Terminal, wireless communication method, and base station

Abstract

A terminal according to one embodiment of the present disclosure comprises: a control unit that, when communicating by using a first radio access technology (RAT), autonomously determines whether to connect to a second RAT; and a reception unit that, when it is determined to connect to the second RAT, measures the second RAT. According to one embodiment of the present disclosure, it is possible to flexibly control to which RAT to connect.

Description

Terminal, Wireless Communication Method, and Base Station

[0001] The present disclosure relates to a terminal, a wireless communication method, and a base station in a next-generation mobile communication system.

[0002] In a Universal Mobile Telecommunications System (UMTS) network, Long Term Evolution (LTE) was standardized for the purpose of further higher data rates, lower latency, etc. (Non-Patent Document 1). Also, for the purpose of further larger capacity and sophistication of LTE (Third Generation Partnership Project (3GPP (registered trademark)) Release (Rel.) 8, 9), LTE-Advanced (3GPP Rel. 10-14) was standardized.

[0003] Successor systems to LTE (for example, also referred to as 5th generation mobile communication system (5G), 5G+ (plus), 6th generation mobile communication system (6G), New Radio (NR), 3GPP Rel. 1 after 5, etc.) are also being considered.

[0004] 3GPP TS 36.300 V8.12.0 "Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2 (Release 8)", April

[0005] In a conventional wireless communication system, when there are a plurality of radio access technologies (Radio Access Technology (RAT)), a method has been used in which a terminal (user terminal, User Equipment (UE)) first connects to one RAT (also called an anchor RAT), then starts measuring the other RAT, and establishes a connection with the other RAT as necessary.

[0006] However, future wireless communication systems are expected to have diverse configurations, and the conventional method of switching / adding RATs based on the anchor RAT may lack flexibility. Furthermore, if RATs cannot be switched / added quickly as needed, communication throughput, resource utilization efficiency, and communication quality may deteriorate.

[0007] Therefore, one of the objectives of this disclosure is to provide a terminal, a wireless communication method, and a base station that can flexibly control the connected RAT.

[0008] A terminal according to one aspect of the present disclosure includes a control unit that autonomously determines whether to connect to a second radio access technology (RAT) when communicating using a first radio access technology (RAT), and a receiving unit that measures the second RAT when it is determined that it should connect to the second RAT.

[0009] According to one aspect of this disclosure, the destination RAT can be flexibly controlled.

[0010] Figure 1 shows an example of a RAT triggering procedure based on UE autonomous decision according to one embodiment of the present disclosure. Figures 2A-2D show an example of a network configuration according to one embodiment of the present disclosure. Figures 3A and 3B show another example of a network configuration according to one embodiment of the present disclosure. Figure 4 shows an example of a schematic configuration of a wireless communication system according to one embodiment. Figure 5 shows an example of a base station configuration according to one embodiment. Figure 6 shows an example of a user terminal configuration according to one embodiment. Figure 7 shows an example of a hardware configuration of a base station and user terminal according to one embodiment. Figure 8 shows an example of a vehicle according to one embodiment.

[0011] (Various substitutions) In this disclosure, words enclosed in parentheses () may indicate an explanation of the preceding word (e.g., an explanation of spelling), a paraphrase, a specific example, or supplementary explanation. Also, in this disclosure, words enclosed in square brackets ([]) may be interpreted as part of the overall meaning of the text, or they may be interpreted as being excluded (ignored). Note that parentheses () and square brackets ([]) may be used for purposes / meanings other than those described above.

[0012] In this disclosure, "A / B" and "at least one of A and B" may be interpreted as mutually exclusive. In this disclosure, "A / B / C" may mean "at least one of A, B, and C".

[0013] In this disclosure, terms such as notice, activate, deactivate, indicate (or specify), select, configure, update, and determine may be interpreted interchangeably. In this disclosure, terms such as support, control, controllable, operate, and capable of operating may be interpreted interchangeably.

[0014] In this disclosure, Radio Resource Control (RRC), RRC parameters, RRC messages, higher-layer parameters, fields, Information Elements (IE), settings, etc., may be interpreted interchangeably. In this disclosure, Medium Access Control elements (MAC Control Elements (CE)), update commands, activation / deactivation commands, etc., may be interpreted interchangeably.

[0015] In this disclosure, the upper layer signaling may be any or a combination thereof, such as Radio Resource Control (RRC) signaling, Medium Access Control (MAC) signaling, broadcast information, and other messages (e.g., messages from the core network, such as positioning protocol messages (e.g., NR Positioning Protocol A (NRPPPa) / LTE Positioning Protocol (LPP)) messages).

[0016] In this disclosure, MAC signaling may include, for example, MAC Control Elements (MAC CEs) and MAC Protocol Data Units (PDUs). Broadcast information may include, for example, Master Information Blocks (MIBs), System Information Blocks (SIBs), Remaining Minimum System Information (RMSIs), and Other System Information (OSIs).

[0017] In this disclosure, physical layer signaling may include, for example, Downlink Control Information (DCI) and Uplink Control Information (UCI).

[0018] Terms related to 5G in this disclosure are interchangeable with terms from other technologies / systems (e.g., 6G). Furthermore, in such cases, it will be obvious to those skilled in the art that, for example, Network Function (NF) can be interpreted as a function (or device having a similar function) similar to that of 5G. The same may apply to other generations of wireless communication systems (e.g., xG, where x is an integer).

[0019] In this disclosure, terms such as signaling and messages may be interpreted interchangeably.

[0020] In this disclosure, thresholds, levels, ranges, etc., may be interpreted interchangeably. Furthermore, each "threshold" described in this disclosure may be different or the same.

[0021] In this disclosure, terms relating to changes, updates, etc., may be interpreted interchangeably. Similarly, in this disclosure, terms relating to requests, recommendations, etc., may be interpreted interchangeably.

[0022] In this disclosure, terms relating to registration, attach, etc., may be interpreted interchangeably.

[0023] In this disclosure, Network (NW), Core Network (CN), System, etc., may be interpreted interchangeably.

[0024] In this disclosure, the terms node, UE, base station (BS), RAN, NF, and any device within the network may be interpreted interchangeably.

[0025] (Control related to the establishment of Radio Access Technology (RAT)) In conventional wireless communication systems, when multiple RATs exist, the UE has been used to first connect to one RAT (also called the anchor RAT), then start measuring the other RAT, and establish a connection with that other RAT as needed.

[0026] For example, if the multiple RATs are a 4th generation mobile communication system (4G) and a 5th generation mobile communication system (5G), the anchor RAT might be 4G, and the other RAT might be 5G. This type of connection method is exemplified by the non-standalone (NSA) E-UTRA-NR Dual Connectivity (EN-DC).

[0027] However, future wireless communication systems are expected to have a variety of configurations, including: • 5G and 6G coexisting, each possessing its own core network (5G Core network (5GC), 6G Core network (6GC)); • 6GC extending 5GC (enhanced 5GC (e5GC)); • 5G / 6G and other generations of networks (e.g., 4G) operating in the same / overlapping areas.

[0028] In some scenarios (for example, scenarios where a UE requires high-speed, high-capacity (enhanced Mobile Broadband (eMBB)) communication while using a 6G Radio Access Network (RAN), or scenarios where a UE requires ultra-reliable and low-latency communications (URLLC) while using a 5G RAN), the conventional method of switching / adding RATs based on the anchor RAT may lack flexibility. Furthermore, the inability to quickly switch / add RATs as needed may lead to a decrease in communication throughput, resource utilization efficiency, and communication quality.

[0029] Therefore, the inventors conceived of a system in which the UE, based on autonomous judgment, initiates a connection to a RAT other than the one it is currently connected to. According to one aspect of this disclosure, even without explicit measurement instructions or connection requests from the RAN side, the UE can internally evaluate communication quality, traffic volume, etc., and appropriately perform a handover to another RAT or establish a dual connection between the current RAT and another RAT.

[0030] The embodiments of this disclosure will be described in detail below with reference to the drawings. Each wireless communication method according to the embodiments may be applied individually or in combination.

[0031] (Wireless communication method) <Criteria for UE autonomous decision regarding initiating connection to another RAT> In one embodiment of the present disclosure, when a UE is communicating in a certain RAT, it may initiate a connection to another RAT based on an autonomous decision (which may also be called a UE autonomous decision, or simply an autonomous decision).

[0032] The UE may make the above autonomous decision based on at least one of the following criteria / metrics: • Required service class, • Required high-capacity communication, • Required ultra-high reliability / low latency communication, • Required network slice, • Required Quality of Service (QoS) parameters, • Required new service, • Required traffic volume / throughput, • Radio quality / power consumption indicators in a given RAT (current RAT), • Required latency, • UE status / resources.

[0033] Furthermore, in these criteria, "required" may also mean "required by one or more applications running on the UE," or "related to one or more applications running on the UE," etc.

[0034] The above service classes may indicate the types of services provided to (or desired by) the UE. Service classes may be divided according to purpose / use and may include, for example, high-capacity communications (or enhanced Mobile Broad Band (eMBB)), ultra-reliable and low-latency communications (or Ultra Reliable and Low Latency Communications (URLLC)), massive machine type communications (or massive machine type communications (mMTC)), etc. In this disclosure, service classes, service types, services, use cases, scenarios, etc., may be interchangeable.

[0035] The above-mentioned high-capacity communication may include communication [planned / requested] of a data volume / traffic volume [of DL / UL] that exceeds a certain threshold.

[0036] The above-mentioned ultra-high reliability / low latency communication may include at least one of the following: communication with reliability exceeding a certain threshold [planned / requested], or communication with latency below a certain threshold [planned / requested].

[0037] The above network slice may include network slices corresponding to slice IDs (e.g., Single Network Slice Selection Assistance Information (S-NSSAI), NSSAI, etc.). The above service type may also be determined by the Slice and Service Type (SST) included in the S-NSSAI.

[0038] The above QoS parameters may include whether or not bandwidth control is enabled, priority, delay allowance (delay budget), loss rate, etc., and may be identified by a QoS class ID (e.g., 5G QoS Identifier (5QI), QoS Class Identifier (QCI), QoS Flow Identifier (QFI))).

[0039] The new services described above may include services that prioritize real-time performance and low power consumption (for example, services not defined in existing service classes).

[0040] The above traffic volume / throughput may include, for example, the traffic volume / data volume / throughput required by applications running on the UE.

