Paging for non-terrestrial networks

Abstract

Techniques for paging a user terminal (UT) in a non-terrestrial network (NTN) are disclosed, which may define multiple NTN tracking areas (TAs). Each NTN TA served by one or more satellite beams may be mobile or may be a geographic area. The UT may report its location before changing its connection state with the NTN, and may also update its location whenever it moves a threshold distance from a previously reported location. The NTN may estimate the current location of the UT based on the last reported location and other factors including UT mobility. The NTN may determine the UT TA as the NTN TA corresponding to the current location, and may page the UT via one or more satellite beams corresponding to the UT TA.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This patent application claims the benefit of U.S. Provisional Patent Application No. 62 / 867,215, filed on June 26, 2019, entitled “PAGING FOR NON-TERRESTRIAL NETWORKS,” and U.S. Non-Provisional Patent Application No. 16 / 909,793, filed on June 23, 2020, entitled “PAGING FOR NON-TERRESTRIAL NETWORKS,” both of which are assigned to their assignees and are expressly incorporated herein by reference in their entireties. Technical Field

[0003] Various aspects described herein relate generally to wireless networks, and more particularly, to paging in non-terrestrial networks (NTNs). Background Art

[0004] Wireless communication systems have evolved over many generations, including first generation analog wireless telephone service (1G), second generation (2G) digital wireless telephone service (including transitional 2.5G and 2.75G networks), third generation (3G) high speed data, wireless service with Internet capabilities, and fourth generation (4G) service (e.g., Long Term Evolution (LTE) or WiMax). Currently, there are many different types of wireless communication systems in use, including cellular and personal communications service (PCS) systems. Examples of known cellular systems include the cellular analog Advanced Mobile Phone System (AMPS), and digital cellular systems based on code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), global system for mobile access (GSM) variants of TDMA, and the like.

[0005] The fifth generation (5G) mobile standard calls for higher data transmission speeds, a greater number of connections, and better coverage, among other improvements. According to the Next Generation Mobile Network Alliance, the 5G standard is designed to provide data rates of tens of megabits per second to each of tens of thousands of users, with 1 gigabit per second provided to dozens of workers on an office floor. It is expected to support hundreds of thousands of simultaneous connections in order to support large sensor deployments. Therefore, one goal is to significantly improve the spectral efficiency of 5G mobile communications. Another goal is to improve signaling efficiency and substantially reduce latency.

[0006] Paging is a feature available in most, if not all, wireless communication systems. It is desirable to ensure that a target user equipment (UE) can be paged at any time and anywhere with minimal delay. In order to enable paging of a UE, the network may have some knowledge of an estimate of the UE's current location, even if the UE is not actively connected to the network. For terrestrial networks, the prior art uses a tracking area (TA) to define a paging area in which the UE is estimated to be located, and paging messages are sent from base stations (e.g., eNBs, gNBs) within the TA. However, for satellite-based networks, such as networks in low earth orbit (LEO) and / or medium earth orbit (MEO) satellites, the prior art may be insufficient because such satellites are constantly moving relative to the surface of the Earth. Summary of the invention

[0007] This Summary identifies features of some example aspects and is not an exclusive or exhaustive description of the disclosed subject matter. Whether a feature or aspect is included in or omitted from this Summary is not intended to indicate the relative importance of these features. Additional features and aspects are described and will become apparent to those skilled in the art after reading the following Detailed Description and viewing the accompanying drawings that form a part thereof.

[0008] One aspect relates to a method performed by a network node of a non-terrestrial network (NTN). The method may include determining a last area of ​​a user terminal (UT). The method may also include determining a UT tracking area (TA) based on the last area. The UT TA may be a non-terrestrial network tracking area (NTN TA) in which the UT is currently located. The UT TA may be one of a plurality of NTNTAs. The method may also include paging the UT using one or more satellite beams corresponding to the UT TA.

[0009] Another aspect relates to a network node of a non-terrestrial network (NTN) disclosed. The network node may include a memory and at least one processor coupled to the memory. The memory and the at least one processor may be configured to determine a last area of ​​a user terminal (UT). The memory and the at least one processor may also be configured to determine a UT tracking area (TA) based on the last area. The UT TA may be a non-terrestrial network tracking area (NTN TA) in which the UT is currently located. The UT TA may be one of a plurality of NTN TAs. The memory and the at least one processor may also be configured to page the UT using one or more satellite beams corresponding to the UT TA.

[0010] Another exemplary network node of a non-terrestrial network (NTN) is disclosed. The network node may include means for determining a last area of ​​a user terminal (UT). The network node may also include means for determining a UT tracking area (TA) based on the last area. The UT TA may be a non-terrestrial network tracking area (NTN TA) in which the UT is currently located. The network node may also include means for paging the UT using one or more satellite beams corresponding to the UT TA.

[0011] An exemplary non-transitory computer-readable medium storing computer-executable instructions for a network node of a non-terrestrial network (NTN) is disclosed. The computer-executable instructions may include one or more instructions for causing the network node to determine a last area of ​​a user terminal (UT). The computer-executable instructions may also include one or more instructions for causing the network node to determine a UT tracking area (TA) based on the last area. The UT TA may be a non-terrestrial network tracking area (NTN TA) in which the UT is currently located. The UT TA may be one of a plurality of NTN TAs. The computer-executable instructions may also include one or more instructions for causing the network node to page the UT using one or more satellite beams corresponding to the UT TA.

[0012] An exemplary method performed by a user terminal (UT) is disclosed. The method may include changing a connection state of the UT with a non-terrestrial network (NTN). The method may also include receiving a paging message from the NTN after changing the connection state.

[0013] An exemplary user terminal (UT) is disclosed. The UT may include a memory and at least one processor coupled to the memory. The memory and the at least one processor may be configured to change a connection state of the UT with a non-terrestrial network (NTN). The memory and the at least one processor may also be configured to receive a paging message from the NTN after changing the connection state.

[0014] Another exemplary user terminal (UT) is disclosed. The UT may include a unit for changing a connection state between the UT and a non-terrestrial network (NTN). The UT may also include a unit for receiving a paging message from the NTN after changing the connection state.

[0015] An exemplary non-transitory computer-readable medium storing computer-executable instructions for a user terminal (UT) is disclosed. The computer-executable instructions may include one or more instructions for causing the UT to change a connection state of the UT with a non-terrestrial network (NTN). The computer-executable instructions may also include one or more instructions for causing the UT to receive a paging message from the NTN after changing the connection state.

[0016] Other objects and advantages associated with the aspects disclosed herein will be apparent to those skilled in the art based on the drawings and detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings are presented to aid in describing examples of one or more aspects of the disclosed subject matter and are provided solely for illustrative and non-limiting examples:

[0018] Figure 1 An exemplary non-terrestrial network serving a user terminal according to various aspects is shown;

[0019] Figure 2 An exemplary paging transmitter in communication with an exemplary paging receiver in accordance with various aspects is shown;

[0020] Figure 3 An exemplary non-terrestrial network node according to various aspects is shown;

[0021] Figure 4A-1 and 4A-2 Examples of non-terrestrial network tracking areas moving relative to the earth's surface according to various aspects are shown;

[0022] Figure 4B-1 and 4B-2 Examples of geographically bound non-terrestrial network tracking areas according to various aspects are shown;

[0023] Figure 5 An example of determining a tracking area for a user terminal based on a last area of ​​the user terminal according to various aspects is shown;

[0024] Figure 6 An example of determining a user terminal tracking area for a user terminal reporting its location in accordance with one or more aspects is shown;

[0025] Figure 7 An example of determining a user terminal tracking area for a user terminal that does not report its location according to various aspects is shown;

[0026] Figure 8 A flow chart illustrating an exemplary method performed by a network node of a non-terrestrial network for paging a user terminal in accordance with various aspects;

[0027] Fig.9A and 9B A flow chart illustrating an exemplary process performed by a network node of a non-terrestrial network for determining a last area of ​​a user terminal in accordance with various aspects;

[0028] Fig.10 A flow chart illustrating an exemplary process performed by a network node of a non-terrestrial network for determining a tracking area for a user terminal in accordance with various aspects;

[0029] Fig.11A and 11B A flow chart illustrating another exemplary process performed by a network node of a non-terrestrial network for determining a tracking area for a user terminal in accordance with various aspects;

[0030] Fig.12 A flow chart illustrating an exemplary process performed by a network node of a non-terrestrial network for determining a tracking area for a user terminal when the mobility of the user terminal is fixed mobility in accordance with various aspects;

[0031] Fig.13 A flow chart illustrating an exemplary process performed by a network node of a non-terrestrial network for paging a user terminal when the mobility of the user terminal is fixed mobility in accordance with various aspects;

[0032] Fig.14 A flow chart illustrating an exemplary method performed by a user terminal for receiving a page from a non-terrestrial network in accordance with various aspects;

[0033] Fig.15 illustrates a simplified block diagram of an example network node of a non-terrestrial network configured to page a user terminal in accordance with various aspects; and

[0034] Fig.16 A simplified block diagram of a user terminal configured to receive a paging message from a non-terrestrial network is shown in accordance with various aspects. DETAILED DESCRIPTION

[0035] Various aspects described herein generally relate to paging in non-terrestrial networks (NTNs). Examples of NTNs include networks based on satellites, balloons, aircraft, unmanned aerial vehicles, etc., which can be classified as high altitude platform stations (HAPS) and satellites. Satellite-based NTNs may include one or more low earth orbit (LEO) satellites and / or one or more medium earth orbit (MEO) satellites. In terrestrial networks (e.g., 5G NR, LTE, etc.), there are technologies for defining paging areas in which UEs are estimated to be located. In terrestrial networks, tracking areas (TAs) are used to define paging areas. Each TA includes multiple cells (e.g., eNBs, gNBs, etc.). TA information is broadcast to all UEs in the cell. When a UE crosses a TA boundary, the UE notifies the terrestrial network.

