Non-terrestrial network apparatus, wireless communication system, and wireless communication method

Abstract

To provide a non-terrestrial network apparatus, a wireless communication system, and a wireless communication method that can improve the inconveniences associated with disconnection of an Xn interface.SOLUTION: A non-terrestrial network apparatus constituting a non-terrestrial network includes a communication unit that, when the non-terrestrial network apparatus has the function of a base station, executes communication via an inter-base station interface between the non-terrestrial network apparatus and an adjacent base station, and a control unit that establishes the inter-base station interface via at least one of a first link between the non-terrestrial network apparatus and an adjacent non-terrestrial network apparatus and a second link between the non-terrestrial network apparatus and a gateway apparatus provided on the ground.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to a non-terrestrial network device, a wireless communication system, and a wireless communication method that are compatible with regenerative NTN. [Background technology]

[0002] The 3rd Generation Partnership Project (3GPP) has developed specifications for the 5th generation mobile communication system (5G, also known as New Radio (NR) or Next Generation (NG)), and is also developing specifications for the next generation, known as Beyond 5G, 5G Evolution, or 6G.

[0003] 3GPP is considering the Non-Terrestrial Network (NTN), which uses a non-terrestrial network consisting of non-terrestrial network devices such as artificial satellites (hereinafter referred to as satellites) and High Altitude Platform Stations (HAPS) to provide edge services to areas that cannot be covered by terrestrial networks due to cost and other reasons (for example, Non-Patent Document 1).

[0004] In NTN, methods such as transparent and regenerative are envisioned. In the transparent type, the non-terrestrial network equipment does not have the functionality of a base station, and simply retransmits signals. In the regenerative type, the non-terrestrial network equipment has some of the functionality of a base station, and regenerates signals (for example, Non-Patent Document 2). [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] “Revised WID: NR NTN (Non-Terrestrial Networks) enhancements”, RP-221819, 3GPP TSG RAN Meeting #96, 3GPP, June 6-9, 2022 [Non-patent document 2] “On support of regenerative payload in NTN”, RP-2402714, 3GPP TSG RAN Meeting #125bis, 3GPP, April 15-19, 2024 Summary of the Invention

[0006] In the regenerative type, it is expected that the interface between base stations installed in non-terrestrial networks (Xn interface) will be connected via a link between non-terrestrial networks (ISL; Inter-Satellite Link).

[0007] Under the above-mentioned background, the inventors have conducted extensive research and found that, in the regenerative type, attention is focused on disconnection of the Xn interface due to movement of non-terrestrial network devices, and that it is necessary to improve inconveniences caused by disconnection of the Xn interface. The inconveniences caused by disconnection of the Xn interface may include suppression of failures in Handover (HO) or RRC re-establishment procedures, reduction of load on base stations, reduction of load on the Xn interface, etc.

[0008] Therefore, the present disclosure has been made to solve the above-mentioned problems, and aims to provide a non-terrestrial network device, a wireless communication system, and a wireless communication method that can improve the inconveniences associated with disconnecting the Xn interface.

[0009] The disclosed aspect is a non-terrestrial network device that constitutes a non-terrestrial network, comprising: a communication unit that, when the non-terrestrial network device has the functionality of a base station, executes communication via a base station-to-base station interface between the non-terrestrial network device and an adjacent adjacent base station; and a control unit that establishes the base station-to-base station interface via at least one of a first link between the non-terrestrial network device and the adjacent adjacent non-terrestrial network device and a second link between the non-terrestrial network device and a gateway device provided on the ground.

[0010] The disclosed aspect is a wireless communication system comprising a non-terrestrial network device constituting a non-terrestrial network and a gateway device provided on the ground, wherein the non-terrestrial network device comprises a communication unit that, when the non-terrestrial network device has the functionality of a base station, executes communication via a base station-to-base station interface between the non-terrestrial network device and an adjacent adjacent base station, and a control unit that establishes the base station-to-base station interface via at least one of a first link between the non-terrestrial network device and the adjacent adjacent non-terrestrial network device and a second link between the non-terrestrial network device and a gateway device provided on the ground.

[0011] The disclosed aspect is a wireless communication method comprising the steps of: when a non-terrestrial network device constituting a non-terrestrial network has base station functionality, performing communication via a base station-to-base station interface between the non-terrestrial network device and an adjacent adjacent base station; and establishing the base station-to-base station interface via at least one of a first link between the non-terrestrial network device and the adjacent adjacent non-terrestrial network device and a second link between the non-terrestrial network device and a gateway device provided on the ground. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram showing the overall schematic configuration of a wireless communication system 10. As shown in FIG. [Figure 2]FIG. 2 is a diagram showing frequency ranges used in the wireless communication system 10. As shown in FIG. [Figure 3] FIG. 3 is a diagram showing an example of the configuration of a radio frame, a subframe, and a slot used in the radio communication system 10. As shown in FIG. [Figure 4] FIG. 4 is a functional block diagram of the UE 200. [Figure 5] FIG. 5 is a functional block diagram of the NTN node 150. [Figure 6] FIG. 6 is a diagram for explaining the protocol. [Figure 7] FIG. 7 is a diagram for explaining TA. [Figure 8] FIG. 8 is a diagram for explaining the Regenerative type of NTN. [Figure 9] FIG. 9 is a diagram for explaining the Regenerative type of NTN. [Figure 10] FIG. 10 is a diagram for explaining the Regenerative type of NTN. [Figure 11] FIG. 11 is a diagram for explaining the first operation example. [Figure 12] FIG. 12 is a diagram illustrating the first operation example. [Figure 13] FIG. 13 is a diagram illustrating the second operation example. [Figure 14] FIG. 14 is a diagram illustrating the second operation example. [Figure 15] FIG. 15 is a diagram illustrating an example of the hardware configuration of the NTN node 150. [Figure 16] FIG. 16 is a diagram showing an example of the configuration of a vehicle 2001. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments will be described with reference to the drawings. Note that the same or similar reference numerals are used to designate the same functions or configurations, and descriptions thereof will be omitted as appropriate.

[0014] (1) Overall configuration of wireless communication system 1 is a schematic diagram of the overall configuration of a wireless communication system 10 according to an embodiment. The wireless communication system 10 is a wireless communication system conforming to 5G New Radio (NR) and includes a Next Generation-Radio Access Network 20 (hereinafter, NG-RAN 20) and a terminal 200 (hereinafter, UE (User Equipment) 200).

[0015] The wireless communication system 10 may be a wireless communication system conforming to a system called Beyond 5G, 5G Evolution, or 6G.

[0016] The NG-RAN 20 includes a base station 100 (hereinafter, gNB 100). Note that the specific configuration of the wireless communication system 10, including the number of gNBs 100 and UEs 200, is not limited to the example shown in FIG.

[0017] The NG-RAN 20 actually includes a plurality of NG-RAN nodes, specifically, gNBs (or ng-eNBs), and is connected to a core network 30 conforming to 5G (for example, 5GC). The NG-RAN 20 and the core network 30 may be simply referred to as a "network."

[0018] The gNB 100 is a radio base station conforming to 5G, and performs 5G radio communication with the UE 200. The gNB 100 and the UE 200 are capable of supporting Massive MIMO (Multiple-Input Multiple-Output), which generates a more directional beam BM by controlling radio signals transmitted from multiple antenna elements, Carrier Aggregation (CA), which aggregates and uses multiple component carriers (CCs), and Dual Connectivity (DC), which simultaneously communicates on two or more transport blocks between the UE and each of two NG-RAN nodes.

[0019] The core network 30 includes a core network device 300. The core network device 300 may include a Location Management Function (LMF). The core network device 300 may include an Access and Mobility management Function (AMF). The core network device 300 may be an Evolved Serving Mobile Location Centre (E-SMLC).

