, i.e., the first recommendation parameter, in the first time information. Exemplarily, the terminal device may send the first recommendation parameter after sending the first time information.

[0262] As an example, when the terminal device is in a communication scenario with discontinuous satellite signal coverage, it may determine a suitable DRX mode, eDRX mode, and / or PSM mode for itself according to the first time information. For example, when the second time period is relatively short, that is, when the time when the satellite is not coverable is relatively short, the terminal device is suitable for the DRX mode. For another example, when the second time period is relatively long, that is, when the time when the satellite is not coverable is relatively long, the terminal device is suitable for the eDRX mode. For another example, when the second time period is long, the terminal device is suitable for the PSM mode.

[0263] As an example, the terminal device may also determine a suitable DRX mode, eDRX mode, and / or PSM mode according to the service type. For example, when the service type of the terminal device requires relatively frequent data transmission, it is suitable for the DRX mode. For another example, when the interval of data transmission of the service type of the terminal device is long, it is suitable for the PSM mode.

[0264] In some embodiments, the first configuration parameter may also be determined according to the recommendation parameter of the terminal device. For example, the PLMN network may determine the first configuration parameter according to the first recommendation parameter of the terminal device. Thus, the terminal device and the core network can negotiate appropriate configuration parameters (such as the timer length) for the relevant PSM / eDRX scheme in the case of discontinuous network coverage.

[0265] Exemplarily, in the case of discontinuous coverage in NTN, it is necessary to solve the misalignment between the PTW and the coverage window. The NAS layer between the terminal device and the core network can negotiate relevant parameters to support discontinuous coverage. Exemplarily, the terminal device and the core network can negotiate the configuration of multiple timers to ensure the optimization of the mobility management function and the energy saving of the terminal device.

[0266] As an example, the terminal device may report the recommended DRX, eDRX, PSM, etc. to the core network according to its own service type, and may negotiate with the AMF / MME to support discontinuous coverage. The MME can consider this recommendation when providing a timer to the terminal device. For example, the AMF / MME can configure a variable period or TAU timer, DRX, eDRX, and PSM mode configurations for the terminal device.

[0267] As an example, the terminal device can determine the first recommendation parameter according to the first time information and the service type. The terminal device can forward the first recommendation parameter to the core network through the network device, so that the core network can determine the first configuration parameter. When the core network determines the first configuration parameter according to the first recommendation parameter, it is beneficial to ensure that the terminal device can have good communication quality when communicating based on modes such as eDRX and PSM in the scenario of discontinuous satellite signal coverage, and further reduce the power consumption of the terminal device.

[0268] As an example, the first recommendation parameter includes relevant parameters such as TAU, eDRX, and PSM recommended by the terminal device.

[0269] As an example, the terminal device can send the determined DRX, eDRX configuration, and / or PSM configuration parameters applicable to the discontinuous satellite signal coverage communication scenario to the core network as the reported information. The core network can refer to the DRX, eDRX configuration, and / or PSM configuration parameters recommended by the terminal device to configure the DRX, eDRX configuration, and / or PSM configuration that matches this communication scenario for the terminal device.

[0270] As an example, when the terminal device determines that the applicable mode is the DRX mode, it can determine the recommended parameters of the DRX configuration suitable for this communication scenario. The first recommendation parameter can include the recommended parameters of this DRX configuration, such as the time parameter and timer parameter of TAU.

[0271] As an example, when the terminal device determines that the applicable mode is the eDRX mode, it can determine the recommended parameters of the eDRX configuration suitable for this communication scenario. The first recommendation parameter can include the recommended parameters of this eDRX configuration, such as the eDRX period.

[0272] As an example, when the terminal device determines that the applicable mode is the PSM mode, it can determine the recommended parameters of the PSM configuration suitable for this communication scenario. The first recommendation parameter can include the recommended parameters of this PSM configuration, such as the PSM duration. As an embodiment, the terminal device can suggest directly entering the PSM state in this communication scenario.

[0273] As an example, when the communication scenario determined by the terminal is applicable to both the eDRX mode and the PSM mode, it can determine the recommended parameters of the eDRX configuration and the PSM configuration suitable for this communication scenario. The first recommendation parameter can include these parameters.

[0274] In some embodiments, the first mode can also be determined according to the capabilities of the terminal device. As can be seen from the foregoing, the core network can determine the corresponding first mode according to the capabilities supported by the terminal device, which will not be elaborated here.

[0275] In some embodiments, the first mode may be determined according to the information obtained by any combination of the above-mentioned multiple pieces of information.

[0276] In some embodiments, the first configuration parameter may include any one or more parameters related to the first mode, which are not limited herein. Exemplarily, the first configuration parameter includes new TAU, eDRX, DRX, and PSM timer parameters. Exemplarily, the first configuration parameter may include parameters such as the period, start time, offset value, duration, etc. of the first mode and timer configuration parameters. Exemplarily, the first configuration parameter may be used for the terminal device to execute the first mode.

[0277] As an example, the first configuration parameter may include the time parameters of the second timer and the third timer. The second timer is used to determine the duration for which the terminal device is in the Radio Resource Control (RRC) idle state. The second timer is, for example, the T3324 timer. The third timer is used to determine the duration for which the terminal device is in the PSM state. The third timer is, for example, the T3412 timer. The start time of the second timer and the third timer may be the end moment of the first time period. That is to say, both timers are started when the first time period ends. Therefore, the duration of the third timer is greater than the duration of the second timer. For example, the duration of the third timer is the sum of the duration of the second timer and the PSM state duration.

[0278] As an example, the setting of the second timer may be determined according to the first time period. For example, the start time of the second timer is the end moment of the first time period (the start moment of the second time period). Also, for example, the duration of the second timer may be dynamically adjusted according to the duration of the first time period to ensure that the device matches the unreachable time and the sleep state when not covered by NTN.

[0279] For example, the second timer starts timing from the end of the first time period. When the second timer expires, the terminal device immediately enters the PSM state.

[0280] As an example, when the terminal device directly enters a no-network-coverage scenario in the RRC active state, the duration of the second timer may be adaptively increased, which helps to match the existing energy-saving configuration and the no-network-coverage scenario.

