Terminal and wireless communication method

Abstract

This terminal communicates wirelessly with a mobile communication network in a first state, in which a specific communication quality in the mobile communication network is guaranteed and the mobile communication network operates normally, and a second state, in which the wireless resources that can be used are more limited than in the first state. In the second state, the terminal connects to the mobile communication network only when a specific condition is satisfied.

Description

Terminal and wireless communication method

[0001] The present disclosure relates to a terminal and a wireless communication method that support communication quality guarantee.

[0002] The 3rd Generation Partnership Project (3GPP: registered trademark) is developing 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] In 5G, the realization of a reliability of up to 99.9999% has been considered for Ultra-Reliable Low Latency Communications (URLLC), but for 6G, an even greater improvement by an order of magnitude (99.99999%) is expected as the target value (Non-Patent Document 1).

[0004] NTT Docomo, "Docomo 6G White Paper 5.0 Edition," [online], July 2023, Internet <URL:https: / / www.docomo.ne.jp / binary / pdf / corporate / technology / whitepaper_6g / DOCOMO_6G_White_PaperJP_20221116.pdf>

[0005] Mobile communication services for 5G and 6G, including URLLC, are basically public network services targeted at an unspecified number of users, and services are provided on a best-effort basis.

[0006] Mobile communication networks based on such best-effort services have been plagued by the problem of being unable to cope with the short-term, explosive increases in traffic volume that can occur when terminals (User Equipment, UE) are concentrated in a specific area, such as at an event or concert venue.

[0007] In particular, with 6G, it is expected that there will be an increasing number of use cases requiring a certain level of communication quality assurance, such as for specific industries. Given this situation, the importance of ensuring communication quality not only for mission-critical cases but also for general users is increasing.

[0008] Furthermore, from the viewpoint of ensuring communication quality more reliably, if a failure occurs in a terrestrial network (TN), which is widely used as a mobile communication network, it is assumed that a non-terrestrial network (NTN) will be used instead. However, in such a case, available radio resources will be more limited than usual, and the question arises as to how to continue guaranteeing communication quality for UE.

[0009] Therefore, the following disclosure has been made in consideration of this situation, and aims to provide a terminal and a wireless communication method that can continue to guarantee a certain level of communication quality even when a failure occurs in a mobile communication network and available wireless resources are more limited than usual.

[0010] One aspect of the present disclosure is a terminal (UE200) that includes a communication unit (radio signal transceiver unit 210) that performs wireless communication with the mobile communication network in a first state in which a specific communication quality in the mobile communication network is guaranteed and the mobile communication network is operating normally, and a second state in which available radio resources are more limited than in the first state, and a control unit (control unit 270) that performs connection with the mobile communication network in the second state only if specific conditions are met.

[0011] One aspect of the present disclosure is a terminal (UE200) that includes a communication unit (radio signal transceiver unit 210) that performs wireless communication via the mobile communication network in a first state in which a specific communication quality in the mobile communication network is guaranteed and the mobile communication network is operating normally, and a second state in which available radio resources are more limited than in the first state, and a control unit (control unit 270) that performs connection with the mobile communication network only at specific timings in the second state.

[0012] FIG. 1 is a schematic diagram of the overall configuration of a wireless communication system 10. FIG. 2 is a diagram showing an example of the configuration of wireless frames, subframes, and slots used in the wireless communication system 10. FIG. 3 is a functional block diagram of a gNB 100 and a UE 200. FIG. 4 is a diagram showing an example of a communication sequence between a UE and a RAN according to an operation example 1. FIG. 5 is a diagram showing an example of a pattern of types of NTN-connectable UE according to an operation example 1. FIG. 6 is a diagram showing an example of a communication sequence between a UE and a RAN according to an operation example 2. FIG. 7 is a diagram showing an example of a communication sequence (dual connectivity connection) between a UE and a RAN according to an operation example 2. FIG. 8 is a diagram showing an example of the hardware configuration of a gNB 100 and a UE 200. FIG. 9 is a diagram showing an example of the configuration of a vehicle 2001.

[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 Schematic Configuration of Wireless Communication System Fig. 1 is a diagram showing the overall schematic configuration of a wireless communication system 10 according to this embodiment. The wireless communication system 10 is a wireless communication system conforming to a standard called Beyond 5G, 5G Evolution, or 6G (hereinafter referred to as 6G), and includes a Radio Access Network 20 (hereinafter referred to as RAN 20) and a terminal 200 (User Equipment 200, hereinafter referred to as UE 200). Note that the wireless communication system 10 may also be a wireless communication system conforming to a specification other than 6G, such as 5G New Radio (NR).

[0015] The RAN 20 includes a radio base station 100 (hereinafter, gNB 100). Note that the specific configuration of the radio communication system 10, including the number of gNBs and UEs, is not limited to the example shown in FIG. 1 .

[0016] The RAN 20 actually includes multiple RAN nodes, specifically, gNBs (or ng-eNBs), and is connected to a core network conforming to 6G. The RAN 20 and the core network may be simply referred to as a "network." The network formed by the UE 200, the RAN 20 (including the gNB 100), and the core network may be referred to as a mobile communication network (PLMN: Public Land Mobile Network).

[0017] The gNB100 is a 6G-compliant radio base station that performs 6G-compliant radio communications with the UE 200. The gNB100 and UE 200 are capable of supporting Massive MIMO, which generates highly directional beams 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 enables simultaneous communication between the UE and multiple NG-RAN nodes.

[0018] The type of DC may be Multi-RAT Dual Connectivity (MR-DC) that uses multiple radio access technologies, or Dual Connectivity that uses only 6G. In MR-DC, one gNB may configure the master node (MN) and the other gNB may configure the secondary node (SN).

[0019] In this embodiment, the wireless communication system 10 may include a non-terrestrial network (hereinafter referred to as NTN). In the NTN, by utilizing an NTN such as an artificial satellite 150 (hereinafter referred to as satellite 150), services are provided to areas that cannot be covered by a terrestrial network (hereinafter referred to as TN) due to cost or other reasons. The NTN can provide more reliable services.