[0036] However, for NTN (e.g., LEO and / or MEO satellite networks, HAPS), there is a need to improve existing technologies for terrestrial networks. This is because NTN stations (e.g., satellites, aircraft, balloons) are constantly moving relative to the earth's surface. This means that in addition to the movement of the UT, it may be desirable to consider the movement of the NTN stations for paging.

[0037] In order to solve the above problems, one or more technologies are proposed to implement paging UT using non-terrestrial network (NTN). In one aspect, when a UT is to be paged, the current location or area of ​​the UT can be determined. For example, the current location or area of ​​the UT can be estimated based on the last location / area of ​​the UT and other factors such as the mobility of the UT. Once the current location / area of ​​the UT is estimated or otherwise determined, the UT can be paged using one or more satellite beams serving the estimated current location / area of ​​the UT.

[0038] These and other aspects are provided in the following description and related drawings of specific examples of the disclosed subject matter. Alternative solutions may be devised without departing from the scope of the disclosed subject matter. In addition, well-known elements will not be described in detail or will be omitted to avoid obscuring the relevant details.

[0039] The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any aspect described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects. Likewise, the term "aspects" does not require that all aspects include the discussed feature, advantage, or mode of operation.

[0040] The terms used herein describe specific aspects only and should not be construed as limiting any aspect disclosed herein. As used herein, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood by those skilled in the art that the terms "comprises, comprising" and / or "includes, including" as used herein specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0041] In addition, various aspects may be described according to a sequence of operations performed, for example, by elements of a computing device. Those skilled in the art will recognize that the various operations described herein may be performed by a specific circuit (e.g., an application specific integrated circuit (ASIC)), by program instructions executed by one or more processors, or by a combination of the two. In addition, these sequences of operations described herein may be considered to be fully embodied in any form of non-transitory computer-readable medium, on which is stored a corresponding set of computer instructions that will cause the associated processor to perform the functionality described herein when executed. Therefore, the various aspects described herein may be embodied in a variety of different forms, all of which are considered to be within the scope of the claimed subject matter. In addition, for each aspect described herein, the corresponding form of any such aspect may be described herein as, for example, "logic configured to perform the described operations" and / or other structural components configured to perform the described operations.

[0042] As used herein, unless otherwise noted, the terms "user equipment" (UE), "user terminal" (UT), and "base station" are not intended to be specific or otherwise limited to any particular radio access technology (RAT). In general, the UE is interchangeable with the UT, and the UE may be any wireless communication device (e.g., a mobile phone, a router, a tablet computer, a laptop computer, a tracking device, an Internet of Things (IoT) device, etc.) used by a user to communicate over a wireless communication network. The UE / UT may be mobile or may be fixed (e.g., at certain times) and may communicate with a radio access network (RAN). As used herein, the interchangeable terms "UE" and "UT" may also be interchangeably referred to as an "access terminal" or "AT", "client device", "wireless device", "user equipment", "user terminal", "user station", "mobile terminal", "mobile station" or variations thereof. In general, the UE may communicate with the core network via the RAN, and through the core network, the UE may connect to external networks such as the Internet and to other UEs. Of course, other mechanisms are also possible for the UE to connect to the core network and / or the Internet, such as through a wired access network, a WiFi network (eg, based on Institute of Electrical and Electronics Engineers (IEEE) 802.11, etc.), and so on.

[0043] A base station may operate according to one of several RATs to communicate with a UE, depending on the network in which the base station is deployed, and may be alternatively referred to as an access point (AP), a network node, a Node B, an evolved Node B (eNB), a general Node B (gNodeB, gNB), etc. In addition, in some systems, a base station may provide pure edge node signaling functions, while in other systems it may provide additional control and / or network management functions.

[0044] The UE may be embodied by any of a variety of types of devices, including but not limited to a printed circuit (PC) card, a compact flash device, an external or internal modem, a wireless or wired phone, a smart phone, a tablet, a tracking device, an asset tag, etc. The communication link that the UE may use to send signals to the RAN is referred to as an uplink channel (e.g., a reverse traffic channel, a reverse control channel, an access channel, etc.). The communication link that the RAN may use to send signals to the UE is referred to as a downlink channel or a forward link channel (e.g., a paging channel, a control channel, a broadcast channel, a forward traffic channel, etc.). As used herein, the term traffic channel (TCH) may refer to an uplink / reverse traffic channel or a downlink / forward traffic channel.

[0045] The term "UE" is generally used in the context of terrestrial networks, while the term "UT" is generally used in the context of satellite-based networks. However, as noted above, these terms may be used interchangeably in the following description.

[0046] As described above, in paging, it is desirable to ensure that a target client device (e.g., UT, UE) can be paged at any time and any place with minimal delay. In the context of paging in a non-terrestrial network (NTN), the initial paging should not fail due to not paging the UT from the correct station or station beam (when the stations of the NTN transmit multiple beams). It is also desirable to minimize the use of system resources. That is, it is not desirable to send pages to the UT over a very large area, i.e., through many station beams. If the network knows the location of the UT or can estimate the location of the UT, two goals can be achieved.

[0047] Figure 1 An example of an NTN 100 serving a UT 130 is shown. Before proceeding further, the following should be noted. Figure 1 In the and other figures, a satellite-based NTN will be described. However, the concepts described can be easily applied to other NTNs. For example, satellite 110 can be generalized as an example of a station, and satellite beam 115 (described below) can be generalized as an example of a station beam.

[0048] exist Figure 1In the NTN 100, the NTN 100 may include one or more satellites 110-1, 110-2, ... 110-n (collectively referred to as satellites 110). Each satellite 110 may be a LEO or MEO satellite. That is, each satellite 110 may move relative to the surface of the earth. The satellite 110 may communicate with the UT 130 using a satellite beam 115, which is a communication beam of the satellite 110. More generally, the station 110 may communicate with the UT 130 using a station beam 115. Each satellite 110 may communicate with the UT 130 using one or more satellite beams 115. For example, in Figure 1 1, satellite 110-1 is shown using two satellite beams 115-1, 115-2 to serve UT 130, and satellite 110-2 is shown using one satellite beam 115-3 to serve UT 130. Satellite beams of other satellites are not shown to reduce clutter.

[0049] Each satellite beam 115 may cover a coverage area 120, and the satellite 110 may serve the UTs 130 within the coverage area 120 via the satellite beam 115. Figure 1 1, satellite beams 115-1, 115-2, 115-3 cover coverage areas 120-1, 120-2, 120-3, respectively. This means that satellite 110-1 can serve UT 130-1 in coverage area 120-1 through satellite beam 115-1, and serve UTs 130-2, 130-3 in coverage area 120-2 through satellite beam 115-2. In addition, satellite 110-2 can serve UT 130-4 in coverage area 120-3 through satellite beam 115-3. In an aspect, each satellite 110 can be identifiable (e.g., by a satellite ID), each satellite beam 115 can be identifiable (e.g., a beam ID), and each satellite beam 115 can be associated with a particular satellite (e.g., a mapping of each beam ID to a satellite ID).

[0050] It can be said that each satellite beam 115 can serve any UT 130 within the coverage area 120 of the satellite beam 115. Of course, it should be recognized that it is actually the satellites 110 that serve the UTs 130. However, as each satellite beam 115 is associated with a particular satellite 110, the statement that the satellite beam 115 serves the UT 130 should not cause any confusion because the satellite 110 associated with a particular satellite beam 115 can be easily identified.

[0051] exist Figure 11, a non-terrestrial network tracking area (NTN TA) 140 is shown. In this case, the NTN TA 140 is covered by the coverage areas 120-1, 120-2, 120-3 of the satellite beams 115-1, 115-2, 115-3. Although only one NTN TA 140 is shown, it should be understood that multiple NTN TAs 140 may be defined in the NTN 100. In addition, the UTs 130 within each NTN TA 140 may be served by one or more satellites 110. That is, each NTN TA 140 may be covered by one or more coverage areas 120 of one or more satellite beams 115 of one or more satellites 110. Note that for the NTN TA 140, the number of satellites 110 and the number of satellite beams 115 do not have to be equal. This is because there may be at least one satellite 110 corresponding to at least two satellite beams 115.

[0052] The NTN may also include a coordinator 180 in communication with the satellite 110. The coordinator 180 may be configured to coordinate the operation of the satellite 110. For example, the coordinator 180 may coordinate the switching of the UT 130 between two satellites 110 and / or between two satellite beams 115. As another example, the coordinator 180 may serve as a gateway for the UT 130 to communicate with terminals of other communication systems such as terrestrial networks (e.g., 5G NR, LTE, PLMN, etc.).

[0053] In one aspect, NTN 100 can be analogous to a terrestrial network. For example, satellite 110 can be analogous to a base station (e.g., eNB, gNB, etc.); satellite beam 115 and / or coverage area 120 can be analogous to a cell or sector; and coordinator 180 can be analogous to a core network device. In another aspect, coordinator 180 can be analogous to a gNB, and satellite 110 can be analogous to a repeater.

[0054] In an alternative view, each satellite 110 may have one or more cells, and each cell may have one or more beams 115 corresponding to one or more coverage areas 120. As a result, each satellite 110 may correspond to one or more cells and / or one or more satellite beams 115 and / or one or more coverage areas 120.

