Terminal, base station, wireless communication system, and wireless communication method

Abstract

To provide a terminal, a base station, a wireless communication system, and a wireless communication method that appropriately perform a function of retaining information about conditional setting in a network and a terminal.SOLUTION: A terminal 200 includes a receiving unit that receives setting information about conditional re-setting and a control unit that executes a procedure related to the conditional re-setting. The control unit executes specific control to retain the setting information after the procedure related to the conditional re-setting is completed when a specific condition is satisfied.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a terminal, a base station, a wireless communication system, and a wireless communication method that support multicast / broadcast services. [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 Release 16 introduced conditional reconfiguration, which performs connection to a target cell without sending a re-establishment request message to the target cell. Conditional reconfiguration may include Conditional Handover (CHO), Conditional PSCell (Primary Secondary Cell) Change (CPC), and Conditional PSCell Addition (CPA).

[0004] In the CPC, the CPC configuration is released upon completion of the CPC (completion of connection to the target cell). However, assuming a case in which a terminal (hereinafter referred to as User Equipment (UE)) repeatedly moves between two or more cells, the setting and release of the CPC configuration may be repeated.

[0005] From this perspective, 3GPP Release 16 discusses support for a function (hereinafter referred to as "Selective activation") that retains information about CPC in the network and UE (e.g., UE context on the network side and CPC configuration on the UE side) (e.g., Non-Patent Document 1). [Prior art documents] [Non-patent literature]

[0006] [Non-Patent Document 1] “New WID on Further NR mobility enhancements”, RP213564, 3GPP TSG RAN Meeting #94e, 3GPP, December 2021 Summary of the Invention

[0007] Under these circumstances, the inventors have conducted extensive research and found that it is necessary to define how selective activation should be performed, including the trigger for selective activation.

[0008] Therefore, the present invention has been made to solve the above-mentioned problems, and has an object to provide a terminal, a base station, a wireless communication system, and a wireless communication method that can appropriately perform selective activation.

[0009] One aspect of the present disclosure is a terminal comprising a receiving unit that receives setting information related to conditional reconfiguration and a control unit that executes a procedure related to the conditional reconfiguration, wherein the control unit executes specific control to retain the setting information after the procedure related to the conditional reconfiguration is completed when specific conditions are met.

[0010] One aspect of the disclosure is a base station comprising a transmitting unit that transmits configuration information related to conditional reconfiguration and a control unit that executes a procedure related to the conditional reconfiguration, wherein the control unit assumes that, when a specific condition is satisfied, the terminal executes specific control to retain the configuration information after the procedure related to the conditional reconfiguration is completed.

[0011] One aspect of the disclosure is a wireless communication system comprising a terminal and a base station, wherein the terminal comprises a receiving unit that receives configuration information related to conditional reconfiguration and a control unit that executes procedures related to the conditional reconfiguration, and wherein the control unit executes specific control to retain the configuration information after the procedures related to the conditional reconfiguration are completed when specific conditions are met.

[0012] One aspect of the disclosure is a wireless communication method comprising the steps of receiving configuration information related to conditional reconfiguration, executing a procedure related to the conditional reconfiguration, and, if a specific condition is met, executing specific control to retain the configuration information after the procedure related to the conditional reconfiguration is completed. [Brief explanation of the drawings]

[0013] [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] Figure 5 is a functional block diagram of gNB100. [Figure 6] FIG. 6 is a diagram for explaining the first operation example. [Figure 7]FIG. 7 is a diagram for explaining the second operation example. [Figure 8] FIG. 8 is a diagram for explaining the third operation example. [Figure 9] FIG. 9 is a diagram for explaining the fourth operation example. [Figure 10] FIG. 10 is a diagram for explaining the fifth operation example. [Figure 11] FIG. 11 is a diagram for explaining the sixth operation example. [Figure 12] FIG. 12 is a diagram for explaining the seventh operation example. [Figure 13] FIG. 13 is a diagram for explaining the eighth operational example. [Figure 14] FIG. 14 is a diagram showing an example of UE Assistance Information (ASN.1 format). [Figure 15] FIG. 15 is a diagram illustrating an example of CondReconfigToAddModList (ASN.1 format). [Figure 16] FIG. 16 is a diagram showing an example of an SN Addition request (ASN.1 format). [Figure 17] FIG. 17 is a diagram showing an example of an HO request (ASN.1 format). [Figure 18] FIG. 18 is a diagram showing an example of the hardware configuration of gNB100 and UE200. [Figure 19] FIG. 19 is a diagram showing an example of the configuration of a vehicle 2001. DETAILED DESCRIPTION OF THE INVENTION

[0014] 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.

[0015] [Embodiment] (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).

[0016] The wireless communication system 10 may be a wireless communication system conforming to a system called Beyond 5G, 5G Evolution, or 6G.

[0017] 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.

[0018] The NG-RAN 20 actually includes a plurality of NG-RAN nodes, specifically, gNBs (or ng-eNBs), and is connected to a 5G-compliant core network (5GC, not shown). The NG-RAN 20 and the 5GC may be simply referred to as a "network."

[0019] 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.