[0020] For example, NTNs are expected to be applied to the Internet of Things (IoT), ships, buses, trains, and critical communications. Furthermore, NTNs offer scalability through efficient multicast or broadcast. The radio resources available through NTNs may be more limited (fewer) than those available through TNs. In other words, the number of UEs that can connect through NTNs may be more limited (fewer) than the number of UEs that can connect through TNs.

[0021] The satellite 150 may have the function of a relay station device, and the relay method may be either a transparent type or a regenerative type.

[0022] Note that a network including the gNB 100 and the UE 200 without including the satellite 150 may be referred to as a TN in contrast to an NTN. The UE 200 may communicate with the RAN 20 via the NTN, or may communicate with the RAN 20 via the TN (i.e., without going through the satellite 150).

[0023] The satellite 150 may also have the functionality of a gNB (radio base station). The type of satellite 150 is not particularly limited, and may be, for example, a geostationary orbit satellite (GEO) or a low earth orbit satellite (LEO). Alternatively, a high-altitude platform station (HAPS) may be used. The satellite 150 is not necessarily limited to these satellites, and may be interpreted as including spaceborne / airborne.

[0024] The gNB 100 may include an NTN gateway (not shown), which transmits downlink (DL) signals to the satellite 150. The NTN gateway receives uplink (UL) signals from the satellite 150.

[0025] The satellite 150 relays downlink signals received from the NTN gateway to the UE 200. The satellite 150 relays uplink signals received from the UE 200 to the NTN gateway. The satellite 150 may be interpreted as a TRP (Transmission-Reception Point), a repeater, or a relay.

[0026] The wireless communication system 10 may also support multiple frequency ranges (FR). Specifically, the wireless communication system 10 may support the following FRs:

[0027] FR1: 410 MHz to 7.125 GHz FR2: FR2-1: 24.25 GHz to 52.6 GHz FR2-2: Over 52.6 GHz to 71 GHz FR1 may use a Sub-Carrier Spacing (SCS) of 15, 30, or 60 kHz and a bandwidth (BW) of 5 to 100 MHz. FR2 is a higher frequency than FR1 and may use an SCS of 60 or 120 kHz (including 240 kHz) and a bandwidth (BW) of 50 to 400 MHz.

[0028] Furthermore, the wireless communication system 10 may also support frequency bands higher than the FR2 frequency band. Specifically, the wireless communication system 10 may support frequency bands above 52.6 GHz up to 114.25 GHz.

[0029] Alternatively, Cyclic Prefix-Orthogonal Frequency Division Multiplexing (CP-OFDM) / Discrete Fourier Transform - Spread (DFT-S-OFDM) with a larger Sub-Carrier Spacing (SCS) may be applied, and DFT-S-OFDM may be applied not only to the uplink (UL) but also to the downlink (DL).

[0030] FIG. 2 shows an example of the configuration of radio frames, subframes, and slots used in the radio communication system 10.

[0031] As shown in Figure 2, one slot consists of 14 symbols, and the larger (wider) the SCS, the shorter the symbol period (and slot period). Note that the number of symbols constituting one slot does not necessarily have to be 14 (e.g., 28 or 56 symbols). The number of slots per subframe may also vary depending on the SCS. Furthermore, the SCS may be wider than 240 kHz (e.g., 480 kHz or 960 kHz, as shown in Figure 2).

[0032] The time direction (t) shown in Fig. 2 may be called a time domain, a symbol period, a symbol time, etc. The frequency direction may be called a frequency domain, a resource block (RB), a resource block group (RBG), a subcarrier, a BWP (Bandwidth part), etc.

[0033] Furthermore, the wireless communication system 10 may employ a mechanism for guaranteeing a certain level of communication quality for the UE 200. The certain level of communication quality may simply mean the lowest level of communication quality that can be guaranteed, but is not necessarily limited to the lowest level of communication quality. For example, different levels of communication quality may be selectively guaranteed depending on factors such as the network status, or different levels of communication quality may be guaranteed depending on factors such as the capabilities of the UE.

[0034] Guaranteed communication quality may mean that a service with that communication quality can be enjoyed without fail during the guaranteed period. In this sense, a service with guaranteed communication quality may be interpreted as a service that is the polar opposite of a best-effort service. However, the level of communication quality is not a factor. For example, Ultra-Reliable Low Latency Communication (URLLC) is a best-effort service in which the level of communication quality that can be enjoyed is reasonably high, but the communication quality is not necessarily guaranteed. On the other hand, even if the level of communication quality is low, if the communication quality can always be enjoyed, the service can be said to have guaranteed communication quality.

[0035] The content of the communication quality is not particularly limited, but typical examples include throughput, latency, and the number of simultaneously connected UEs. Furthermore, the guarantee of communication quality may be guaranteed not only when the mobile communication network is operating normally, but also when the mobile communication network is not operating normally. Typical examples of a state in which the mobile communication network is not operating normally include a power outage, a network (equipment) failure, and network congestion due to a concentration of traffic to be processed. A state in which the mobile communication network is not operating normally may be interpreted as a state in which available radio resources are more limited (fewer) than in a state in which the mobile communication network is operating normally (first state).

[0036] A UE that is subject to guaranteed communication quality may be called a High priority UE. High priority UE may also be interpreted as a UE with guaranteed communication quality, a UE requesting guaranteed communication quality, a UE with guaranteed minimum quality, a Guaranteed UE, or a UE supporting a quality guarantee function.

[0037] A UE that is not subject to a guaranteed communication quality may be called a Low priority UE. Low priority UE may also be interpreted as a UE for which communication quality is not guaranteed, a UE that does not require communication quality guarantee, a non-guaranteed UE, or a UE that does not support a quality guarantee function.

[0038] Furthermore, the UE 200 may operate as a high priority UE or a low priority UE depending on the capability or state of the UE 200. In other words, whether the UE 200 is a high priority UE or not may be changed dynamically.