[0281] As an example, the duration of the third timer may be determined according to the second time period to ensure that the end time of the PSM state matches the end time of no-network-coverage or device unreachability, thereby preventing the terminal device from being awakened when there is no network coverage. Herein, the second time period may refer to the entire time period predicted and estimated by the terminal device during which it cannot be covered by the network.

[0282] As an example, the end time of the third timer is not earlier than the end time of the second time period. That is to say, the end time of the third timer can be equal to or later than the end time of the second time period. When the end time of the third timer is the end time of the second time period, the end time of the PSM state can be the end point of the device being unreachable or having no network coverage. When the end time of the third timer is later than the end time of the second time period, the end time of the PSM state can be the same as the original end point.

[0283] As an example, when the end time of the second time period is later than the start time of a TAU cycle, the terminal device remains in the PSM state throughout that TAU cycle.

[0284] In some embodiments, the network device may receive first time information from the terminal device. When the first time information indicates the first time period, the network device may, after the duration of the first time period has elapsed, instruct the terminal device to enter the RRC idle state. Alternatively, the terminal device may autonomously enter the RRC idle state according to the predicted duration of the first time period. Although the terminal device enters the RRC idle state, since it enters a network coverage loss scenario after the first time period, the terminal device cannot receive paging. In this scenario, the duration of the second timer can be reduced so that the terminal device can quickly enter the PSM state. Since the time of the PSM state is increased, power saving can be further achieved.

[0285] As an example, when the second timer is the T3324 timer and the third timer is the T3412 timer, the ratio of the duration of the second timer to the duration of the third timer is less than the first parameter. The first parameter can be A, where 0 < A < 0.5. A is, for example, 0.25.

[0286] For ease of understanding, below, Figure 5 taking the T3324 timer and the T3412 timer in Figure 10 as examples, the configuration parameters of the timers are exemplarily described in combination with

[0287] two examples in Figure 10 . T1 represents the first time period, and T2 represents the second time period. Compared with Figure 5 , in Example 1 and Example 2, the start times of the T3324 timer and the T3412 timer are both advanced to the end time of the first time period. Since the terminal device is in the RRC active state at the end time of the first time period, the start times of both timers are advanced from the original idle state start time to within the active state period.

[0288] Comparing Comparative Example 1 and Example 2, it can be seen that the duration of the T3324 timer in Example 1 is much longer than that of the T3324 timer in Example 2. Therefore, Example 2 can achieve further power saving.

[0289] In Figure 10 , the end time of the T3412 timer is the termination moment of the second time period. It should be noted that the end time of the T3412 timer can also be Figure 10 the original end point of the first figure in

[0290] In some embodiments, when the first mode is the eDRX mode, the first configuration parameter may include the configuration parameter of the eDRX mode. As an example, the first configuration parameter may determine the time parameter of the PTW within each eDRX cycle. The time parameter of the PTW can also be replaced by the actual window of the PTW. The terminal device or the network device can calculate the calculation window of the PTW according to the cycle information sent by the core network, and then adjust the calculation window to determine the actual window of the PTW.

[0291] As an example, the time parameter of the PTW can be determined according to the calculation window of the PTW and the first time information. The calculation window of the PTW refers to the time window determined according to the calculation formulas of PH, PTW_start, and PTW_end mentioned above. Generally, the eDRX cycle may overlap with the second time period, and the positions of PH and PTW_start may also be earlier than the termination moment of the second time period. If PH and PTW_start are determined only according to the existing calculation, the terminal device may start monitoring the PTW during the period without network coverage, resulting in unnecessary power consumption. To solve this problem, when the calculation window of the PTW overlaps with the second time period, the actual window of the PTW can be determined by adjustment.

[0292] As an example, the first configuration parameter may include various parameters for adjusting the PTW calculation window.

[0293] As an example, when the start position of the calculation window of the PTW is within the second time period, the terminal device skips the PTW or part of the PO within the PTW. The terminal device skipping the PTW or PO means that the terminal device does not detect paging on this PTW or PO.

[0294] As an example, when the start position of the calculation window of the PTW is within the second time period, the network device skips the PTW or part of the PO within the PTW. The network device skipping the PTW or PO means that the network device does not page the terminal device on this PTW or PO.

[0295] For example, if the start positions of the calculated PH and PTW are within the second time period, the terminal device (and the network) can skip PH and PTW, or at least some of the POs within the duration of the overlap between the second time period and PTW. Considering that the maximum length of PTW is only 4 superframes (for NB-IoT), once the terminal device skips some or all of the POs in the current PTW and the remaining paging fails to be sent to the terminal device, it waits for the PTW in the next eDRX cycle.

[0296] As an example, when the start position of the calculation window of PTW is within the second time period, the start position of the actual window of PTW is the sum of the start position of the calculation window and the first offset value. The first offset value can be determined according to the duration of the overlapping time period. That is, when the PTW in the eDRX cycle partially overlaps with the second time period, the start position of PTW (PTW_start) is adjusted so that the start position of the PTW in the eDRX cycle aligns with or is after the termination moment of the no-network coverage.

[0297] The following combines Figure 11 to make an exemplary description. Wherein, T2 represents the second time period. In Figure 11 , the terminal device and the core network can calculate the PTW and the offset L (the first offset value) between PTW_start and the termination moment of the second time period. The terminal device can clearly know the duration of the second time period through prediction, and can also know the period of eDRX, the position of the paging superframe, and the relevant parameters of PTW.

[0298] As Figure 11 shown, delay the start position PTW_start of the calculation window of the PTW in the next eDRX cycle by this offset L. L may be greater than the paging superframe. That is, the start position of the actual window of PTW is the position after offsetting the start position of the calculation window by L. Through adjustment, within this eDRX cycle, the PTW is completely within the network coverage time, without wasting resources to initiate paging for unreachable terminal devices, and the terminal device will not lose important paging information. Therefore, the start position PTW_start' of the actual window of PTW can be expressed as:

[0299] PTW_start' = PTW_start + L.

[0300] For another example, the terminal device can adjust the relevant parameters of PTW within each eDRX cycle, that is, the relevant parameters of PTW within each eDRX cycle can change dynamically.

[0301] As an example, when the end position of the calculation window of the PTW is within the second time period, the end position of the actual window of the PTW is the difference between the end position of the calculation window and the second offset value. The second offset value can be determined according to the duration of the overlapping time period. That is, when the PTW in the eDRX cycle partially overlaps with the second time period, adjust the end position (PTW_end) of the PTW so that the end position of the PTW in the eDRX cycle aligns with or before the start time of the network coverage loss.