[0041] The above-mentioned RAT (current RAT) may include, for example, any measurement metric related to received power / received quality, as described later with respect to Figure 1, or it may include the amount of power consumption required by the application operating in the UE.

[0042] The above delays may include, for example, application delays, network delays, latency, and round-trip time required by applications running on the UE.

[0043] The status / resources of the UE may include, for example, computing resources (performance of available processors, amount of available memory) in the UE, battery power, etc.

[0044] Note that in the present disclosure, the service class may be defined including the above service classes (e.g., URLLC, eMBB, mMTC) and other parameters (e.g., QoS parameters).

[0045] The UE may perform the above autonomous determination at any timing. For example, the UE may perform the above autonomous determination at specific intervals, or may perform the above autonomous determination when a specific event occurs (e.g., a certain signal is received, etc.). Also, the UE may monitor the above determination criteria / metrics and perform the above autonomous determination.

[0046] <RAT Triggering Procedure> FIG. 1 is a diagram showing an example of a RAT triggering procedure based on UE autonomous determination according to an embodiment of the present disclosure. In this example, the UE supports communication with a first RAN using a first RAT and communication with a second RAN using a second RAT different from the first RAT.

[0047] In step S101, the UE is communicating with the first RAN using the first RAT. Note that step S101 only requires that the UE be in a state where it can communicate with the first RAN immediately, and the UE may be in a connected state (e.g., RRC connected state) with the first RAN. Note that the UE may also be in other states (e.g., [RRC] inactive state, [RRC] idle state).

[0048] In step S102, the UE may determine whether to connect to the second RAT (whether to trigger the second RAT) based on the above UE autonomous determination.

[0049] A UE may decide to connect to a second RAT if, for example, at least one of the following conditions is met: • A specific service class is required, • High-capacity communication is required, • Ultra-high reliability / low-latency communication is required, • A specific network slice is required, • Specific QoS parameters are required, • A new service is required, • A traffic volume / throughput above a threshold is required, • The radio quality / power consumption [indicators] of the first RAT (the current RAT) is below a threshold, • Latency below a threshold is required, • The UE's status / resources meet the conditions.

[0050] For example, under the condition "a traffic volume / throughput above a threshold is required," if the application requests a certain level of throughput (e.g., several hundred Mbps or more), the UE can decide to use a second RAT in addition to the first RAT.

[0051] For example, the condition "the signal quality / power consumption [index] of the first RAT (current RAT) is below the threshold" indicates that the coverage of the frequency band of the first RAT has deteriorated. Furthermore, the measurement in step S103 described later may indicate that the frequency band of the second RAT is more stable.

[0052] For example, under the condition "a delay below a threshold is required," it can be determined that a delay requirement of the URLLC class is necessary, and the latency characteristics of the second RAT can be utilized.

[0053] For example, if the condition "UE status / resources meet the requirements" indicates that the first RAT transmitter requires high transmission power, but it is determined that using a second RAT in conjunction is more advantageous for battery saving, then the system can decide to use the second RAT.

[0054] The decision of whether or not to connect to the second RAT may be made based on the network configuration of the first RAN / second RAN, the UE's capabilities, etc. The UE may be notified in advance of the above network configuration information.

[0055] Figures 2A-2D show an example of a network configuration according to one embodiment of the present disclosure. In this example and Figures 3A and 3B, the first RAN / second RAN is a 5G / 6G RAN, and the first RAT / second RAT is a 5G / 6G. These figures show a control plane (C-plane) used for communication of control signals and a user plane (U-plane) used for communication of user data signals.

[0056] Figure 2A shows an example of a configuration where 5G and 6G are provided in standalone (SA) mode. In this configuration, 5GC and 6GC are separated, and the UE uses 5GC when connected to the 5G RAN and 6GC when connected to the 6G RAN. Furthermore, in this configuration, it is assumed that the UE is registered with only one of 5GC or 6GC. Therefore, when the UE switches its connection from 5G to 6G (or vice versa), an inter-RAT handover (IRAT HO) is required.

[0057] Figure 2B shows an example of a configuration known as RAN aggregation. In this configuration, both 5G RANs and 6G RANs are connected to (managed by) the 6GC. UEs utilize the 6GC regardless of which RAN they connect to. In this configuration, UEs only need to be registered with the 6GC. In the example in Figure 2B, the 6G side is the master configuration, and the 5G RAN / UE can exchange control signals (e.g., RRC signaling) and data signals via the 6G RAN. The 5G side is the secondary configuration, and UEs can also exchange data signals via the 5G RAN. Of course, a configuration where the 5G side is the master is also possible.

[0058] Figure 2C shows an example of a configuration known as CN aggregation. In this configuration, both 5G RANs and 6G RANs are connected to (managed by) the 6GC, similar to Figure 2B. The difference from Figure 2B is that the 5G RAN connects directly to the 6GC, rather than connecting via the 6G RAN. The UE uses the 6GC regardless of which RAN it connects to. In this configuration, it is sufficient for the UE to be registered with the 6GC. In this example, neither RAN is considered the master, and the UE can exchange control signals (e.g., RRC signaling) such as settings via at least one of the RANs.

[0059] Figure 2D shows an example of a configuration known as dual registration. In this configuration, similar to Figure 2A, there is a connection relationship between 5G RAN-5GC and 6G RAN-6GC. The difference from Figure 2A is that the UE can register with both 5GC and 6GC simultaneously. In this configuration, because the UE can connect to both RANs simultaneously (dual connectivity), even when switching to the other RAN while connected to one RAN, the connection to the other RAN can be added while maintaining the connection to the first RAN. Note that Figure 2D shows a configuration that does not utilize aggregation as in Figures 2B / 2C, but RAN / CN aggregation may also be used simultaneously in dual registration.

[0060] In this disclosure, RAN may be interpreted as at least one node of RAN (for example, a master node (MN) and a secondary node (SN) for dual connectivity).

[0061] Figures 3A and 3B show another example of a network configuration according to one embodiment of the present disclosure. This example illustrates how 5GC and 6GC are connected.

[0062] Figure 3A shows an example where 5GC and 6GC have independent configurations (which may also be called independent core configurations). 5GC and 6GC may communicate using a specific interface, but they are still separate systems and are controlled independently.

[0063] Figure 3B shows an example where 5GC and 6GC take an inclusive configuration (which may also be called an extended core configuration). In this example, an enhanced 5GC (e5GC) that extends 5GC supports 6GC functionality, and the UE may connect to the e5GC via a 5G RAN and to the 6GC functionality within the e5GC via a 6G RAN. The extended core configuration can be said to correspond in some sense to the CN aggregation described above. Conversely, if 6GC includes 5GC functionality, the UE may connect to the 5GC functionality within the 6GC via a 5G RAN and to the 6GC via a 6G RAN.

[0064] The RAT triggering procedure in Figure 1 may be used in at least one of these network configurations. For example, the RAT triggering procedure in Figure 1 may be used to dynamically switch measurement / connection to a different RAT (and different CN) with a different UE in an independent core configuration. Alternatively, the RAT triggering procedure in Figure 1 may be used to dynamically switch measurement / connection to a different RAT with a different UE in an extended core configuration.

[0065] As mentioned above, the first RAN and the second RAN may be connected to different CNs (the first CN (e.g., 5GC) and the second CN (e.g., 6GC)), or they may be connected to the same CN (e.g., e5GC).

[0066] Returning to step S102, whether or not to connect to the second RAT may be determined based on the network configuration shown in Figures 2A-2D, 3A-3B, etc. For a network configuration including the first RAN and the second RAN, whether or not to connect to the second RAT may be determined based on, for example, at least one of the following conditions: ・RAN aggregation is used and the first RAN (e.g., 5G RAN) is the master, ・RAN aggregation is used and the second RAN (e.g., 6G RAN) is the master, ・CN aggregation is used, ・Aggregation is not used.

[0067] If it is determined in step S102 that a connection to the second RAT should be made, in step S103 the UE performs a measurement of the second RAT. The measurement in step S103 may mean measuring (deriving) an arbitrary measurement metric related to received power / received quality. Such measurement metrics may include, for example, at least one of the following: Channel State Information (CSI), Reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), Received Signal Strength Indicator (RSSI), Signal to Interference plus Noise Ratio (SINR), or Signal to Noise Ratio (SNR).

[0068] Furthermore, the measurement in step S105 may correspond to a Radio Resource Management (RRM) measurement or to a Layer X measurement (where X is an integer; for example, X = 1, 2, 3, ...). In other words, the above measurement metric may correspond to a Layer X measurement metric.

[0069] In this disclosure, terms such as measurement, estimation, prediction, and inference may be interpreted interchangeably. For example, the measurement in step S103 may be a prediction of the determination result of the second RAT based on the measurement result of the first RAT.

[0070] The measurement in step S103 may be a measurement of a specific signal in a defined frequency band (e.g., a Synchronization Signal Block (SSB)) similar to a normal cell search performed by the UE in the second RAT. The measurement in step S103 may be performed in a narrower frequency band than the normal cell search (for faster scanning). The measurement in step S103 may be performed in a frequency band that has been scanned (or accessed) in the past (e.g., recently).

[0071] Furthermore, for the measurement in step S103, information regarding at least one of the following may be received in advance from the first RAN: • the type of signal for measurement (e.g., a Reference Signal (RS)), • the resources for measurement (e.g., time / frequency resources), • the type of RAT for measurement, • specific conditions for detecting an appropriate cell / beam from the measurement results (e.g., thresholds described below).

[0072] The measurement in step S103 is an autonomous measurement based on the result of the autonomous decision in step S102, and is not a measurement triggered by instructions from RAN / CN.

[0073] In step S104, the UE determines whether a suitable cell / beam has been detected based on the measurement results from step S103. The suitable cell / beam may be a cell / beam that satisfies specific conditions, for example, a cell / beam whose measurement metric exceeds a threshold value.

[0074] If at least one suitable cell / beam is detected in step S104, the UE may select one to connect to. In step S105, the UE may initiate a procedure to establish a connection between the UE and the second RAN (or trigger the second RAT), such as an initial access procedure, for the selected cell / beam. For example, in step S105, a connection procedure to the CN (or second RAT) to which the second RAN belongs (e.g., performing an initial access procedure, establishing an RRC connection, registering with the CN) may be performed between the UE and the second RAN.