[0039] (2) Functional Block Configuration of Wireless Communication System Next, a functional block configuration of the wireless communication system 10 will be described. Specifically, a functional block configuration of the UE 200 will be described. Fig. 3 is a functional block configuration diagram of the gNB 100 and the UE 200.

[0040] As shown in FIG. 3 , the UE 200 includes a radio signal transmitting / receiving unit 210, an amplifier unit 220, a modulation / demodulation unit 230, a control signal / reference signal processing unit 240, an encoding / decoding unit 250, a data transmitting / receiving unit 260, and a control unit 270.

[0041] It should be noted that Fig. 3 shows only the main functional blocks relevant to the description of the embodiment, and that the UE 200 (gNB 100) has other functional blocks (e.g., a power supply unit, etc.). Fig. 3 shows the functional block configuration of the UE 200, and for the hardware configuration, please refer to Fig. 8.

[0042] The radio signal transmitting / receiving unit 210 transmits and receives radio signals conforming to 6G. The radio signal transmitting / receiving unit 210 can support Massive MIMO, which generates a more directional beam by controlling radio (RF) signals transmitted from multiple antenna elements, Carrier Aggregation (CA), which aggregates and uses multiple component carriers (CCs), and Dual Connectivity (DC), which simultaneously communicates between a UE and two NG-RAN nodes.

[0043] The wireless signal transceiver 210 may perform wireless communication via a mobile communication network in the first state and the second state. In this embodiment, the wireless signal transceiver 210 may constitute a communication unit.

[0044] The first state may be interpreted as a state in which a specific communication quality is guaranteed in the mobile communication network and the mobile communication network is operating normally. The specific communication quality is not particularly limited, but for example, at least one of the following KPIs (Key Performance Indicators) related to the minimum quality guarantee may be specified. Note that a combination of multiple KPIs may also be applied.

[0045] UE throughput; Minimum / maximum value in communication of the UE; and / or; Statistical value (for example, CDF (Cumulative Distribution Function) 50%, CDF 5% value, etc.).

[0046] 5%。 English: Latency Minimum / maximum value in communication of the UE, and / or Statistical value (e.g., CDF 50%, CDF 5% value, etc.) Cell capacity (total throughput of all UEs in a cell) Minimum / maximum value and / or Statistical value (e.g., CDF 50%, CDF 5% value, etc.) Reliability Minimum / maximum value in communication of the UE, and / or Statistical value (e.g., CDF 50%, CDF 5% value, etc.) Positioning Minimum / maximum value in positioning accuracy of the UE, and / or Statistical value (e.g., CDF 50%, CDF 5% value, etc.) The second state may be interpreted as a state in which available radio resources are more limited than in the first state. In the first state, the radio signal transceiver 210 may perform radio communication with the mobile communication network via a normal network that is available only in the first state and a specific network that is also available in the second state.

[0047] The normal network available only in the first state may be, for example, a terrestrial network (TN), and the specific network available also in the second state may be, for example, a non-terrestrial network (NTN). In this case, the NTN, which has a wide coverage area and is less susceptible to disasters than the TN, may be prepared as a backup network in a situation where the TN is unavailable due to a failure or the like or where connection of the UE 200 is restricted.

[0048] 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.

[0049] The modem unit 230 performs data modulation / demodulation, transmission power setting, resource block allocation, etc. for each predetermined communication destination (e.g., gNB 100). 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).

[0050] The control signal and reference signal processor 240 executes 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 .

[0051] Specifically, the control signal / reference signal processing unit 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. In addition, the control signal / reference signal processing unit 240 transmits various control signals to the gNB 100 via a predetermined control channel.

[0052] 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).

[0053] DMRS is a terminal-specific reference signal (pilot signal) known between the base station and the terminal to estimate the fading channel used for data demodulation, while PTRS is a terminal-specific reference signal intended to estimate phase noise, which is an issue in high frequency bands.

[0054] In addition to the DMRS and PTRS, the reference signals may also include a Channel State Information-Reference Signal (CSI-RS), a Sounding Reference Signal (SRS), and a Positioning Reference Signal (PRS) for position information.

[0055] The channels include a control channel and a data channel. The control channels may include a Physical Downlink Control Channel (PDCCH), a Physical Uplink Control Channel (PUCCH), a Random Access Channel (RACH, Downlink Control Information (DCI) including a Random Access Radio Network Temporary Identifier (RA-RNTI)), a Physical Broadcast Channel (PBCH), etc.

[0056] Furthermore, the data channel includes a PDSCH, a PUSCH, etc. Data may refer to data transmitted via a data channel.

[0057] Furthermore, the control signal and reference signal processing unit 240 may transmit to the network capability information indicating the terminal capability of the UE 200. For example, the control signal and reference signal processing unit 240 can transmit to the gNB 100 UE Capability Information related to guarantee of communication quality.

[0058] For example, the control signal / reference signal processing unit 240 may transmit to the gNB 100 UE capability information indicating whether the UE has the necessary terminal capabilities as a high priority UE, the level of communication quality that can be supported, and the like.

[0059] The encoding / decoding unit 250 performs data division / concatenation and channel coding / decoding for each predetermined communication destination (gNB 100 or another gNB).

[0060] 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.

[0061] 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 Hybrid Automatic Repeat Request (Hybrid ARQ).

[0062] The control unit 270 controls each functional block constituting the UE 200. In particular, in this embodiment, the control unit 270 can execute control related to guaranteeing a specific communication quality in a mobile communication network.

[0063] Specifically, in the second state (a state in which available radio resources are more limited than in the first state), the control unit 270 may execute connection to the mobile communication network only when certain conditions are met. The certain conditions may include, for example, the following situations:

[0064] First, the UE 200 may be connected to a specific network (e.g., NTN) used in the second state in the first state, or may be a high-priority UE that is guaranteed a specific communication quality in the first state.