[0020] The wireless communication system 10 also supports a plurality of frequency ranges (FR).

[0021] 2, the wireless communication system 10 supports FR1 and FR2. The frequency bands of each FR are as follows:

[0022] FR1: 410 MHz to 7.125 GHz FR2: 24.25 GHz~52.6 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.

[0023] 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.

[0024] Furthermore, the wireless communication system 10 also supports frequency bands higher than the FR2 frequency band. Specifically, the wireless communication system 10 supports frequency bands above 52.6 GHz up to 71 GHz or 114.25 GHz. For convenience, such high frequency bands may be referred to as "FR2x."

[0025] To solve the problem of increased phase noise in high frequency bands, when using bands above 52.6 GHz, Cyclic Prefix-Orthogonal Frequency Division Multiplexing (CP-OFDM) / Discrete Fourier Transform - Spread (DFT-S-OFDM) with larger Sub-Carrier Spacing (SCS) may be applied.

[0026] FIG. 3 shows an example of the configuration of a radio frame, a subframe, and a slot used in the radio communication system 10. In FIG.

[0027] 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). The SCS is not limited to the interval (frequency) shown in Figure 3. For example, 480 kHz, 960 kHz, etc. may be used.

[0028] 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.

[0029] 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.

[0030] DMRS is a type of reference signal and is prepared for various channels. Here, unless otherwise specified, it may refer to a downlink data channel, specifically, a DMRS for a PDSCH (Physical Downlink Shared Channel). However, a DMRS for an uplink data channel, specifically, a PUSCH (Physical Uplink Shared Channel), may be interpreted as being the same as a DMRS for a PDSCH.

[0031] The DMRS may be used for channel estimation at the device, for example, as part of coherent demodulation at the UE 200. The DMRS may only be present in resource blocks (RBs) used for PDSCH transmission.

[0032] A DMRS may have multiple mapping types. Specifically, a DMRS has mapping type A and mapping type B. In mapping type A, the first DMRS is placed in the second or third symbol of a slot. In mapping type A, the DMRS may be mapped based on the slot boundary, regardless of where in the slot actual data transmission starts. The reason why the first DMRS is placed in the second or third symbol of a slot may be interpreted as being to place the first DMRS after a control resource set (CORESET).

[0033] In mapping type B, the first DMRS may be placed in the first symbol of the data allocation, i.e., the position of the DMRS may be given relative to where the data is placed, rather than relative to the slot boundary.

[0034] Furthermore, DMRS may have multiple types. Specifically, DMRS has Type 1 and Type 2. Type 1 and Type 2 differ in frequency domain mapping and the maximum number of orthogonal reference signals. Type 1 is a single-symbol DMRS that can output up to four orthogonal signals, while Type 2 is a double-symbol DMRS that can output up to eight orthogonal signals.

[0035] Here, the above-mentioned DC may include any of the following DCs: EN-DC (E-UTRA-NR Dual Connectivity), NE-DC (NR-EUTRA Dual Connectivity), and NR-DC (NR-NR Dual Connectivity).

[0036] In the above-mentioned CA or DC, a group of cells that can perform processes related to the C-plane (control plane) and the U-plane (user plane) may be referred to as a first cell group (MCG; Master Cell Group). In the above-mentioned DC, a group of cells that can perform processes related to the U-plane (user plane) may be referred to as a second cell group (SCG; Secondary Cell Group). Cells included in the MCG may include a Primary Cell (hereinafter, PCell). A node having a cell included in the MCG may be referred to as an MN (Master Node). Cells included in the SCG may be referred to as a Secondary Cell (hereinafter, PCell). An SCell may include a Primary Secondary Cell (hereinafter, PSCell). A node having a cell included in the SCG may be referred to as an SN (Secondary Node).

[0037] (2) Functional block configuration of wireless communication system Next, the functional block configuration of the wireless communication system 10 will be described.

[0038] First, the functional block configuration of the UE 200 will be described.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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).

[0043] 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 .

[0044] 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.

[0045] 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).

[0046] 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.

[0047] 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.

[0048] 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).

[0049] 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.

[0050] 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.

[0051] 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.

[0052] In an embodiment, the control signal / reference signal processor 240 configures a receiver that receives configuration information related to conditional reconfiguration. The conditional reconfiguration may include Conditional Handover (CHO), Conditional PSCell (Primary Secondary Cell) Change (CPC), and Conditional PSCell Addition (CPA). The configuration information may be referred to as ConditionalReconfiguration. The ConditionalReconfiguration may include Special Cell (hereinafter, SpCell) configuration. The SpCell may include a PCell or a PSCell. That is, the SpCell configuration is configuration information related to candidate target cells in conditional reconfiguration (CHO, CPC, or CPA). The ConditionalReconfiguration may be included in RRC Reconfiguration.

[0053] The encoding / decoding unit 250 performs data division / concatenation and channel coding / decoding for each predetermined communication destination (gNB100 or another gNB).

[0054] 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.

[0055] 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).