[0075] In the connection procedure (initial access procedure), the UE may, for example, send a Physical Random Access Channel (PRACH) for initial access to the second RAN, send a message for establishing an RRC connection (e.g., an RRC setup request message), send a message for registration (e.g., a registration request message), or send a message for handover (e.g., a handover request message). In step S105, the first RAN / second RAN may notify the UE of information for the connection procedure (e.g., an RRC connection reset message).

[0076] In step S106, the second RAN may coordinate with the second CN to determine (evaluate) whether to accept the UE (for example, whether the UE is allowed to communicate using the second RAT). If the second RAN determines not to accept the UE, it may notify the UE of a connection failure / access denied. If the second CN determines to accept the UE, it may request the second RAN to set up the UE context (for example, it may send an [initial] context setup request message).

[0077] Although not shown in the diagram, in an independent core configuration, UE context information is transferred from the first CN to the second CN (for example, using a service operation related to UEContextTransfer), and at least a part of the UE context related to the second RAN may be determined based on the UE context. Thus, the processing in step S106 may be carried out in cooperation with the second RAN, the first CN, the second CN, etc.

[0078] Furthermore, in step S106, the second RAN may secure the necessary radio resources for establishing communication with the second RAT. If the second RAN has secured the radio resources, it may send a response message to the second CN for the request for the UE context setup described above.

[0079] In step S107, the second RAN may transmit to the UE information for allocating the radio resources, a communication [start] instruction for the second RAT, etc. For example, the communication [start] instruction for the second RAT may include an RRC connection reset message indicating a connection instruction for the second RAT / second RAN.

[0080] The UE may initiate the requested service (such as eMBB) / communication (e.g., high-capacity communication) used in the determination in step S102 during the communication in step S108.

[0081] The RAT connection based on the RAT triggering procedure in Figure 1 may also be called an autonomous [RAT] connection because it is based on autonomous decision-making.

[0082] According to the RAT triggering procedure described above, the UE can autonomously connect to a different RAT than the one it is currently connected to (for example, establish a dual connection) without instructions from the RAN / CN (e.g., explicit measurement instructions, connection requests, service request triggers, etc.) by internally evaluating communication quality, data volume, and application requirements.

[0083] Furthermore, because other RATs can only be accessed when necessary, the overall control load on the network can be reduced. In addition, by allowing the UE to understand the actual traffic situation, QoS requests, etc., and connect to the optimal RAT in a timely manner, an improvement in the user experience can be expected.

[0084] <Variations of the RAT Triggering Procedure> The UE may determine that the RAT triggering in Figure 1 did not occur (failed) after a certain period of time (time window) has elapsed from a certain point in time. This prevents the situation where the UE continues to wait indefinitely for an RAT that is not actually usable.

[0085] The aforementioned timing may correspond to the timing at which transmission / reception / processing / decision related to the first step in Figure 1 (for example, at least one of steps S102 to S104) takes place. The UE may start a timer for RAT triggering at the aforementioned timing, and if the second step in Figure 1 (for example, step S106) is not completed before the timer expires, the UE may determine that the RAT triggering did not occur (failed). The UE does not need to make autonomous decisions while the timer is running.

[0086] If the UE determines that RAT triggering did not occur (failed), it may restart the RAT triggering procedure (for example, by performing an autonomous UE decision).

[0087] These modifications allow each node to respond appropriately even if unforeseen circumstances occur during the RAT triggering procedure.

[0088] <Specific Example 1 of RAT Triggering Procedure: Autonomous Connection in Cases Requiring High-Capacity Communication> Below, a specific example of the RAT triggering procedure shown in Figure 1 is presented.

[0089] Specific example 1 is a case where, in the procedure shown in Figure 1, the first RAT is 6G, the first RAN is 6G RAN, the first CN is 6GC, the second RAT is 5G, the second RAN is 5G RAN, and the second CN is 5GC, and triggering 5G is required for high-capacity communication. For each step, we will not repeat explanations of the content that overlaps with the procedure shown in Figure 1.

[0090] In step S101, the UE is connected to the 6G RAN and is communicating via 6GC or e5GC (it is registered with 6GC or e5GC). At this stage, the UE is performing normal communication (e.g., web browsing, low-resolution video streaming), but the bandwidth requirements are relatively low.

[0091] Here, we assume that an application within the UE switches to a situation where it requires high-capacity communication (for example, communication for high-resolution video streaming or virtual reality (VR) content).

[0092] The UE monitors its own traffic volume, QoS requests, etc., and in step S102, it autonomously determines that a 5G connection is necessary (it is difficult to meet the desired throughput with 6G RAN alone).

[0093] While maintaining the connection with the 6G RAN, in step S103, the UE performs a 5G measurement (autonomously scans).

[0094] In step S104, the UE may select a cell in which the radio wave quality (RSRP, SINR, etc.) exceeds a threshold.

[0095] In step S105, the UE initiates the initial access procedure for the selected cell.

[0096] The UE establishes an RRC connection state with the 5G RAN, and in step S108, performs 5G communication based, for example, on a handover from 6G communication or dual connectivity with 6G communication. The UE may initiate the above high-capacity communication in the 5G communication in step S108.

[0097] According to the specific example 1 of the RAT triggering procedure described above, even if the throughput is insufficient with only the connected 6G communication, it is possible to autonomously connect to 5G and continue communication appropriately.

[0098] <Specific Example 2 of RAT Triggering Procedure: Autonomous Connection During 6G Coverage Decrease> Specific Example 2 is a case where, in the procedure shown in Figure 1, the first RAT is 6G, the first RAN is 6G RAN, the first CN is 6GC, the second RAT is 5G, the second RAN is 5G RAN, and the second CN is 5GC, and triggering to 5G occurs due to deterioration of radio wave quality. For each step, we will not repeat explanations of content that overlaps with the procedure in Figure 1.

[0099] In step S101, the UE is connected to the 6G RAN and is communicating via 6GC or e5GC (it is registered with 6GC or e5GC). The UE is communicating in the 6G high-frequency band (such as millimeter waves), achieving the ultra-high-speed communication unique to 6G.

[0100] Typically, millimeter-wave cells have narrow coverage and require beamforming. Here, we assume, for example, that the 6G radio wave quality (RSRP, SINR) deteriorates due to building obstruction as a result of the UE moving.

[0101] The UE monitors the radio wave quality of the 6G communication and, in step S102, autonomously determines that a 5G connection is necessary (indicating an increased risk of 6G communication disconnection).

[0102] While maintaining the connection with the 6G RAN, in step S103, the UE performs a 5G (e.g., sub-6GHz band) measurement (autonomously scanning).

[0103] In step S104, the UE may select a cell in which the radio wave quality (RSRP, SINR, etc.) exceeds or stabilizes a threshold.

[0104] In step S105, the UE initiates the initial access procedure for the selected cell.

[0105] The UE establishes an RRC connection with the 5G RAN, and in step S108, performs 5G communication based, for example, on a handover from 6G communication or dual connectivity with 6G communication. If the UE determines that 5G communication is more stable, it may release 6G communication.

[0106] According to the specific example 2 of the RAT triggering procedure described above, even if the 6G communication being connected deteriorates, it is possible to autonomously connect to 5G and continue communication effectively.

[0107] <Note> The above explanation uses the example where the first RAT / second RAT is 5G / 6G, but it is not limited to this. The first RAT and the second RAT can be different, and each can correspond to any communication technology (for example, 4G, 7G, IEEE 802.11 (Wi-Fi®), etc.).

[0108] Furthermore, simultaneous use of the first RAT and the second RAT may be performed not in the form of dual connectivity, but for example, in the form of carrier aggregation. For example, a UE may use a first cell following the first RAT and a second cell following the second RAT for communication using carrier aggregation. In this case, the first RAN and the second RAN may correspond to the same node.

[0109] <<Notification of Information to the UE>> In the embodiments described above, notification of any information from the Network (NW) (e.g., Base Station (BS)) to the UE (in other words, reception of any information from the BS at the UE) may be performed using physical layer signaling (e.g., DCI), higher layer signaling (e.g., RRC signaling, MAC CE), specific signals / channels (e.g., PDCCH, PDSCH, reference signal), or a combination thereof.

[0110] If the above notification is made by a MAC CE, the MAC CE may be identified by the inclusion of a new Logical Channel ID (LCID) not defined in existing standards in the MAC subheader.

[0111] If the above notification is made by DCI, the notification may be made by a specific field of the DCI, a Radio Network Temporary Identifier (RNTI) used to scramble the Cyclic Redundancy Check (CRC) bits assigned to the DCI, or the format of the DCI.

[0112] Furthermore, the notification of arbitrary information to the UE in the above-described embodiment may be periodic, semi-persistent, or aperiodic.

[0113] <<Notification of Information from UE>> Notification of any information from the UE to the NW in the embodiments described above (in other words, transmission / reporting of any information from the UE to the BS) may be performed using physical layer signaling (e.g., UCI), higher layer signaling (e.g., RRC signaling, MAC CE), specific signals / channels (e.g., PUCCH, PUSCH, PRACH, reference signals), or a combination thereof.

[0114] If the above notification is made by a MAC CE, the MAC CE may be identified by the inclusion of a new LCID not specified in existing standards in the MAC subheader.

[0115] If the above notice is made by the UCI, the notice may be transmitted using PUCCH or PUSCH.

[0116] Furthermore, the notification of any information from the UE in the above-described embodiment may be periodic, semi-persistent, or aperiodic.

[0117] <<Regarding the application of each embodiment>> In UE / BS, specific (one or more) processes / operations / controls / assumptions / information for at least one of the embodiments described above may be applied (or used) if any or more of the following conditions are met: - A higher-layer parameter indicating the specific process / operation / control / assumption / information is set; - The specific process / operation / control / assumption / information is determined based on the relevant higher-layer parameter; - The specific process / operation / control / assumption / information is designated / activated / triggered by MAC CE / DCI / UCI / Resource / Channel / RS; - A specific UE capability indicating (or related to) the specific process / operation / control / assumption / information is reported or supported; - The application of the specific process / operation / control / assumption / information is determined based on specific conditions.

[0118] The above-mentioned specific UE capability may represent at least one of the following: supporting the above-mentioned specific processing / operation / control / assumption / information (e.g., RAT triggering procedure, service request).