[0065] In this way, the control unit 270 may perform connection to the mobile communication network in the second state if the UE200 was already connected to a specific network used in the second state in the first state (a state in which a specific communication quality in the mobile communication network is guaranteed and the mobile communication network is operating normally), or if the UE200 is subject to a specific communication quality guarantee in the first state.

[0066] Furthermore, if UE 200 is subject to a guarantee of a specific communication quality even in the second state, control unit 270 may execute connection to the mobile communication network in the second state. That is, regardless of whether UE 200 was already connected to a specific network (e.g., NTN) used in the second state in the first state, if UE 200 is subject to a guarantee of a specific communication quality even in the second state, control unit 270 may execute connection to the mobile communication network in the second state.

[0067] In addition, if UE200 does not fall into such a situation, for example, if UE200 is not subject to communication quality guarantee (low priority UE), the control unit 270 may still perform connection to the mobile communication network in the second state.

[0068] Furthermore, in the second state, the control unit 270 may execute connection to the mobile communication network only at specific timings. The specific timings may include, for example, the following timings.

[0069] First, it may be when it is recognized that a normal network (e.g., TN) that is available only in the first state is unavailable due to a fault such as a power outage or congestion. Alternatively, it may be when a timer that was started after it was recognized that the network was unavailable expires. In this case, the number of connection attempts may be adjusted according to a certain probability after the timer expires.

[0070] Furthermore, the control unit 270 may control execution of dual connectivity (DC) via the TN and the NTN. In particular, in this embodiment, the control unit 270 may control the wireless signal transceiver unit 210 to perform wireless communication with the mobile communication network, specifically, simultaneous connection to the TN and the NTN, via a normal network (e.g., TN) that is available only in the first state (a state in which a specific communication quality in the mobile communication network is guaranteed and the mobile communication network is operating normally), and a specific network (e.g., NTN) that is also available in the second state (a state in which available wireless resources are more limited than in the first state).

[0071] If a failure occurs in the TN (corresponding to the second state) while such a DC (simultaneous connection to the TN and the NTN) is being performed, the control unit 270 may continue wireless communication with the mobile communication network via a specific network (NTN) in the second state.

[0072] In this embodiment, TN and NTN are described as examples, but the network types are not necessarily limited to these. For example, the specific network available in the second state may be an ad-hoc network formed using a large-zone wireless base station, or an ad-hoc network formed using a mobile wireless base station. Furthermore, the normal network available only in the first state is not particularly limited to TN, and may include TN and NTN, or may include a network that is not clearly distinguished from TN or NTN. Furthermore, NTN may not necessarily have more limited available wireless resources than TN, and may have more available wireless resources than TN.

[0073] (3) Operation of the Wireless Communication System Next, a description will be given of the operation of the wireless communication system 10. Specifically, a description will be given of the operation relating to guaranteeing communication quality in the wireless communication system 10 (mobile communication network).

[0074] (3.1) Assumptions and Issues As mentioned above, mobile communications using public networks are generally based on a "best effort" approach. This means that network operators who provide communications services over mobile networks cannot control sudden increases in traffic volume. For example, if traffic increases explosively in a crowded environment such as a concert, it becomes impossible to guarantee a minimum level of communication quality (for example, users may be unable to make phone calls or browse websites).

[0075] Mission-critical use cases (e.g., URLLC) have been discussed as a use case for 5G. However, when mission-critical communication services are provided using public networks, as mentioned above, if the surrounding traffic increases or if the traffic within the mission-critical communication service increases, the desired communication quality (throughput, latency, number of simultaneous connections, etc.) cannot be achieved.

[0076] In particular, with 6G, it is expected that there will be an increasing number of use cases, such as those for specific industries, that require a certain level of communication quality assurance. Given this situation, the importance of ensuring communication quality not only for mission-critical cases but also for general users is increasing. A system that guarantees a "minimum communication quality" is required for both general users and mission-critical use cases.

[0077] Furthermore, with 6G, it is expected that minimum quality guarantees will be required even in the event of a power outage or network (equipment) failure. For example, if the terrestrial network (TN) becomes unavailable, it is expected that minimum quality guarantees will be applied using the non-terrestrial network (NTN).

[0078] However, since NTN resources are generally more limited than TN resources, the number of UEs for which quality can be guaranteed is considered to be even more limited. Furthermore, if multiple UEs for which minimum quality is guaranteed simultaneously issue connection requests (including retries) to the mobile communication network via the NTN, resources may become congested, potentially inducing new failures.

[0079] (3.2) Overview of Operation Below, we will explain an example of operation related to minimum quality guarantee that can solve the above-mentioned problems. A system that realizes minimum quality guarantee can be realized by a network operator conditionally guaranteeing a predetermined quality to users based on quality statistics. The conditions, predetermined quality, and statistics may be assumed as follows:

[0080] (Condition): The users for whom minimum quality can be guaranteed are determined for each cell. For example, in cell #1, minimum quality may be guaranteed for only X number of users (number of UEs). If the number of users for whom minimum quality can be guaranteed exceeds the capacity, the guarantee may not be required or may not be possible.

[0081] The minimum quality guarantee may be guaranteed only when a specific area / predetermined reception quality (e.g., RSRP: Reference Signal Received Power, RSRQ: Reference Signal Received Quality, SINR: Signal-to-Interference plus Noise power Ratio) is met. For example, areas that are difficult to cover, such as underwater or in the air, may be excluded. Another condition may be that the UE does not enter an environment where radio waves are significantly attenuated, such as a room surrounded by lead or the user not covering the antenna with their hand.

[0082] (Predetermined quality) (Proposal 1): The network notifies the UE of the minimum quality that can be guaranteed according to the capability of each UE. For example, for UE with Reduced UE Capability (RedCap), throughput: XXX bps and delay: XXX ms may be guaranteed, and for enhanced Mobile Broadband (eMBB) UE (high-end UE), throughput: YYY bps and delay: YYY ms (YYY ≥ XXX) may be guaranteed. UE for URLLC may also be included.