[0020] In the embodiment, a non-terrestrial network (hereinafter referred to as NTN) is assumed. The NTN uses non-terrestrial network devices 150 to provide edge services in areas that cannot be covered by a terrestrial network (hereinafter referred to as TN) due to cost or other reasons. The non-terrestrial network devices 150 may be referred to as NTN nodes 150. The NTN can provide more reliable edge services. For example, the NTN is expected to be applied to IoT (Internet of Things), ships, buses, trains, and critical communications. The NTN also has scalability through efficient multicast or broadcast. The NTN nodes 150 may include satellites such as LEO (Low Earth Orbit) and GEO (Geostationary Earth Orbit). The NTN nodes 150 may also include flying objects such as HAPS (High Altitude Platform Station), aircraft, drones, helicopters, and balloons.

[0021] In addition, a network including a gNB 100 and a UE 200 without including an NTN node 150 may be referred to as a terrestrial network (TN) in contrast to an NTN.

[0022] The wireless communication system 10 includes a TN gateway 100X. The TN gateway 100X transmits a downlink signal to an NTN node 150. The TN gateway 100X receives an uplink signal from the NTN node 150. The gNB 100 has a cell C1 as its coverage area.

[0023] The NTN node 150 relays or transmits a downlink signal received from the TN gateway 100X to the UE 200. The NTN node 150 relays or receives an uplink signal received from the UE 200 to the TN gateway 100X. The NTN node 150 has cell C2 as its coverage area. The NTN node 150 may be considered to be a TRP (Transmission-Reception Point).

[0024] The wireless communication system 10 also supports a plurality of frequency ranges (FR).

[0025] First, the wireless communication system 10 may support multiple frequency ranges (FR) as shown in Fig. 2. For example, the wireless communication system 10 supports FR1, FR2-1, and FR2-2. The frequency bands of each FR are as follows:

[0026] FR1: 410 MHz to 7.125 GHz FR2-1: 24.25 GHz to 52.6 GHz ·FR2-2: More than 52.6GHz~71GHz FR1 may use a Sub-Carrier Spacing (SCS) of 15, 30, or 60 kHz, and may use a bandwidth (BW) of 5 to 100 MHz. FR2 is a higher frequency than FR1, and may use an SCS of 60 kHz or 120 kHz (including 240 kHz), and may use a bandwidth (BW) of 50 to 400 MHz.

[0027] Note that SCS may be interpreted as numerology, which is defined in 3GPP TS38.300 and corresponds to one subcarrier spacing in the frequency domain.

[0028] Furthermore, the wireless communication system 10 may also be compatible with frequency bands higher than the FR2 frequency band. Specifically, the wireless communication system 10 may be compatible with frequency bands exceeding 52.6 GHz up to 71 GHz or 114.25 GHz.

[0029] Second, the wireless communication system 10 may support the radio frames, subframes, and slots shown in FIG.

[0030] As shown in Figure 3, one slot consists of 14 symbols, and the larger (wider) the SCS, the shorter the symbol period (and slot period). In addition to 15 kHz, 30 kHz, 60 kHz, 120 kHz, and 240 kHz, the SCS may also use 480 kHz, 960 kHz, etc.

[0031] Furthermore, the number of symbols constituting one slot does not necessarily have to be 14 (for example, 28 symbols or 56 symbols). Furthermore, the number of slots per subframe may differ depending on the SCS.

[0032] The time direction (t) shown in Fig. 3 may be called a time domain, a symbol period, or a symbol time, etc. The frequency direction may be called a frequency domain, a resource block, a subcarrier, a bandwidth part (BWP), etc.

[0033] (2) Functional block configuration of wireless communication system The functional block configuration of the wireless communication system 10 will be described below.

[0034] First, the functional block configuration of the UE 200 will be described.

[0035] Fig. 4 is a functional block diagram of UE 200. As shown in Fig. 4, UE 200 includes radio signal transmitting / receiving unit 210, amplifier unit 220, modem unit 230, control signal / reference signal processing unit 240, encoding / decoding unit 250, data transmitting / receiving unit 260, and control unit 270.

[0036] The radio signal transmitting / receiving unit 210 transmits and receives radio signals conforming to NR. The radio signal transmitting / receiving unit 210 supports Massive MIMO, CA that uses a bundle of multiple CCs, and DC that simultaneously communicates between a UE and two NG-RAN nodes.

[0037] The amplifier unit 220 is configured by a PA (Power Amplifier) / LNA (Low Noise Amplifier), etc. The amplifier unit 220 amplifies the signal output from the modulation / demodulation unit 230 to a predetermined power level. The amplifier unit 220 also amplifies the RF signal output from the radio signal transmission / reception unit 210.

[0038] The modem unit 230 performs data modulation / demodulation, transmission power setting, resource block allocation, etc. for each predetermined communication destination (gNB 100 or another gNB). The modem unit 230 may apply Cyclic Prefix-Orthogonal Frequency Division Multiplexing (CP-OFDM) / Discrete Fourier Transform - Spread (DFT-S-OFDM). Furthermore, DFT-S-OFDM may be used not only for the uplink (UL) but also for the downlink (DL).

[0039] The control signal / reference signal processor 240 performs processing related to various control signals transmitted and received by the UE 200 and processing related to various reference signals transmitted and received by the UE 200 .

[0040] Specifically, the control signal / reference signal processor 240 receives various control signals, for example, control signals of a radio resource control layer (RRC), transmitted via a predetermined control channel from the gNB 100. The control signal / reference signal processor 240 also transmits various control signals to the gNB 100 via a predetermined control channel.

[0041] The control signal / reference signal processor 240 performs processing using reference signals (RS) such as a Demodulation Reference Signal (DMRS) and a Phase Tracking Reference Signal (PTRS).

[0042] DMRS is a reference signal (pilot signal) known between the base station and the terminal for estimating the fading channel used for data demodulation. PTRS is a terminal-specific reference signal for estimating phase noise, which is an issue in high frequency bands.

[0043] In addition to the DMRS and PTRS, the reference signals may include a Channel State Information-Reference Signal (CSI-RS), a Sounding Reference Signal (SRS), and a Positioning Reference Signal (PRS) for position information.

[0044] The channels include control channels and data channels, such as a PDCCH (Physical Downlink Control Channel), a PUCCH (Physical Uplink Control Channel), a RACH (Random Access Channel), Downlink Control Information (DCI) including a Random Access Radio Network Temporary Identifier (RA-RNTI), and a Physical Broadcast Channel (PBCH).

[0045] Furthermore, the data channel includes a PDSCH (Physical Downlink Shared Channel) and a PUSCH (Physical Uplink Shared Channel). Data refers to data transmitted via the data channel. The data channel may be interpreted as a shared channel.

[0046] Here, the control signal and reference signal processor 240 may receive downlink control information (DCI). The DCI includes existing fields for storing DCI Formats, Carrier indicator (CI), BWP indicator, Frequency Domain Resource Assignment (FDRA), Time Domain Resource Assignment (TDRA), Modulation and Coding Scheme (MCS), HARQ Process Number (HPN), New Data Indicator (NDI), Redundancy Version (RV), etc.

[0047] The value stored in the DCI Format field is an information element that specifies the format of the DCI. The value stored in the CI field is an information element that specifies the CC to which the DCI applies. The value stored in the BWP indicator field is an information element that specifies the BWP to which the DCI applies. The BWP that can be specified by the BWP indicator is set by an information element (BandwidthPart-Config) included in the RRC message. The value stored in the FDRA field is an information element that specifies the frequency domain resource to which the DCI applies. The frequency domain resource is identified by the value stored in the FDRA field and an information element (RA Type) included in the RRC message. The value stored in the TDRA field is an information element that specifies the time domain resource to which the DCI applies. The time domain resource is identified by the value stored in the TDRA field and information elements (pdsch-TimeDomainAllocationList, pusch-TimeDomainAllocationList) included in the RRC message. The time domain resource may be identified by the value stored in the TDRA field and a default table. The value stored in the MCS field is an information element that specifies the MCS to which the DCI applies. The MCS is identified by the value stored in the MCS and an MCS table. The MCS table may be specified by an RRC message or may be determined by RNTI scrambling. The value stored in the HPN field is an information element that specifies the HARQ process to which the DCI is applied. The value stored in the NDI field is an information element for specifying whether the data to which the DCI is applied is initial transmission data. The value stored in the RV field is an information element that specifies the redundancy of the data to which the DCI is applied.