[0302] The following is an exemplary description in conjunction with Figure 12 where T1 represents the first time period and T2 represents the second time period. In Figure 12 , when the terminal device needs to enter the RRC idle state autonomously or according to the network device notification, it will send the first time information. As described above, the terminal device can predict the time when it leaves the network coverage through the ephemeris parameters sent by the network device and its own location information. Further, after the terminal device obtains the ephemeris parameters of other satellites from the first satellite, it can predict the time when it will be covered by other satellites again, so as to estimate the time period during which it has no network coverage, that is, the second time period. After the terminal device and the core network calculate the PTW and PTW_start, they can adjust the PTW_end in the eDRX cycle in combination with the relevant parameters of the eDRX and the duration of the second time period.

[0303] As Figure 12 shown, the terminal device estimates that it will enter the time of no network coverage (the second time period) after a duration of T1. In the first eDRX cycle, the second time period partially overlaps with the duration of the PTW. The terminal device can determine the overlapping duration t (the second offset value) through the parameters related to the PTW, so as to adjust the PTW_end. Therefore, the end position PTW_end' of the actual window of the PTW can be expressed as:

[0304] PTW_end' = PTW_end - t.

[0305] It can be seen from Figure 12 that since the end position of the PTW is adjusted, the durations of the calculation window PTW1 and the actual window PTW2 are different.

[0306] As an example, when the calculation window of the PTW in the eDRX cycle overlaps with the H-SFN at the end time of the second time period, the terminal device can use offset_PH to adjust the PH so that it aligns with the H-SFN where the end time of the second time period is located.

[0307] It should be noted that although the second time period is a parameter specific to the terminal device, the termination times of the second time periods of multiple terminal devices may be very close. Therefore, in order to allocate PTW_start to different terminal devices (for example, allocate pending paging when resuming coverage), it may still be necessary for the core network to configure different specific offsets for different terminal devices.

[0308] As an example, when the second time period overlaps with the calculation windows of PTW in two adjacent eDRX cycles, the end position of the actual window of PTW in the first eDRX cycle is not later than the start time of the second time period, and the start position of the actual window of PTW in the second eDRX cycle is not earlier than the termination time of the second time period. Considering that the granularity of the second time period may be relatively large (such as minutes or hours), the second time period may overlap with PTW in two adjacent eDRXs.

[0309] The following will be combined with Figure 13 for exemplary illustration. The term explanations carried out in Figure 11 and Figure 12 will not be elaborated again. As shown in Figure 13 , T2 partially overlaps with PTW in two eDRX cycles. The overlapping duration of PTW in the first eDRX cycle and the second time period is t, and the offset between PTW_start in the second eDRX cycle and the termination time of the second time period is L. Since the adjustment of PTW_start or PTW_end occurs within its corresponding eDRX cycle, Figure 13 PTW_start and PTW_end are adjusted simultaneously to avoid the terminal device performing paging detection during the time of no network coverage and save power consumption.

[0310] In some embodiments, the first configuration parameter may include the eDRX cycle. The eDRX cycle can be dynamically adjusted according to the change in the duration of the second time period. As can be seen from the foregoing, discontinuous coverage may occur periodically. The eDRX cycle configured by the core network may be similar to the cycle of network non-coverage. Therefore, during the period of no network coverage, the terminal device is likely to miss PTW or a part of PTW every time, thus affecting the paging effect. To solve this problem, the cycle of eDRX can be dynamically configured and be consistent with the time of the second time period. Optionally, the cycle of eDRX can be dynamically configured according to the change in the length of the second time period.

[0311] As an example, the eDRX cycle is proportional to the duration of the second time period. If the second time period is longer, the eDRX cycle can be configured to be longer accordingly; if the second time period is shorter, the eDRX cycle can be configured to be shorter accordingly.

[0312] Continue to refer toFigure 9 In step S930, the core network sends the first configuration parameter to the network device. In step S940, the terminal device receives the first configuration parameter forwarded by the network device.

[0313] The first configuration parameter can be used for the terminal device to perform state transition. In some embodiments, the state transition performed by the terminal device may include a transition between any two of the following three states: RRC active state, RRC idle state, and PSM state.

[0314] From Figure 9 it can be seen that the core network can determine the first configuration parameter according to the first time information and / or the first recommended parameter of the terminal device, so as to avoid the terminal device performing paging detection during the time without network coverage as much as possible, and also avoid the network device paging the terminal device during the time when the terminal device is unreachable, so as to save the power consumption of the terminal device and the network device.

[0315] As can be seen from the foregoing, the first time information can be determined according to the relevant information of multiple satellites related to the terminal device. Further, the relevant information of the multiple satellites can be carried in one or more of the following information: SIB3, SIB31, SIB32. Based on SIB3, SIB31, and SIB32, the terminal device can estimate whether the remaining coverage time of the cell or satellite is short.

[0316] In some embodiments, SIB32 may include auxiliary information of up to 4 satellites. Due to the mobility and service characteristics of the terminal device, some information in SIB32 may not be relevant to the terminal device. For example, SIB32 notifies that a satellite will arrive within the next 6 hours, while the terminal device does not expect to send data within 8 hours. In this case, the terminal device can request information about the expected coverage availability after 8 hours, and the network device can provide such satellite auxiliary information in a dedicated RRC.

[0317] In some embodiments, when the satellite information in SIB32 is not relevant to the terminal device, the terminal device may request the network device to provide satellite auxiliary information. The satellite auxiliary information includes the relevant information of satellites not included in the current SIB.

[0318] As an example, the terminal device can request the network to provide satellite auxiliary information through a dedicated RRC. The dedicated RRC may include satellites that do not currently belong to SIB32 or other SIBs.

[0319] In some embodiments, the terminal device may receive System Information Blocks (SIBs) broadcast by different Public Land Mobile Networks (PLMNs). Among them, the broadcast SIBs may include SIB3, SIB31, and SIB32, etc. Exemplarily, in a Non-Terrestrial Network (NTN) system with discontinuous coverage, the terminal device may obtain temporary parameters and coverage parameters from the currently or previously received SystemInformationBlockType32, SystemInformationBlockType31, or SystemInformationBlockType3. Based on the temporary parameters, the terminal device may determine whether it is outside the radio signal coverage. That is, the terminal device may determine whether it is currently in a scenario without network coverage. If the terminal device is in a scenario without network coverage, in response, the terminal device may deactivate the access stratum function to save power.