[0119] Furthermore, the above-mentioned specific UE capability may be a capability that applies across all frequencies (commonly regardless of frequency), a capability per frequency (e.g., one or a combination thereof, such as cell, band, band combination, BWP, component carrier, etc.), a capability per frequency range (e.g., Frequency Range 1 (FR1), FR2, FR3, FR4, FR5, FR2-1, FR2-2), a capability per subcarrier spacing (SCS), or a capability per feature set (FS) or feature set per component-carrier (FSPC).

[0120] Furthermore, the specific UE capabilities described above may be capabilities that apply across all duplexing schemes (common to all duplexing schemes regardless of the duplexing scheme), or they may be capabilities specific to each duplexing scheme (e.g., Time Division Duplex (TDD), Frequency Division Duplex (FDD)).

[0121] If the above conditions are not met, UE / BS may follow the behavior specified in existing 3GPP releases.

[0122] (Note) The following inventions are added with respect to one embodiment of the present disclosure. [Note 1] A terminal (e.g., UE) having: a control unit that autonomously determines whether to connect to a second RAT when communicating using a first Radio Access Technology (RAT); and a receiving unit that measures the second RAT when it is determined that to connect to the second RAT. [Note 2] The terminal according to Note 1, wherein the determination is based on the amount of traffic or delay related to an application running on the terminal. [Note 3] The terminal according to Note 1 or Note 2, wherein the control unit detects a cell that satisfies a specific condition (e.g., the measurement result is higher than a threshold) based on the measurement result of the second RAT. [Note 4] The terminal according to Note 3, wherein the control unit initiates an initial access procedure to the cell. [Note 5] A wireless communication method for a terminal, comprising the steps of: autonomously determining whether to connect to a second RAT when communicating using a first radio access technology (RAT); and, if it is determined that to connect to the second RAT, measuring the second RAT. [Note 6] A base station (e.g., a second RAN) comprising: a receiving unit that receives signals for the initial access procedure of the second RAT (e.g., PRACH (or random access preamble), a message for establishing an RRC connection, a message for registration, a message for handover) transmitted when a terminal communicating using a first radio access technology (RAT) autonomously determines whether to connect to the second RAT; and a control unit that determines whether the terminal may perform communication using the second RAT.

[0123] (Wireless Communication System) The configuration of a wireless communication system according to one embodiment of this disclosure will be described below. In this wireless communication system, communication is performed using any of the wireless communication methods according to the above embodiments of this disclosure, or a combination thereof.

[0124] Figure 4 shows an example of a schematic configuration of a wireless communication system according to one embodiment. The wireless communication system 1 (which may also be simply called system 1) may be a system that realizes communication using Long Term Evolution (LTE), 5th generation mobile communication system New Radio (5G NR), etc., as specified by the Third Generation Partnership Project (3GPP).

[0125] Furthermore, the wireless communication system 1 may support dual connectivity between multiple Radio Access Technologies (RATs) (Multi-RAT Dual Connectivity (MR-DC)). MR-DC may include dual connectivity between LTE (Evolved Universal Terrestrial Radio Access (E-UTRA)) and NR (E-UTRA-NR Dual Connectivity (EN-DC)), dual connectivity between NR and LTE (NR-E-UTRA Dual Connectivity (NE-DC)), and the like.

[0126] In EN-DC, the LTE (E-UTRA) base station (eNB) is the Master Node (MN), and the NR base station (gNB) is the Secondary Node (SN). In NE-DC, the NR base station (gNB) is the MN, and the LTE (E-UTRA) base station (eNB) is the SN.

[0127] The wireless communication system 1 may support dual connectivity between multiple base stations within the same RAT (for example, dual connectivity where both MN and SN are NR base stations (gNB) (NR-NR Dual Connectivity (NN-DC))).

[0128] The wireless communication system 1 may include a base station 11 that forms a macrocell C1 with relatively wide coverage, and base stations 12 (12a-12c) located within the macrocell C1 that form a small cell C2 that is narrower than the macrocell C1. User terminals 20 may be located within at least one cell. The arrangement, number, shape, size, etc., of each cell and user terminal 20 are not limited to the configuration shown in the figure. Hereinafter, when base stations 11 and 12 are not distinguished, they will be collectively referred to as base station 10.

[0129] The wireless communication system 1 may utilize Multi Input Multi Output (MIMO). For example, one cell may be formed by one antenna / base station 10, or by multiple antennas / base stations 10. One [virtual] cell (which may be called a supercell, for example) may be composed of multiple [virtual] cells (which may be called subcells, for example). A supercell may correspond to a cell with a fixed physical range, and a subcell may correspond to a cell whose physical range fluctuates quasi-statically / dynamically. In this case, the wireless communication system 1 may be called a cell-free system.

[0130] The user terminal 20 may be connected to at least one of the multiple base stations 10. The user terminal 20 may utilize at least one of Carrier Aggregation (CA) using multiple Component Carriers (CC) and Dual Connectivity (DC).

[0131] Each CC may be included in at least one of the first frequency band (Frequency Range 1 (FR1)) and the second frequency band (Frequency Range 2 (FR2)). A macrocell C1 may be included in FR1, and a small cell C2 may be included in FR2. For example, FR1 may be a frequency band of 6 GHz or less (sub-6 GHz), and FR2 may be a frequency band above 24 GHz. Note that the frequency bands and definitions of FR1 and FR2 are not limited to these, and for example, FR1 may be in a frequency band higher than FR2.

[0132] Furthermore, the user terminal 20 may communicate in each CC using at least one of Time Division Duplex (TDD) and Frequency Division Duplex (FDD).

[0133] Multiple base stations 10 may be connected by wire (e.g., optical fiber compliant with Common Public Radio Interface (CPRI), X2 / Xn interface, etc.) or wireless (e.g., NR communication). For example, when NR communication is used as a backhaul between base stations 11 and 12, base station 11, which is the upstream station, may be called an Integrated Access Backhaul (IAB) donor, and base station 12, which is the relay station, may be called an IAB node.

[0134] Base station 10 may be connected to the core network 30 via other base stations 10 or directly. The core network 30 may include at least one of the following: Evolved Packet Core (EPC), 5G Core Network (5GCN), Next Generation Core (NGC), etc.

[0135] The core network 30 may include network functions (NF) such as User Plane Function (UPF), Access and Mobility Management Function (AMF), Session Management Function (SMF), Unified Data Management (UDM), Application Function (AF), Data Network (DN), Location Management Function (LMF), and Operation, Administration and Maintenance (Management) (OAM). Multiple functions may be provided by a single network node. Furthermore, communication with an external network (e.g., the Internet) may occur via the DN.

[0136] The user terminal 20 may be a terminal that supports at least one of the following communication methods: LTE, LTE-A, 5G, etc.

[0137] In the wireless communication system 1, an orthogonal frequency division multiplexing (OFDM)-based wireless access scheme may be used. For example, Cyclic Prefix OFDM (CP-OFDM), Discrete Fourier Transform Spread OFDM (DFT-s-OFDM), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier Frequency Division Multiple Access (SC-OFDM), etc., may be used in at least one of the downlink (DL) and uplink (UL).

[0138] The wireless access method may also be called a waveform. In wireless communication system 1, other wireless access methods (for example, other single-carrier transmission methods, other multi-carrier transmission methods) may be used for the UL and DL wireless access methods.

[0139] In the wireless communication system 1, a Physical Downlink Shared Channel (PDSCH), a Broadcast Channel (PBCH), or a Physical Downlink Control Channel (PDCCH) may be used as the downlink channel, which is shared by each user terminal 20.

[0140] Furthermore, in the wireless communication system 1, the uplink channel may include a Physical Uplink Shared Channel (PUSCH), a Physical Uplink Control Channel (PUCCH), a Physical Random Access Channel (PRACH), or the like, all of which are shared by each user terminal 20.

[0141] User data, higher-layer control information, and System Information Blocks (SIBs) are transmitted via PDSCH. User data and higher-layer control information may also be transmitted via PUSCH. Furthermore, Master Information Blocks (MIBs) may be transmitted via PBCH.

[0142] Lower-layer control information may be transmitted by PDCCH. The lower-layer control information may include, for example, Downlink Control Information (DCI) which includes scheduling information for at least one of PDSCH and PUSCH.

[0143] Furthermore, the DCI that schedules PDSCH may be called DL assignment, DL DCI, etc., and the DCI that schedules PUSCH may be called UL grant, UL DCI, etc. Furthermore, PDSCH may be read as DL data, and PUSCH may be read as UL data.

[0144] PDCCH detection may utilize a Control Resource Set (CORESET) and a search space. A CORESET corresponds to the resources used to search for DCIs. A search space corresponds to the search area and search method for PDCCH candidates. A single CORESET may be associated with one or more search spaces. A UE may monitor CORESETs associated with a given search space based on the search space configuration.

[0145] A single search space may correspond to one or more PDCCH candidates corresponding to aggregation levels. One or more search spaces may be referred to as a search space set. In this disclosure, "search space," "search space set," "search space configuration," "search space set configuration," "CORESET," and "CORESET configuration" may be interpreted interchangeably.

[0146] PUCCH may transmit uplink control information (UCI) including at least one of channel state information (CSI), delivery acknowledgment information (for example, Hybrid Automatic Repeat reQuest ACKnowledgement (HARQ-ACK), ACK / NACK, etc.), and scheduling request (SR). PRACH may transmit a random access preamble for establishing a connection with the cell.

[0147] In this disclosure, downlinks, uplinks, etc., may be expressed without the prefix "link." Also, the prefix "physical" may be omitted from the names of various channels.

[0148] In the wireless communication system 1, a synchronization signal (SS), a downlink reference signal (DL-RS), etc., may be transmitted. In the wireless communication system 1, the DL-RS may include a cell-specific reference signal (CRS), a channel state information reference signal (CSI-RS), a demodulation reference signal (DMRS), a positioning reference signal (PRS), a phase tracking reference signal (PTRS), etc.

[0149] The synchronization signal may be, for example, at least one of a Primary Synchronization Signal (PSS) and a Secondary Synchronization Signal (SSS). A signal block including SS (PSS, SSS) and PBCH (and DMRS for PBCH) may be called an SS / PBCH block, SS Block (SSB), etc. Note that SS, SSB, etc. may also be called reference signals.