[0048] The encoding / decoding unit 250 performs data division / concatenation and channel coding / decoding for each predetermined communication destination (gNB100 or another gNB).

[0049] Specifically, the encoding / decoding unit 250 divides the data output from the data transmitting / receiving unit 260 into pieces of a predetermined size, performs channel coding on the divided data, decodes the data output from the modem unit 230, and concatenates the decoded data.

[0050] The data transmitter / receiver 260 transmits and receives Protocol Data Units (PDUs) and Service Data Units (SDUs). Specifically, the data transmitter / receiver 260 assembles and disassembles PDUs / SDUs in multiple layers (such as a Medium Access Control layer (MAC), a Radio Link Control layer (RLC), and a Packet Data Convergence Protocol layer (PDCP)). The data transmitter / receiver 260 also performs data error correction and retransmission control based on HARQ (Hybrid Automatic Repeat Request).

[0051] The control unit 270 controls each functional block constituting the UE 200. In an embodiment, the control unit 270 may control transmission of information specifying an edge service requested by the UE 200. The edge service requested by the UE 200 may be an edge service provided by the NTN.

[0052] Secondly, a description will be given of the functional block configuration of the NTN node 150. In the embodiment, the NTN node 150 may have the functionality of a base station.

[0053] 5 is a functional block diagram of the NTN node 150. As shown in FIG. 5, the NTN node 150 includes a receiving unit 151, a transmitting unit 152, and a control unit 153.

[0054] The receiving unit 151 receives various signals from the UE 200. The receiving unit 151 may receive an UL signal via a PUCCH or a PUSCH. The receiving unit 151 receives various signals from the gNB 100.

[0055] When the NTN node 150 has the function of a base station, the receiving unit 151 may receive information from a neighboring base station via an inter-base station interface (Xn interface).

[0056] The transmitter 152 transmits various signals to the UE 200. The transmitter 152 may transmit DL signals via a PDCCH or a PDSCH. The transmitter 152 transmits various signals to the gNB 100.

[0057] When the NTN node 150 has the function of a base station, the transmitting unit 152 may transmit information to a neighboring base station via an inter-base station interface (Xn interface).

[0058] In an embodiment, the receiving unit 151 and the transmitting unit 152 may constitute a communication unit that performs communication via a base station interface (Xn interface) between the non-terrestrial network device and an adjacent neighboring base station when the non-terrestrial network device (NTN 150) has the functionality of a base station.

[0059] The control unit 153 controls the NTN node. In an embodiment, the control unit 153 may be configured as a control unit that establishes an interface between base stations via at least one of a first link between a non-terrestrial network device and an adjacent non-terrestrial network device and a second link with a gateway device () provided on the ground.

[0060] (3) Overview of NTN First, we explain the protocol for NTN.

[0061] 6, the gNB 100 has a protocol stack including PHY, MAC, RLC, PDCP, RRC / SDAP, etc. Similarly, the UE 200 has a protocol stack including PHY, MAC, RLC, PDCP, RRC / SDAP, etc. The NTN node 150 relays communication between the gNB 100 and the UE 200.

[0062] Here, the link between the TN gateway 100X and the NTN node 150 may be referred to as a Feeder Link. The link between the NTN node 150 and the UE 200 may be referred to as a Service link. The interface between the gNB 100 and the UE 200 may be referred to as an NR Uu.

[0063] NTN's network architecture may be FDD or TDD. Terrestrial cells may be fixed or mobile. UE 200 may be capable of supporting GNSS (Global Navigation Satellite System). UE 200 may be a power class 3 handheld device in FR1, and may be a VSAT (Very Small Aperture Terminal) at least in FR2.

[0064] NTN's network architecture may assume regenerative payloads. For example, the gNB100 functionality may be mounted on a satellite or an air vehicle. Alternatively, a gNB-DU (Distributed Unit) may be mounted on a satellite or an air vehicle, and a gNB-CU (Central Unit) may be deployed as a ground station.

[0065] Secondly, we will explain TA (Timing Advance) regarding NTN.

[0066] As shown in Figure 7, the full TA in an NTN can be expressed as "Full TA = Feeder Link TA + Service Link TA".

[0067] The TA of the Feeder Link corresponds to the round trip delay (RTT) of the Feeder Link, and is calculated as 2 × (User transparent + N TA,common) User transparent is a value that is transparent to the UE 200 and is a value that is compensated by the network (gNB 100). To simplify the implementation of the gNB 100, the value of User transparent may be a constant. N TA,common is the TA common to the beam or cell of the NTN node 150. TA,common is set based on the RP (Reference Point).

[0068] The TA of the service link corresponds to the round trip delay (RTT) of the service link, and is 2 × N TA,UE-specific It can be expressed as N TA,UE-specific is a value specific to the UE 200.

[0069] Here, TA may be expressed by the following formula:

[0070] T TA = (N TA +N TA,UE-specific +N TA,common +N TA,offset ) × Tc T TA :Timing advance between downlink and uplink N TA :Timing advance between downlink and uplink N TA,UE-specific :UE-derived timing correction N TA,common :Network-controlled timing correction N TA,offset :A fixed offset used to calculate the timing advance Tc: Basic time unit for NR N TA is the closed loop TA. N TAis defined as 0 for the Physical Random Access Channel (PRACH). TA is updated based on the TA Command field of msg2 / msgB and the TA command of the Medium Access Control Control Element (MAC CE) of the medium access control layer.

[0071] N TA,UE-specific is the open loop TA. N TA,UE-specific is a TA for compensating for delay in the service link, and is autonomously updated by the UE 200. TA,UE-specific is calculated based on the location information of the UE 200 and the orbit information of the NTN node 150. For example, the location information of the UE 200 may be acquired based on a radio signal from a satellite positioning system (not shown).

[0072] N TA,common is the open loop TA. N TA,common is a common TA controlled by the network (gNB100). TA,common is autonomously updated by UE200 using parameters (parameters for determining common TA) notified by gNB100.

[0073] In addition, N TA,common The Reference Point (RP) that defines the N may be set anywhere on the Feeder Link. The RP may be set in the gNB 100, in the NTN node 150, or between the gNB 100 and the NTN node 150. When the RP is set in the gNB 100, there is an advantage that the burden on the gNB 100 is reduced. When the RP is set in the NTN node 150, TA,common This has the advantage of reducing the burden on UE200.

[0074] (4) Issues The problems of the embodiment will be described below.

[0075] The NTN described above can be of two types: transparent and regenerative. In the transparent type, the NTN node 150 does not have the functionality of a base station, and simply retransmits signals. In the regenerative type, the NTN node 150 has some of the functionality of a base station, and regenerates signals.

[0076] The following options are possible for the regenerative NTN node 150:

[0077] In Option A, as shown in Figure 8, the NTN node 150 may have a Distributed Unit (DU) and a Radio Unit (RU). The RU may be a logical node that hosts the PHY-Low layer and RF processing based on the lower layer functional division. The DU may be a logical node that hosts the Radio Link Control layer (RLC), Medium Access Control layer (MAC), and PHY-High layer based on the lower layer functional.

[0078] In Option B, the NTN node 150 may have a Control Unit (CU) in addition to the DU and RU, as shown in Figure 9. The CU may be a logical node that hosts the Packet Data Convergence Protocol (PDCP), Radio Resource Control (RRC), Service Data Adaptation Protocol (SDAP), and other control functions.

[0079] In option C, as shown in FIG. 10, the NTN node 150 may have a UPF (User Plane Function) in addition to the DU, RU, and CU. The UPF may have a function to perform processing related to the U-plane (processing related to data signals). The UPF may have a function to communicate with an MEC (Multi-Access Edge Computing) server. The NTN node 150 may have an MEC server.

[0080] Under the above-mentioned background, the inventors have conducted extensive research and found that, in the regenerative type, attention is focused on disconnection of the Xn interface due to movement of non-terrestrial network devices, and that there is a need to improve inconveniences associated with disconnection of the Xn interface. The inconveniences associated with disconnection of the Xn interface may include suppressing failures in handover (HO) or RRC re-establishment procedures, reducing the load on base stations, reducing the load on the Xn interface, etc.