[0055] Figure 1100A and a user terminal device 100B are further shown in the figure. The network node device 100A may include at least a transceiver 102A and a tracking area determiner 104A, and the user terminal (UT) device 100B may include at least a transceiver 102B and a location determiner 104B. As will be described in more detail below, the tracking area determiner 104A (e.g., which may be implemented as a processing function via a processor on the network node device 100A) may execute logic to determine a user terminal tracking area (UT TA). In addition, the location determiner 104B (e.g., which may be implemented as a processing function via a processor on the UT device 100B) may execute logic to determine the location of the UT device 100B and report the location to the network node device 100A. The network node device 100A and the UT device 100B are intended to represent various exemplary network nodes, and the UT may perform certain aspects of the present disclosure. Therefore, the network node device 100A and the UT device 100B appear in some of the following figures to emphasize the configuration of various network nodes and UTs. also, Fig.15 The network node device 1300 and Fig.16 The UT device 1400 shows a more detailed implementation example of the network node device 100A and the UT device 100B according to various aspects.

[0056] According to various aspects, Figure 2 An exemplary paging transmitter 210 (e.g., a satellite) is shown in communication with an exemplary paging receiver 250 (e.g., a user terminal). Internet Protocol (IP) packets may be provided to a controller / processor 275. The controller / processor 275 may implement functionality for a radio resource control (RRC) layer, a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a medium access control (MAC) layer. The controller / processor 275 may provide: RRC layer functions associated with broadcasting of system information (e.g., MIB, SIB), RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), inter-RAT mobility, and measurement configuration for paging receiver measurement reporting; PDCP layer functions associated with header compression / decompression, security (encryption, decryption, integrity protection, integrity verification), and handover support functions; RLC layer functions associated with transmission of upper layer packet data units (PDUs), error correction through ARQ, concatenation, segmentation and reassembly of RLC service data units (SDUs), re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functions associated with mapping between logical channels and transport channels, scheduling information reporting, error correction, priority handling, and logical channel prioritization.

[0057] The transmit (TX) processor 216 and the receive (RX) processor 270 can implement layer 1 functions associated with various signal processing functions. Layer 1 including the physical (PHY) layer can include error detection on the transmission channel, forward error correction (FEC) encoding / decoding of the transmission channel, interleaving, rate matching, mapping to the physical channel, modulation / demodulation of the physical channel, and multiple input multiple output (MIMO) antenna processing. The TX processor 216 can process the mapping to the signal constellation based on various modulation schemes (e.g., binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), M phase shift keying (M-PSK), M quadrature amplitude modulation (M-QAM)). The coded and modulated symbols can then be divided into parallel streams. Each stream can then be mapped to an orthogonal frequency division multiplexing (OFDM) subcarrier, multiplexed with a reference signal (e.g., pilot) in the time domain and / or frequency domain, and then combined together using an inverse fast Fourier transform (IFFT) to produce a physical channel carrying a time domain OFDM symbol stream. The OFDM stream is spatially precoded to produce multiple spatial streams. Channel estimates from channel estimator 274 can be used to determine coding and modulation schemes, as well as for spatial processing. Channel estimates can be derived from reference signals and / or channel condition feedback sent by paging receiver 250. Each spatial stream can then be provided to one or more different antennas 220 via a separate transmitter 218a. Each transmitter 218a can modulate an RF carrier with a respective spatial stream for transmission.

[0058] At the paging receiver 250, each receiver 254a can receive a signal through its respective antenna 252. Each receiver 254a can recover the information modulated onto the RF carrier and can provide the information to the RX processor 256. The TX processor 268 and the RX processor 256 can implement layer 1 functions associated with various signal processing functions. The RX processor 256 can perform spatial processing on the information to recover any spatial streams destined for the paging receiver 250. If multiple spatial streams are destined for the paging receiver 250, the RX processor 256 can combine them into a single OFDM symbol stream. The RX processor 256 can then use a fast Fourier transform (FFT) to convert the OFDM symbol stream from the time domain to the frequency domain. The frequency domain signal may include a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier and the reference signal can be recovered and demodulated by determining the most likely signal constellation point sent by the paging transmitter 210. These soft decisions can be based on the channel estimates calculated by the channel estimator 258. The soft decisions may then be decoded and deinterleaved to recover the data and control signals originally sent on the physical channel by the paging transmitter 210. The data and control signals may then be provided to a controller / processor 259 that implements layer 3 and layer 2 functionality.

[0059] The controller / processor 259 may be associated with a memory 260 that stores program codes and data. The memory 260 may be referred to as a computer readable medium. In the UL, the controller / processor 259 may provide demultiplexing between transport channels and logical channels, packet reassembly, decryption, header decompression, and control signal processing to recover IP packets from the core network. The controller / processor 259 may also be responsible for error detection.

[0060] Similar to the functions described for T2R transmission performed in conjunction with the paging transmitter 210, the controller / processor 259 can provide: RRC layer functions associated with system information (e.g., MIB, SIB) acquisition, RRC connection, and measurement reporting; PDCP layer functionality associated with header compression / decompression and security (encryption, decryption, integrity protection, integrity verification); RLC layer functions associated with transmission of upper layer PDUs, error correction through ARQ, concatenation, segmentation and reassembly of RLC SDUs, re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functions associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto TBs, demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.

[0061] Channel estimates derived by the channel estimator 258 from a reference signal or feedback sent by the paging transmitter 210 may be used by the TX processor 268 to select the appropriate coding and modulation schemes and to facilitate spatial processing. The spatial streams generated by the TX processor 268 may be provided to different antennas 252 via separate transmitters 254 b. Each transmitter 254 b may modulate an RF carrier with a respective spatial stream for transmission.

[0062] The UL transmission may be processed at the paging transmitter 210 in a manner similar to that described in conjunction with the receiver functionality at the paging receiver 250. Each receiver 218b may receive a signal through its respective antenna 220. Each receiver 218b may recover the information modulated onto the RF carrier and may provide the information to the RX processor 270.

[0063] The controller / processor 275 may be associated with a memory 276 that stores program codes and data. The memory 276 may be referred to as a computer readable medium. In the UL, the controller / processor 275 may provide demultiplexing between transport channels and logical channels, packet reassembly, decryption, header decompression, control signal processing to recover IP packets from the paging receiver 250. The IP packets from the controller / processor 275 may be provided to the core network. The controller / processor 275 may also be responsible for error detection.

[0064] In the paging receiver 250, the transmitter 254b and the receiver 254a may together form the transceiver 254. In the paging transmitter 210, the transmitter 218a and the receiver 218b may together form the transceiver 218.

[0065] The paging transmitter 210 and the paging receiver 250 may be configured to implement the proposed preamble format allocation method. In this method, a paging transmitter (e.g., gNB, cell) may allocate multiple PRACH preamble formats and send or broadcast the allocated preamble formats in one or more SSBs. The SSBs may be broadcast periodically. The paging receiver (e.g., UT) may receive the allocated preamble formats in one or more SSBs. In order to perform initial access, the UT may select a preamble format from a plurality of allocated preamble formats based on one or more metrics (e.g., RSRP, SNR, SINR, BER, etc.) and send a preamble accordingly.

[0066] Figure 3 An exemplary NTN coordinator 300 (e.g., coordinator 180) is shown. Coordinator 300 may include one or more processors 301 coupled to volatile memory 302 and a large non-volatile memory 303 such as a disk drive. Coordinator 300 may include a floppy disk drive, compact disk (CD) or DVD optical drive 306, which is also coupled to processor 301. Processor 301 may be associated with any or all of memories 302, 303, 306 that store program codes and data. Any or all of memories 302, 303, 306 may be referred to as computer-readable media. Coordinator 300 may include a communication port or transceiver 304 coupled to processor 301 for establishing communications with satellite 110, and communications with UT 130 through satellite 110.

[0067] Return to reference Figure 1 , the concept of a tracking area - NTN TA 140 - can be used for paging in NTN 100. However, NTN TA 140 is different from the tracking area of ​​the terrestrial network. Recall that in the terrestrial network, each tracking area is associated with a number of base stations. Since the location of the base stations in the terrestrial network is usually fixed, this means that each terrestrial tracking area is geographically bound and is associated with a base station at the same time.

[0068] However, in a satellite-based network such as network 100, both cannot occur simultaneously. That is, an NTN TA 140 may be associated with a set of one or more satellite beams 115 (more generally, a set of one or more station beams). However, because the one or more satellites 110 corresponding to the satellite beams 115 move relative to the surface of the Earth, the associated NTN TA 140 also moves relative to the surface of the Earth.

[0069] This is Figure 4A-1 and 4A-2 In Figure 4A-1 and 4A-2 In the present invention, it can be assumed that NTN TA 140 (which is one of a number of NTN TAs defined in network 100) is covered by one or more coverage areas 120 of one or more satellite beams 115 (not shown to reduce clutter) of one or more satellites (e.g., satellites 110-1 ... 110-n). It can also be assumed that NTN TA 140 is associated with satellites 110-1 ... 110-n. Note that UT 130 is in Figure 4A-1 4. The NTN TA 140 is also labeled as UT TA 440. That is, UT TA 440 is the NTN TA 140 where UT 130 is currently located.

[0070] Since the NTN TA 140 is associated with the satellites 110-1 ... 110-n that move relative to the ground, the NTN TA 140 also moves relative to the ground, such as Figure 4A-2 When the satellites 110-1 ... 110-n move far enough so that the coverage area 120 of the satellites 110-1 ... 110-n does not cover the UT 130, the NTN TA 140 is no longer a UT TA 440. This means that the UT 130 may cross a TA boundary even if the UT 130 itself does not move or moves very little. In one aspect, the UT 130 may report crossing the NTN TA boundary.

[0071] Alternatively, the NTN TA 140 may be a geographic area on the surface of the Earth. However, since the satellites 110 of the network 100 move relative to the surface of the Earth, the NTN TA 140 may be covered by different coverage areas 120 at different times. Figure 4B-1 and 4B-2 In Figure 4B-1 and 4B-2 In , it can be assumed that NTN TA 140 (which is one of a number of NTN TAs defined in network 100) is a geographical area. Figure 4B-1At a particular moment in time, the NTN TA 140 is covered by one or more coverage areas 120 of one or more satellite beams 115 (not shown to reduce clutter) of one or more satellites (e.g., satellites 110-1 ... 110-n). Since the UT 130 is within the NTN TA 140, the NTN TA 140 is Figure 4B-1 Also marked as UT TA440.