[0150] Furthermore, in the wireless communication system 1, the uplink reference signal (UL-RS) may include a sounding reference signal (SRS), a demodulation reference signal (DMRS), etc. The DMRS may also be called a user-specific reference signal (UE-specific Reference Signal).

[0151] (Base Station) Figure 5 shows an example of the configuration of a base station according to one embodiment. The base station 10 includes a control unit 110, a transmitting / receiving unit 120, a transmitting / receiving antenna 130, and a transmission line interface 140. Note that one or more of the control unit 110, the transmitting / receiving unit 120, the transmitting / receiving antenna 130, and the transmission line interface 140 may be provided.

[0152] In this example, the functional blocks of the characteristic parts of this embodiment are mainly shown, and it may be assumed that the base station 10 also has other functional blocks necessary for wireless communication. Some of the processing of each part described below may be omitted.

[0153] The control unit 110 controls the entire base station 10. The control unit 110 can be composed of a controller, control circuit, etc., as described based on common understanding in the technical field related to this disclosure.

[0154] The control unit 110 may control signal generation, scheduling (e.g., resource allocation, mapping), etc. The control unit 110 may also control transmission and reception, measurement, etc., using the transmitting / receiving unit 120, transmitting / receiving antenna 130, and transmission path interface 140. The control unit 110 may generate data to be transmitted as signals, control information, sequences, etc., and transfer them to the transmitting / receiving unit 120. The control unit 110 may also perform call processing of communication channels (setting, releasing, etc.), status management of the base station 10, management of wireless resources, etc.

[0155] The transmitting / receiving unit 120 may include a baseband unit 121, a radio frequency (RF) unit 122, and a measurement unit 123. The baseband unit 121 may include a transmission processing unit 1211 and a reception processing unit 1212. The transmitting / receiving unit 120 can be composed of a transmitter / receiver, RF circuit, baseband circuit, filter, phase shifter, measurement circuit, transmitting / receiving circuit, etc., as described based on common understanding in the art relating to this disclosure.

[0156] The transmitting / receiving unit 120 may be configured as an integrated transmitting / receiving unit, or it may be composed of a transmitting unit and a receiving unit. The transmitting unit may consist of a transmitting processing unit 1211 and an RF unit 122. The receiving unit may consist of a receiving processing unit 1212, an RF unit 122 and a measuring unit 123.

[0157] The transmitting and receiving antenna 130 can be composed of an antenna described based on common understanding in the art relating to this disclosure, such as an array antenna.

[0158] The transmitting / receiving unit 120 may transmit the downlink channel, synchronization signal, downlink reference signal, etc. The transmitting / receiving unit 120 may also receive the uplink channel, uplink reference signal, etc.

[0159] The transmitting / receiving unit 120 may use digital beamforming (e.g., precoding), analog beamforming (e.g., phase rotation), or the like to form at least one of the transmitting beam and the receiving beam.

[0160] The transmitting / receiving unit 120 (transmission processing unit 1211) may perform processing on data and control information acquired from the control unit 110, for example, at the Packet Data Convergence Protocol (PDCP) layer, the Radio Link Control (RLC) layer (e.g., RLC retransmission control), and the Medium Access Control (MAC) layer (e.g., HARQ retransmission control), to generate a bit sequence to be transmitted.

[0161] The transmitting / receiving unit 120 (transmission processing unit 1211) may perform transmission processing on the bit sequence to be transmitted, such as channel coding (which may include error correction coding), modulation, mapping, filtering, discrete Fourier transform (DFT) processing (if necessary), inverse fast Fourier transform (IFFT) processing, precoding, and digital-to-analog conversion, and output a baseband signal.

[0162] The transmitting / receiving unit 120 (RF unit 122) may perform modulation, filtering, amplification, etc., of the baseband signal to the radio frequency band and transmit the signal in the radio frequency band via the transmitting / receiving antenna 130.

[0163] On the other hand, the transmitting / receiving unit 120 (RF unit 122) may perform amplification, filtering, demodulation to a baseband signal, etc., on the radio frequency band signal received by the transmitting / receiving antenna 130.

[0164] The transmitting / receiving unit 120 (receiving processing unit 1212) may apply reception processing such as analog-to-digital conversion, Fast Fourier Transform (FFT) processing, Inverse Discrete Fourier Transform (IDFT) processing (if necessary), filtering, demapping, demodulation, decoding (may include error correction decoding), MAC layer processing, RLC layer processing, and PDCP layer processing to the acquired baseband signal to acquire user data, etc.

[0165] The transmitting / receiving unit 120 (measurement unit 123) may perform measurements related to the received signal. For example, the measurement unit 123 may perform Radio Resource Management (RRM) measurements, Channel State Information (CSI) measurements, etc., based on the received signal. The measurement unit 123 may also measure received power (e.g., Reference Signal Received Power (RSRP)), reception quality (e.g., Reference Signal Received Quality (RSRQ), Signal to Interference plus Noise Ratio (SINR), Signal to Noise Ratio (SNR)), signal strength (e.g., Received Signal Strength Indicator (RSSI)), propagation path information (e.g., CSI), etc. The measurement results may be output to the control unit 110.

[0166] The transmission path interface 140 may send and receive signals (backhaul signaling) with devices included in the core network 30 (e.g., network nodes that provide NF), other base stations 10, etc., and may acquire and transmit user data (user plane data), control plane data, etc. for the user terminal 20.

[0167] In this disclosure, the transmitting and receiving units of the base station 10 may consist of at least one of a transmitting / receiving unit 120, a transmitting / receiving antenna 130, and a transmission path interface 140.

[0168] The base station 10 may be separated into three elements: a Radio Unit (RU), a Distributed Unit (DU), and a Central Unit (CU). For example, the RU may implement RF processing (digital beamforming, digital-to-analog conversion, analog beamforming, etc.) and lower-level physical layer functions (precoding, IFFT, FFT, etc.). The DU may implement higher-level physical layer functions (coding to resource element mapping, etc.), MAC layer functions, and RLC layer functions. The CU may implement PDCP layer, Service Data Adaptation Protocol (SDAP) layer, and RRC layer functions.

[0169] In this disclosure, base station 10 may include a single device that implements all the functions of RU, DU, and CU, or it may include multiple devices that each implement some of the functions of RU, DU, and CU and are connected to each other. In this disclosure, base station 10 may be interpreted as RU / DU / CU.

[0170] The transmitting / receiving unit 120 may autonomously determine whether a terminal communicating using the first Radio Access Technology (RAT) should connect to the second RAT and receive signals for the initial access procedure of the second RAT (for example, PRACH (or random access preamble), RRC connection establishment message, registration message, handover message). The control unit 110 may determine whether the terminal is allowed to communicate using the second RAT.

[0171] Furthermore, in this disclosure, the network device in the first CN / second CN (for example, an AMF node) may be a device that has the same configuration as the base station 10 (for example, a control unit 110 and a transceiver unit 120) as in Figure 5. In other words, in the description relating to Figure 5, the configuration of the network device according to one embodiment may be covered by replacing the base station with the network device.

[0172] (User Terminal) Figure 6 shows an example of the configuration of a user terminal according to one embodiment. The user terminal 20 includes a control unit 210, a transmitting / receiving unit 220, and a transmitting / receiving antenna 230. Note that one or more of the control unit 210, the transmitting / receiving unit 220, and the transmitting / receiving antenna 230 may be provided.

[0173] In this example, the functional blocks of the characteristic parts of this embodiment are mainly shown, and it may be assumed that the user terminal 20 also has other functional blocks necessary for wireless communication. Some of the processing of each part described below may be omitted.

[0174] The control unit 210 controls the entire user terminal 20. The control unit 210 can be composed of a controller, control circuit, etc., as described based on common understanding in the technical field related to this disclosure.

[0175] The control unit 210 may control signal generation, mapping, etc. The control unit 210 may also control transmission and reception, measurement, etc., using the transmitting / receiving unit 220 and the transmitting / receiving antenna 230. The control unit 210 may generate data to be transmitted as signals, control information, sequences, etc., and transfer them to the transmitting / receiving unit 220.

[0176] The transmitting / receiving unit 220 may include a baseband unit 221, an RF unit 222, and a measurement unit 223. The baseband unit 221 may include a transmission processing unit 2211 and a reception processing unit 2212. The transmitting / receiving unit 220 can be composed of a transmitter / receiver, RF circuit, baseband circuit, filter, phase shifter, measurement circuit, transmitting / receiving circuit, etc., as described based on common understanding in the art relating to this disclosure.

[0177] The transmitting / receiving unit 220 may be configured as an integrated transmitting / receiving unit, or it may be composed of a transmitting unit and a receiving unit. The transmitting unit may consist of a transmitting processing unit 2211 and an RF unit 222. The receiving unit may consist of a receiving processing unit 2212, an RF unit 222 and a measuring unit 223.

[0178] The transmitting and receiving antenna 230 can be composed of an antenna described based on common understanding in the art relating to this disclosure, such as an array antenna.

[0179] The transmitting / receiving unit 220 may receive the downlink channel, synchronization signal, downlink reference signal, etc. The transmitting / receiving unit 220 may also transmit the uplink channel, uplink reference signal, etc.

[0180] The transmitting / receiving unit 220 may use digital beamforming (e.g., precoding), analog beamforming (e.g., phase rotation), or the like to form at least one of the transmitting beam and the receiving beam.

[0181] The transmitting / receiving unit 220 (transmission processing unit 2211) may perform PDCP layer processing, RLC layer processing (e.g., RLC retransmission control), MAC layer processing (e.g., HARQ retransmission control), etc., on data and control information acquired from the control unit 210 to generate a bit sequence to be transmitted.

[0182] The transmitting / receiving unit 220 (transmission processing unit 2211) may perform transmission processing on the bit sequence to be transmitted, such as channel coding (which may include error correction coding), modulation, mapping, filtering, DFT processing (if necessary), IFFT processing, precoding, and digital-to-analog conversion, and output a baseband signal.

[0183] Whether or not to apply DFT processing may be based on the transform precoding settings. The transmitting / receiving unit 220 (transmission processing unit 2211) may perform DFT processing as part of the transmission process to transmit a channel (for example, PUSCH) using a DFT-s-OFDM waveform if transform precoding is enabled for that channel, or it may not perform DFT processing as part of the transmission process if transform precoding is not enabled for that channel.

[0184] The transmitting / receiving unit 220 (RF unit 222) may perform modulation, filtering, amplification, etc., of the baseband signal to the radio frequency band and transmit the signal in the radio frequency band via the transmitting / receiving antenna 230.