[0056] The control unit 270 controls each functional block constituting the UE 200. In the embodiment, the control unit 270 constitutes a control unit that executes a procedure related to conditional reconfiguration. When a specific condition is satisfied, the control unit 270 executes specific control (hereinafter, referred to as Selective Activation) to retain configuration information (hereinafter, referred to as SpCell configuration) after the procedure related to conditional reconfiguration is completed.

[0057] The specific condition may include a condition for receiving an indication for Selective Activation from the network (hereinafter referred to as the first condition). The indication may be included in RRC Reconfiguration related to conditional reconfiguration. The specific condition may also include a condition for transmitting a message requesting Selective Activation to the network (hereinafter referred to as the second condition). The message may be UE Assistance Information. The specific condition may include both the first condition and the second condition.

[0058] Whether to perform Selective Activation may be determined based on the mobility pattern of UE 200. For example, control unit 270 may determine whether to perform Selective Activation based on an information element (VisitedCellInfoList) defined in 3GPP TS38.331. VisitedCellInfoList may include up to 16 cells as cells that UE 200 has most recently visited. Control unit 270 may determine to perform Selective Activation when the pattern of Cell IDs included in VisitedCellInfoList is a pattern in which the same Cell IDs appear repeatedly (e.g., "Cell #1", "Cell #2", "Cell #1", "Cell #2", ...).

[0059] Secondly, we will explain the functional block configuration of gNB100.

[0060] Fig. 5 is a functional block diagram of the gNB 100. As shown in Fig. 5, the gNB 100 includes a receiving unit 110, a transmitting unit 120, and a control unit 130.

[0061] The receiving unit 110 receives various signals from the UE 200. The receiving unit 110 may receive an UL signal via a PUCCH or a PUSCH.

[0062] The transmitter 120 transmits various signals to the UE 200. The transmitter 120 may transmit the DL signal via a PDCCH or a PDSCH. In the embodiment, the transmitter 120 constitutes a transmitter that transmits configuration information related to conditional reconfiguration.

[0063] The control unit 130 controls the gNB 100. In the embodiment, the control unit 130 is configured to execute a procedure related to conditional reconfiguration. The control unit 130 assumes that the UE executes selective activation when a specific condition is met.

[0064] The specific condition may include a condition (first condition) for transmitting an indication instructing Selective Activation to the UE 200. The indication may be included in RRC Reconfiguration related to conditional reconfiguration. The specific condition may include a condition (second condition) for receiving a message requesting Selective Activation from the UE 200. The message may be UE Assistance Information. The specific condition may include both the first condition and the second condition.

[0065] Whether to perform selective activation may be determined based on the mobility pattern of UE 200. For example, control unit 130 may determine whether to perform selective activation based on information elements (UE History Information) defined in 3GPP TS38.423. The Last Visited Cell List included in the UE History Information may include up to 16 cells where UE 200 has most recently visited. Control unit 270 may determine to perform selective activation when the pattern of cell IDs included in the Last Visited Cell List is a pattern in which the same cell IDs repeatedly appear (e.g., "Cell #1", "Cell #2", "Cell #1", "Cell #2", ...). Alternatively, control unit 130 may determine whether to perform selective activation based on UE trajectory. UE trajectory may include UE location information (latitude, longitude, altitude), timestamp, and velocity (horizontal velocity, vertical velocity). The control unit 130 may identify the route of the UE 200 based on the UE trajectory, and may determine to execute selective activation when the route of the UE 200 repeats a certain path.

[0066] Here, when it is determined to perform Selective Activation, control unit 130 may retain the UE context after the procedure related to conditional reconfiguration is completed, even if UE 200 is not connected to its own cell in the conditional reconfiguration. In such a case, control unit 130 may retain one or more information elements selected from UE Config, SCG Config, and CPC Config in addition to the UE context.

[0067] (3) Issues In the conditional reconfiguration, the SpCell configuration is released upon completion of the conditional reconfiguration (i.e., completion of connection to the target cell). However, assuming a case in which the UE 200 repeatedly moves between two or more cells, the configuration and release of the SpCell configuration may be repeated.

[0068] From this perspective, support for a function (hereinafter referred to as Selective activation) that retains information related to conditional reconfiguration in the network and UE (e.g., UE context on the network side, SpCell configuration on the UE side) is being discussed.

[0069] Under these circumstances, the inventors have conducted extensive research and found that it is necessary to define how selective activation should be performed, including the trigger for selective activation.

[0070] (4) Example of operation Next, an example of operation of the embodiment will be described, in which a procedure for executing selective activation will be described.

[0071] (4.1) Example 1 In operation example 1, CPC from a Source SN (hereinafter referred to as S-SN) to a Target SN (T-SN) will be described. In operation example 1, a case will be described in which the decision on whether to perform CPC (CPC decision) is made by the S-SN, and the derivation of the mobility pattern of UE 200 is made by the MN. Note that the T-SNs shown in Fig. 6 may be considered as T-SN candidates.

[0072] 6, in step S10, the UE 200 transmits a Measurement Report to the S-SN. The Measurement Report includes the quality of the S-SN and the quality of neighboring cells of the S-SN.

[0073] In step S11, the S-SN determines whether to execute CPC based on the Measurement Report. Here, the case where it is determined that CPC is to be executed will be described.