[0320] After the second time period, how the terminal device operates is also an issue that needs to be considered.

[0321] In some embodiments, after the second time period, the terminal device may receive the data cached by the core network. For example, when the terminal device does not need to re-register with the PLMN network, the terminal device may receive the data cached by the core network during the cache timer.

[0322] In some embodiments, after the second time period, the terminal device may enter the automatic network selection mode. For example, when the terminal device needs to re-register with the PLMN network, the terminal device may enter the automatic network selection mode.

[0323] In some embodiments, when the terminal device is in a scenario without network coverage or during an unreachable time, the access stratum (AS) layer of the terminal device has been disconnected, but the non-access stratum (NAS) layer remains connected. In certain scenarios, when the terminal device is in the Power Saving Mode (PSM) during the second time period, although the terminal device no longer receives paging messages, the terminal device is still registered in the network. When the UE context reserved by the NTN network and the PLMN network is consistent with the information for the terminal device to re-establish the Radio Resource Control (RRC) connection, the terminal device does not need to re-register with the network after waking up from the sleep state and can perform data transmission and reception. That is, although the terminal device is in an unreachable state, it is still registered in the initially selected PLMN network.

[0324] In some embodiments, the UE context reserved by the NTN network and the PLMN network may be inconsistent with the information for the terminal device to re-establish the RRC connection, or the terminal device needs to re-select the PLMN network. In this scenario, the terminal device re-registers with the PLMN.

[0325] As an example, the process of PLMN re-registration is as follows: The terminal device first selects the PLMN that it has registered with most recently, then selects the PLMN service with a higher priority, and then selects a PLMN from the list of PLMNs (equivalent PLMN, EPLMN) at the same level as the previous one, and attempts to register with the selected PLMN. It should be noted that the terminal device may postpone the attempt to obtain service on a PLMN with a higher priority because the access stratum is deactivated due to discontinuous coverage.

[0326] As an example, the terminal device can be configured in the automatic network selection mode. In the automatic network selection mode in NTN, the NB-IoT terminal device can make selections according to the sequence between the visited PLMN (VPLMN) and the HPLMN / equivalent home PLMN (EHPLMN).

[0327] As an example, the terminal device can register with the VPLMN and obtain service on the VPLMN.

[0328] As an example, the terminal device can start a timer according to the configured automatic network selection mode and make periodic attempts to obtain service on the HPLMN or EHPLMN. When the access stratum of the terminal device is deactivated due to discontinuous coverage in NTN, it is necessary to redefine the behavior of periodically attempting to access the HPLMN or EHPLMN with a higher priority.

[0329] For ease of understanding, taking the core network of the NTN system as a PLMN as an example, combined with Figure 14 and Figure 15 an exemplary description is given of the method for the terminal device and the PLMN to negotiate the energy-saving configuration during the period of no network coverage. The dotted line in the figure represents a possible embodiment.

[0330] Figure 14 and Figure 15 are all written from the perspective of the interaction among the terminal device, NTN, and PLMN. In Figure 14 , the PLMN will set a timer T2 for caching the data to be sent. In Figure 15 , the PLMN does not set a timer.

[0331] See Figure 14 , in step S1401, the terminal device enters the automatic network selection mode.

[0332] In step S1402, the terminal device completes PLMN registration. After the terminal device successfully selects a PLMN, it completes the registration and proceeds with the normal communication process.

[0333] In step S1403, the NTN system broadcasts and sends SIB3, SIB31, and SIB32.

[0334] In step S1404, the terminal device establishes a communication connection with the NTN system. The terminal device can know the ephemeris parameters of the current satellite covering itself and the ephemeris parameters of several adjacent satellites around it based on the broadcast.

[0335] In step S1405, the terminal device predicts the out-of-coverage time. The out-of-coverage time information is the first time period and the second time period related to the first time information. The terminal device can perform prediction and estimation based on its current location information or triggered by the network device.

[0336] In step S1406, the terminal device reports the first time information to the NTN network. The terminal device can report the coverage information through a dedicated RRC signaling message and send it to the NTN network.

[0337] In step S1407, the NTN network reports the first time information to the PLMN network. Based on the first time information, the PLMN network can determine that the terminal device will soon leave the network coverage area after time T1.

[0338] In step S1408, the terminal device reports the first recommended parameters to the NTN network. The terminal device can report parameters such as DRX, eDRX, and PSM recommended to the core network according to its service type, so as to negotiate with the AMF / MME to support the configuration of discontinuous coverage.

[0339] In step S1409, the NTN network reports the first recommended parameters to the PLMN network.

[0340] In step S1410, the PLMN network determines the first configuration parameters and sets a timer T2. The PLMN network can update and set the information of each DRX or eDRX cycle according to the first time information and the first recommended parameters, and update the timer information such as T3324 and T3412. The timer T2 is a buffer timer. The first configuration parameters can include configuration parameters such as the periodic TAU timer, DRX, eDRX, and PSM modes. For example, the AMF / MME provides the timer configuration to the terminal device after comprehensive consideration.

[0341] In steps S1411 and S1412, the PLMN network sends the first configuration parameters to the NTN network, and the NTN network sends the first configuration parameters to the terminal device. The terminal device and the NTN network can calculate the PTW parameters within each eDRX cycle based on this information.

[0342] In step S1413, the terminal device enters the DRX and eDRX cycles.

[0343] In step S1414, the terminal device enters an area without network coverage. During the first time period (T1), the terminal device autonomously or according to an indication enters the RRC idle state. After T1, the terminal device enters the scenario of no network coverage according to the predicted time.

[0344] In step S1415, the PLMN network starts timer T2 and caches data.

[0345] In step S1416, the terminal device enters the network coverage scenario after the second time period (T2).

[0346] In step S1417, the PLMN network determines that timer T2 has expired.

[0347] In steps S1418 and S1419, the PLMN network sends the cached data to the NTN network, and the NTN network forwards it to the terminal device.