[0185] On the other hand, the transmitting / receiving unit 220 (RF unit 222) may perform amplification, filtering, demodulation to a baseband signal, etc., on the radio frequency band signal received by the transmitting / receiving antenna 230.

[0186] The transmitting / receiving unit 220 (receiving processing unit 2212) may apply reception processing such as analog-to-digital conversion, FFT processing, IDFT processing (if necessary), filtering, demapping, demodulation, decoding (may include error correction decoding), MAC layer processing, RLC layer processing, and PDCP layer processing to the acquired baseband signal to acquire user data, etc.

[0187] The transmitting / receiving unit 220 (measuring unit 223) may perform measurements related to the received signal. For example, the measuring unit 223 may perform RRM measurement, CSI measurement, etc., based on the received signal. The measuring unit 223 may also measure received power (e.g., RSRP), received quality (e.g., RSRQ, SINR, SNR), signal strength (e.g., RSSI), propagation path information (e.g., CSI), etc. The measurement results may be output to the control unit 210.

[0188] The measurement unit 223 may derive channel measurements for CSI calculation based on channel measurement resources. Channel measurement resources may be, for example, Non Zero Power (NZP) CSI-RS resources. The measurement unit 223 may also derive interference measurements for CSI calculation based on interference measurement resources. Interference measurement resources may be at least one of the following: NZP CSI-RS resources for interference measurement, CSI-Interference Measurement (IM) resources, etc. CSI-IM may also be called CSI-Interference Management (IM), and may be interpreted interchangeably with Zero Power (ZP) CSI-RS. In this disclosure, CSI-RS, NZP CSI-RS, ZP CSI-RS, CSI-IM, CSI-SSB, etc., may be interpreted interchangeably.

[0189] In this disclosure, the transmitting unit and receiving unit of the user terminal 20 may be composed of at least one of a transmitting / receiving unit 220 and a transmitting / receiving antenna 230.

[0190] The control unit 210 may autonomously determine whether to connect to the second RAT when communicating using the first radio access technology (RAT). The transmitting / receiving unit 220 (measurement unit 223) may perform a measurement of the second RAT if it is determined that a connection to the second RAT should be made.

[0191] The aforementioned determination is based on the amount of traffic or latency related to the application running on the terminal as described in Appendix 1.

[0192] The control unit 210 is a terminal described in Appendix 1 or Appendix 2 that detects cells that satisfy specific conditions based on the measurement results of the second RAT.

[0193] The control unit 210 may perform control to initiate the initial access procedure for the cell.

[0194] (Hardware Configuration) The block diagram used in the description of the above embodiment shows functional units. 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 one device that is physically or logically coupled, or it may be realized using two or more physically or logically separated devices that are directly or indirectly connected (for example, using wired or wireless connections). A functional block may also be realized by combining the above one device or the above multiple devices with software.

[0195] Here, functions include, but are not limited to, judgment, decision, determination, calculation, calculation, processing, derivation, investigation, exploration, confirmation, reception, transmission, output, access, resolution, selection, selection, establishment, comparison, assumption, expectation, consideration, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating (mapping), and assigning. For example, a functional block (configuration part) that enables transmission may be called a transmitting unit or transmitter. In all cases, as mentioned above, the method of implementation is not particularly limited.

[0196] For example, a base station, user terminal, etc. in one embodiment of the present disclosure may function as a computer that processes the wireless communication method of the present disclosure. Figure 7 is a diagram showing an example of the hardware configuration of a base station and user terminal according to one embodiment. The base station 10 and user terminal 20 described above may be physically configured as a computer device including a processor 1001, memory 1002, storage 1003, communication device 1004, input device 1005, output device 1006, bus 1007, etc.

[0197] In this disclosure, terms such as apparatus, circuit, device, section, and unit are interchangeable. The hardware configuration of the base station 10 and the user terminal 20 may include one or more of the devices shown in the figure, or it may be configured without some of the devices.

[0198] For example, although only one processor 1001 is shown in the diagram, there may be multiple processors. Furthermore, the processing may be performed by one processor, or it may be performed by two or more processors simultaneously, sequentially, or by other means. Note that the processor 1001 may be implemented using one or more chips.

[0199] Each function in the base station 10 and the user terminal 20 is realized, for example, by loading predetermined software (programs) onto hardware such as the processor 1001 and memory 1002, which allows the processor 1001 to perform calculations and control communication via the communication device 1004, or control at least one of reading and writing data in the memory 1002 and storage 1003.

[0200] The processor 1001 controls the entire computer, for example, by running an operating system. The processor 1001 may be composed of a central processing unit (CPU) that includes interfaces with peripheral devices, control devices, arithmetic units, registers, etc. For example, at least a part of the control unit 110 (210) and the transmitting / receiving unit 120 (220) described above may be implemented by the processor 1001.

[0201] Furthermore, the processor 1001 reads programs (program code), 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 accordingly. The program used is one that causes the computer to execute at least a part of the operations described in the above embodiment. For example, the control unit 110 (210) may be implemented by a control program stored in the memory 1002 and running on the processor 1001, and other functional blocks may be implemented similarly.

[0202] The memory 1002 is a computer-readable recording medium and may consist of at least one of the following: Read Only Memory (ROM), Erasable Programmable ROM (EPROM), Electrically EPROM (EEPROM), Random Access Memory (RAM), or other suitable storage medium. The memory 1002 may also be called a register, cache, or main memory. The memory 1002 can store executable programs (program code), software modules, etc., for carrying out a wireless communication method according to one embodiment of the present disclosure.

[0203] The storage 1003 is a computer-readable recording medium and may consist of at least one of the following: a flexible disk, a floppy disk, a magneto-optical disk (e.g., a Compact Disk (Compact Disc ROM (CD-ROM)), a Digital Use Disk, a Blu-ray (registered trademark) disk), a removable disk, a hard disk drive, a smart card, a flash memory device (e.g., a card, stick, key drive), a magnetic stripe, a database, a server, or other suitable storage medium. The storage 1003 may also be called an auxiliary storage device.

[0204] The communication device 1004 is hardware (transmitting / receiving device) for communicating between computers via at least one of a wired network and a wireless network, and is also referred to as a network device, network controller, network card, communication module, etc. The communication device 1004 may be configured to include, for example, a high-frequency switch, duplexer, filter, frequency synthesizer, etc., in order to implement at least one of frequency division duplex (FDD) and time division duplex (TDD). For example, the above-mentioned transmitting / receiving unit 120 (220), transmitting / receiving antenna 130 (230), etc., may be implemented by the communication device 1004. The transmitting / receiving unit 120 (220) may be implemented with physically or logically separated transmitting unit 120a (220a) and receiving unit 120b (220b).

[0205] The input device 1005 is an input device that accepts input from an external source (e.g., a keyboard, mouse, microphone, switch, button, sensor, etc.). The output device 1006 is an output device that outputs to an external source (e.g., a display, speaker, light-emitting diode (LED) lamp, etc.). The input device 1005 and the output device 1006 may be configured as an integrated unit (e.g., a touch panel).

[0206] Furthermore, each device, such as the processor 1001 and memory 1002, is connected by a bus 1007 for communicating information. The bus 1007 may be configured using a single bus, or different buses may be configured for each device.

[0207] Furthermore, the base station 10 and the user terminal 20 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), and a field programmable gate array (FPGA), and some or all of each functional block may be implemented using such hardware. For example, the processor 1001 may be implemented using at least one of these hardware components.

[0208] Furthermore, devices included in the core network 30 (for example, network nodes that provide NF) may also be implemented using the functional block / hardware configuration described above.

[0209] (Variations) Terms used in this disclosure and terms necessary for understanding this disclosure may be replaced with terms having the same or similar meanings. For example, channel, symbol and signal (signal or signaling) may be used interchangeably. Also, a signal may be a message. A reference signal may be abbreviated as RS and may be called a pilot, pilot signal, etc., depending on the applicable standard. Also, a component carrier (CC) may be called a cell, frequency carrier, carrier frequency, etc.

[0210] A wireless frame may consist of one or more periods (frames) in the time domain. Each of these periods (frames) constituting a wireless frame may be called a subframe. Furthermore, a subframe may consist 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.

[0211] Here, the neurology may be communication parameters applied to at least one of the transmission and reception of a signal or channel. The neurology may be, for example, at least one of the following: subcarrier spacing (SCS), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI), number of symbols per TTI, radio frame configuration, specific filtering processes performed by the transceiver in the frequency domain, and specific windowing processes performed by the transceiver in the time domain.

[0212] A slot may consist of one or more symbols in the time domain (such as Orthogonal Frequency Division Multiplexing (OFDM) symbols or Single Carrier Frequency Division Multiple Access (SC-FDMA) symbols). Alternatively, a slot may be a time unit based on neurology.

[0213] A slot may include multiple minislots. Each minislot may consist of one or more symbols in the time domain. Minislots may also be called subslots. Minislots may consist of fewer symbols than a slot. A PDSCH (or PUSCH) transmitted in a time unit larger than a minislot may be called a PDSCH (PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using minislots may be called a PDSCH (PUSCH) mapping type B.

[0214] Wireless frames, subframes, slots, minislots, and symbols all represent units of time when transmitting a signal. Wireless frames, subframes, slots, minislots, and symbols may each be referred to by different names. Furthermore, the units of time such as frames, subframes, slots, minislots, and symbols in this disclosure may be interpreted as interchangeable.

[0215] For example, one subframe may be called a TTI, multiple consecutive subframes may be called a TTI, and one slot or one mini-slot may be called a TTI. In other words, at least one of a subframe and a TTI may be a subframe in existing LTE (1 ms), a period shorter than 1 ms (e.g., 1-13 symbols), or a period longer than 1 ms. Note that the unit representing a TTI may be called a slot, mini-slot, etc., instead of a subframe.

[0216] Here, TTI refers to, for example, the smallest time unit for scheduling in wireless communication. For example, in an LTE system, the base station schedules each user terminal to allocate wireless resources (such as the frequency bandwidth and transmission power available to each user terminal) in TTI units. However, the definition of TTI is not limited to this.