[0072] However, as the satellites 110-1 ... 110-n move relative to the surface of the earth, the corresponding coverage areas 120 also move. This means that the UT TA 440 / NTN TA 140 may be covered by the coverage areas 120 (not shown) of other satellites 110. When the satellites 110-1 ... 110-n move far enough so that the coverage areas 120 of the satellites 110-1 ... 110-n no longer cover any part of the UT TA 440, the UT TA 440 will be covered by a completely different coverage area 120.

[0073] For paging purposes, regardless of whether the NTN TA 140 is mobile (i.e., associated with a group of satellite beams 115) or geographically fixed (i.e., defines a geographic area), a UT TA 440 may be determined for the UT 130. Once the UT TA 440 is determined, the UT 130 may be paged using one or more satellites 115 corresponding to the UT TA 440. That is, the satellites 110 used to page the UT 130 may be one or more satellites 110 corresponding to one or more satellite beams 115 whose one or more coverage areas 120 cover the UT TA 440.

[0074] In an aspect, the UT TA 440 may be determined based on the current location of the UT 130. The current location of the UT 130 may be determined (e.g., estimated) based on the last location of the UT 130. To account for error tolerance in making such location determinations, it may be stated as follows: the UT TA 440 may be determined based on the current area of ​​the UT 130, which may be estimated based on the last area of ​​the UT 130. The current area may contain the current location, and the last area may contain the last location.

[0075] The current region may depend at least in part on the mobility of the UT. If the UT has low mobility (i.e., moves slowly), the distance that the UT 130 may have traveled since the last region was determined will be small. Therefore, the current region may be relatively small because the distance from the last region considered by the current region is relatively small.

[0076] On the other hand, if the UT's mobility is high (ie, moves fast), the distance that the UT 130 may have traveled since the last region was determined may be large. Thus, the current region may be relatively large because the distance considered by the current region from the last region is relatively large.

[0077] In one aspect, the UT 130 may report its mobility to the network 100, e.g., to the coordinator 180 and / or to the satellite 110. The mobility may be reported as one of a plurality of mobility types. Each mobility type may correspond to a mobility level or range of mobility. For example, mobility type 0 may indicate fixed mobility, i.e., the location of the UT is permanent or otherwise immovable, at least while the UT is operating. As another example, mobility type 1 may indicate stationary mobility, i.e., the UT 130 does not move. The difference between fixed mobility type and stationary mobility type is further explained below. As other examples, mobility type 2 may indicate low mobility (e.g., walking), mobility type 3 may indicate medium mobility (e.g., car, boat, truck, etc.), and mobility type 4 may indicate high mobility (e.g., airplane). Of course, these are merely examples, and the granularity of the mobility types may be fine or coarse as desired.

[0078] In one aspect, UT 130 may report its mobility to network 100, e.g., to coordinator 180 and / or to satellite 110. Mobility may be reported as one of a plurality of mobility types. Each mobility type may correspond to a mobility level or mobility range. For example, mobility type 1 may indicate stationary mobility, i.e., UT 130 is not moving. As other examples, mobility type 2 may indicate low mobility (e.g., walking), mobility type 3 may indicate medium mobility (e.g., car, boat, truck, etc.), and mobility type 4 may indicate high mobility (e.g., airplane).

[0079] In addition, the mobility type of UT 130 does not need to remain the same, i.e., it can change at different times. For example, UT 130 can identify its current speed and can report a mobility type appropriate for the current speed to network 100. For example, UT 130 can identify that it is moving at a speed less than 10 mph (indicating walking speed) and can report a mobility type of 2. Later, if UT 130 identifies that it is traveling at a speed greater than 20 mph (indicating vehicle speed), UT 130 can update its mobility type to 3.

[0080] As described above, both mobility types 0 and 1 apply to situations where the UT 130 is not moving. Note that there may be different reasons why the UT 130 is not moving. In one example, the UT 130 itself may be mobile (e.g., a satellite phone), i.e., capable of being moved. But at a given moment, it may not be moving. For example, the user may have simply put the UT 130 down. Mobility type 1 - stationary mobility - is intended to cover this situation where the UT is not moving.

[0081] However, in another example, the location of the UT 130 may be permanently fixed or simply "fixed." As an illustration, many satellite dishes are not expected to move once installed. In non-terrestrial networks, fixed satellite dishes may represent a significant portion of all UTs 130. For such fixed UTs 130, once installed, their physical locations may be stored in the NTN 100, such as in the coordinator 180, satellite 110, etc. Mobility Type 0 - Fixed Mobility - is intended to cover the case of such non-moving UTs.

[0082] As shown, determining the current region may also depend on the last region of UT 130. Figure 5 130, it may be assumed that the last region 550 of the UT 130 has been determined. In particular, the last region 550 is shown as a region surrounding the last location of the UT 130. That is, the last region 550 may be the region in which the UT 130 was last located. In one aspect, the last location of the UT 130 may be determined, and the last region 550 represents the uncertainty margin when determining the last location. The last region 550 is shown in FIG. Figure 5 However, the final region 550 may be of any shape.

[0083] The last area 550 may be determined in various ways. In one aspect, UT 130 may obtain its location. For example, UT 130 may have GNSS, GPS capabilities. As another example, UT 130 may be able to determine its location by measuring signals from ground network base stations (e.g., eNB, gNB) and / or signals from non-ground stations (e.g., UT 130 may use signals from multiple NTN satellites to obtain its location). In yet another example, the ground network may determine the location of UT 130 (e.g., by a signal sent by UT 130) and provide the location back to UT 130.

[0084] UT 130 may report its acquired position to network 100 (e.g., to coordinator 180 and / or to satellite 110). For example, UT 130 may send its position each time UT 130 exits a connected state (e.g., exits RRC_CONNECTED state). UT 130 may send such a position report more than once (e.g., periodically, as needed, based on a triggering event, etc.). For example, when UT 130 determines that it has traveled at least a threshold distance (described in more detail below) from its last reported position, UT 130 may send its updated position to network 100. In one aspect, UT 130 may send the position report in a radio resource control (RRC) message.

[0085] For each location report, the network 100 may determine the region containing the reported location. The region determined to contain the most recently reported location may then become the last region 550. Note that for a UT 130 of mobility type 0 (fixed mobility), the network 100 may obtain the location of the UT during the installation and / or startup process.

[0086] On the other hand, the last area 550 may be determined when the UT 130 is unable to acquire its location and / or unable to provide a location report. In this case, the last area 550 may be determined based on the most recent communication with the UT 130. For example, the last area 550 may be determined as the coverage area 120 of the satellite beam 115 that served the UT 130 when the UT 130 exited its previous connection state (e.g., RRC_CONNECTED, RRC_INACTIVE, RRC_IDLE, etc.).

[0087] As described above, the UT TA 440 may be determined based on the current area. In general, an NTN TA 140 (among the plurality of NTN TAs 140) covered by at least one satellite beam 115 whose coverage area 120 at least partially overlaps with the current area may be determined as the UT TA 440. For the UT 130 of mobility type 1, the last area 550 may be considered as the current area, so that the UT TA 440 may be determined based on the last area 550. The UT TA 440 may be determined as the NTN TA 140 corresponding to at least one satellite beam 115 whose coverage area 120 at least partially overlaps with the last area 550. That is, the UT TA 440 may be the NTN TA 140 corresponding to the coverage area 120 of at least one satellite beam 115 at least partially overlapping with the last area 550.

[0088] For example, from Figure 51, NTN TA 140 is covered by three coverage areas 120 (the corresponding satellite beams 115 are not shown to reduce clutter). One of the coverage areas 120 at least partially overlaps with the last area 550. Therefore, this NTN TA 140 is determined to be UT TA 440. In one aspect, if UT 130 has mobility type 1, then determining UT TA 440 based on last area 550 may also be sufficient.

[0089] On the other hand, when the UT 130 has a mobility type 0, the last area 550, the current location, and the current area can all be narrowed down to a specific location - the installation location of the UT. This is because for mobility type 0, the location of the UT is not expected to change from its installation location. Therefore, although not specifically shown, the NTN TA 140 having a coverage area 120 covering the installation location of the UT can be determined as the UT TA 440.

[0090] However, if the movement of the UT 130 is sufficient that it may have traveled outside of the last region 550 since the last region 550 was determined, it is advisable to consider the distance the UT 130 may have traveled. Figure 6 4 shows a UT TA 440 that determines a UT 130 to report its location to the network 100. Recall above that for a UT 130 that is reporting a location, the UT 130 may report an updated location report whenever it has traveled at least a threshold distance from its previously reported location. Figure 6 In FIG. 1 , it is assumed that UT 130 is configured to report such location updates. That is, the threshold distance is the maximum distance that UT 130 travels before updating its location through another location report.

[0091] like Figure 6 , a threshold distance 662 may be determined, and a threshold area 660 (shown as a dash-dotted ellipse) may be determined based on the threshold distance 662. Although the threshold area 660 is shown as an ellipse, the threshold area 660 may be any shape. As indicated, the threshold distance 662 represents the maximum distance that the UT 130 may have traveled since its last position report. Therefore, areas beyond the threshold distance 662 relative to the last area 550 may not need to be considered.

[0092] In one aspect, the threshold region 660 may be determined to have at least the following two characteristics. The first characteristic is that at least a portion of the last region 550 is inside the threshold region 660. Figure 6 In , the entire last region 550 is inside the threshold region 660. The second feature is that the distance from the last region 550 to at least a portion of the edge of the threshold region 660 is based on the threshold distance 662. Figure 6, a distance between at least one edge portion of the final region 550 and at least one edge portion of the threshold region 660 is a threshold distance 662 .