[0083] ・(Proposal 2): ​​Only the quality that can be guaranteed by mandatory capabilities is guaranteed as the minimum quality. For example, it is not always necessary to guarantee 8-layer MIMO x 32CC CA x 1024QAM as the minimum quality. For example, it is possible to guarantee the minimum quality achieved by 4-layer x 1CC x 64QAM.

[0084] (Statistical Value): It may be guaranteed that the statistical value of the quality achieved within a predetermined period is higher than a threshold. For example, an average throughput of XXX bps and a delay of XXX ms over one minute may be guaranteed.

[0085] In particular, in the following operation example 1, when a TN failure occurs, UEs that can connect to the NTN may be limited (coexistence with normal UEs). Furthermore, UEs that are subject to the minimum quality guarantee that can connect to the NTN may be limited according to UE capabilities, etc.

[0086] In addition, in the following operation example 2, the timing at which the UE executes a connection request to the NTN may be restricted.

[0087] (3.3) Operation Example 1 As described above, since NTN resources are more limited than TN resources, the number of UEs for which quality can be guaranteed is further limited. Therefore, not all UEs that are guaranteed a minimum quality in the TN can necessarily be guaranteed a minimum quality in the NTN as high priority UEs.

[0088] Therefore, the following actions may be applied:

[0089] (Operation example 1-1): Restrict UE that can connect to NTN (coexistence with normal UE).

[0090] Connection priorities may be defined for UEs already connected to NTN, UEs with guaranteed minimum quality, and normal UEs.

[0091] (Operation example 1-2): Limit the minimum quality guaranteed UE that can connect to NTN.

[0092] For example, classification may be applied to UEs that are subject to quality guarantees, such as high-priority UEs that are always guaranteed a minimum quality, and UEs that are guaranteed a minimum quality under normal circumstances but not in the event of a failure, etc. Charges may be set according to the class.

[0093] (3.3.1) Operation Example 1-1 Fig. 4 shows an example of a communication sequence between a UE and a RAN according to Operation Example 1. As shown in Fig. 4, when a failure occurs in a TN (which may also be referred to as a TN cell), the UE may perform cell (re)selection to an NTN cell and transmit a connection request (Initial Access).

[0094] The UE may explicitly or implicitly recognize the occurrence of a failure based on at least one of the following events (however, the UE's recognition of the occurrence of a failure does not necessarily constitute a condition for performing the above-mentioned operations):

[0095] - If a cell search is performed for X seconds or Y times, but no connectable cell is found.

[0096] - Access to the RAN or core network is prohibited or not permitted.

[0097] - When X seconds have passed since the UE executed the connection request and the timer expired, or when the connection request was retransmitted Y times and the specified number of times was exceeded.

[0098] - When a cause of a failure or a specific cause is received from the core network.

[0099] - A combination of the above events.

[0100] Also, as shown in Fig. 4, the UE may acquire information (which may be called ntn-Config) about the configuration of NTN cells surrounding the TN cell by broadcast information (SIB: System Information Block) from the TN cell. Note that the timing of acquiring the SIB (ntn-Config) does not necessarily have to be the timing shown in Fig. 4, and may be, for example, a SIB that can be received before the completion of the RRC connection.

[0101] Fig. 5 shows an example of a pattern of types of UEs that can be connected to the NTN according to Operation Example 1. When a UE requests a connection to an NTN, as shown in Fig. 5, restrictions may be placed on the UEs that can be connected to the NTN using one of the following options.

[0102] (Opt.1): Allows the use of NTN only for UEs with minimum quality guarantee.

[0103] In this case, even if the UE was originally connected to the NTN, it may be disconnected if it is not a minimum quality guaranteed UE.

[0104] (Opt.2): Allows minimum quality guaranteed UE and UE already connected to NTN to use NTN.

[0105] Priority may be set between the UEs with the lowest guaranteed quality and the UEs that were originally connected to the NTN. For example, the UEs with the lowest guaranteed quality may be prioritized, and the UEs that were already connected to the NTN may be excluded depending on the network conditions.

[0106] In addition, an indicator indicating a priority according to the UE type or a priority regardless of the UE type may be introduced. When requesting a connection to the NTN, the UE may also transmit information regarding the priority.

[0107] (Opt.3): Minimum quality guaranteed UE, UE already connected to NTN, and normal UE are permitted to use NTN.

[0108] Priority may be set between the UEs with guaranteed minimum quality, the UEs that were originally connected to the NTN, and the normal UEs. For example, the UEs with guaranteed minimum quality may be prioritized, and the UEs that were already connected to the NTN and the normal UEs may be excluded depending on the network situation.

[0109] In addition, an indicator indicating a priority according to the UE type or a priority regardless of the UE type may be introduced. When requesting a connection to the NTN, the UE may also transmit information regarding the priority.

[0110] (3.3.2) Operation Example 1-2 In this operation example, the UE may also obtain information (ntn-Config) about the configuration of NTN cells surrounding the TN cell by broadcast information (SIB) from the TN cell. When the UE requests a connection to the NTN, restrictions may be placed on the UEs that can connect to the NTN by one of the following options.

[0111] (Opt.1): Allows the use of NTN for all UEs with minimum quality guarantee.

[0112] - (Opt.2): Allow the use of NTN for some UEs with minimum quality guarantee.

[0113] The minimum quality guaranteed UEs may be classified into, for example, UEs for which the minimum quality is always guaranteed by the NTN and UEs for which the minimum quality is guaranteed only under normal circumstances by the TN.

[0114] Specifically, the classification method may be included in the minimum quality assurance requirement or permit. Also, a minimum quality assurance requirement for NTN may be required separately from the minimum quality assurance requirement for TN.

[0115] The frequency of the class request may be at least one of the following: when requesting a minimum quality guarantee; when reconnecting to the network (e.g., when the UE state changes (RRC IDLE / RRC CONNECTED)); when an associated timer expires; on an on-demand basis (e.g., when the service being performed by the UE changes); or a combination of these.