[0081] (5) Example of operation To solve the above-mentioned problem, the NTN node 150 may establish an Xn interface via a first link (ISL: Inter-Satellite Link) between the NTN node 150 and an adjacent NTN node adjacent to the NTN node 150. The NTN node 150 may establish an Xn interface via a second link (Feeder Link) between the NTN node 150 and the TN gateway 100X. The NTN node 150 may establish an Xn interface via both the ISL and the Feeder Link.

[0082] Neighboring NTN nodes may include satellites such as LEO and GEO, similar to NTN node 150. Neighboring NTN nodes may include flying objects such as HAPS, aircraft, drones, helicopters, and balloons, similar to NTN node 150. Neighboring NTN nodes may have some of the functions of a base station, similar to NTN node 150.

[0083] In an operational example, the Feeder Link may be expressed as follows: Specifically, the Feeder Link is a transport link that may transport the Xn interface between gNBs hosted by two generative payloads.

[0084] In an operational example, the Feeder Link may be expressed as follows: Specifically, the Feeder Link is a transport link that may transport the NG interface between a gNB hosted by generative payloads and 5GC, and the Xn interface between two gNBs hosted by generative payloads.

[0085] Furthermore, the following operation example is conceivable.

[0086] (5.1) Example 1 In Operation Example 1, communication of information about the Xn interface may be performed between adjacent NTN nodes. The information about the Xn interface may include at least one of information about the type of link establishing the Xn interface, information about the amount of delay expected in the Xn interface, information about the location of the base station provided in the NTN node 150, and information about the location of the adjacent base station provided in the adjacent NTN node. Operation Example 1 may be considered to be an example of operation at the stage of establishing the Xn interface or after the Xn interface has been established.

[0087] For example, the relationship between Satellite gNB#1, Satellite gNB#2, and TN Gateway will be described. Satellite gNB#1 may be an example of an NTN node 150 or a base station mounted on the NTN node 150. Satellite gNB#2 may be an example of an adjacent NTN node or an adjacent base station mounted on the adjacent NTN node. The TN Gateway may be an example of a TN gateway 100X installed on the ground.

[0088] As shown in FIG. 11, in step S10, Satellite gNB#1 may send an Xn Setup Request to Satellite gNB#2 via the TN Gateway (Feeder Link).

[0089] In step S11, Satellite gNB#2 may send an Xn Setup Response to Satellite gNB#1 via the TN Gateway (Feeder Link).

[0090] Steps S10 and S11 may be considered to be a procedure for establishing an Xn interface via a Feeder Link, that is, steps S10 and S11 may establish an Xn interface via a Feeder Link.

[0091] In step S12, Satellite gNB#1 may send an Xn Setup Request to Satellite gNB#2 via ISL.

[0092] In step S13, Satellite gNB#2 may send an Xn Setup Response to Satellite gNB#1 via the ISL.

[0093] Steps S12 and S13 may be considered to be a procedure for establishing an Xn interface via an ISL, that is, steps S12 and S13 may establish an Xn interface via an ISL.

[0094] Note that steps S12 and S13 may be performed after steps S10 and S11, or may be performed before steps S10 and S11.

[0095] In step S20, Satellite gNB#1 may send an NG-RAN node configuration Update to Satellite gNB#2 via the TN Gateway (Feeder Link).

[0096] In step S21, Satellite gNB#2 may send an NG-RAN node configuration Update Ack to Satellite gNB#1 via the TN Gateway (Feeder Link).

[0097] Steps S20 and S21 may be a procedure for modifying the Xn interface via the Feeder Link, that is, steps S20 and S21 may establish the Xn interface via the Feeder Link.

[0098] In step S22, Satellite gNB#1 may send an NG-RAN node configuration Update to Satellite gNB#2 via ISL.

[0099] In step S23, Satellite gNB#2 may send an NG-RAN node configuration Update Ack to Satellite gNB#1 via ISL.

[0100] Steps S22 and S23 may be a procedure for modifying the Xn interface via the ISL, that is, steps S22 and S23 may establish the Xn interface via the ISL.

[0101] Note that steps S22 and S23 may be performed after steps S20 and S21, or may be performed before steps S20 and S21.

[0102] Here, messages such as Xn Setup Request, Xn Setup Response, NG-RAN node configuration Update, and NG-RAN node configuration Update Ack may include the information (NTN Transport Link Assistance Information) shown in Fig. 12. NTN Transport Link Assistance Information is a newly introduced information element. NTN Transport Link Assistance Information may include Transport Link Indication, Feeder Link Delay, Ephemeris Information, etc.

[0103] The Transport Link Indication is an example of information about the type of link that establishes the Xn interface. Possible values ​​of the Transport Link Indication include a value indicating an ISL and a value indicating a Feeder Link.

[0104] Feeder Link Delay is a type of information about the delay amount expected in the Xn interface. The Feeder Link Delay may be information indicating the delay amount expected in the Feeder Link, information indicating the delay amount expected in the interface between the gNB and the core network (NG interface), or information indicating the sum of the delay amounts expected in the Feeder Link and the NG interface.

[0105] The delay amount may be a round trip time or a one-way delay amount. The delay amount may be expressed in time units such as msec or sec. The delay amount may be expressed by an integer. The unit and maximum value of the delay amount may be configured in the gNB by OAM (Operation Administration and Management).

[0106] Ephemeris information is an example of information about the location of a base station installed in the NTN node 150 or information about the location of a neighboring base station installed in a neighboring NTN node. Ephemeris information is information that indicates the trajectory of the NTN node that sent the message. Ephemeris information may include an EphemerisInfo IE specified in 3GPP TS38.331 as a container. Ephemeris information may be a list that includes some or all of the information specified in 3GPP TS38.300 (§16.14.7), or may be information that is specified independently of such information.

[0107] In step S31, Satellite gNB#1 and Satellite gNB#2 decide whether to use the Xn interface via the ISL or the Xn interface via the Feeder Link. The Xn interface via which link to use may be decided based on the information included in steps S10 to S13 (NTN Transport Link Assistance Information), or may be decided based on the information included in steps S20 to S23 (NTN Transport Link Assistance Information).

[0108] As described above, the information about the Xn interface may be notified on the Xn AP or on the NG AP. Furthermore, the information about the Xn interface may be notified on a transport layer higher than the Xn AP and the NG AP.

[0109] (5.2) Example 2 In operation example 2, the NTN node 150 may communicate information about the Xn interface with an upper node (e.g., OAM). The information about the Xn interface may include at least one of the following: a delay amount related to a base station installed in the NTN node 150, a delay amount related to an adjacent base station, a delay amount of the Xn interface, information about the location of the adjacent base station, and information about the location of the TN gateway to which the adjacent base station connects. Operation example 2 may be considered an example of an operation prior to establishing the Xn interface.

[0110] For example, the relationship between Satellite gNB#1, Satellite gNB#2, and OAM will be described. Satellite gNB#1 may be an example of NTN node 150 or a base station mounted on NTN node 150. Satellite gNB#2 may be an example of an adjacent NTN node or an adjacent base station mounted on an adjacent NTN node. OAM is an example of an upper node.

[0111] As shown in FIG. 13, in step S40, the OAM transmits Satellite Assistance Information to Satellite gNB#1 and Satellite gNB#2.

[0112] Here, the Satellite Assistance Information may include information about the Xn interface described above.

[0113] For example, as shown in FIG. 14, the Satellite Assistance Information may include ephemeris information about neighbor base stations (Above information of neighbor gNB(s) in FIG. 14). The neighbor base stations may include neighbor base stations that connect the Xn interface, or neighbor base stations installed in all neighbor NTN nodes that are adjacent to the NTN node 150. The ephemeris information about neighbor base stations is an example of information about the location of the neighbor base station and information about the location of the TN gateway to which the neighbor base station is connected. For example, as shown in FIG. 14, the Satellite Assistance Information may include the delay amount related to the Xn interface (in FIG. 14, "The delay of Xn interface between neighbor gNBs").

[0114] For example, as shown in Fig. 14, the Satellite Assistance Information may include a delay amount (in Fig. 14, "The delay of NG interface or feeder link of the gNB or neighbor gNB") related to the base station installed in the NTN node 150. The delay amount related to the base station may include a delay amount of the NG interface of the base station, or may include a delay amount of the feeder link of the base station.