[0348] Different from Figure 14 is that Figure 15 in, the PLMN does not set timer T2, and the terminal device re-registers with the PLMN after entering the area without network coverage. For the sake of brevity, Figure 14 the process explanation carried out in Figure 15 will not be elaborated herein.

[0349] Refer to Figure 15 , steps S1501 to S1509, steps S1511 to S1514 will not be elaborated herein.

[0350] In step S1510, the PLMN network only determines the first configuration parameter and does not set a timer. The first recommended parameter of the terminal device can enable the negotiation of energy-saving configuration between the terminal device and the core network.

[0351] In step S1515, the terminal device enters the automatic network selection mode.

[0352] As described above in conjunction with Figures 1 to 15 , the method embodiments of the present application have been described in detail. Next, in conjunction with Figures 16 to 18 , the device embodiments of the present application will be described in detail. It should be understood that the description of the device embodiments corresponds to the description of the method embodiments, and therefore, for the parts not described in detail, reference may be made to the previous method embodiments.

[0353] Figure 16 is a schematic block diagram of a device for wireless communication according to an embodiment of the present application. The device 1600 may be any of the terminal devices described above. Figure 16 The device 1600 shown in

[0354] A determination unit 1610, which can be used to determine first time information.

[0355] A first execution unit 1620, which can be used to perform a transition from a first state to a second state based on the first time information; wherein, the first time information is related to a first time period and / or a second time period, the first time period is the time period from the current moment to the starting moment when the terminal device enters a network coverage - free area, and the second time period is the duration of the network coverage - free period.

[0356] Optionally, the first state is the RRC idle state or the PSM state, and the first time information further includes a third time period during which the first serving cell provides services to the terminal device, and the duration of the third time period is used by the terminal device to determine whether to establish an RRC connection with the first serving cell.

[0357] Optionally, the first state is the RRC active state, the second state is the RRC idle state, and the apparatus 1600 further includes a first sending unit, which can be used to send the first time information to a network device. A first receiving unit, which can be used to receive a first indication information sent by the network device, and the first indication information includes the transition timing for the terminal device to transition from the RRC active state to the RRC idle state.

[0358] Optionally, the first state is the RRC active state, the second state is the RRC idle state, and the apparatus 1600 further includes: a processing unit, which can be used to start a first timer when sending the first time information, and the first timer is used by the terminal device to determine the transition timing from the RRC active state to the RRC idle state.

[0359] Optionally, the apparatus 1600 further includes a second sending unit, which can be used to send second indication information to the network device, and the second indication information indicates that the RRC idle state is the preferred state; the first execution unit 1620 is further used to transition from the RRC active state to the RRC idle state when the first timer expires.

[0360] Optionally, the transition timing is related to one or more of the following information: the service type of the terminal device, the service priority of the terminal device, and the downlink data of the network device.

[0361] Optionally, the transition timing is determined according to a first factor δ(x,y), where x is related to the service type, y is related to the service priority, and 0 < δ(x,y) ≤ 1.

[0362] Optionally, the fourth time period between the transition timing and the current moment is the product of the first time period and a second factor, and the second factor is greater than 0 and less than 1.

[0363] Optionally, the first state is the PSM state, and the determination unit is further used to determine the wake - up timing based on a first period; wherein, the first period is determined according to the first time period and the second time period.

[0364] Optionally, the terminal device is located within the service area of the first satellite in the NTN at the current moment.

[0365] Optionally, the first time information is related to one or more of the following: the location information of the terminal device; the relative location information between the terminal device and the first satellite; and the related information of multiple satellites related to the terminal device; wherein, the multiple satellites include the first satellite, and the related information of the multiple satellites includes at least one of the ephemeris information of the multiple satellites, the location information of the multiple satellites, the beam information of the multiple satellites, and the time information for the multiple satellites to provide services to the terminal device.

[0366] Optionally, the relative location information includes the elevation angle of the terminal device relative to the first satellite, and / or the distance between the terminal device and the edge of the service area.

[0367] Optionally, the apparatus 1600 further includes a third sending unit, which can be used to send the first time information when the system information block includes the beam information of any satellite among the multiple satellites.

[0368] Optionally, the first satellite is one of the multiple satellites related to the terminal device, the multiple satellites further include one or more satellites other than the first satellite, the first time period is determined according to the first duration and the second duration, the first duration is the duration between the current moment and the moment when the terminal device leaves the service area, and the second duration is the minimum value among one or more durations between the current moment and one or more moments when one or more satellites start to provide services to the terminal device respectively.

[0369] Optionally, the apparatus 1600 further includes a second execution unit, which is used to perform a handover from the first satellite to the second satellite corresponding to the second duration according to the first condition when the first duration is greater than or equal to the second duration; the first execution unit 1620 is further used to switch from the RRC active state to the RRC idle state when the first duration is less than the second duration.

[0370] Optionally, the first condition is related to the handover condition for the terminal device to perform satellite handover and / or the service requirements of the terminal device.

[0371] Optionally, the first time information is carried in one or more of the following: the auxiliary information of the terminal device, the downlink channel quality report, and the access stratum release assistance indication.

[0372] Optionally, the first execution unit 1620 is further used to switch from the RRC active state to the RRC idle state after triggering a radio link failure N times when the actual time when the terminal device enters a network coverage-free area is earlier than the time indicated by the first time information, where N is a natural number greater than or equal to 1.

[0373] Figure 17 It is a schematic block diagram of another device for wireless communication according to an embodiment of the present application. The device 1700 may be any one of the network devices described above. Figure 17 The illustrated device 1700 includes a determination unit 1710 and an indication unit 1720.

[0374] The determination unit 1710 is configured to determine first time information.

[0375] The indication unit 1720 is configured to, based on the first time information, instruct the terminal device to perform a transition from a first state to a second state; wherein, the first time information is related to a first time period and / or a second time period, the first time period is the time period from the current moment to the starting moment when the terminal device enters a network coverage - free area, and the second time period is the duration of the network coverage - free period.

[0376] Optionally, the first state is the RRC idle state or the PSM state, and the first time information further includes a third time period during which the first serving cell provides services to the terminal device, and the duration of the third time period is used by the terminal device to determine whether to establish an RRC connection with the first serving cell.

[0377] Optionally, the first state is the RRC active state, the second state is the RRC idle state, and the device 1700 further includes a first receiving unit configured to receive the first time information sent by the terminal device; and a sending unit configured to send first indication information to the terminal device, where the first indication information includes the transition timing for the terminal device to transition from the RRC active state to the RRC idle state.