[0217] TTI may be a transmission time unit for channel-encoded data packets (transport blocks), code blocks, code words, etc., or it may be a processing unit for scheduling, link adaptation, etc. When a TTI is given, the actual time interval (e.g., number of symbols) in which the transport block, code block, code word, etc. are mapped may be shorter than the TTI.

[0218] Furthermore, if one slot or one mini-slot is referred to as a TTI, then one or more TTIs (i.e., one or more slots or one or more mini-slots) may constitute the minimum time unit for scheduling. In addition, the number of slots (number of mini-slots) that constitute this minimum time unit for scheduling may be controlled.

[0219] A TTI with a time length of 1 ms may be called a normal TTI, long TTI, normal subframe, long subframe, slot, etc. A TTI shorter than a normal TTI may be called a shortened TTI, short TTI, partial or fractional TTI, shortened subframe, short subframe, mini slot, sub slot, slot, etc.

[0220] Furthermore, long TTIs (e.g., normal TTIs, subframes, etc.) may be interpreted as TTIs with a time length exceeding 1 ms, and short TTIs (e.g., shortened TTIs, etc.) may be interpreted as TTIs with a TTI length less than that of a long TTI but 1 ms or more.

[0221] A Resource Block (RB) is a resource allocation unit in the time domain and frequency domain, and in the frequency domain, it may contain one or more consecutive subcarriers. The number of subcarriers in an RB may be the same regardless of the neurology, for example, 12. The number of subcarriers in an RB may be determined based on the neurology.

[0222] Furthermore, an RB may contain one or more symbols in the time domain and may have the length of one slot, one minislot, one subframe, or one TTI. One TTI, one subframe, etc., may each consist of one or more resource blocks.

[0223] One or more RBs may also be called Physical RBs (PRBs), Sub-Carrier Groups (SCGs), Resource Element Groups (REGs), PRB pairs, RB pairs, etc.

[0224] Furthermore, a resource block may consist of one or more resource elements (REs). For example, one RE may be a radio resource area comprising one subcarrier and one symbol.

[0225] A Bandwidth Part (BWP), also known as a partial bandwidth, may represent a subset of consecutive common resource blocks (RBs) for a given neurology in a given carrier. These common RBs may be identified by an index of the RBs relative to a common reference point of the carrier. The PRBs may be defined and numbered within a given BWP.

[0226] A BWP may include UL BWP (BWP for UL) and DL BWP (BWP for DL). One or more BWPs may be configured within a single carrier for a UE.

[0227] At least one of the configured BWPs may be active, and the UE does not need to assume that it will transmit or receive a predetermined signal / channel outside of the active BWP. In this disclosure, terms such as "cell" and "carrier" may be read as "BWP".

[0228] The structures of wireless frames, subframes, slots, minislots, and symbols described above are merely examples. For example, the number of subframes included in a wireless frame, the number of slots per subframe or wireless 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, and the number of symbols, symbol length, and cyclic prefix (CP) length within the TTI can be varied in various ways.

[0229] Furthermore, the information, parameters, etc., described in this disclosure may be expressed using absolute values, relative values ​​from a predetermined value, or corresponding other information. For example, wireless resources may be indicated by a predetermined index.

[0230] The names used for parameters and other elements in this disclosure are not restrictive in any way. Furthermore, mathematical formulas and other elements using these parameters may differ from those expressly disclosed in this disclosure. Various channels (PUCCH, PDCCH, etc.) and information elements can be identified by any suitable name, and therefore, the various names assigned to these various channels and information elements are not restrictive in any way.

[0231] The information, signals, etc. described in this disclosure may be represented using any of the various different techniques. For example, the data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description may be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

[0232] Furthermore, information, signals, etc., can be output from upper layers to lower layers and from lower layers to upper layers, or to at least one of the two. Information, signals, etc., may also be input and output via multiple network nodes.

[0233] Input and output information and signals may be stored in a specific location (e.g., memory) or managed using a management table. Input and output information and signals may be overwritten, updated, or appended to. Output information and signals may be deleted. Input information and signals may be transmitted to other devices.

[0234] Any information described in this disclosure (e.g., variables, constants, parameters) may be communicated from any first device (e.g., UE / base station) to any second device (e.g., base station / UE) that indicates / specifies (or relates to) the value of such any information, even if not specifically stated in the embodiments described above.

[0235] Information notification is not limited to the embodiments described herein and may be carried out by other means. For example, information notification in this disclosure may be carried out by physical layer signaling (e.g., Downlink Control Information (DCI), Uplink Control Information (UCI)), higher layer signaling (e.g., Radio Resource Control (RRC) signaling, broadcast information (Master Information Block (MIB), System Information Block (SIB)), Medium Access Control (MAC) signaling), other signals, or a combination thereof.

[0236] Physical layer signaling may also be called Layer 1 / Layer 2 (L1 / L2) control information (L1 / L2 control signals), L1 control information (L1 control signals), etc. RRC signaling may also be called RRC messages, for example, RRC Connection Setup messages, RRC Connection Reconfiguration messages, etc. MAC signaling may also be communicated using, for example, MAC Control Elements (CEs).

[0237] Furthermore, notification of the specified information (for example, notification that "X is the case") is not limited to explicit notification, but may also be made implicitly (for example, by not providing notification of the specified information or by providing notification of other information).

[0238] The determination may be made by a value represented by one bit (0 or 1), by a boolean value represented as true or false, or by a numerical comparison (for example, a comparison with a predetermined value).

[0239] Software should be broadly interpreted to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, and so on, whether they are called software, firmware, middleware, microcode, hardware description languages, or by any other name.

[0240] Furthermore, software, instructions, information, etc., may be transmitted and received via a transmission medium. For example, if software is transmitted from a website, server, or other remote source using at least one of wired technology (such as coaxial cable, fiber optic cable, twisted pair, or Digital Subscriber Line (DSL)) and wireless technology (such as infrared or microwave), then at least one of these wired and wireless technologies is included in the definition of a transmission medium.

[0241] The terms “system” and “network” as used in this disclosure may be used interchangeably. “Network” may also mean the equipment included in the network (e.g., base stations).

[0242] In this disclosure, terms such as “precoding,” “precoder,” “weight (precoding weight),” “quasi-co-location (QCL),” “transmission configuration indication state (TCI state),” “spatial relation,” “spatial domain filter,” “transmit power,” “phase rotation,” “antenna port,” “layer,” “number of layers,” “rank,” “resource,” “resource set,” “beam,” “beam width,” “beam angle,” “antenna,” “antenna element,” “panel,” “UE panel,” “transmitting entity,” and “receiving entity” may be used interchangeably.

[0243] In this disclosure, "antenna port" may be interpreted interchangeably with "antenna port for any signal / channel" (e.g., a Demodulation Reference Signal (DMRS) port). In this disclosure, "resource" may be interpreted interchangeably with "resource for any signal / channel" (e.g., a reference signal resource, an SRS resource, etc.). Resources may include time / frequency / code / spatial / power resources. Furthermore, a spatial domain transmit filter may include at least one of a spatial domain transmit filter and a spatial domain receive filter.

[0244] The above group may include, for example, at least one of the following: a spatial relationship group, a code division multiplexing (CDM) group, a reference signal (RS) group, a control resource set (CORESET) group, a PUCCH group, an antenna port group (e.g., a DMRS port group), a layer group, a resource group, a beam group, an antenna group, or a panel group.

[0245] Furthermore, in this disclosure, terms such as beam, SRS Resource Indicator (SRI), CORESET, CORESET pool, PDSCH, PUSCH, Codeword (CW), Transport Block (TB), and RS may be interpreted interchangeably.

[0246] Furthermore, in this disclosure, TCI state, downlink TCI state (DL TCI state), uplink TCI state (UL TCI state), unified TCI state, common TCI state, joint TCI state, etc., may be interpreted interchangeably.

[0247] Furthermore, in this disclosure, terms such as "QCL," "QCL assumption," "QCL relationship," "QCL type information," "QCL property / properties," "specific QCL type (e.g., Type A, Type D) properties," and "specific QCL type (e.g., Type A, Type D)" may be interpreted interchangeably.

[0248] In this disclosure, terms such as index, identifier (ID), indicator, indication, and resource ID may be interpreted interchangeably. In this disclosure, terms such as sequence, list, set, group, cluster, subset may be interpreted interchangeably.

[0249] Furthermore, the spatial relationship information Identifier (ID) (TCI state ID) and spatial relationship information (TCI state) may be interpreted as mutually exclusive. "Spatial relationship information (TCI state)" may be interpreted as mutually exclusive as "a set of spatial relationship information (TCI state)," "one or more pieces of spatial relationship information," etc. TCI state and TCI may be interpreted as mutually exclusive. Spatial relationship information and spatial relationship may be interpreted as mutually exclusive.

[0250] In this disclosure, terms such as “Base Station (BS),” “wireless base station,” “fixed station,” “NodeB,” “eNB (eNodeB),” “gNB (gNodeB),” “access point,” “Transmission Point (TP),” “Reception Point (RP),” “Transmission / Reception Point (TRP),” “panel,” “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.

[0251] A base station may house one or more (e.g., three) cells. If a base station houses multiple cells, the entire coverage area of ​​the base station may be divided into several smaller areas, each of which may also be provided with communication services by a base station subsystem (e.g., a small indoor base station (Remote Radio Head (RRH))). The terms “cell” or “sector” refer to part or all of the coverage area of ​​at least one of the base station and / or base station subsystems that provide communication services in that coverage.

[0252] In this disclosure, the transmission of information by a base station to a terminal may be interpreted as the base station instructing the terminal to perform a control / operation based on said information.

[0253] In this disclosure, terms such as "Mobile Station (MS)," "user terminal," "User Equipment (UE)," and "terminal" may be used interchangeably.

[0254] A mobile station may also be called 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 appropriate term.

[0255] At least one of the base station and the mobile station may be called a transmitting device, a receiving device, a wireless communication device, etc. At least one of the base station and the mobile station may also be a device mounted on a moving object, the moving object itself, etc.

[0256] The term "mobile object" refers to any movable object, regardless of its speed, and naturally includes cases where the mobile object is stationary. Examples of such mobile objects include, but are not limited to, vehicles, transport vehicles, automobiles, motorcycles, bicycles, connected cars, excavators, bulldozers, wheel loaders, dump trucks, forklifts, trains, buses, handcarts, rickshaws, ships and other watercraft, airplanes, rockets, satellites, drones, multicopters, quadcopters, balloons, and items carried on them. Furthermore, such mobile objects may be autonomously driven objects operating based on operational commands.