[0115] For example, as shown in Fig. 14, the Satellite Assistance Information may include a delay amount related to a neighboring base station (in Fig. 14, the delay of the NG interface or the feeder link of the gNB or neighbor gNB). The delay amount related to the neighboring base station may include a delay amount of the NG interface of the neighboring base station, or may include a delay amount of the feeder link of the neighboring base station.

[0116] In step S41, Satellite gNB#1 and Satellite gNB#2 execute the Xn Setup procedure. Here, Satellite gNB#1 and Satellite gNB#2 determine the link (ISL or Feeder Link) to be used in the Xn interface based on the Satellite Assistance Information, and establish the Xn interface using the determined link.

[0117] (6) Action and effect In the embodiment, the NTN node 150 establishes the Xn interface via at least one of an ISL and a Feeder Link. This configuration increases the possibility that the Xn interface can be established via an appropriate link, and can alleviate the inconvenience associated with disconnection of the Xn interface.

[0118] In an embodiment, the NTN node 150 may communicate information about the Xn interface with neighboring NTN nodes (neighboring base stations). According to such a configuration, the Xn interface can be established with an appropriate link based on the information about the Xn interface.

[0119] In an embodiment, the NTN node 150 may communicate information about the Xn interface with an upper node (OAM). According to such a configuration, the Xn interface can be established with an appropriate link based on the information about the Xn interface.

[0120] (7) Other embodiments The present invention has been described above in accordance with the embodiments, but it will be obvious to those skilled in the art that the present invention is not limited to these descriptions and that various modifications and improvements are possible.

[0121] In the above disclosure, a case has been exemplified in which a non-terrestrial network device that relays a UL signal or a DL signal in an NTN is an NTN node 150. However, the above disclosure is not limited to this. The non-terrestrial network device may be any node that constitutes an NTN in the air, and may be referred to as an aerial node, a floating body, an air vehicle, or a flying object.

[0122] In the above disclosure, the Feeder Link Delay is exemplified as the delay amount expected in the Xn interface, but the above disclosure is not limited to this. The delay amount expected in the Xn interface may include the delay amount expected in the ISL.

[0123] In the above disclosure, configure, activate, update, indicate, enable, specify, and select may be interchangeable. Similarly, link, associate, correspond, and map may be interchangeable, and allocate, assign, monitor, and map may be interchangeable.

[0124] Furthermore, specific, dedicated, UE-specific, and UE-dedicated may be interchangeable. Similarly, common, shared, group-common, UE-common, and UE-shared may be interchangeable.

[0125] The block diagrams (FIGS. 4 and 5) used in the description of the above-described embodiments show functional blocks. These functional blocks (components) are realized by any combination of at least one of hardware and software. Furthermore, the method of realizing each functional block is not particularly limited. That is, each functional block may be realized using a single device that is physically or logically coupled, or may be realized using two or more physically or logically separated devices that are connected directly or indirectly (for example, by wire, wirelessly, etc.) and these multiple devices. The functional block may also be realized by combining the single device or multiple devices with software.

[0126] Functions include, but are not limited to, judgment, determination, judgment, calculation, computation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, resolution, selection, election, establishment, comparison, assumption, expectation, regard, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, and assignment. For example, a functional block (component) that performs transmission is called a transmitting unit or transmitter. As mentioned above, there are no particular limitations on how each is implemented.

[0127] Furthermore, the above-mentioned NTN node 150 (the device) may function as a computer that performs processing of the wireless communication method of the present disclosure. Fig. 15 is a diagram showing an example of the hardware configuration of the device. As shown in Fig. 15, the device may be configured as a computer device including a processor 1001, a memory 1002, a storage 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, etc.

[0128] In the following description, the term "apparatus" can be interpreted as a circuit, a device, a unit, etc. The hardware configuration of the apparatus may be configured to include one or more of the apparatuses shown in the drawings, or may be configured to exclude some of the apparatuses.

[0129] Each functional block of the device (see FIG. 5) is realized by any hardware element of the computer device or a combination of the hardware elements.

[0130] In addition, each function of the device is realized by loading specified software (programs) onto hardware such as processor 1001 and memory 1002, causing processor 1001 to perform calculations, control communication via communication device 1004, and control at least one of reading and writing data in memory 1002 and storage 1003.

[0131] The processor 1001 controls the entire computer by running, for example, an operating system, and may be configured as a central processing unit (CPU) including an interface with peripheral devices, a control unit, an arithmetic unit, a register, and the like.

[0132] The processor 1001 also reads programs (program codes), software modules, data, etc. from at least one of the storage 1003 and the communication device 1004 into the memory 1002, and executes various processes in accordance with these. The programs used are those that cause a computer to execute at least some of the operations described in the above-mentioned embodiments. Furthermore, the various processes described above may be executed by one processor 1001, or may be executed simultaneously or sequentially by two or more processors 1001. The processor 1001 may be implemented by one or more chips. The programs may be transmitted from a network via a telecommunications line.

[0133] The memory 1002 is a computer-readable recording medium and may be configured by, for example, at least one of a read-only memory (ROM), an erasable programmable ROM (EPROM), an electrically erasable programmable ROM (EEPROM), a random access memory (RAM), etc. The memory 1002 may also be called a register, a cache, a main memory (primary storage device), etc. The memory 1002 can store a program (program code), a software module, etc. that can execute a method according to an embodiment of the present disclosure.

[0134] Storage 1003 is a computer-readable recording medium, and may be, for example, at least one of an optical disk such as a Compact Disc ROM (CD-ROM), a hard disk drive, a flexible disk, a magneto-optical disk (e.g., a compact disk, a digital versatile disk, a Blu-ray disc), a smart card, a flash memory (e.g., a card, a stick, a key drive), a floppy disk, a magnetic strip, etc. Storage 1003 may also be referred to as an auxiliary storage device. The above-mentioned recording medium may be, for example, a database, a server, or other appropriate medium including at least one of memory 1002 and storage 1003.

[0135] The communication device 1004 is hardware (transmission / reception device) for communicating between computers via at least one of a wired network and a wireless network, and is also called, for example, a network device, a network controller, a network card, or a communication module.

[0136] The communication device 1004 may be configured to include a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc. to realize, for example, at least one of Frequency Division Duplex (FDD) and Time Division Duplex (TDD).

[0137] The input device 1005 is an input device (for example, a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.) that receives input from the outside. The output device 1006 is an output device (for example, a display, a speaker, an LED lamp, etc.) that performs output to the outside. Note that the input device 1005 and the output device 1006 may be integrated into one device (for example, a touch panel).

[0138] Furthermore, each device such as the processor 1001 and the memory 1002 is connected to a bus 1007 for communicating information. The bus 1007 may be configured using a single bus, or may be configured using different buses between each device.

[0139] Furthermore, the device may be configured to include hardware such as a microprocessor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a programmable logic device (PLD), or a field programmable gate array (FPGA), and some or all of the functional blocks may be realized by the hardware. For example, the processor 1001 may be implemented using at least one of these pieces of hardware.

[0140] Furthermore, the notification of information is not limited to the aspects / embodiments described in the present disclosure, and may be performed using other methods. For example, the notification of information may be performed by physical layer signaling (e.g., Downlink Control Information (DCI), Uplink Control Information (UCI)), higher layer signaling (e.g., RRC signaling, Medium Access Control (MAC) signaling, broadcast information (Master Information Block (MIB), System Information Block (SIB))), other signals, or a combination thereof. Furthermore, the RRC signaling may be referred to as an RRC message, and may be, for example, an RRC Connection Setup message, an RRC Connection Reconfiguration message, or the like.

[0141] Each aspect / embodiment described in the present disclosure may be applied to at least one of a system using Long Term Evolution (LTE), LTE-Advanced (LTE-A), SUPER 3G, IMT-Advanced, a 4th generation mobile communication system (4G), a 5th generation mobile communication system (5G), a 6th generation mobile communication system (6G), an xth generation mobile communication system (xG) (where x is, for example, an integer or a decimal), Future Radio Access (FRA), New Radio (NR), W-CDMA (registered trademark), GSM (registered trademark), CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, Ultra-WideBand (UWB), Bluetooth (registered trademark), or other suitable systems, and next-generation systems enhanced based on these. In addition, a combination of multiple systems (for example, a combination of at least one of LTE and LTE-A with 5G) may be applied.