[0093] A threshold area 660 has been determined, which may be considered as the current area, and thus the UT TA 440 may be determined based on the threshold area 660. That is, the UT TA 440 may be determined as an NTN TA 140 covered by at least one satellite beam 115 whose coverage area 120 at least partially overlaps with the threshold area 660. That is, the UT TA 440 may be an NTN TA 140 corresponding to at least one satellite beam 115 whose coverage area 120 at least partially overlaps with the threshold area 660. Figure 6 As can be seen in FIG. 6 , the NTN TA 140 is covered by three coverage areas 120 (the corresponding satellite beams 115 are not shown to reduce clutter). All three coverage areas 120 at least partially overlap with the threshold area 660. Therefore, the NTN TA 140 is determined to be the UT TA 440.

[0094] The threshold distance 662 may be a set threshold distance. Alternatively or additionally, the threshold distance 662 may be determined based on one or a combination of a variety of factors. These factors include the mobility of the UT 130, the size of the coverage area 120 of the satellite beam 115 serving the UT 130 when the network 100 received the last position, and the satellite deployment density of the network 100, etc.

[0095] Figure 7 Also shown is the UT TA 440 that determines the mobile UT 130. Figure 7 In the example, it is assumed that UT 130 does not report its location to the network. UT 130 may not be able to obtain its location. Alternatively, UT 130 may be capable of reporting location, but is operated such that it does not report location (e.g., UT 130 may be placed in a low power mode).

[0096] In this case, the mobility of UT 130 may be determined. Recall above that UT 130 may report its mobility. Thus, one way to determine mobility is to receive mobility from UT 130. Alternatively or in addition thereto, network 100 may assume a default mobility. Further, alternatively or in addition thereto, network 100 may estimate mobility based on a determination of the last area 550 of UT 130 in the past. Recall above that the last area 550 may be determined even if UT 130 is unable or unwilling to provide a location report.

[0097] like Figure 7, a movement distance 762 may be determined based on mobility, and a movement region 760 (shown as a double-dashed ellipse) may be determined based on the movement distance 762. Although the movement region 760 is shown as an ellipse, the movement region 760 may be any shape. In this case, it may be said that the movement distance 762 is related to the distance that the UT 130 may have traveled from the last region 550 since the last region 550 was determined. That is, the region beyond the movement distance 762 relative to the last region 550 may not need to be considered.

[0098] In one aspect, the moving region 760 can be determined to have at least the following two characteristics. The first characteristic is that at least a portion of the last region 550 is inside the moving region 760. Figure 7 In , the entire last region 550 is inside the moving region 760. The second feature is that the distance from the last region 550 to at least a portion of the edge of the moving region 760 is based on the moving distance 762. Figure 7 , a distance between at least one edge portion of the final region 550 and at least one edge portion of the moving region 760 is a moving distance 762 .

[0099] A mobile area 760 has been determined, which can be considered as a current area, so that the UT TA 440 can be determined based on the mobile area 760. The UT TA 440 can be determined as an NTN TA 140 covered by at least one satellite beam 115 whose coverage area 120 at least partially overlaps with the mobile area 760. That is, the UT TA 440 can be an NTN TA 140 corresponding to at least one satellite beam 115 whose coverage area 120 at least partially overlaps with the mobile area 760. Figure 7 As can be seen in FIG. 4 , the NTN TA 140 is covered by three coverage areas 120 (the corresponding satellite beams 115 are not shown to reduce clutter). All three coverage areas 120 at least partially overlap with the mobile area 760. Therefore, the NTN TA 140 is determined to be a UT TA 440.

[0100] Figure 8 An exemplary method 800 is shown as being performed by a node of a non-terrestrial network (e.g., NTN 100). In one aspect, the network node performing the method 800 may be a coordinator 180, 300. In this case, one or more stations 110 (e.g., satellite, HAPS) may facilitate communication between the coordinator 180, 300 and the UT 130. In another aspect, the network node performing the method 800 may be a station 110 or a combination of multiple stations 110. In yet another aspect, the coordinator 180, 300 and one or more stations 110 may perform the method 800 together.

[0101] As described above, a satellite 110 (e.g., identified by a satellite ID) may correspond to one or more cells. In addition, each cell (e.g., identified by a cell ID) may correspond to one or more satellite beams 115. Each satellite beam 115 (e.g., identified by a beam ID) may correspond to a coverage area 120. Also as indicated above, each NTN TA 140 in the plurality of NTN TAs 140 may be covered by one or more coverage areas 120 of the corresponding one or more satellite beams 115. This means that each NTN TA 140 may be mapped to any combination of one or more satellites 110 and / or one or more cells and / or one or more satellite beams 115 and / or one or more coverage areas 120.

[0102] Note that UT TA 440 may be defined as the NTN TA 140 in which UT 130 is located. This means that to page UT 130, the NTN node may map the location (or estimate of the location) of the UT to one or more coverage areas 120 at the time of paging, and then the corresponding satellite beams 115 may be used to page UT 130.

[0103] As the satellites 110 move relative to the surface of the earth, the UT TA 440 may be time-varying. That is, the satellite(s) / cell(s) / beam(s) / coverage area(s) corresponding to or otherwise mapped to the UT TA 440 at one time may be different from the satellite(s) / cell(s) / beam(s) / coverage area(s) at another time. This is true regardless of whether the NTN TAs 140 are defined as fixed geographic areas or whether they are associated with groups of satellite(s) / cell(s) / beam(s) / coverage areas.

[0104] When each NTN TA 140 is associated with a specific geographic area, this means that the mapping between the UT TA 440 and the NTN TA 140 is not time-varying. However, since the satellite 110 moves relative to the surface of the earth, the satellite(s) / cell(s) / beam(s) / coverage area(s) serving the NTN TA 140 are time-varying. Therefore, the mapping between the UT TA 440 and the satellite(s) / cell(s) / beam(s) / coverage area(s) is time-varying.

[0105] When each NTN TA 140 is associated with a specific combination of satellite(s) / cell(s) / beam(s) / coverage area(s), this means that the mapping between the NTA 140 and the satellite(s) / cell(s) / beam(s) / coverage area(s) is not time-varying. However, since the satellite 110 moves, the association between the UT TA 440 and the NTN TA 140 is time-varying. Therefore, the mapping between the UT TA 440 and the satellite(s) / cell(s) / beam(s) / coverage area(s) is again time-varying.

[0106] In method 800, the time-varying characteristics of the UT TA 440 are considered when determining the UT TA 440 for paging. At block 810, a network node (specifically, the transceiver 304 and / or the processor 301 of the coordinator 300 and / or the transceiver 218 and / or the RX processor 270 of the station 110) may receive a mobility report from the UT 130. The mobility may be received as one of a plurality of mobility types. Each mobility type may correspond to a mobility level or mobility range. For example, the mobility type may include fixed mobility, stationary mobility, low mobility, high mobility, etc. The mobility type may be stored on the network side (e.g., at the coordinator 180, 300; the satellite 130) and may be called for use as needed or necessary.

[0107] At block 820 , the network node may determine the last area 550 of the UT 130 . Fig.9A An example process performed by a network node to implement block 820 is shown. Fig.9A In the embodiment of the present invention, it is assumed that UT 130 is able to obtain its location and report the obtained location. At block 910, the network node (specifically, the transceiver 304 and / or the processor 301 of the coordinator 300 and / or the transceiver 218 and / or the RX processor 270 of the station 110) can receive a location report from UT 130. The location report can include the last location. In one aspect, the location report can be received in a radio resource control (RRC) message.

[0108] At block 920, the network node (specifically, the processor 301 of the coordinator 300 and / or the controller / processor 275 of the station 110) may determine the last area 550 based on the location report. For example, the last area 550 may be determined as the area containing the last location. The last area 550 may be of any shape.

[0109] Fig. 9B Another example process performed by a network node to implement block 820 is shown. Fig. 9B, it is assumed that UT 130 is unable or unwilling to report its location. At block 915, the network node (specifically, the processor 301 of the coordinator 300 and / or the controller / processor 275 of the station 110) may determine the last area 550 of the most recent communication with the UT 130. For example, the last area 550 may be determined as the coverage area 120 of the station beam 115 (e.g., a satellite beam) that served the UT 130 when the UT 130 exited its previous connection state.

[0110] Return to reference Figure 8 At block 830 , the network node may determine the UT TA 440 of the UT 130 . Fig.10 An example process performed by a network node to implement block 830 is shown. In one aspect, Fig.10 The process shown in can be viewed as Fig.9A , i.e., is considered to determine the UT TA 440 based on the last area 550 determined from the UT 130 that reported its location. Alternatively, Fig.10 The process shown in can be viewed as Fig. 9B 4. The UT TA 440 is determined based on the last area 550 of the determination of the UT 130 that is deemed to be unwilling or unable to report its location.

[0111] At block 1010, the network node (specifically, the processor 301 of the coordinator 300 and / or the controller / processor 275 of the station 110) may select or otherwise determine a UT TA 440 from among a plurality of NTN TAs 140 defined in the network 100 based on the last area 550. In particular, an NTN TA 140 covered by at least one station beam 115 whose coverage area 120 at least partially overlaps with the last area 550 may be selected as the UT TA 440. That is, the UT TA 440 may be an NTN TA 140 corresponding to at least one station beam 115 whose coverage area 120 at least partially overlaps with the last area 550. For example, block 1010 may be performed when the mobility of the UT 130 is low, i.e., below a low mobility threshold (e.g., equal to or below mobility type 1). Fig.9A , 9B and the flowchart of 10 may correspond to Figure 5 The scene shown in .

[0112] Fig.11A Another example process performed by a network node to implement block 830 is shown. In one aspect, Fig.11A The process illustrated in the figure can be viewed as Fig.9A , i.e., is considered to determine the UT TA 440 based on the last area 550 determined from the UT 130 that reported its location.