[0378] Optionally, the first state is the RRC active state, the second state is the RRC idle state, and the device 1700 further includes a second receiving unit configured to receive second indication information sent by the terminal device, where the second indication information indicates that the RRC idle state is the preferred state, and the second indication information is used by the terminal device to determine the transition timing from the RRC active state to the RRC idle state according to a first timer.

[0379] Optionally, the transition timing is related to one or more of the following information: the service type of the terminal device, the service priority of the terminal device, and the downlink data of the network device.

[0380] Optionally, the transition timing is determined according to a first factor δ(x,y), where x is related to the service type, y is related to the service priority, and 0 < δ(x,y) ≤ 1.

[0381] Optionally, the fourth time period between the transition timing and the current moment is the product of the first time period and a second factor, and the second factor is greater than 0 and less than 1.

[0382] Optionally, the network device includes a first satellite in the NTN, and the terminal device is located within the service area of the first satellite at the current moment.

[0383] Optionally, the first time information is related to one or more of the following: the location information of the terminal device; the relative position information between the terminal device and the first satellite; and the related information of multiple satellites related to the terminal device; wherein, the multiple satellites include the first satellite, and the related information of the multiple satellites includes at least one of the ephemeris information of the multiple satellites, the location information of the multiple satellites, the beam information of the multiple satellites, and the time information for the multiple satellites to provide services to the terminal device.

[0384] Optionally, the relative position information includes the elevation angle of the terminal device relative to the first satellite, and / or, the distance between the terminal device and the edge of the service area.

[0385] Optionally, the apparatus 1700 further includes a third receiving unit, which can be used to receive the first time information when the system information block includes the beam information of any one of the multiple satellites.

[0386] Optionally, the first satellite is one of the multiple satellites related to the terminal device, the multiple satellites further include one or more satellites other than the first satellite, the first time period is determined according to the first duration and the second duration, the first duration is the duration between the current moment and the moment when the terminal device leaves the service area, and the second duration is the minimum value of one or more durations between the current moment and one or more moments when one or more satellites start to provide services to the terminal device.

[0387] Optionally, the first time information is carried in one or more of the following: the auxiliary information of the terminal device, the downlink channel quality report, and the access stratum release assistance indication.

[0388] Figure 18 The following shows a schematic structural diagram of a communication apparatus according to an embodiment of the present application. Figure 18 The dotted lines therein indicate that the unit or module is optional. The apparatus 1800 can be used to implement the method described in the above method embodiment. The apparatus 1800 can be a chip, a terminal device, or a network device.

[0389] The device 1800 may include one or more processors 1810. The processor 1810 can support the device 1800 to implement the methods described in the foregoing method embodiments. The processor 1810 can be a general-purpose processor or a dedicated processor. For example, the processor can be a central processing unit (CPU). Alternatively, the processor can also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc.

[0390] The device 1800 may also include one or more memories 1820. A program is stored on the memory 1820, and the program can be executed by the processor 1810, so that the processor 1810 executes the methods described in the foregoing method embodiments. The memory 1820 can be independent of the processor 1810 or integrated in the processor 1810.

[0391] The device 1800 may also include a transceiver 1830. The processor 1810 can communicate with other devices or chips through the transceiver 1830. For example, the processor 1810 can send and receive data with other devices or chips through the transceiver 1830.

[0392] An embodiment of the present application also provides a computer-readable storage medium for storing a program. The computer-readable storage medium can be applied to the terminal device or network device provided in the embodiments of the present application, and the program enables the computer to execute the methods executed by the terminal device or network device in various embodiments of the present application.

[0393] The computer-readable storage medium can be any available medium readable by a computer or a data storage device such as a server, a data center, etc. that includes one or more integrated available media. The available medium can be a magnetic medium (for example, a floppy disk, a hard disk, a magnetic tape), an optical medium (for example, a digital video disc (DVD)), or a semiconductor medium (for example, a solid state disk (SSD)), etc.

[0394] An embodiment of the present application also provides a computer program product. The computer program product includes a program. The computer program product can be applied to the terminal device or network device provided by the embodiments of the present application, and the program enables the computer to execute the methods performed by the terminal or network device in the various embodiments of the present application.

[0395] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the processes or functions described in the embodiments of the present application are generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from a website, computer, server, or data center to another website, computer, server, or data center by wire (such as coaxial cable, fiber optic, digital subscriber line (DSL)) or wirelessly (such as infrared, wireless, microwave, etc.).

[0396] An embodiment of the present application also provides a computer program. The computer program can be applied to the terminal device or network device provided by the embodiments of the present application, and the computer program enables the computer to execute the methods performed by the terminal or network device in the various embodiments of the present application.

[0397] In the present application, the terms "system" and "network" can be used interchangeably. Additionally, the terms used in the present application are only for explaining the specific embodiments of the present application and are not intended to limit the present application. The terms "first", "second", "third", and "fourth", etc. in the specification, claims, and drawings of the present application are used to distinguish different objects and not to describe a specific order. Furthermore, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion.

[0398] In the embodiments of the present application, the "indication" mentioned can be a direct indication, an indirect indication, or a representation of an associated relationship. For example, A indicates B, which can mean that A directly indicates B. For example, B can be obtained through A; it can also mean that A indirectly indicates B. For example, A indicates C, and B can be obtained through C; it can also mean that there is an associated relationship between A and B.

[0399] In the embodiments of the present application, the term "corresponding" may indicate a direct or indirect corresponding relationship between two entities, or may indicate an associated relationship between them, or may be a relationship such as indication and being indicated, configuration and being configured, etc.

[0400] In the embodiments of the present application, "predefined" or "preconfigured" can be implemented by pre-saving corresponding codes, tables or other means that can be used to indicate relevant information in a device (for example, including a terminal device and a network device). The present application does not limit its specific implementation manner. For example, predefined can refer to what is defined in a protocol.

[0401] In the embodiments of the present application, the "protocol" may refer to a standard protocol in the communication field. For example, it may include the LTE protocol, the NR protocol, and related protocols applied to future communication systems. The present application does not limit this.

[0402] In the embodiments of the present application, determining B based on A does not mean determining B only based on A. B can also be determined based on A and / or other information.