[0142] The order of the procedures, sequences, flowcharts, etc. of each aspect / embodiment described in this disclosure may be changed unless it is consistent. For example, the methods described in this disclosure present elements of various steps using an example order, and are not limited to the particular order presented.

[0143] In the present disclosure, a specific operation described as being performed by a base station may be performed by its upper node in some cases. In a network consisting of one or more network nodes having a base station, it is clear that various operations performed for communication with a terminal may be performed by at least one of the base station and another network node other than the base station (for example, but not limited to, an MME or an S-GW). Although the above example illustrates a case where there is one other network node other than the base station, a combination of multiple other network nodes (for example, an MME and an S-GW) may also be used.

[0144] Information, signals (information, etc.) may be output from a higher layer (or a lower layer) to a lower layer (or a higher layer), or may be input / output via multiple network nodes.

[0145] The input and output information may be stored in a specific location (for example, memory) or may be managed using a management table. The input and output information may be overwritten, updated, or added. The output information may be deleted. The input information may be sent to another device.

[0146] The determination may be made based on a value represented by one bit (0 or 1), a Boolean value (true or false), or a numerical comparison (e.g., comparison with a predetermined value).

[0147] Each aspect / embodiment described in this disclosure may be used alone, in combination, or switched depending on the implementation. Furthermore, notification of predetermined information (e.g., notification that "X is true") is not limited to being done explicitly, but may be done implicitly (e.g., by not notifying the predetermined information).

[0148] Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

[0149] Software, instructions, information, etc. may also be transmitted or received over a transmission medium. For example, if software is transmitted from a website, server, or other remote source using wired technologies (such as coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL)), and / or wireless technologies (such as infrared, microwave), then these wired and / or wireless technologies are included within the definition of transmission media.

[0150] The information, signals, etc. described in this disclosure may be represented using any of a variety of different technologies. For example, data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

[0151] Note that terms explained in this disclosure and terms necessary for understanding this disclosure may be replaced with terms having the same or similar meanings. For example, at least one of a channel and a symbol may be a signal (signaling). Furthermore, a signal may be a message. Furthermore, a component carrier (CC) may be called a carrier frequency, a cell, a frequency carrier, etc.

[0152] As used in this disclosure, the terms "system" and "network" are used interchangeably.

[0153] Furthermore, the information, parameters, etc. described in the present disclosure may be expressed using absolute values, may be expressed using relative values ​​from a predetermined value, or may be expressed using other corresponding information. For example, a radio resource may be indicated by an index.

[0154] The names used for the above-described parameters are not intended to be limiting in any way. Furthermore, the mathematical expressions using these parameters may differ from those explicitly disclosed in this disclosure. The various channels (e.g., PUCCH, PDCCH, etc.) and information elements may be identified by any suitable names, and therefore the various names assigned to these various channels and information elements are not intended to be limiting in any way.

[0155] In this disclosure, terms such as "base station (BS)," "radio base station," "fixed station," "NodeB," "eNodeB (eNB)," "gNodeB (gNB)," "access point," "transmission point," "reception point," "transmission / reception point," "cell," "sector," "cell group," "carrier," and "component carrier" may be used interchangeably. Base stations may also be referred to by terms such as macrocell, small cell, femtocell, and picocell.

[0156] A base station can accommodate one or more (e.g., three) cells (also called sectors). When a base station accommodates multiple cells, the entire coverage area of ​​the base station can be divided into multiple smaller areas, and each smaller area can also provide communication edge services by a base station subsystem (e.g., a small indoor base station (Remote Radio Head: RRH)).

[0157] The terms "cell" or "sector" refer to part or all of the coverage area of ​​a base station and / or base station subsystem that provides communication edge services in that coverage.

[0158] In the present disclosure, the base station transmitting information to a terminal may be interpreted as the base station instructing the terminal to control or operate based on the information.

[0159] In this disclosure, the terms "Mobile Station (MS)," "user terminal," "User Equipment (UE)," "terminal," etc. may be used interchangeably.

[0160] A mobile station may also be referred to by those skilled in the art as a subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, or some other suitable terminology.

[0161] At least one of the base station and the mobile station may be called a transmitting device, a receiving device, a communication device, etc. At least one of the base station and the mobile station may be a device mounted on a mobile body, the mobile body itself, etc. The mobile body may be a vehicle (e.g., a car, an airplane, etc.), an unmanned mobile body (e.g., a drone, an autonomous vehicle, etc.), or a robot (manned or unmanned). At least one of the base station and the mobile station may also include devices that do not necessarily move during communication operations. For example, at least one of the base station and the mobile station may be an Internet of Things (IoT) device such as a sensor.

[0162] Furthermore, a base station in the present disclosure may be read as a mobile station (user terminal, the same applies hereinafter). For example, the aspects / embodiments of the present disclosure may be applied to a configuration in which communication between a base station and a mobile station is replaced with communication between multiple mobile stations (which may be called, for example, Device-to-Device (D2D) or Vehicle-to-Everything (V2X)). In this case, the mobile station may be configured to have the functions of a base station. Furthermore, terms such as "uplink" and "downlink" may be read as terms corresponding to communication between terminals (for example, "side"). For example, terms such as uplink channel and downlink channel may be read as side channel.

[0163] Similarly, a mobile station in the present disclosure may be interpreted as a base station, in which case the base station may have the functions of a mobile station.

[0164] A radio frame may be composed of one or more frames in the time domain, each of which may be called a subframe.

[0165] A subframe may further be composed of one or more slots in the time domain, and may have a fixed time length (e.g., 1 ms) that is independent of numerology.

[0166] Numerology may be a communication parameter applied to at least one of transmission and reception of a signal or channel, such as subcarrier spacing (SCS), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI), number of symbols per TTI, radio frame structure, specific filtering operations performed by a transceiver in the frequency domain, and specific windowing operations performed by a transceiver in the time domain.

[0167] A slot may consist of one or more symbols in the time domain (such as an Orthogonal Frequency Division Multiplexing (OFDM) symbol or a Single Carrier Frequency Division Multiple Access (SC-FDMA) symbol). A slot may be a time unit based on numerology.

[0168] A slot may include multiple minislots. Each minislot may consist of one or multiple symbols in the time domain. A minislot may also be called a subslot. A minislot may consist of fewer symbols than a slot. A PDSCH (or PUSCH) transmitted in a time unit larger than a minislot may be called PDSCH (or PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using a minislot may be called PDSCH (or PUSCH) mapping type B.

[0169] The radio frame, subframe, slot, minislot, and symbol all represent time units for transmitting signals, and may be referred to by other names corresponding to the radio frame, subframe, slot, minislot, and symbol.

[0170] For example, one subframe may be called a transmission time interval (TTI), multiple consecutive subframes may be called a TTI, or one slot or one minislot may be called a TTI. That is, at least one of the subframe and the TTI may be a subframe (1 ms) in existing LTE, a period shorter than 1 ms (e.g., 1-13 symbols), or a period longer than 1 ms. Note that the unit representing the TTI may be called a slot, minislot, etc., instead of a subframe.

[0171] Here, TTI refers to, for example, the smallest time unit for scheduling in wireless communication. For example, in an LTE system, a base station performs scheduling to allocate radio resources (such as frequency bandwidth and transmission power that can be used by each user terminal) to each user terminal in TTI units. However, the definition of TTI is not limited to this.

[0172] The TTI may be a transmission time unit for a channel-encoded data packet (transport block), a code block, a code word, etc., or may be a processing unit for scheduling, link adaptation, etc. When a TTI is given, the time interval (e.g., the number of symbols) to which a transport block, a code block, a code word, etc. is actually mapped may be shorter than the TTI.

[0173] When one slot or one minislot is called a TTI, one or more TTIs (i.e., one or more slots or one or more minislots) may be the minimum time unit for scheduling. Also, the number of slots (minislots) constituting the minimum time unit for scheduling may be controlled.