[0113] At block 1110, the network node (specifically, the processor 301 of the coordinator 300 and / or the controller / processor 275 of the station 110) may determine a threshold distance 662 for the UT 130. In one aspect, recall that for a UT 130 reporting and updating its location, the threshold distance 662 may represent the maximum distance that the UT 130 travels between location reporting opportunities. The threshold distance 662 may be a set threshold distance. Alternatively, the threshold distance 662 may be determined based on any one or more of the size of the coverage area 120 of the station beam 115 serving the UT 130 when the network 100 received the last location, the mobility of the UT 130, and the density of the station deployment of the network 100, etc.

[0114] At block 1120, the network node (specifically, the processor 301 of the coordinator 300 and / or the controller / processor 275 of the station 110) may determine a threshold area 660 based on the threshold distance 662. The threshold area 660 may be any shape. In one aspect, the threshold area 660 may be determined such that at least a portion of the last area 550 is inside the threshold area 660. Alternatively or additionally, the threshold area 660 may be determined such that a distance from the last area 550 to at least a portion of an edge of the threshold area 660 is based on the threshold distance 662.

[0115] At block 1130, the network node (specifically, the processor 301 of the coordinator 300 and / or the controller / processor 275 of the station 110) may select or otherwise determine a UT TA 440 from among a plurality of NTN TAs 140 defined in the network 100 based on the threshold area 660. For example, an NTN TA 140 covered by at least one station beam 115 whose coverage area 120 at least partially overlaps with the threshold area 660 may be selected as the UT TA 440. That is, the UT TA 440 may be an NTN TA 140 corresponding to at least one satellite beam 115 whose coverage area 120 at least partially overlaps with the threshold area 660.

[0116] In one aspect, blocks 1110, 1120, 1130 may be performed for a UT 130 reporting its location, for example, when the mobility of the UT 130 is high, i.e., below a low mobility threshold (e.g., above mobility type 1). In another aspect, blocks 1110, 1120, 1130 may be performed for a UT 130 reporting its location, regardless of mobility. Fig.9A and 11A The flowchart can correspond to Figure 6 The scene shown in .

[0117] Fig. 11BAnother example process performed by a network node to implement block 830 is shown. In one aspect, Fig. 11B The process shown in can be viewed as Fig. 9B , i.e., determining the UT TA 440 of the UT 130 that does not report its location.

[0118] At block 1105, the network node (specifically, the transceiver 304 and / or the processor 301 of the coordinator 300 and / or the transceiver 218, the RX processor 270, and / or the controller / processor 275 of the station 110) may determine the mobility of the UT 130. The mobility may be determined based on any one or more of receiving mobility from the UT 130, assuming a default mobility, estimating mobility based on the last area 550 determination in the past, and the like.

[0119] At block 1115, the network node (specifically, the processor 301 of the coordinator 300 and / or the controller / processor 275 of the station 110) may determine a movement distance 762 based on mobility. In an aspect, the movement distance 762 may represent a distance that the UT 130 may have traveled from the last area 550 since the last area 550 was determined.

[0120] At block 1125, the network node (specifically, the processor 301 of the coordinator 300 and / or the controller / processor 275 of the station 110) may determine a movement area 760 based on the movement distance 762. The movement area 760 may be of any shape. In one aspect, the movement area 760 may be determined such that at least a portion of the last area 550 is inside the movement area 760. Alternatively or additionally, the movement area 760 may be determined such that a distance from the last area 550 to at least a portion of an edge of the movement area 760 is based on the movement distance 762.

[0121] At block 1135, the network node (specifically, the processor 301 of the coordinator 300 and / or the controller / processor 275 of the station 110) may select or otherwise determine a UT TA 440 from among a plurality of NTN TAs 140 defined in the network 100 based on the mobility area 760. For example, an NTN TA 140 covered by at least one station beam 115 whose coverage area 120 at least partially overlaps with the mobility area 760 may be selected as the UT TA 440. That is, the UT TA 440 may be an NTN TA 140 corresponding to at least one satellite beam 115 whose coverage area 120 at least partially overlaps with the mobility area 760.

[0122] In one aspect, for example, when the mobility of the UT 130 is high, i.e., below a low mobility threshold (e.g., above mobility type 1), blocks 1105, 1115, 1125, 1135 may be performed for a UT 130 that does not report its location. In another aspect, blocks 1105, 1115, 1125, 1135 may be performed for a non-location reporting UT 130 regardless of mobility. Fig. 9B and 11B The flowchart can correspond to Figure 7 The scene shown in .

[0123] Fig.12 An example process performed by a network node to implement blocks 820 and 830 is shown. In this case, the mobility of UT 130 is assumed to be fixed mobility. That is, the location of UT 130 is fixed to its installation location. Recall that once a UT 130 such as a satellite dish is installed, the location is more or less permanent. Of course, it should be recognized that the dish can be moved, for example, when a user moves to a new residence. However, at least when UT 130 is in operation, its location will be the installation location. In this case, when UT 130 is installed and / or started, the location of the UT can be stored on the network side (e.g., at coordinator 180, 300 and / or at satellite 110). The mobility of the UT can also be recorded on the network side.

[0124] Since the location of the UT 130 is not expected to change, the last area 550, the current location, and the current area of ​​the UT 130 can all be narrowed down to a specific location - the installation location of the UT 130. Therefore, in block 1210, the network node (specifically, the processor 301 of the coordinator 300 and / or the controller / processor 275 of the station 110) may determine the NTN TA 140 covered by at least one satellite beam 115 whose coverage area 120 covers the installation location of the UT 130 as the UT TA 440. That is, the UT TA 440 may be the NTN TA 140 corresponding to the at least one satellite beam 115 whose coverage area 120 covers the installation location. The network node may be configured to perform block 1210 when the mobility of the UT 130 recorded on the network side indicates that the mobility is fixed mobility.

[0125] Return to reference Figure 8, when the UT TA 440 is determined for the UT 130, at block 840, the network node (specifically, the transceiver 304 and / or the processor 301 of the coordinator 300 and / or the transceiver 218 and / or the TX processor 216 of the station 110) may page the UT 130 through one or more station beams 115 corresponding to the UT TA 440. That is, the station 110 having the station beam 115 covering the UT TA 440 may be used to page the UT 130.

[0126] It is reiterated that the UT TA 440 is an NTN TA 140 that covers or otherwise at least partially overlaps the current area. It is also recalled that the current area is the area in which the UT 130 is estimated to be located at the time of paging. This means that the UT TA 440 is one of multiple NTN TAs 140, and paging is restricted to using satellite beams 115 within the UT TA 440. This is desirable because network resources in areas where the UT 130 is unlikely to be located will not be used to page the UT 130. Therefore, in one aspect, some or all station beams (e.g., satellite beams) 115 of the UT TA 440 can be used to page the UT 130 regardless of the mobility of the UT 130, including fixed mobility.

[0127] But in an alternative aspect, there may be an opportunity to further reduce network resource usage when the mobility of UT 130 is fixed mobility. In this case, since the location of UT 130 is fixed to the installation location, there is little uncertainty about the location of UT 130 when paging. Thus, simply using a satellite beam 115 with a coverage area 120 covering the installation location is sufficient.

[0128] Fig.13 An example process performed by a network node to implement block 840 when the mobility of the UT 130 is fixed mobility is shown. In block 1310, the network node (specifically, the transceiver 304 and / or the processor 301 of the coordinator 300 and / or the transceiver 218 and / or the TX processor 216 of the station 110) may page the UT 130 using only one or more satellite beams 115 whose coverage area 120 covers the installation location. That is, in this alternative aspect, there is no need to use the satellite beams 115 of the UT TA 440 whose coverage area 120 does not cover the installation location. The network node may be configured to perform block 1310 when the mobility of the UT 130 recorded on the network side indicates that the mobility is fixed mobility.

[0129] Fig.14An exemplary method 1400 for receiving a page from a non-terrestrial network (e.g., NTN 100) performed by a user terminal (e.g., UT 130, paging receiver 250) is shown. At block 1410, the user terminal (specifically, transceiver 254 and / or TX processor 268) may send the mobility of the user terminal to network 100. The mobility may be reported as one of a plurality of mobility types. Each mobility type may correspond to a mobility level or mobility range.

[0130] At block 1420, the user terminal (specifically, the transceiver 254 and / or the TX processor 268) may send a location report including its current location to the network 100. The location report may be sent as a radio resource control (RRC) message. Block 1420 is dashed to indicate that it is optional, as not all user terminals report their locations.

[0131] At block 1430, the user terminal (specifically, the controller / processor 259) may change the connection state (e.g., RRC_CONNECTED, RRC_INACTIVE, RRC_IDLE, etc.) with the network 100. In this case, if block 1420 is performed, the reported location may be considered to be the last location of the user terminal before the connection state was changed.

[0132] At block 1440, the user terminal (specifically, the transceiver 254 and / or the RX processor 256) may determine whether a page has been received. If so, at block 1450, the user terminal (specifically, the controller / processor 259) may process the page.

[0133] At block 1460, the user terminal (specifically, the controller / processor 259) may determine the moving distance of the user terminal. In this case, the moving distance may represent the distance between the current position of the user terminal and the previous position, wherein the previous position is the position of the user terminal previously reported to the network.

[0134] At block 1470, the user terminal (specifically, the controller / processor 259) may determine whether the movement distance is equal to or greater than the threshold distance 662. If so, at block 1480, the user terminal (specifically, the transceiver 354 and / or the TX processor 268) may send a location report, e.g., in an RRC message, to update the network 100 with the current location. Again, blocks 1460, 1470, 1480 are dashed to indicate that it is optional, as not all user terminals report their locations.