[0074] In step S12, the S-SN transmits a message (SN change required) requesting a CPC to the MN. The SN change required includes information about T-SN candidates (for example, CellID, etc.).

[0075] In step S13, the MN derives a mobility pattern of the UE 200. The mobility pattern of the UE 200 is derived based on UE History Information or UE trajectory. The MN determines whether to perform selective activation based on the mobility pattern of the UE 200. Here, the case where it is determined that selective activation is to be performed will be described.

[0076] In step S14, the MN transmits a message (SN Addition Request) to one or more T-SN candidates requesting preparation for addition as a PSCell. The SN Addition Request may include an indication of selective activation.

[0077] In step S15, one or more T-SN candidates transmit a response message (SN Addition Request ACK) to the MN in response to the SN Addition Request.

[0078] In step S16, the MN transmits a message (RRC Reconfiguration) instructing CPC to the UE 200. The RRC Reconfiguration includes setting information (SpCell configuration) related to T-SN candidates. The RRC Reconfiguration includes an indication instructing Selective activation.

[0079] In step S17, the UE 200 transmits a response message (RRC Reconfiguration Complete) to the MN in response to the RRC Reconfiguration.

[0080] In step S20, the UE 200 performs a connection procedure for a T-SN selected from the T-SN candidates. Specifically, the UE 200 performs a Random Access (RA) procedure for the selected T-SN.

[0081] In step S21, after the procedure related to CPC is completed (in other words, after the connection to the T-SN is completed), the UE 200 holds configuration information related to the CPC (for example, an SpCell configuration or a CPC configuration). The SpCell configuration may be referred to as a PSCell Config. The SpCell configuration includes configuration information related to T-SN candidates to which the UE 200 was not connected in the procedure related to CPC.

[0082] In step S22, the T-SN candidate may hold the UE context after the CPC-related procedure is completed (in other words, after the connection for the T-SN is completed). In such a case, the T-SN candidate may hold one or more information elements selected from the UE Config, the SCG Config, and the CPC Config in addition to the UE context. Here, the T-SN candidate may be considered to be a T-SN candidate to which the UE 200 did not connect in the CPC-related procedure.

[0083] In the first operational example, the specific condition may be considered to be condition 1, that is, receiving an indication of selective activation in step S16.

[0084] (4.2) Example 2 In operation example 2, CPC from S-SN to T-SN will be described. In operation example 2, a case will be described in which the decision on whether to perform CPC (CPC decision) is made by the S-SN, and the derivation of the mobility pattern of UE 200 is made by UE 200. Note that the T-SNs shown in Fig. 7 may be considered as T-SN candidates.

[0085] In the following, the same step numbers are assigned to processes that are the same as those in Operation Example 1. Therefore, the following description will mainly focus on the differences from Operation Example 1. Specifically, step S10X is executed instead of step S13 described above.

[0086] As shown in FIG. 7, in step S10X, UE 200 derives a mobility pattern of UE 200. The mobility pattern of UE 200 is derived based on VisitedCellInfoList. UE 200 determines whether to perform Selective activation based on the mobility pattern of UE 200. Here, the case where it is determined that Selective activation is to be performed will be described. UE 200 transmits a message (UE Assistance Information) requesting Selective activation to MN. The UE Assistance Information includes information elements related to the mobility pattern of UE 200.

[0087] In the second operation example, the determination of whether to perform selective activation may be made by the MN based on UE Assistance Information received from the UE 200.

[0088] In the second example operation, the specific condition may include a second condition of sending a message requesting selective activation. The specific condition may also be considered to include a first condition of receiving an indication of selective activation in step S16.

[0089] (4.3) Example 3 In operation example 3, CPC from S-SN to T-SN will be described. In operation example 3, a case will be described in which the decision on whether to perform CPC (CPC decision) is made by the S-SN, and the derivation of the mobility pattern of UE 200 is made by the S-SN. Note that the T-SNs shown in Fig. 8 may be considered as T-SN candidates.

[0090] In the following, the same step numbers are assigned to processes that are the same as those in Operation Example 1. Therefore, the following mainly describes the differences from Operation Example 1. Specifically, step S31 is executed instead of step S13 described above.

[0091] As shown in Fig. 8, in step S31, the S-SN derives a mobility pattern of the UE 200. The mobility pattern of the UE 200 is derived based on UE History Information or UE trajectory. The S-SN determines whether to perform selective activation based on the mobility pattern of the UE 200. Here, the case where it is determined that selective activation should be performed will be described.

[0092] In the third operational example, in step S12, the S-SN may transmit an SN change required containing an indication instructing selective activation to the MN.

[0093] In the third operational example, the specific condition may be considered to be condition 1, that is, receiving an indication of selective activation in step S16.

[0094] (4.4) Example 4 In operation example 4, CPC from S-SN to T-SN will be described. In operation example 4, a case will be described in which the decision on whether to perform CPC (CPC decision) is made by the S-SN, and the derivation of the mobility pattern of UE 200 is made by UE 200. Note that the T-SNs shown in Fig. 9 may be considered as T-SN candidates.