[0174] A TTI having a time length of 1 ms may be called a regular TTI (TTI in LTE Rel. 8-12), normal TTI, long TTI, regular subframe, normal subframe, long subframe, slot, etc. A TTI shorter than a regular TTI may be called a shortened TTI, short TTI, partial or fractional TTI, shortened subframe, short subframe, minislot, subslot, slot, etc.

[0175] In addition, a long TTI (e.g., a normal TTI, a subframe, etc.) may be interpreted as a TTI having a time length of more than 1 ms, and a short TTI (e.g., a shortened TTI, etc.) may be interpreted as a TTI having a TTI length shorter than the TTI length of a long TTI and equal to or greater than 1 ms.

[0176] A resource block (RB) is a resource allocation unit in the time domain and frequency domain, and may include one or more consecutive subcarriers in the frequency domain. The number of subcarriers included in an RB may be the same regardless of numerology, for example, 12. The number of subcarriers included in an RB may also be determined based on numerology.

[0177] The time domain of an RB may include one or more symbols and may have a length of one slot, one minislot, one subframe, or one TTI. One TTI, one subframe, etc. may each be composed of one or more resource blocks.

[0178] Note that one or more RBs may also be called a physical resource block (PRB), a sub-carrier group (SCG), a resource element group (REG), a PRB pair, an RB pair, or the like.

[0179] Furthermore, a resource block may be composed of one or more resource elements (REs). For example, one RE may be a radio resource region of one subcarrier and one symbol.

[0180] A Bandwidth Part (BWP) (which may also be referred to as a fractional bandwidth) may represent a subset of contiguous common resource blocks (RBs) for a given numerology on a given carrier, where the common RBs may be identified by their index relative to a common reference point of the carrier. PRBs may be defined in a given BWP and numbered within that BWP.

[0181] The BWP may include a BWP for UL (UL BWP) and a BWP for DL ​​(DL BWP). One or more BWPs may be configured for a UE within one carrier.

[0182] At least one of the configured BWPs may be active, and the UE may not expect to transmit or receive a given signal / channel outside the active BWP. Note that the terms "cell," "carrier," etc. in this disclosure may be read as "BWP."

[0183] The above-described structures of radio frames, subframes, slots, minislots, symbols, etc. are merely examples. For example, the number of subframes included in a radio frame, the number of slots per subframe or radio frame, the number of minislots included in a slot, the number of symbols and RBs included in a slot or minislot, the number of subcarriers included in an RB, the number of symbols in a TTI, the symbol length, the cyclic prefix (CP) length, etc. may be changed in various ways.

[0184] The terms "connected," "coupled," or any variation thereof, refer to any direct or indirect connection or coupling between two or more elements, and may include the presence of one or more intermediate elements between two elements that are "connected" or "coupled" to each other. The coupling or connection between elements may be physical, logical, or a combination thereof. For example, "connected" may be read as "access." As used in this disclosure, two elements may be considered to be "connected" or "coupled" to each other using one or more wires, cables, and / or printed electrical connections, as well as electromagnetic energy having wavelengths in the radio frequency range, microwave range, and optical (both visible and invisible) range, as some non-limiting and non-exhaustive examples.

[0185] The reference signal may also be abbreviated as Reference Signal (RS), and may also be called a pilot depending on the applicable standard.

[0186] As used in this disclosure, the phrase "based on" does not mean "based only on," unless expressly stated otherwise. In other words, the phrase "based on" means both "based only on" and "based at least on."

[0187] The "means" in the configuration of each of the above devices may be replaced with "part," "circuit," "device," etc.

[0188] As used in this disclosure, any reference to an element using a designation such as "first," "second," etc. does not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient method of distinguishing between two or more elements. Thus, a reference to a first and a second element does not imply that only two elements may be employed therein or that the first element must precede the second element in some way.

[0189] When used in this disclosure, the terms "include," "including," and variations thereof are intended to be inclusive, similar to the term "comprising." Furthermore, when used in this disclosure, the term "or" is not intended to be an exclusive or.

[0190] In this disclosure, where articles are added by translation, such as a, an, and the in English, the disclosure may include that the nouns following these articles are in the plural form.

[0191] As used in this disclosure, the terms "determining" and "determining" may encompass a wide variety of actions. "Determining" and "determining" may include, for example, judging, calculating, computing, processing, deriving, investigating, looking up, searching, inquiring (e.g., searching in a table, database, or other data structure), ascertaining, and the like. "Determining" and "determining" may also include receiving (e.g., receiving information), transmitting (e.g., sending information), input, output, accessing (e.g., accessing data in memory), and the like. Furthermore, "judgment" and "decision" can include regarding resolving, selecting, choosing, establishing, comparing, etc. as having been "judged" or "decided." In other words, "judgment" and "decision" can include regarding some action as having been "judged" or "decided." Furthermore, "judgment (decision)" can be interpreted as "assuming," "expecting," "considering," etc.

[0192] In the present disclosure, the term "A and B are different" may mean "A and B are different from each other." The term may also mean "A and B are each different from C." Terms such as "separate" and "coupled" may also be interpreted in the same way as "different."

[0193] Fig. 16 shows an example of the configuration of a vehicle 2001. As shown in Fig. 16, the vehicle 2001 includes a drive unit 2002, a steering unit 2003, an accelerator pedal 2004, a brake pedal 2005, a shift lever 2006, left and right front wheels 2007, left and right rear wheels 2008, an axle 2009, an electronic control unit 2010, various sensors 2021 to 2029, an information edge service unit 2012, and a communication module 2013.

[0194] The drive unit 2002 is composed of, for example, an engine, a motor, or a hybrid of an engine and a motor.

[0195] The steering unit 2003 includes at least a steering wheel (also called a handle), and is configured to steer at least one of the front wheels and the rear wheels based on the operation of the steering wheel operated by the user.

[0196] The electronic control unit 2010 is composed of a microprocessor 2031, a memory (ROM, RAM) 2032, and a communication port (IO port) 2033. Signals are input to the electronic control unit 2010 from various sensors 2021 to 2027 provided in the vehicle. The electronic control unit 2010 may also be called an ECU (Electronic Control Unit).

[0197] The signals from the various sensors 2021 to 2028 include a current signal from a current sensor 2021 that senses the current of the motor, a rotation speed signal of the front and rear wheels obtained by a rotation speed sensor 2022, an air pressure signal of the front and rear wheels obtained by an air pressure sensor 2023, a vehicle speed signal obtained by a vehicle speed sensor 2024, an acceleration signal obtained by an acceleration sensor 2025, an accelerator pedal depression amount signal obtained by an accelerator pedal sensor 2029, a brake pedal depression amount signal obtained by a brake pedal sensor 2026, a shift lever operation signal obtained by a shift lever sensor 2027, and a detection signal for detecting obstacles, vehicles, pedestrians, etc. obtained by an object detection sensor 2028.

[0198] The information edge service unit 2012 is composed of various devices, such as a car navigation system, an audio system, speakers, a television, and a radio, for providing various types of information such as driving information, traffic information, and entertainment information, and one or more ECUs for controlling these devices. The information edge service unit 2012 uses information obtained from external devices via the communication module 2013, etc., to provide various types of multimedia information and multimedia edge services to the occupants of the vehicle 1.

[0199] The driving assistance system unit 2030 is composed of various devices that provide functions for preventing accidents and reducing the driver's driving burden, such as millimeter-wave radar, LiDAR (Light Detection and Ranging), cameras, positioning locators (e.g., GNSS, etc.), map information (e.g., high-definition (HD) maps, autonomous vehicle (AV) maps, etc.), gyro systems (e.g., IMU (Inertial Measurement Unit), INS (Inertial Navigation System), etc.), AI (Artificial Intelligence) chips, and AI processors, as well as one or more ECUs that control these devices. The driving assistance system unit 2030 also transmits and receives various information via the communication module 2013 to realize driving assistance functions or autonomous driving functions.