[0403] The term "and / or" in the embodiments of the present application is merely a description of the associated relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0404] In the embodiments of the present application, the magnitudes of the sequence numbers of the above processes do not mean the order of execution. The order of execution of each process should be determined by its function and internal logic, and should not impose any limitation on the implementation process of the embodiments of the present application.

[0405] In several embodiments provided by the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division. In actual implementation, there can be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed coupling or direct coupling or communication connection between each other can be through some interfaces. The indirect coupling or communication connection of the device or unit can be in an electrical, mechanical or other form.

[0406] The unit described as a separation component may or may not be physically separated. The component shown as a unit may or may not be a physical unit, that is, it may be located in one place or may be distributed over multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0407] In addition, each functional unit in various embodiments of the present application may be integrated into one processing unit, may exist as individual physical units, or two or more units may be integrated into one unit.

[0408] As described above, the above are only specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed in the present application can easily think of changes or substitutions, which should be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for wireless communication, characterized in that, Including: The terminal device determines the first time information; When the system information block SIB includes the beam information of any one of the multiple satellites related to the terminal device, the terminal device sends the first time information; Based on the first time information, the terminal device performs a transition from a first state to a second state; Wherein, the first time information is related to a first time period and a second time period. The first time period is the time period from the current moment to the starting moment when the terminal device enters a network coverage-free area, and the second time period is the continuous time period of the network coverage-free area; the SIB is SIB32. When the SIB32 contains the beam information of the serving satellite, the cell corresponding to the serving satellite supports discontinuous coverage; the first state is the radio resource control (RRC) idle state or the power saving mode (PSM) state. The first time information further includes a third time period, and the third time period is the remaining duration for the first serving cell to provide services to the terminal device. The remaining duration is used for the terminal device to determine whether to establish an RRC connection with the first serving cell, and the second state is one of the RRC active state, the RRC idle state, and the PSM state.

2. The method according to claim 1, characterized in that, The first state is the PSM state, and the method further includes: The terminal device determines the wake-up time based on a first period; Wherein, the first period is determined according to the first time period and the second time period.

3. The method according to claim 1 or 2, characterized in that, The terminal device is within the service area of the first satellite in the non-terrestrial network (NTN) at the current moment.

4. The method according to claim 3, characterized in that, The first time information is related to one or more of the following information: The location information of the terminal device; The relative position information between the terminal device and the first satellite; and The relevant information of the multiple satellites; Wherein, the multiple satellites include the first satellite, and the relevant information of the multiple satellites includes at least one of the ephemeris information of the multiple satellites, the location information of the multiple satellites, the beam information of the multiple satellites, and the time information for the multiple satellites to provide services to the terminal device.

5. The method according to claim 4, wherein The relative position information includes the elevation angle of the terminal device relative to the first satellite, and / or, the distance between the terminal device and the edge of the service area.

6. The method according to claim 3, wherein The first satellite is one of the multiple satellites related to the terminal device. The multiple satellites further include one or more satellites other than the first satellite. The first time period is determined according to a first duration and a second duration. The first duration is the duration between the current moment and the moment when the terminal device leaves the service area, and the second duration is the minimum value of one or more durations between the current moment and one or more moments when the one or more satellites start to provide services to the terminal device.

7. The method according to claim 6, wherein The method further includes: When the first duration is greater than or equal to the second duration, the terminal device performs a handover from the first satellite to the second satellite corresponding to the second duration according to a first condition; When the first duration is less than the second duration, the terminal device converts from the RRC active state to the RRC idle state.

8. The method according to claim 7, wherein The first condition is related to the handover condition for the terminal device to perform satellite handover and / or the service requirements of the terminal device.

9. The method according to claim 1 or 2, characterized in that The first time information is carried in one or more of the following: the auxiliary information of the terminal device, the downlink channel quality report, and the access stratum release assistance indication.

10. The method according to claim 1 or 2, characterized in that, The method further includes: When the actual time when the terminal device enters a network coverage - free area is earlier than the time indicated by the first time information, the terminal device switches from the RRC active state to the RRC idle state after triggering a radio link failure N times, where N is a natural number greater than or equal to 1.

11. A method for wireless communication, characterized in that, including: When the system information block SIB includes the beam information of any one of multiple satellites related to the terminal device, the network device receives the first time information; Based on the first time information, the network device instructs the terminal device to perform a conversion from a first state to a second state; wherein, the first time information is related to a first time period and a second time period. The first time period is the time period from the current moment to the start moment when the terminal device enters a network coverage - free area, and the second time period is the duration of the network coverage - free area; the SIB is SIB32. When the SIB32 contains the beam information of the serving satellite, the cell corresponding to the serving satellite supports discontinuous coverage; the first state is the radio resource control (RRC) idle state or the power saving mode (PSM) state. The first time information further includes a third time period, and the third time period is the remaining duration for the first serving cell to provide services to the terminal device. The remaining duration is used for the terminal device to determine whether to establish an RRC connection with the first serving cell, and the second state is one of the RRC active state, the RRC idle state, and the PSM state.

12. The method according to claim 11, wherein The network device includes a first satellite in the non - terrestrial network (NTN), and the terminal device is located within the service area of the first satellite at the current moment.

13. The method according to claim 12, wherein The first time information is related to one or more of the following: the location information of the terminal device; the relative position information between the terminal device and the first satellite; and the relevant information of the multiple satellites; wherein, the multiple satellites include the first satellite, and the relevant information of the multiple satellites includes at least one of the ephemeris information of the multiple satellites, the position information of the multiple satellites, the beam information of the multiple satellites, and the time information for the multiple satellites to provide services to the terminal device.

14. The method according to claim 13, wherein The relative position information includes the elevation angle of the terminal device relative to the first satellite and / or the distance between the terminal device and the edge of the service area.

15. The method according to claim 12, wherein The first satellite is one of a plurality of satellites related to the terminal device. The plurality of satellites further includes one or more satellites other than the first satellite. The first time period is determined according to a first duration and a second duration. The first duration is the duration between the current moment and the moment when the terminal device leaves the service area. The second duration is the minimum value among one or more durations between the current moment and one or more moments when the one or more satellites start to provide services to the terminal device.

16. The method according to claim 11, wherein The first time information is carried in one or more of the following information: auxiliary information of the terminal device, downlink channel quality report, access stratum release assistance indication.