[0095] In the following, the same step numbers are assigned to processes that are the same as those in Operation Example 3. Therefore, the following description will mainly focus on the differences from Operation Example 3. Specifically, step S10Y is executed instead of step S31 described above.

[0096] As shown in FIG. 9 , in step S10Y, UE 200 derives a mobility pattern of UE 200. The mobility pattern of UE 200 is derived based on VisitedCellInfoList. UE 200 determines whether to perform Selective activation based on the mobility pattern of UE 200. Here, the case where it is determined that Selective activation is to be performed will be described. UE 200 transmits a message (UE Assistance Information) requesting Selective activation to S-SN. The UE Assistance Information includes information elements related to the mobility pattern of UE 200.

[0097] In the fourth operation example, the determination of whether to perform selective activation may be made by the S-SN based on UE Assistance Information received from the UE 200.

[0098] In the fourth example operation, the specific condition may include a second condition of sending a message requesting selective activation. The specific condition may also be considered to include a first condition of receiving an indication of selective activation in step S16.

[0099] (4.5) Example 5 In operation example 5, CPC from S-SN to T-SN will be described. In operation example 5, a case will be described in which the decision on whether to perform CPC (CPC decision) is made by the MN, and the derivation of the mobility pattern of UE 200 is made by the MN. Note that the T-SNs shown in Fig. 10 may be considered as T-SN candidates.

[0100] In the following, the same step numbers are assigned to processes that are the same as those in Operation Example 1. Therefore, the following description will mainly focus on the differences from Operation Example 1. Specifically, steps S40 to S41 are executed instead of steps S10 to S12 described above.

[0101] 10, in step S40, the UE 200 transmits a Measurement Report to the MN. The Measurement Report includes the quality of the S-SN and the quality of the neighboring cells of the S-SN.

[0102] In step S41, the MN determines whether to execute the CPC based on the Measurement Report. Here, the case where it is determined that the CPC is to be executed will be explained.

[0103] In the fifth operational example, the specific condition may be considered to be condition 1, that is, receiving an indication of selective activation in step S16.

[0104] (4.6) Example 6 In operation example 6, CPC from S-SN to T-SN will be described. In operation example 6, a case will be described in which the decision on whether to perform CPC (CPC decision) is made by the MN, and the derivation of the mobility pattern of UE 200 is made by UE 200. Note that the T-SNs shown in Fig. 11 may be considered as T-SN candidates.

[0105] In the following, the same step numbers are assigned to processes that are the same as those in Operation Example 5. Therefore, the following description will mainly focus on the differences from Operation Example 5. Specifically, step S40X is executed instead of step S13 described above.

[0106] As shown in FIG. 11 , in step S40X, UE 200 derives a mobility pattern of UE 200. The mobility pattern of UE 200 is derived based on VisitedCellInfoList. UE 200 determines whether to perform Selective activation based on the mobility pattern of UE 200. Here, the case where it is determined that Selective activation is to be performed will be described. UE 200 transmits a message (UE Assistance Information) requesting Selective activation to MN. The UE Assistance Information includes information elements related to the mobility pattern of UE 200.

[0107] In the sixth operation example, the determination of whether to perform selective activation may be made by the MN based on UE Assistance Information received from the UE 200.

[0108] In the sixth example operation, the specific condition may include a second condition of sending a message requesting selective activation. The specific condition may also be considered to include a first condition of receiving an indication of selective activation in step S16.

[0109] (4.7) Example 7 In operation example 7, a CHO from a Source MN (hereinafter referred to as S-MN) to a Target MN (T-MN) will be described. In operation example 7, a case will be described in which the decision on whether to perform CHO (HO decision) is made by the S-MN, and the derivation of the mobility pattern of UE 200 is made by the MN. Note that the T-MN shown in Fig. 12 may be considered as a candidate T-MN.

[0110] 12, in step S60, the UE 200 transmits a Measurement Report to the S-MN. The Measurement Report includes the quality of the S-MN and the quality of neighboring cells of the S-MN.

[0111] In step S61, the S-MN determines whether to execute CHO based on the Measurement Report. Here, the case where it is determined that CHO is to be executed will be explained.

[0112] In step S62, the MN derives a mobility pattern of the UE 200. The mobility pattern of the UE 200 is derived based on UE History Information or UE trajectory. The MN determines whether to perform selective activation based on the mobility pattern of the UE 200. Here, the description continues for the case where it is determined that selective activation is to be performed.

[0113] In step S63, the MN transmits a message (Handover request) to one or more T-MN candidates requesting preparation for addition as a PCell. The Handover request may include an indication of Selective activation.

[0114] In step S64, one or more T-MN candidates transmit a response message (Handover request ACK) to the MN in response to the Handover request.

[0115] In step S65, the MN transmits a message (RRC Reconfiguration) instructing CHO to the UE 200. The RRC Reconfiguration includes configuration information (PCell configuration) related to the T-MN candidate. The RRC Reconfiguration includes an indication instructing Selective activation.

[0116] In step S66, the UE 200 transmits a response message (RRC Reconfiguration Complete) to the MN in response to the RRC Reconfiguration.