[0200] The communication module 2013 can communicate with the microprocessor 2031 and components of the vehicle 1 via the communication port. For example, the communication module 2013 transmits and receives data via the communication port 2033 to and from a drive unit 2002, a steering unit 2003, an accelerator pedal 2004, a brake pedal 2005, a shift lever 2006, left and right front wheels 2007, left and right rear wheels 2008, an axle 2009, a microprocessor 2031 and memory (ROM, RAM) 2032 in the electronic control unit 2010, and sensors 2021 to 2028, which are provided in the vehicle 2001.

[0201] The communication module 2013 is a communication device that can be controlled by the microprocessor 2031 of the electronic control unit 2010 and can communicate with an external device. For example, it transmits and receives various information to and from the external device via wireless communication. The communication module 2013 may be located either inside or outside the electronic control unit 2010. The external device may be, for example, a base station, a mobile station, or the like.

[0202] The communication module 2013 transmits, via wireless communication to an external device, a current signal from the current sensor that is input to the electronic control unit 2010. The communication module 2013 also transmits, via wireless communication to an external device, the rotation speed signals of the front and rear wheels acquired by a rotation speed sensor 2022, the air pressure signals of the front and rear wheels acquired by an air pressure sensor 2023, the vehicle speed signal acquired by a vehicle speed sensor 2024, the acceleration signal acquired by an acceleration sensor 2025, the accelerator pedal depression amount signal acquired by an accelerator pedal sensor 2029, the brake pedal depression amount signal acquired by a brake pedal sensor 2026, the shift lever operation signal acquired by a shift lever sensor 2027, and the detection signals for detecting obstacles, vehicles, pedestrians, etc. acquired by an object detection sensor 2028, all of which are input to the electronic control unit 2010.

[0203] The communication module 2013 receives various information (traffic information, traffic signal information, vehicle distance information, etc.) transmitted from external devices and displays it on the information edge service unit 2012 provided in the vehicle. The communication module 2013 also stores the various information received from the external devices in a memory 2032 that can be used by the microprocessor 2031. Based on the information stored in the memory 2032, the microprocessor 2031 may control the drive unit 2002, steering unit 2003, accelerator pedal 2004, brake pedal 2005, shift lever 2006, left and right front wheels 2007, left and right rear wheels 2008, axle 2009, sensors 2021 to 2028, and the like provided in the vehicle 2001.

[0204] Although the present disclosure has been described in detail above, it is clear to those skilled in the art that the present disclosure is not limited to the embodiments described herein. The present disclosure can be implemented in modified and altered forms without departing from the spirit and scope of the present disclosure as defined by the claims. Therefore, the description of the present disclosure is intended to be illustrative and does not have any limiting meaning on the present disclosure.

[0205] (Addendum) The above disclosure may be expressed as follows:

[0206] A first feature is a non-terrestrial network device that constitutes a non-terrestrial network, comprising: a communication unit that, when the non-terrestrial network device has the functionality of a base station, executes communication via an inter-base station interface between the non-terrestrial network device and an adjacent adjacent base station; and a control unit that establishes the inter-base station interface via at least one of a first link between the non-terrestrial network device and the adjacent adjacent non-terrestrial network device and a second link between the non-terrestrial network device and a gateway device provided on the ground.

[0207] A second feature is the non-terrestrial network device of the first feature, wherein the control unit communicates information related to the inter-base station interface with the neighboring base station, and the information related to the inter-base station interface includes at least one of information related to a type of link establishing the inter-base station interface, information related to an expected amount of delay in the inter-base station interface, information related to a position of the base station, and information related to a position of the neighboring base station.

[0208] A third feature is the non-terrestrial network device according to the first or second feature, wherein the control unit communicates information related to the inter-base station interface with an upper node, and the information related to the inter-base station interface includes at least one of a delay amount related to the base station, a delay amount related to the adjacent base station, a delay amount of the inter-base station interface, information related to a position of the adjacent base station, and information related to a position of a gateway device to which the adjacent base station is connected.

[0209] A fourth feature is a wireless communication system comprising: a non-terrestrial network device constituting a non-terrestrial network; and a gateway device provided on the ground, wherein the non-terrestrial network device comprises: a communication unit that, when the non-terrestrial network device has a base station function, executes communication via a base station-to-base station interface between the non-terrestrial network device and an adjacent adjacent base station; and a control unit that establishes the base station-to-base station interface via at least one of a first link between the non-terrestrial network device and the adjacent adjacent non-terrestrial network device and a second link between the non-terrestrial network device and a gateway device provided on the ground.

[0210] A fifth feature is a wireless communication method comprising: when a non-terrestrial network device constituting a non-terrestrial network has a base station function, a step of performing communication via an inter-base station interface between the non-terrestrial network device and an adjacent adjacent base station; and a step of establishing the inter-base station interface via at least one of a first link between the non-terrestrial network device and the adjacent adjacent non-terrestrial network device and a second link between the non-terrestrial network device and a gateway device provided on the ground. [Explanation of symbols]

[0211] 10. Wireless communication systems 20 NG-RAN 30 Core Network 100 gNB 100X TN Gateway 150 NTN Node 151 Receiving unit 152 Transmitter 153 Control Unit 200 UE 210 Radio signal transmitter / receiver 220 Amplifier section 230 Modulation and Demodulation Unit 240 Control signal / reference signal processing section 250 Encoding / Decoding Unit 260 Data transmission and reception unit 270 Control Unit 1001 processor 1002 memory 1003 Storage 1004 Communication equipment 1005 Input Device 1006 Output Device 1007 Bus 2001 Vehicle 2002 Drive unit 2003 Steering Section 2004 accelerator pedal 2005 brake pedal 2006 Shift Lever 2007 Left and right front wheels 2008 Left and right rear wheels 2009 Axle 2010 Electronic Control Unit 2012 Information Edge Services Department 2013 Communication Module 2021 Current Sensor 2022 RPM Sensor 2023 Air Pressure Sensor 2024 Vehicle speed sensor 2025 Acceleration Sensor 2026 Brake pedal sensor 2027 Shift lever sensor 2028 Object Detection Sensor 2029 Accelerator pedal sensor 2030 Driving Assistance Systems Department 2031 microprocessor 2032 memory (ROM, RAM) 2033 communication port

Claims

1. A non-terrestrial network device constituting a non-terrestrial network, a communication unit that performs communication between the non-terrestrial network device and an adjacent base station via an inter-base station interface when the non-terrestrial network device has a function of a base station; a control unit that establishes the base station-to-base station interface via at least one of a first link between the non-terrestrial network device and an adjacent non-terrestrial network device and a second link between the non-terrestrial network device and a gateway device provided on the ground.

2. the control unit executes communication of information regarding the inter-base station interface with the neighboring base station; 2. The non-terrestrial network device according to claim 1, wherein the information relating to the base station-to-base station interface includes at least one of information relating to a type of link establishing the base station-to-base station interface, information relating to an expected delay amount in the base station-to-base station interface, information relating to a location of the base station, and information relating to a location of the neighboring base station.

3. the control unit executes communication of information relating to the inter-base station interface with an upper node; 2. The non-terrestrial network device according to claim 1, wherein the information relating to the inter-base station interface includes at least one of a delay amount relating to the base station, a delay amount relating to the adjacent base station, a delay amount of the inter-base station interface, information relating to a position of the adjacent base station, and information relating to a position of a gateway device to which the adjacent base station is connected.

4. a non-terrestrial network device that configures a non-terrestrial network; a gateway device provided on the ground, The non-terrestrial network device a communication unit that performs communication between the non-terrestrial network device and an adjacent base station via an inter-base station interface when the non-terrestrial network device has a function of a base station; a control unit that establishes the base station-to-base station interface via at least one of a first link between the non-terrestrial network device and an adjacent non-terrestrial network device and a second link between the non-terrestrial network device and a gateway device provided on the ground.

5. When a non-terrestrial network device constituting a non-terrestrial network has a function of a base station, performing communication between the non-terrestrial network device and an adjacent adjacent base station via an inter-base station interface; establishing the base station-to-base station interface via at least one of a first link between the non-terrestrial network device and an adjacent non-terrestrial network device and a second link between the non-terrestrial network device and a gateway device provided on the ground.

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