[0116] The frequency of class notification may be when notifying the grant of a minimum quality guarantee, upon expiration of an associated timer, on an on-demand basis (e.g. when a request is sent from the UE, when a change is required in the network, etc.), or at least a combination of these.

[0117] According to this operation example, in the event of a TN failure, it is possible to limit the UEs that can connect to the NTN or limit the UEs that can connect to the NTN with a minimum guaranteed quality, so that even if a failure occurs in the mobile communication network and available radio resources are more limited than usual, a certain level of communication quality can be guaranteed.

[0118] (3.4) Operation Example 2 In this operation example, if a failure occurs in the TN, the UE may limit the timing of requesting a connection to the NTN. Note that four patterns of failure may be assumed here, and each may be expressed as follows:

[0119] - In the event of a RAN failure: loses coverage of a cell - In the event of RAN restriction: access attempt is barred - In the event of a core network failure: timer XXX expires The lack of a response from the core network may be determined by the passage of a certain amount of time (timer expiration or excessive number of retransmissions) after the UE sends a specific message.

[0120] - When core network is restricted: not accepted by the network This may mean that the request from the UE is not accepted by the core network.

[0121] Fig. 6 shows an example of a communication sequence between a UE and a RAN according to operation example 2. As shown in Fig. 6, when a failure occurs in a TN, the UE may limit the timing of requesting a connection to an NTN cell.

[0122] As in operation example 1, the UE may explicitly / implicitly recognize the occurrence of a failure based on at least one of the following events (however, the UE's recognition of the occurrence of a failure does not necessarily constitute a condition for performing the above-mentioned operation):

[0123] - If a cell search is performed for X seconds or Y times, but no connectable cell is found.

[0124] - Access to the RAN or core network is prohibited or not permitted.

[0125] - When X seconds have passed since the UE executed the connection request and the timer expired, or when the connection request was retransmitted Y times and the specified number of times was exceeded.

[0126] - When a cause of a failure or a specific cause is received from the core network.

[0127] - A combination of the above events.

[0128] Also, as shown in Figure 6, the UE may obtain information (ntn-Config) regarding the configuration of NTN cells surrounding the TN cell through broadcast information (SIB) from the TN cell.

[0129] The UE may send a connection request via the NTN based on any of the following:

[0130] ・(Opt.1): Follows the same regulatory behavior as existing 5G (NR).

[0131] In the event of a RAN failure, UEs with minimum quality guarantees send connection requests simultaneously.

[0132] - During RAN restriction, the UE sends a connection request according to a certain probability after a specified timer expires (even if the timer expires, the connection request is sent according to the specified probability).

[0133] In the event of a core failure or restriction, a connection request is sent after the timer expires.

[0134] - (Opt.2): Even in the event of a RAN failure, a connection request is sent after the timer expires.

[0135] When the above-mentioned explicit / implicit failure occurrence event occurs, the UE may start a timer. Also, even if the timer expires, a connection request may be transmitted with a certain probability, or different timer values ​​and / or probabilities may be set for each UE.

[0136] The timer value may be assumed to be set in advance from the network, may be set to a constant value at all times, or may be set to a variable value each time a retry is made.

[0137] (Opt.3): The UE executes dual connectivity (DC) with the TN and NTN, ensuring connection to both networks. When any of the following events occurs, the UE transmits and receives various signals (including reference signals) and data only via the NTN (redundant access path to the RAN).

[0138] FIG. 7 shows an example of a communication sequence between a UE and a RAN according to the second operation example (dual connectivity connection).

[0139] As in operation example 1, the UE may explicitly / implicitly recognize the occurrence of a failure based on at least one of the following events (however, the UE's recognition of the occurrence of a failure does not necessarily constitute a condition for performing the above-mentioned operation):

[0140] - If a cell search is performed for X seconds or Y times, but no connectable cell is found.

[0141] - Access to the RAN or core network is prohibited or not permitted.

[0142] - When X seconds have passed since the UE executed the connection request and the timer expired, or when the connection request was retransmitted Y times and the specified number of times was exceeded.

[0143] - When a cause of a failure or a specific cause is received from the core network.

[0144] - A combination of the above events.

[0145] Even in this case, the UE may obtain information (ntn-Config) regarding the configuration of NTN cells surrounding the TN cell through broadcast information (SIB) from the TN cell.

[0146] Furthermore, the UE may maintain the DC state at all times, or may maintain the DC state for a certain period at regular intervals.

[0147] In the DC state, if a failure occurs on the TN side, the UE communicates with the RAN only via the NTN. In addition, when the DC state is not present, either the above-mentioned operation (Opt. 1) or (Opt. 2) may be applied. On the other hand, in the DC state, the UE may operate as follows.

[0148] - Use both the TN and NTN to communicate with the RAN, or - If the TN is available, the NTN is in standby mode and is not used for communication.

[0149] Furthermore, the cycle and period of DC may be specified as a timer, or may be instructed by the network by higher layer signaling or the like.

[0150] According to this operation example, if a failure occurs in the TN, the UE can limit the timing at which it requests a connection to the NTN. Therefore, even if a failure occurs in the mobile communication network and available radio resources become more limited than usual, a certain level of communication quality can be maintained.

[0151] (4) Other Embodiments Although the embodiments have been described above, it will be obvious to those skilled in the art that the present invention is not limited to the description of the embodiments, and that various modifications and improvements are possible.

[0152] For example, the above-described embodiment is based on the assumption that 6G is used, but the above-described minimum quality guarantee mechanism may be provided in wireless communication methods other than 6G, such as 5G / NR.

[0153] In the above-described embodiment, terms such as communication quality, quality, wireless quality, and performance are used, and these terms may be interpreted as having similar meanings.

[0154] Also, in the above description, 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.

[0155] Furthermore, specific, dedicated, UE-specific, and UE-dedicated may be interchangeable. Similarly, common, shared, group-common, UE-common, and UE-shared may be interchangeable.