[0117] In step S70, the UE 200 executes a connection procedure for a T-MN selected from among the T-MN candidates. Specifically, the UE 200 executes an RA (Random Access) procedure for the selected T-MN.

[0118] In step S71, after the procedure related to CHO is completed (in other words, after the connection to the T-MN is completed), the UE 200 holds configuration information related to CHO (for example, SpCell configuration). The SpCell configuration may be referred to as PCell Config. The SpCell configuration includes configuration information related to T-MN candidates to which the UE 200 did not connect in the procedure related to CPC.

[0119] In step S72, the T-MN candidate may hold the UE context after the CHO-related procedure is completed (in other words, after the connection to the T-MN is completed). In such a case, the T-MN candidate may hold the UE Config and / or the MCG Config in addition to the UE context. Here, the T-MN candidate may be considered to be a T-MN candidate to which the UE 200 did not connect in the CHO-related procedure.

[0120] In the seventh operational example, the specific condition may be considered to be condition 1, that is, receiving an indication of selective activation in step S66.

[0121] (4.8) Example 8 In operation example 8, CHO from S-MN to T-MN will be described. In operation example 8, a case will be described in which the decision on whether to perform CHO (HO decision) is made by S-MN, and the derivation of the mobility pattern of UE 200 is made by UE 200. Note that T-MN shown in Fig. 13 may be considered as a candidate T-MN.

[0122] In the following, the same step numbers are assigned to processes that are the same as those in Operation Example 7. Therefore, the following mainly describes the differences from Operation Example 7. Specifically, step S60X is executed instead of step S62 described above.

[0123] As shown in FIG. 13, in step S60X, UE 200 derives a mobility pattern of UE 200. The mobility pattern of UE 200 is derived based on VisitedCellInfoList. UE 200 determines whether to perform Selective activation based on the mobility pattern of UE 200. Here, the case where it is determined that Selective activation is to be performed will be described. UE 200 transmits a message (UE Assistance Information) requesting Selective activation to MN. The UE Assistance Information includes information elements related to the mobility pattern of UE 200.

[0124] In the eighth operation example, the determination of whether to perform selective activation may be made by the S-MN based on UE Assistance Information received from the UE 200.

[0125] In the eighth operational example, the specific condition may include a second condition of sending a message requesting selective activation. The specific condition may also be considered to include a first condition of receiving an indication instructing selective activation in step S66.

[0126] (5) Example of information element configuration First, we will explain the UE Assistance Information used in steps S10X, S10Y, S40X, and S60X in operation examples 2, 4, 6, and 8. As shown in Fig. 14, the UE Assistance Information may include a selectiveActivationRequest. The selectiveActivationRequest is an example of an information element requesting selective activation.

[0127] Secondly, we will explain CondReconfigToAddModList included in RRC Reconfiguration used in step S16 of Operation Examples 1 to 6 and step S65 of Operation Examples 7 and 8. As shown in Fig. 15, CondReconfigToAddModList may include maintainCandidateCellConfig. maintainCandidateCellConfig is an information element that instructs maintaining the SpCell configuration of the target cell, and may be considered to be an example of an information element that instructs selective activation.

[0128] Thirdly, the SN Addition request used in step S14 in operation examples 1 to 6 will be described. As shown in Fig. 16, the SN Addition request may include a Maintain UE config indication. The Maintain UE config indication is an information element that instructs the maintenance of configuration information such as UE context, UE Config, SCG Config, and CPC Config, and may be considered to be an example of an information element that instructs Selective activation.

[0129] Fourth, we will explain the HO request used in step S63 in operation examples 7 and 8. As shown in Fig. 17, the HO request may include a Maintain UE config indication. The Maintain UE config indication is an information element that instructs the maintenance of configuration information such as UE context, UE Config, and MCG Config, and may be considered an example of an information element that instructs selective activation.

[0130] (6) Actions and Effects In the embodiment, when a specific condition is satisfied, the UE 200 may perform Selective Activation, in which the UE 200 retains the configuration information (SpCell configuration) without releasing it after the procedure related to the conditional reconfiguration is completed. With this configuration, by defining the specific condition, the UE 200 can appropriately perform Selective Activation.

[0131] In the embodiment, when it is determined that Selective Activation is to be performed, the gNB 100 may retain the configuration information (such as the UE context) without releasing it after the procedure related to the conditional reconfiguration is completed, even if the UE 200 is not connected to the own cell in the conditional reconfiguration. With this configuration, it is possible to appropriately perform Selective Activation.

[0132] (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.

[0133] In the above disclosure, when a specific condition is satisfied, the UE 200 performs Selective Activation to retain the SpCell configuration after the procedure related to conditional reconfiguration is completed. In Selective Activation, the UE 200 may perform a connection to a target cell selected from candidate target cells included in the retained SpCell configuration (e.g., an RA procedure for the selected target cell). The connection to the selected target cell does not require transmission of a Measurement Report to the network, and may not require a trigger from the network. More specifically, the UE 200 may perform the RA procedure for the selected target cell when an execution condition is satisfied. The execution condition is an example of configuration information received from the network, and may be considered to be an example of an information element to be retained even after the procedure related to conditional reconfiguration is completed in Selective Activation.