[0135] Method 1400 may end or may return to any of blocks 1410, 1420, 1430, 1440, 1460 as shown to indicate that the user terminal may repeatedly send mobility and / or location reports and / or receive paging.

[0136] It should be noted that it is not necessary to implement Figure 8-12 All the blocks shown in the figure, that is, some blocks may be optional. Moreover, the reference numerals of the blocks in these figures should not be regarded as requiring that these blocks should be executed in a specific order. In fact, some blocks can be executed simultaneously.

[0137] Fig.15 The method for implementing the present invention according to aspects of the present disclosure is shown. Figure 8-1 1, which is represented as a series of related functional modules. In the example shown, the apparatus 1500 may include: a module 1510 for determining the last area of ​​the user terminal, a module 1520 for determining the user terminal tracking area (UT TA), and a module 1530 for paging the user terminal. The module 1510 for determining the last area of ​​the user terminal can be configured to determine the last area 550 (e.g., Figure 8 Module 1520 for determining user terminal tracking area may be configured to determine UT TA 440 based on last area 550 (e.g., Figure 8 The module 1530 for paging the user terminal may be configured to page the UT 130 using one or more station beams 115 corresponding to the UT TA 440 (e.g., block 840).

[0138] Fig.16 An example apparatus 1600 for implementing the method 1400 according to aspects of the present disclosure is shown, which is represented as a series of related functional modules. In the example shown, the apparatus 1600 may include a module 1610 for providing mobility, a module 1620 for sending a location report, a module 1630 for changing a connection state, a module 1640 for receiving a paging message, a module 1650 for determining a moving distance, and a module 1660 for comparing the moving distance with a threshold distance.

[0139] The module for providing mobility 1610 may be configured to provide mobility of UT 130 to NTN 100 (e.g., Fig.14 Module 1620 for sending location report may be configured to send a location report including the last location of UT 130 (e.g., Fig.141420 and 1480). The module for changing the connection state 1630 may be configured to change the connection state between the UT 130 and the NTN (e.g., Fig.14 The module 1640 for receiving a paging message may be configured to receive a paging message from the NTN 100 (e.g., Fig.14 Module 1650 for determining travel distance may be configured to determine the travel distance of UT 130 (e.g., Fig.14 Module 1660 for comparing the moving distance to the threshold distance may be configured to determine whether the moving distance is greater than or equal to the threshold distance (e.g., Fig.14 1470).

[0140] The following provides an overview of examples of the present disclosure:

[0141] Example 1: A method of a network node of a non-terrestrial network (NTN), comprising: determining a last area of ​​a user terminal (UT); determining a UT tracking area (TA) based on the last area, the UT TA being a non-terrestrial network tracking area (NTN TA) in which the UT is currently located, the UT TA being one of multiple NTN TAs; and paging the UT using one or more satellite beams corresponding to the UT TA.

[0142] Example 2: The method of Example 1, wherein at least one NTN TA is associated with a set of one or more satellite beams such that the at least one NTN TA moves relative to the surface of the Earth according to movement of one or more satellites corresponding to the one or more satellite beams.

[0143] Example 3: The method of any of Examples 1 to 2, wherein at least one NTN TA is a geographic area on the surface of the Earth.

[0144] Example 4: A method according to any one of Examples 1 to 3, wherein determining the last area comprises: receiving a location report from the UT, the location report comprising a last location of the UT; and determining an area including the last location as the last area.

[0145] Example 5: The method of Example 4, wherein determining the UT TA comprises determining, as the UT TA, an NTN TA corresponding to at least one satellite beam whose coverage area at least partially overlaps with the last area.

[0146] Example 6: A method according to any one of Examples 4 to 5, wherein determining the UT TA includes: determining a threshold distance of the UT, the threshold distance being a maximum distance traveled by the UT before updating its position through another position report; determining a threshold area so that: at least a portion of the last area is inside the threshold area, and a distance from the last area to at least a portion of an edge of the threshold area is based on the threshold distance; and determining an NTN TA corresponding to at least one satellite beam whose coverage area at least partially overlaps with the threshold area as the UT TA.

[0147] Example 7: A method according to Example 6, wherein the threshold distance is determined based on any one or more of the size of the coverage area of ​​the satellite beam serving the UT when the network node receives the last position, the mobility of the UT, and the density of satellite deployment of the NTN.

[0148] Example 8: The method according to any one of Examples 1 to 7, wherein determining the last area includes: determining a coverage area of ​​a satellite beam serving the UT when the UT exits its previous connection state as the last area.

[0149] Example 9: The method of Example 8, wherein determining the UT TA comprises determining, as the UT TA, an NTN TA corresponding to at least one satellite beam whose coverage area at least partially overlaps with the last area.

[0150] Example 10: A method according to any one of Examples 8 to 9, wherein determining the UT TA includes: determining the mobility of the UT; determining a moving distance of the UT based on the mobility, the moving distance being related to a distance that the UT may have traveled from the last area since the last area was determined; determining a moving area so that: the last area is inside the moving area, and a distance from the last area to at least a portion of an edge of the moving area is based on the moving distance; and determining an NTN TA corresponding to at least one satellite beam whose coverage area at least partially overlaps with the moving area as the UT TA.

[0151] Example 11: A method according to Example 10, wherein determining the mobility includes: receiving the mobility from the UT, wherein the mobility is received as a mobility type, wherein the received mobility type is one of a plurality of mobility types, each mobility type corresponding to a mobility level.

[0152] Example 12: The method of Example 11, wherein at least one of the plurality of mobility types is fixed mobility indicating that the location of the UT is fixed to its installation location.

[0153] Example 13: A method according to any one of Examples 1 to 12, wherein the mobility of the UT is fixed mobility, the fixed mobility indicating that the position of the UT is fixed to its installation location, and wherein determining the last area and determining the UTTA include: determining an NTN TA corresponding to at least one satellite beam whose coverage area covers the installation location of the UT as the UT TA.

[0154] Example 14: The method of Example 13, wherein paging the UT comprises paging the UT using only one or more satellite beams corresponding to a coverage area of ​​the UT TA that covers an installation location of the UT.

[0155] Example 15: A network node of a non-terrestrial network (NTN), comprising a processor and a memory coupled to the processor, the processor and the memory being configured to perform the method of any one of Examples 1 to 14.

[0156] Example 16: A network node of a non-terrestrial network (NTN), comprising at least one unit for performing the method of any one of Examples 1 to 14.

[0157] Example 17: A non-transitory computer-readable medium storing code for a network node for a non-terrestrial network (NTN), the network node comprising a processor, a memory coupled to the processor, and instructions stored in the memory and executable by the processor to cause the network node to perform the method of any one of Examples 1 to 14.

[0158] Example 18: A method of a user terminal (UT), comprising: changing a connection state of the UT with a non-terrestrial network (NTN); and receiving a paging message from the NTN after changing the connection state.

[0159] Example 19: The method according to Example 18 also includes: sending a location report including the last location of the UT before changing the connection state of the UT.

[0160] Example 20: According to the method of Example 19, it also includes: determining a moving distance, wherein the moving distance is the distance between the current position and the previous position of the UT, wherein the previous position is the position of the UT previously reported to the NTN; and whenever the moving distance exceeds a threshold distance, sending another position report to the NTN to update the position of the UT using the current position.

[0161] Example 21: A method according to Example 20, wherein the threshold distance is determined based on any one or more of the size of the coverage area of ​​the satellite beam serving the UT when the network node receives the last position, the mobility of the UT, and the density of satellite deployment of the NTN.

[0162] Example 22: The method of any one of Examples 20 to 21, wherein the location of the UT and one or more updates to the location of the UT are reported to the NTN in a radio resource control (RRC) message.

[0163] Example 23: The method according to any one of Examples 18 to 22 further includes: providing the mobility of the UT to the NTN, wherein the mobility is provided as a mobility type, and wherein the provided mobility type is one of a plurality of mobility types, each mobility type corresponding to a mobility level.

[0164] Example 24: The method of Example 23, wherein at least one of the plurality of mobility types is fixed mobility indicating that the location of the UT is fixed to its installation location.

[0165] Example 25: A user terminal (UT), comprising a processor, a memory coupled to the processor, the processor and the memory configured to perform the method of any one of Examples 18 to 24.

[0166] Example 26: A user terminal (UT), comprising at least one unit for performing the method of any one of Examples 18 to 24.

[0167] Example 27: A non-transitory computer-readable medium storing code for a user terminal (UT), the user terminal comprising a processor, a memory coupled to the processor, and instructions stored in the memory and executable by the processor to cause the network node to perform the method of any one of Examples 18 to 24.

[0168] Those skilled in the art will appreciate that any of a variety of different techniques and methods may be used to represent information and signals. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be mentioned throughout the above description may be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, light fields or optical particles, or any combination thereof.

[0169] In addition, those skilled in the art will appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in conjunction with the aspects disclosed herein may be implemented as electronic hardware, computer software, or a combination of both. In order to clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system. A skilled person may implement the described functionality in different ways for each specific application, but such implementation decisions should not be interpreted as departing from the scope of the various aspects described herein.

[0170] The various illustrative logical blocks, modules, and circuits described in conjunction with the aspects disclosed herein may be implemented or performed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, a combination of one or more microprocessors with a DSP core, or other such configurations).

[0171] The methods, sequences and / or algorithms described in conjunction with the aspects disclosed herein may be directly embodied in hardware, in a software module executed by a processor, or in a combination of the two. The software module may reside in a random access memory (RAM), flash memory, read-only memory (ROM), erasable programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), registers, hard disks, removable disks, CD-ROMs, or any other form of non-transitory computer-readable medium known in the art. An exemplary non-transitory computer-readable medium may be coupled to a processor so that the processor can read information from the non-transitory computer-readable medium and write information to the non-transitory computer-readable medium. In an alternative, the non-transitory computer-readable medium may be integrated with the processor. The processor and the non-transitory computer-readable medium may reside in an ASIC. The ASIC may reside in a user device (e.g., UT) or a base station. In an alternative, the processor and the non-transitory computer-readable medium may be discrete components in a user device or a base station.