17. A device for wireless communication, characterized in that, The device is a terminal device, and the device includes: a determination unit, configured to determine first time information; a third transmission unit, configured to transmit the first time information when the system information block SIB includes beam information of any satellite among the plurality of satellites related to the terminal device; a first execution unit, configured to perform a transition from a first state to a second state based on the first time information; wherein, the first time information is related to a first time period and a second time period. The first time period is the time period from the current moment to the starting moment when the terminal device enters an area without network coverage. The second time period is the duration of the area without network coverage. The SIB is SIB32. When the SIB32 contains beam information of the serving satellite, the cell corresponding to the serving satellite supports discontinuous coverage. The first state is the radio resource control (RRC) idle state or the power saving mode (PSM) state. The first time information further includes a third time period, and the third time period is the remaining duration for the first serving cell to provide services to the terminal device. The remaining duration is used for the terminal device to determine whether to establish an RRC connection with the first serving cell. The second state is one of the RRC active state, the RRC idle state, and the PSM state.

18. The device according to claim 17, wherein The first state is the PSM state, and the determination unit is further configured to determine the wake-up timing based on a first period. Wherein, the first period is determined according to the first time period and the second time period.

19. The device according to claim 17 or 18, characterized in that The terminal device is within the service area of the first satellite in the non-terrestrial network (NTN) at the current moment.

20. The device according to claim 19, wherein The first time information is related to one or more of the following information: the location information of the terminal device; the relative position information between the terminal device and the first satellite; and the related information of the plurality of satellites; wherein, the plurality of satellites includes the first satellite, and the related information of the plurality of satellites includes at least one of the ephemeris information of the plurality of satellites, the location information of the plurality of satellites, the beam information of the plurality of satellites, and the time information for the plurality of satellites to provide services to the terminal device.

21. The device according to claim 20, characterized in that, The relative position information includes the elevation angle of the terminal device relative to the first satellite, and / or, the distance between the terminal device and the edge of the service area.

22. The device according to claim 19, characterized in that, The first satellite is one of a plurality of satellites associated with the terminal device. The plurality of satellites further includes one or more satellites other than the first satellite. The first time period is determined based on a first duration and a second duration. The first duration is the duration between the current moment and the moment when the terminal device leaves the service area. The second duration is the minimum value among one or more durations between the current moment and one or more moments when the one or more satellites start providing services to the terminal device respectively.

23. The device according to claim 22, characterized in that, The apparatus further includes: A second execution unit, configured to perform a handover from the first satellite to a second satellite corresponding to the second duration according to a first condition when the first duration is greater than or equal to the second duration. The first execution unit is further configured to perform a transition from the RRC active state to the RRC idle state when the first duration is less than the second duration.

24. The device according to claim 23, characterized in that, The first condition is related to a handover condition for the terminal device to perform satellite handover and / or the service requirements of the terminal device.

25. The device according to claim 17 or 18, characterized in that, The first time information is carried in one or more of the following: the auxiliary information of the terminal device, the downlink channel quality report, and the access stratum release assistance indication.

26. The device according to claim 17 or 18, characterized in that, The first execution unit is further configured to perform a transition from the RRC active state to the RRC idle state after triggering a radio link failure N times when the actual time when the terminal device enters a network coverage-free area is earlier than the time indicated by the first time information, where N is a natural number greater than or equal to 1.

27. A device for wireless communication, characterized in that, The apparatus is a network device, and the apparatus includes: A third receiving unit, configured to receive first time information when the system information block SIB includes beam information of any one of a plurality of satellites associated with the terminal device. An indication unit, configured to indicate the terminal device to perform a transition from a first state to a second state based on the first time information. Wherein, the first time information is related to a first time period and a second time period. The first time period is the time period from the current moment to the starting moment when the terminal device enters a network coverage-free area. The second time period is the duration of the network coverage-free area. The SIB is SIB32. When the SIB32 includes the beam information of the serving satellite, the cell corresponding to the serving satellite supports discontinuous coverage. The first state is the radio resource control RRC idle state or the power saving mode PSM state. The first time information further includes a third time period, and the third time period is the remaining duration for the first serving cell to provide services to the terminal device, and the remaining duration is used for the terminal device to determine whether to establish an RRC connection with the first serving cell. The second state is one of the RRC active state, the RRC idle state, and the PSM state.

28. The device according to claim 27, wherein The network device includes a first satellite in the non-terrestrial network NTN. The terminal device is within the service area of the first satellite at the current moment.

29. The device according to claim 28, wherein The first time information is related to one or more of the following: The location information of the terminal device; The relative position information between the terminal device and the first satellite; and The relevant information of the plurality of satellites; Among them, the multiple satellites include the first satellite, and the related information of the multiple satellites includes at least one of the ephemeris information of the multiple satellites, the position information of the multiple satellites, the beam information of the multiple satellites, and the time information for which the multiple satellites provide services to the terminal device.

30. The device according to claim 29, characterized in that, The relative position information includes the elevation angle of the terminal device relative to the first satellite and / or the distance between the terminal device and the edge of the service area.

31. The device according to claim 28, characterized in that, The first satellite is one of the multiple satellites related to the terminal device. The multiple satellites further include one or more satellites other than the first satellite. The first time period is determined according to a first duration and a second duration. The first duration is the duration between the current moment and the moment when the terminal device leaves the service area. The second duration is the minimum value among one or more durations between the current moment and one or more moments when the one or more satellites start to provide services to the terminal device.

32. The device according to claim 27, wherein, The first time information is carried in one or more of the following information: the auxiliary information of the terminal device, the downlink channel quality report, and the access stratum release assistance indication.

33. A communication device, characterized in that, It includes a memory and a processor. The memory is used to store a program, and the processor is used to call the program in the memory to execute the method according to any one of claims 1-16.

34. A communication device, characterized in that, It includes a processor for calling a program from a memory to execute the method according to any one of claims 1-16.

35. A chip, characterized in that, It includes a processor for calling a program from a memory so that the device installed with the chip executes the method according to any one of claims 1-16.

36. A computer-readable storage medium, characterized in that, A program is stored thereon, and the program causes a computer to execute the method according to any one of claims 1-16.

37. A computer program product, characterized in that, It includes a program that causes a computer to execute the method according to any one of claims 1-16.

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