[0156] The block diagram ( FIG. 3 ) used to explain the above-described embodiment shows functional blocks. These functional blocks (components) are realized by any combination of hardware and / or software. Furthermore, the method for 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 directly or indirectly connected (e.g., wired, wireless, etc.) and these multiple devices. The functional block may also be realized by combining software with the single device or multiple devices.

[0157] Functions include, but are not limited to, judgment, determination, judgment, calculation, computation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, resolution, selection, selection, establishment, comparison, assumption, expectation, consideration, 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.

[0158] Furthermore, the above-described gNB100 and UE200 (the devices) may function as a computer that performs processing of the wireless communication method of the present disclosure. Figure 8 is a diagram showing an example of the hardware configuration of the devices. As shown in Figure 8, the devices 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.

[0159] 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.

[0160] Each functional block of the device (see FIG. 3) is realized by any hardware element of the computer device or a combination of the hardware elements.

[0161] 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.

[0162] 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, and registers.

[0163] 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-described embodiments. Furthermore, the various processes described above may be executed by a single 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.

[0164] The memory 1002 is a computer-readable recording medium and may be configured by at least one of, for example, 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 may store a program (program code), a software module, etc., capable of executing a method according to an embodiment of the present disclosure.

[0165] 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 suitable medium including at least one of memory 1002 and storage 1003.

[0166] 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.

[0167] 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).

[0168] The input device 1005 is an input device (e.g., 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 (e.g., a display, a speaker, an LED lamp, etc.) that outputs to the outside. Note that the input device 1005 and the output device 1006 may be integrated into one device (e.g., a touch panel).

[0169] 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.

[0170] 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.

[0171] 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.

[0172] 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 system, and a next-generation system extended based on these. Furthermore, a combination of multiple systems (e.g., a combination of at least one of LTE and LTE-A with 5G) may also be applied.

[0173] 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.

[0174] In the present disclosure, a specific operation described as being performed by a base station may also 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 (e.g., MME or S-GW, etc., but are not limited to these). 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 (e.g., MME and S-GW) may also be used.

[0175] 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 and output via multiple network nodes.

[0176] The input and output information may be stored in a specific location (for example, a memory) or may be managed using a management table. The input and output information may be overwritten, updated, or added to. The output information may be deleted. The input information may be transmitted to another device.

[0177] 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).

[0178] The aspects / embodiments described in this disclosure may be used alone, in combination, or switched depending on the implementation. Notification of predetermined information (e.g., notification that "X is true") is not limited to explicit notification, but may be implicit (e.g., not notifying the predetermined information).

[0179] 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.

[0180] 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.

[0181] 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.

[0182] Note that terms described 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.

[0183] As used in this disclosure, the terms "system" and "network" are used interchangeably.

[0184] 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.

[0185] 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.

[0186] 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.

[0187] A base station can accommodate one or more (e.g., three) cells (also called sectors). When a base station accommodates multiple cells, the overall coverage area of ​​the base station can be divided into multiple smaller areas, and each smaller area can be provided with communication services by a base station subsystem (e.g., a small indoor base station (Remote Radio Head: RRH)).

[0188] 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 services within that coverage area.

[0189] 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.

[0190] In this disclosure, the terms "Mobile Station (MS)," "user terminal," "User Equipment (UE)," "terminal," etc. may be used interchangeably.

[0191] 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.

[0192] At least one of the base station and the mobile station may be referred to as 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 object, the mobile object itself, etc. The mobile object may be a vehicle (e.g., a car, an airplane, etc.), an unmanned mobile object (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.

[0193] 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 terminal-to-terminal communication (for example, "side"). For example, terms such as an uplink channel and a downlink channel may be read as a side channel (or sidelink).

[0194] 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.

[0195] A radio frame may be composed of one or more frames in the time domain. Each of the one or more frames in the time domain may be called a subframe. A subframe may further be composed of one or more slots in the time domain. A subframe may have a fixed time length (e.g., 1 ms) that is independent of numerology.

[0196] Numerology may be communication parameters that apply to the transmission and / or 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 the transceiver in the frequency domain, and specific windowing operations performed by the transceiver in the time domain.

[0197] A slot may consist of one or more symbols in the time domain (such as an Orthogonal Frequency Division Multiplexing (OFDM) symbol, a Single Carrier Frequency Division Multiple Access (SC-FDMA) symbol, etc.) A slot may be a numerology-based time unit.

[0198] A slot may include multiple minislots. Each minislot may consist of one or more 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.

[0199] 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.

[0200] For example, one subframe may be referred to as a transmission time interval (TTI), multiple consecutive subframes may be referred to as a TTI, or one slot or one minislot may be referred to as 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.

[0201] Here, TTI refers to, for example, the smallest time unit for scheduling in wireless communication. For example, in an LTE system, a base station schedules each user terminal to allocate radio resources (such as frequency bandwidth and transmission power that can be used by each user terminal) in TTI units. Note that the definition of TTI is not limited to this.

[0202] 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.

[0203] In addition, 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, and the number of slots (minislots) constituting the minimum time unit for scheduling may be controlled.

[0204] A TTI having a time length of 1 ms may be referred to as 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 referred to as a shortened TTI, short TTI, partial or fractional TTI, shortened subframe, short subframe, minislot, subslot, slot, etc.

[0205] 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.

[0206] A resource block (RB) is a resource allocation unit in the time domain and the 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 be determined based on numerology.

[0207] 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, each of which may consist of one or more resource blocks.

[0208] 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, etc.

[0209] 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.

[0210] 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.

[0211] 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.

[0212] 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."

[0213] The above-described structures of the radio frame, subframe, slot, minislot, and symbol 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, and other configurations may be changed in various ways.

[0214] 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.

[0215] The reference signal may also be abbreviated as Reference Signal (RS) and may be called a pilot depending on the applicable standard.

[0216] 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."

[0217] The "means" in the configuration of each of the above devices may be replaced with "part," "circuit," "device," etc.

[0218] 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.

[0219] When the terms "include," "including," and variations thereof are used in this disclosure, these terms are intended to be inclusive, similar to the term "comprising." Furthermore, when the term "or" is used in this disclosure, it is not intended to be an exclusive or.