[0172] In one or more exemplary aspects, the functions described herein may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored as one or more instructions or codes on a non-transitory computer-readable medium or sent via a non-transitory computer-readable medium. Computer-readable media may include storage media and / or communication media, including any non-transitory media that may help send a computer program from one place to another. Storage media may be any available medium that can be accessed by a computer. As an example and not limitation, such computer-readable media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage devices, magnetic disk storage devices or other magnetic storage devices, or any other medium that can be used to carry or store the required program code in the form of an instruction or data structure and can be accessed by a computer. Moreover, any connection is appropriately referred to as a computer-readable medium. For example, if software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwaves, then coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwaves are included in the definition of medium. The terms "disc" and "disc" are used interchangeably herein and include compact disc (CD), laser disc, optical disc, digital video disc (DVD), floppy disk and Blu-ray disc, which typically reproduce data magnetically and / or optically using lasers. Combinations of the above should also be included within the scope of computer-readable media.

[0173] Although the foregoing disclosure shows illustrative aspects, those skilled in the art will appreciate that various changes and modifications may be made herein without departing from the scope of the present disclosure as defined in the appended claims. In addition, based on the various illustrative aspects described herein, those skilled in the art will appreciate that the functions, steps, and / or operations in any method described above and / or in any method claim attached hereto need not be performed in any particular order. In addition, with respect to any element described above or in the appended claims in the singular, those skilled in the art will appreciate that the singular also encompasses the plural unless expressly stated to be limited to the singular.

Claims

1. A method performed by a network node of a non-terrestrial network (NTN), the method comprising: Determine the last area of ​​the user terminal (UT); determining a UT Tracking Area (TA) based on the last area, the UT TA being a Non-Terrestrial Network Tracking Area (NTN TA) in which the UT is currently located, the UT TA being one of a plurality of NTN TAs; and paging the UT using one or more satellite beams corresponding to the UT TA, Wherein, determining the UT TA further comprises one of the following: (a) determining a threshold distance of the UT, the threshold distance being a maximum distance traveled by the UT before updating its position via another position report; determining a threshold region such that: at least a portion of the last region is inside the threshold region, and a distance from the last region to at least a portion of an edge of the threshold region is based on the threshold distance; and determining, as the UT TA, an NTNTA corresponding to at least one satellite beam whose coverage area at least partially overlaps with the threshold area, or (b) determining the mobility of the UT; determining a travel distance of the UT based on the mobility, the travel distance being related to a distance the UT may have traveled from the last area since determining the last area; determining a movement region such that: the last region is inside the movement region, and a distance from the last region to at least a portion of an edge of the movement region is based on the movement distance; and An NTNTA corresponding to at least one satellite beam whose coverage area at least partially overlaps with the movement area is determined as the UT TA.

2. The method according to claim 1, wherein: At least one NTN TA is associated with a set of one or more satellite beams such that the at least one NTN TA moves relative to the surface of the Earth according to movement of one or more satellites corresponding to the one or more satellite beams.

3. The method according to claim 1, wherein: At least one NTN TA is a geographical area on the surface of the Earth.

4. The method according to claim 1, wherein: For (a), determining the last region includes: receiving a location report from the UT, the location report comprising a last location of the UT; and An area including the last position is determined as the last area.

5. The method according to claim 4, wherein: The threshold distance is determined based on any one or more of a set distance, a size of a coverage area of ​​a satellite beam serving the UT when the network node receives the last location, mobility of the UT, and a density of satellite deployment of the NTN.

6. The method according to claim 1, wherein: For (b), determining the last area includes determining a coverage area of ​​a satellite beam serving the UT when the UT exits its previous connection state as the last area.

7. The method according to claim 1, wherein: Determining the mobility includes: receiving the mobility from the UT, wherein the mobility is received as a mobility type, The received mobility type is one of multiple mobility types, and each mobility type corresponds to a mobility level.

8. The method according to claim 7, wherein: At least one of the plurality of mobility types is fixed mobility indicating that the location of the UT is fixed to its installation location.

9. A method of operating a user terminal (UT), the method comprising: sending a location report to a non-terrestrial network (NTN), the location report including the last location of the UT; changing the connection state between the UT and the NTN after sending the location report; receiving a paging message from the NTN after changing the connection state, wherein the paging message is sent according to an NTN tracking area (TA) of the UT; determining a travel distance, the travel distance being a distance between a current location of the UT and a previous location, the previous location being a location of the UT previously reported to the NTN; and Whenever the moving distance exceeds a threshold distance, another position report is sent to the NTN to update the position of the UT using the current position, so that the NTN can determine the threshold area by making at least a portion of the last area of ​​the UT inside the threshold area, and determine the NTN TA corresponding to at least one satellite beam whose coverage area at least partially overlaps with the threshold area as the NTN TA of the UT, wherein the distance of the last area of ​​the UT to at least a portion of an edge of the threshold area is based on the threshold distance, and wherein the last area of ​​the UT is an area containing the position in the another position report.

10. The method according to claim 9, wherein: The threshold distance is determined based on any one or more of a set distance, a size of a coverage area of ​​a satellite beam serving the UT when a network node of the NTN receives the last location, mobility of the UT, and a density of satellite deployment of the NTN.

11. The method according to claim 9, wherein: The location of the UT and one or more updates to the location of the UT are reported to the NTN in a radio resource control (RRC) message.

12. The method according to claim 9, further comprising: providing mobility of the UT to the NTN, wherein the mobility is provided as a mobility type, and The provided mobility type is one of multiple mobility types, and each mobility type corresponds to a mobility level.

13. The method according to claim 12, wherein: At least one of the plurality of mobility types is fixed mobility indicating that the location of the UT is fixed to its installation location.

14. A network node of a non-terrestrial network (NTN), the network node comprising: a memory and at least one processor coupled to the memory, Wherein, the memory and the at least one processor are configured to: Determine the last area of ​​the user terminal (UT); determining a UT Tracking Area (TA) based on the last area, the UT TA being a Non-Terrestrial Network Tracking Area (NTN TA) in which the UT is currently located, the UT TA being one of a plurality of NTN TAs; and Page the UT using one or more satellite beams corresponding to the UT TA Wherein, when determining the UT TA, the memory and the at least one processor are configured as one of the following: (a) determining a threshold distance of the UT, the threshold distance being a maximum distance traveled by the UT before updating its position via another position report; determining a threshold region such that: at least a portion of the last region is inside the threshold region, and a distance from the last region to at least a portion of an edge of the threshold region is based on the threshold distance; and determining, as the UT TA, an NTNTA corresponding to at least one satellite beam whose coverage area at least partially overlaps with the threshold area, or (b) determining the mobility of the UT; determining a travel distance of the UT based on the mobility, the travel distance being related to a distance the UT may have traveled from the last area since determining the last area; determining a movement region such that: the last region is inside the movement region, and a distance from the last region to at least a portion of an edge of the movement region is based on the movement distance; and An NTNTA corresponding to at least one satellite beam whose coverage area at least partially overlaps with the movement area is determined as the UT TA.

15. The network node according to claim 14, wherein: At least one NTN TA is a geographical area on the surface of the Earth.

16. The network node according to claim 14, wherein: The network node further comprises a transceiver coupled to the at least one processor, and wherein, for (a), the memory, the transceiver and the at least one processor are configured to: receiving a location report from the UT, the location report comprising a last location of the UT; and An area including the last position is determined as the last area.

17. The network node according to claim 14, wherein: With respect to (b), the memory and the at least one processor are configured to: The coverage area of ​​the satellite beam serving the UT when the UT exits its previous connection state is determined as the last area.

18. The network node according to claim 14, wherein: The memory and the at least one processor are configured to: receiving the mobility from the UT, wherein the mobility is received as a mobility type, The received mobility type is one of multiple mobility types, and each mobility type corresponds to a mobility level.

19. A user terminal (UT), comprising: a memory and at least one processor coupled to the memory, Wherein, the memory and the at least one processor are configured to: sending a location report to a non-terrestrial network (NTN), the location report including the last location of the UT; changing the connection state between the UT and the NTN after sending the location report; receiving a paging message from the NTN after changing the connection state, wherein the paging message is sent based on an NTN tracking area (TA) of the UT; determining a travel distance, the travel distance being a distance between a current location of the UT and a previous location, the previous location being a location of the UT previously reported to the NTN; and Whenever the moving distance exceeds a threshold distance, another position report is sent to the NTN to update the position of the UT using the current position, so that the NTN can determine the threshold area by making at least a portion of the last area of ​​the UT inside the threshold area, and determine the NTN TA corresponding to at least one satellite beam whose coverage area at least partially overlaps with the threshold area as the NTN TA of the UT, wherein the distance of the last area of ​​the UT to at least a portion of an edge of the threshold area is based on the threshold distance, and wherein the last area of ​​the UT is an area containing the position in the another position report.

20. The UT of claim 19, wherein: The threshold distance is determined based on any one or more of a set distance, a size of a coverage area of ​​a satellite beam serving the UT when a network node of the NTN receives the last location, mobility of the UT, and a density of satellite deployment of the NTN.

21. The UT of claim 19, wherein: The UT further comprises a transceiver coupled to the at least one processor, and wherein the memory, the transceiver, and the at least one processor are configured to: providing mobility of the UT to the NTN, wherein the mobility is provided as a mobility type, wherein the provided mobility type is one of a plurality of mobility types, each mobility type corresponds to a mobility level, and At least one mobility type among the plurality of mobility types is fixed mobility, and the fixed mobility indicates that the position of the UT is fixed to its installation location.

Images