[0134] Although not specifically mentioned in the above disclosure, the UE 200 may release the configuration information (SpCell configuration) when a release condition is satisfied in Selective Activation, in which the UE 200 retains the configuration information without releasing it. The release condition may be a condition that a certain time period has elapsed since receiving an indication (e.g., maintainCandidateCellConfig included in RRC Reconfiguration) from the network. The certain time period may be specified by the expiration of a timer that is activated in response to receiving the indication. The release condition may be a condition that an explicit or implicit instruction is received from the network.

[0135] Although not specifically mentioned in the above disclosure, in a case where the gNB 100 retains configuration information (such as UE context) without releasing it, the gNB 100 may release the configuration information if a release condition is met. The release condition may be a condition where a certain time has elapsed since receiving an indication (e.g., a Maintain UE config indication included in an SN Addition request or an HO request) from the source node. The certain time may be specified by the expiration of a timer that is activated in response to receiving the indication. Under the assumption that the configuration information is released after a certain time, the certain time used in a case where Selective Activation is applied may be longer than the certain time used in a case where Selective Activation is not applied. The release condition may also be a condition where an explicit or implicit instruction is received from the source node.

[0136] Here, the release condition for the gNB 100 may be the following condition. Here, a T-SN candidate for the CPC is exemplified. However, a T-MN candidate for the CHO may also perform the same operation.

[0137] First, the T-SN candidate may release the UE configuration if the conditions for canceling all target candidate PSCells (release conditions) are met at the time when the CPAC cancel indication is received from the MN in the SN modification request. The T-SN candidate may retain the UE configuration until receiving the CPAC cancel indication.

[0138] Second, when the load of the T-SN candidate is greater than a threshold, the T-SN candidate may send an SN modification required to the MN and request CAPC cancellation from the MN, and may release the UE config when the conditions for canceling all target candidate PSCells (release conditions) are met.

[0139] Third, when an MN sends an SN addition / modification request to a T-SN candidate, it may also send a T_maintainUEconfig to the T-SN candidate simultaneously with a maintain UE config indication. The T_maintainUEconfig may include a timer value that defines the time for which the UE config should be maintained. The T-SN candidate may start a timer upon receiving the maintain UE config indication (timer value), and release the UE config when the timer expiration condition (release condition) is met. In such a case, in an SN-initiated CPC, the timer value may be set by the SN. For example, the SN may send an SN change required to the MN, and the MN may send the timer value set by the SN to the T-SN candidate.

[0140] Fourth, the T-SN candidate may have a T_maintainUEconfig in advance. In other words, the timer value may be determined by the T-SN candidate. The T-SN candidate may start the timer when it receives the maintain UE config indication, and release the UE config when the timer expiration condition (release condition) is met.

[0141] Fifth, when transmitting RRC Reconfiguration to UE 200, the MN may transmit T_maintainCPCconfig to UE 200 simultaneously with maintainCandidateCellConfig. T_maintainCPCconfig may include a timer value defining the time for which the CPC Config should be maintained. UE 200 may start a timer when it receives maintainCandidateCellConfig (timer value), and release the CPC Config when the condition for the timer to expire (release condition) is met. In such a case, in SN-initiated CPC, the timer value may be set by the SN. For example, the SN may transmit SN change required to the MN, and the MN may transmit the timer value set by the SN to UE 200.

[0142] Sixth, the UE 200 may have T_maintainCPCconfig in advance. In other words, the timer value may be determined by the UE 200. The UE 200 may start the timer when it receives maintainCandidateCellConfig, and release the CPC Config when the condition for the timer to expire (release condition) is satisfied.

[0143] The above-mentioned release condition may include a condition that the mobility pattern of UE200 is a specific pattern that disables Selective Activation. For example, in Operation Examples 1 and 5, the MN may transmit an indication to UE200 and T-SN candidates to cancel Selective Activation when the mobility pattern of UE200 is a specific pattern. In Operation Example 3, the S-SN may transmit an indication to MN to cancel Selective Activation when the mobility pattern of UE200 is a specific pattern, and the MN may transmit an indication to UE200 and T-SN candidates to cancel Selective Activation. In Operation Example 7, the S-MN may transmit an indication to UE200 and T-MN candidates to cancel Selective Activation when the mobility pattern of UE200 is a specific pattern. In Operation Examples 2, 4, 6, and 8, the UE200 may transmit an indication to the network to cancel Selective Activation when the mobility pattern of UE200 is a specific pattern. The nodes (UE 200, T-SN candidate, T-MN candidate) that receive the indication to cancel Selective Activation release the configuration information in response to receiving the indication.

[0144] Although not specifically mentioned in the above disclosure, a node may be read as a cell. For example, an MN may be read as a cell (e.g., a PCell) included in an MCG, and an SN may be read as a cell (e.g., an SCell or a PSCell) included in an SCG.

[0145] Although not specifically mentioned in the above disclosure, the operation of UE200 may be interpreted as follows: When maintainCandidateCellConfig is set, UE200 retains all entries included in the variable (VarConditionalReconfig) retained by UE200, and in other cases, UE200 deletes all entries included in the variable (VarConditionalReconfig) retained by UE200. Note that VarConditionalReconfig is a variable in which SpCell configuration is stored.