[0220] 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.

[0221] 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.

[0222] 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."

[0223] 9 shows an example of the configuration of a vehicle 2001. As shown in Fig. 9, 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 service unit 2012, and a communication module 2013.

[0224] The drive unit 2002 is composed of, for example, an engine, a motor, or a hybrid of an engine and a motor. 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. The electronic control unit 2010 is composed of a microprocessor 2031, memory (ROM, RAM) 2032, and a communication port (IO port) 2033. Signals from various sensors 2021 to 2027 provided in the vehicle are input to the electronic control unit 2010. The electronic control unit 2010 may also be called an ECU (Electronic Control Unit).

[0225] 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.

[0226] The information 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 (outputting) various types of information, such as driving information, traffic information, and entertainment information, and one or more ECUs for controlling these devices. The information service unit 2012 uses information acquired from external devices via the communication module 2013, etc., to provide various types of multimedia information and multimedia services to the occupants of the vehicle 1.

[0227] The information service unit 2012 may include input devices (e.g., keyboards, mice, microphones, switches, buttons, sensors, touch panels, etc.) that accept input from the outside, and may also include output devices (e.g., displays, speakers, LED lamps, touch panels, etc.) that output to the outside.

[0228] 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.

[0229] 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 driving 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.

[0230] 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.

[0231] The communication module 2013 may transmit at least one of signals from the above-mentioned various sensors 2021 to 2028 input to the electronic control unit 2010, information obtained based on the signals, and information based on input from the outside (user) obtained via the information service unit 2012 to an external device via wireless communication. The electronic control unit 2010, the various sensors 2021 to 2028, the information service unit 2012, etc. may be referred to as input units that accept input. For example, the PUSCH transmitted by the communication module 2013 may include information based on the above-mentioned input.

[0232] The communication module 2013 receives various information (traffic information, traffic signal information, vehicle-to-vehicle information, etc.) transmitted from external devices and displays it on an information service unit 2012 provided in the vehicle. The information service unit 2012 may also be called an output unit that outputs information (for example, outputs information to a device such as a display or speaker based on the PDSCH (or data / information decoded from the PDSCH) received by the communication module 2013). The communication module 2013 also stores the various information received from 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, axles 2009, sensors 2021 to 2028, and the like provided in the vehicle 2001.

[0233] 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.

[0234] (Additional Note) The above disclosure may be expressed as follows: A first feature is a terminal including: a communication unit that performs wireless communication with a mobile communication network in a first state in which a specific communication quality in the mobile communication network is guaranteed and the mobile communication network is operating normally, and a second state in which available wireless resources are more limited than in the first state, and a control unit that performs connection with the mobile communication network in the second state only when a specific condition is satisfied.

[0235] A second feature is that, in the first feature, the control unit executes a connection to the mobile communication network in the second state if the terminal was already connected to a specific network used in the second state in the first state, or if the terminal is subject to the guarantee of the specific communication quality in the first state.

[0236] A third feature is, in the first or second feature, when the terminal is subject to the guarantee of the specific communication quality even in the second state, the control unit executes a connection to the mobile communication network in the second state.

[0237] A fourth feature is a terminal that includes a communication unit that performs wireless communication via the mobile communication network in a first state in which a specific communication quality in the mobile communication network is guaranteed and the mobile communication network is operating normally, and a second state in which available wireless resources are more limited than in the first state, and a control unit that performs connection with the mobile communication network only at specific timings in the second state.

[0238] A fifth feature is that in the fourth feature, in the first state, the communication unit performs wireless communication with the mobile communication network via a normal network that is available only in the first state and a specific network that is also available in the second state, and the control unit continues wireless communication with the mobile communication network via the specific network in the second state.

[0239] 10 Wireless communication system 20 RAN 100 gNB 150 Satellite 200 UE 210 Radio signal transceiver 220 Amplifier 230 Modulation / demodulation unit 240 Control signal / reference signal processing unit 250 Encoding / decoding unit 260 Data transceiver 270 Control unit 1001 Processor 1002 Memory 1003 Storage 1004 Communication device 1005 Input device 1006 Output device 1007 Bus 2001 Vehicle 2002 Drive unit 2003 Steering unit 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 service unit 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 system section 2031 Microprocessor 2032 Memory (ROM, RAM) 2033 Communication port

Claims

1. A terminal comprising: a communication unit that performs wireless communication with a mobile communication network in a first state in which a specific communication quality in a mobile communication network is guaranteed and the mobile communication network is operating normally, and in a second state in which available wireless resources are more limited than in the first state; and a control unit that performs connection with the mobile communication network in the second state only when specific conditions are satisfied.

2. A terminal as described in claim 1, wherein the control unit executes a connection to the mobile communications network in the second state if the terminal was already connected to a specific network used in the second state in the first state, or if the terminal is subject to the guarantee of the specific communication quality in the first state.

3. A terminal according to claim 1, wherein the control unit executes a connection to the mobile communication network in the second state if the terminal is subject to the guarantee of the specific communication quality even in the second state.

4. A terminal comprising: a communication unit that performs wireless communication via a mobile communication network in a first state in which a specific communication quality in the mobile communication network is guaranteed and the mobile communication network is operating normally, and in a second state in which available wireless resources are more limited than in the first state; and a control unit that performs connection to the mobile communication network only at specific timing in the second state.

5. The terminal described in claim 4, wherein the communication unit, in the first state, performs wireless communication with the mobile communication network via a normal network that is available only in the first state and a specific network that is also available in the second state, and the control unit, in the second state, continues wireless communication with the mobile communication network via the specific network.

6. A wireless communication method in a terminal, comprising: a step of performing wireless communication with the mobile communication network in a first state in which a specific communication quality in the mobile communication network is guaranteed and the mobile communication network is operating normally, and in a second state in which available wireless resources are more limited than in the first state; and a step of performing connection with the mobile communication network in the second state only when specific conditions are satisfied.

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