[0146] 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 be realized by combining the single device or the multiple devices with software.

[0147] 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.

[0148] Furthermore, the above-described gNB100 and UE200 (the device) may function as a computer that performs processing of the wireless communication method of the present disclosure. Figure 18 is a diagram showing an example of the hardware configuration of the device. As shown in Figure 18, 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.

[0149] 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.

[0150] Each functional block of the device (see FIG. 4) is realized by any hardware element of the computer device or a combination of the hardware elements.

[0151] 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.

[0152] 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.

[0153] 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.

[0154] 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.

[0155] 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.

[0156] 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.

[0157] 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).

[0158] 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).

[0159] 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.

[0160] 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.

[0161] 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.

[0162] 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), 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 and 5G) may also be applied.

[0163] 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.

[0164] 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.

[0165] 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.

[0166] 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.

[0167] 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).

[0168] 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).

[0169] 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.

[0170] 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.

[0171] 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.

[0172] 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.

[0173] As used in this disclosure, the terms "system" and "network" are used interchangeably.

[0174] 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.

[0175] 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.

[0176] 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.

[0177] 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 service by a base station subsystem (e.g., a small indoor base station (Remote Radio Head: RRH)).

[0178] 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.

[0179] In this disclosure, the terms "Mobile Station (MS)," "user terminal," "User Equipment (UE)," "terminal," etc. may be used interchangeably.

[0180] 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.

[0181] 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.

[0182] 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.

[0183] 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.

[0184] A radio frame may be made up of one or more frames in the time domain, each of which may be called a subframe.

[0185] 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.

[0186] 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.

[0187] 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.

[0188] 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.

[0189] 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.

[0190] 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.

[0191] 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.

[0192] 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.

[0193] 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.

[0194] 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.

[0195] 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.

[0196] 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.

[0197] 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.

[0198] 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.

[0199] 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.

[0200] 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.

[0201] 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.

[0202] 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."

[0203] 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.

[0204] 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.

[0205] The reference signal may also be abbreviated as Reference Signal (RS), and may also be called a pilot depending on the applicable standard.

[0206] 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."

[0207] The "means" in the configuration of each of the above devices may be replaced with "part," "circuit," "device," etc.

[0208] 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.

[0209] 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.

[0210] 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.

[0211] 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.

[0212] 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."

[0213] Fig. 19 shows an example of the configuration of a vehicle 2001. As shown in Fig. 19, 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.

[0214] The drive unit 2002 is composed of, for example, an engine, a motor, or a hybrid of an engine and a motor.

[0215] 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.

[0216] 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).

[0217] 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.

[0218] 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 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 obtained 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.

[0219] 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.

[0220] 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.

[0221] 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.

[0222] 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.

[0223] The communication module 2013 receives various information (traffic information, traffic signal information, vehicle distance information, etc.) transmitted from external devices and displays it on an information 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 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, sensors 2021 to 2028, and the like provided in the vehicle 2001.

[0224] 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. [Explanation of symbols]

[0225] 10. Wireless communication systems 20 NG-RAN 100 gNB 110 Receiving unit 120 Transmitter 130 control section 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 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 receiving unit that receives a radio resource control reconfiguration message including configuration information related to conditional reconfiguration of a secondary node addition or change; a control unit that executes a procedure related to the conditional resetting, When the radio resource control reconfiguration message includes configuration information related to the conditional reconfiguration, the control unit retains the configuration information even after completion of a procedure related to the conditional reconfiguration.

2. The terminal according to claim 1 , wherein the radio resource control reconfiguration message is received from a master node that transmits a secondary node addition or change message to a secondary node candidate, the secondary node addition or change message including information indicating retention of configuration information regarding the conditional reconfiguration.

3. a transmitter configured to transmit a radio resource control reconfiguration message to a terminal, the radio resource control reconfiguration message including configuration information related to conditional reconfiguration of a secondary node addition or change; a control unit that executes a procedure related to the conditional resetting, When the control unit includes configuration information regarding the conditional reconfiguration in the radio resource control reconfiguration message, the control unit assumes that the terminal will retain the configuration information even after completion of the procedure regarding the conditional reconfiguration.

4. A communication system comprising a terminal and a base station, The base station a transmitter configured to transmit a radio resource control reconfiguration message including configuration information related to conditional reconfiguration of a secondary node addition or change to the terminal; The terminal a receiving unit that receives the radio resource control reconfiguration message from the base station; a control unit that executes a procedure related to the conditional resetting, When the radio resource control reconfiguration message includes configuration information related to the conditional reconfiguration, the control unit retains the configuration information even after completion of a procedure related to the conditional reconfiguration.

5. receiving a radio resource control reconfiguration message including configuration information related to conditional reconfiguration of a secondary node addition or change; executing a procedure for conditional resetting; and if the radio resource control reconfiguration message includes configuration information related to the conditional reconfiguration, retaining the configuration information even after completion of a procedure related to the conditional reconfiguration.

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