[0257] The mobile entity may be a vehicle (e.g., a car, an airplane), an unmanned mobile entity (e.g., a drone, an autonomous vehicle), or a robot (manned or unmanned). At least one of the base station and the mobile station may be a device that does 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.

[0258] Figure 8 shows an example of a vehicle according to one embodiment. The vehicle 40 includes a drive unit 41, a steering unit 42, an accelerator pedal 43, a brake pedal 44, a shift lever 45, left and right front wheels 46, left and right rear wheels 47, an axle 48, an electronic control unit 49, various sensors (including a current sensor 50, a rotation speed sensor 51, a pneumatic pressure sensor 52, a vehicle speed sensor 53, an acceleration sensor 54, an accelerator pedal sensor 55, a brake pedal sensor 56, a shift lever sensor 57, and an object detection sensor 58), an information service unit 59, and a communication module 60.

[0259] The drive unit 41 consists of, for example, at least one of an engine, a motor, or an engine-motor hybrid. The steering unit 42 includes at least a steering wheel (also called a handle) and is configured to steer at least one of the front wheels 46 and the rear wheels 47 based on the operation of the steering wheel operated by the user.

[0260] The electronic control unit 49 consists of a microprocessor 61, memory (ROM, RAM) 62, and communication ports (e.g., input / output (IO) ports) 63. Signals from various sensors 50-58 installed in the vehicle are input to the electronic control unit 49. The electronic control unit 49 may also be called an Electronic Control Unit (ECU).

[0261] Signals from various sensors 50-58 include current signals from current sensor 50 for sensing motor current, rotational speed signals of front wheels 46 / rear wheels 47 acquired by rotational speed sensor 51, air pressure signals of front wheels 46 / rear wheels 47 acquired by air pressure sensor 52, vehicle speed signals acquired by vehicle speed sensor 53, acceleration signals acquired by acceleration sensor 54, accelerator pedal depression amount signals acquired by accelerator pedal sensor 55, brake pedal depression amount signals acquired by brake pedal sensor 56, operation signals of shift lever 45 acquired by shift lever sensor 57, and detection signals acquired by object detection sensor 58 for detecting obstacles, vehicles, pedestrians, etc.

[0262] The information service unit 59 consists of various devices for providing (outputting) various types of information such as driving information, traffic information, and entertainment information, including a car navigation system, audio system, speakers, display, television, and radio, and one or more ECUs that control these devices. The information service unit 59 uses information acquired from external devices via a communication module 60 or the like to provide various types of information / services (for example, multimedia information / multimedia services) to the occupants of the vehicle 40.

[0263] The information service unit 59 may include input devices that accept input from the outside (e.g., keyboard, mouse, microphone, switch, button, sensor, touch panel, etc.) or output devices that perform output to the outside (e.g., display, speaker, LED lamp, touch panel, etc.).

[0264] The driver assistance system unit 64 consists of various devices that provide functions to prevent accidents or reduce the driver's workload, such as millimeter-wave radar, Light Detection and Ranging (LiDAR), cameras, positioning locators (e.g., Global Navigation Satellite System (GNSS)), map information (e.g., High Definition (HD) maps, Autonomous Vehicle (AV) maps), gyro systems (e.g., Inertial Measurement Unit (IMU), Inertial Navigation System (INS)), artificial intelligence (AI) chips, and AI processors, as well as one or more ECUs that control these devices. The driver assistance system unit 64 also transmits and receives various information via the communication module 60 to realize driver assistance functions or autonomous driving functions.

[0265] The communication module 60 can communicate with the microprocessor 61 and components of the vehicle 40 via the communication port 63. For example, the communication module 60 sends and receives data (information) via the communication port 63 to the drive unit 41, steering unit 42, accelerator pedal 43, brake pedal 44, shift lever 45, left and right front wheels 46, left and right rear wheels 47, axle 48, the microprocessor 61 and memory (ROM, RAM) 62 in the electronic control unit 49, and various sensors 50-58 provided in the vehicle 40.

[0266] The communication module 60 is a communication device that can be controlled by the microprocessor 61 of the electronic control unit 49 and can communicate with external devices. For example, it can send and receive various types of information to and from external devices via wireless communication. The communication module 60 may be located either inside or outside the electronic control unit 49. The external device may be, for example, the base station 10 or the user terminal 20 described above. Alternatively, the communication module 60 may be, for example, at least one of the base station 10 and the user terminal 20 (it may function as at least one of the base station 10 and the user terminal 20).

[0267] The communication module 60 may transmit at least one of the following to an external device via wireless communication: signals from the various sensors 50-58 input to the electronic control unit 49, information obtained based on said signals, and information based on input from an external source (user) obtained via the information service unit 59. The electronic control unit 49, the various sensors 50-58, the information service unit 59, etc., may also be called input units that accept input. For example, the PUSCH transmitted by the communication module 60 may include the information based on the above input.

[0268] The communication module 60 receives various information (traffic information, signal information, inter-vehicle information, etc.) transmitted from an external device and displays it on the information service unit 59 installed in the vehicle. The information service unit 59 may also be called an output unit, which outputs information (for example, it outputs information to devices such as displays and speakers based on the PDSCH (or data / information decoded from the PDSCH) received by the communication module 60).

[0269] Furthermore, the communication module 60 stores various information received from external devices in a memory 62 that can be used by the microprocessor 61. Based on the information stored in the memory 62, the microprocessor 61 may control the drive unit 41, steering unit 42, accelerator pedal 43, brake pedal 44, shift lever 45, left and right front wheels 46, left and right rear wheels 47, axle 48, various sensors 50-58, etc., which are provided in the vehicle 40.

[0270] Furthermore, the term "base station" in this disclosure may be interpreted as "user terminal." For example, the various aspects / embodiments of this disclosure may be applied to a configuration in which communication between a base station and a user terminal is replaced with communication between multiple user terminals (which may be called, for example, Device-to-Device (D2D), Vehicle-to-Everything (V2X)). In this case, the user terminal 20 may have the functions of the base station 10 described above. Also, terms such as "uplink" and "downlink" may be interpreted as terms corresponding to terminal-to-terminal communication (for example, "sidelink"). For example, uplink channel, downlink channel, etc., may be interpreted as sidelink channel.

[0271] Similarly, the term "user terminal" in this disclosure may be replaced with "base station." In this case, the base station 10 may be configured to have the same functions as the user terminal 20 described above.

[0272] In this disclosure, operations performed by a base station may, in some cases, be performed by its upper node. In a network including one or more network nodes having base stations, it is clear that various operations performed for communication with terminals may be performed by the base station, one or more network nodes other than the base station (for example, a Mobility Management Entity (MME), a Serving Gateway (S-GW), etc., but not limited to these), or a combination thereof.

[0273] Each aspect / embodiment described in this disclosure may be used individually, in combination, or switched between as needed during execution. Furthermore, the processing procedures, sequences, flowcharts, etc., of each aspect / embodiment described in this disclosure may be rearranged in order, provided they are consistent. For example, the methods described in this disclosure present various step elements using exemplary order and are not limited to the specific order presented.

[0274] Each aspect / embodiment described in this disclosure is Long Term Evolution (LTE), LTE-Advanced (LTE-A), LTE-Beyond (LTE-B), SUPER 3G, IMT-Advanced, 4th generation mobile communication system (4G), 5th generation mobile communication system (5G), 6th generation mobile communication system (6G), xth generation mobile communication system (xG (where x is, for example, an integer or decimal)), Future Radio Access (FRA), New-Radio Access Technology (RAT), New Radio (NR), New radio access (NX), Future generation radio access (FX), Global System for Mobile communications (GSM®), CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi®), IEEE 802.16 (WiMAX®), IEEE 802.20, systems utilizing Ultra-WideBand (UWB), Bluetooth®, or other appropriate wireless communication methods, and next-generation systems extended, modified, created, or defined based thereon may also be applied. Furthermore, multiple systems may be applied in combination (for example, a combination of LTE or LTE-A and 5G).

[0275] In this disclosure, the phrase "based on" does not mean "based solely on" unless otherwise specified. In other words, the phrase "based on" means both "based solely on" and "based at least on."

[0276] Any reference to elements using the designations “first,” “second,” etc., as used in this disclosure does not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient way to distinguish between two or more elements. Accordingly, the references to the first and second elements do not imply that only two elements may be employed or that the first element must precede the second element in any way.

[0277] The term “determining” as used in this disclosure may encompass a wide variety of actions. For example, “determining” may be considered to mean judging, calculating, computing, processing, deriving, investigating, looking up, searching, or inquiring (e.g., searching in tables, databases, or other data structures), ascertaining, etc.

[0278] Furthermore, "judgment (decision)" may be considered as "judging (deciding)" things like receiving (e.g., receiving information), transmitting (e.g., sending information), input, output, accessing (e.g., accessing data in memory).

[0279] Furthermore, “judgment (decision)” may be considered as “judgment (decision)” of resolving, selecting, choosing, establishing, comparing, etc. In other words, “judgment (decision)” may be considered as “judgment (decision)” of some action. In this disclosure, “judgment (decision)” may be interpreted as mutually interchangeable with the actions described above.

[0280] Furthermore, in this disclosure, “determine / determining” may be interpreted as “assume / assuming,” “expect / expecting,” or “consider / considering.” In addition, in this disclosure, “not expecting to do…” may be interpreted as “expecting not to do….”

[0281] In this disclosure, "expect" may be rephrased as "be expected." For example, "expect(s) ..." (where "..." may be expressed as a that clause, an infinitive, etc.) may be rephrased as "be expected ..." or "do (the verb without "to" if "..." is an infinitive)." Similarly, "does not expect ..." may be rephrased as "be not expected ..." or "do not (the verb without "to" if "..." is an infinitive)." Furthermore, "An apparatus A is not expected ..." may be rephrased as "An apparatus B other than apparatus A does not expect ... from apparatus A" (for example, if apparatus A is a UE, apparatus B may be a base station).

[0282] The term "maximum transmit power" as used in this disclosure may mean the maximum transmit power, the nominal UE maximum transmit power, or the rated UE maximum transmit power.

[0283] As used in this disclosure, the terms “connected,” “coupled,” and any variations thereof mean any direct or indirect connection or coupling between two or more elements, and may include one or more intermediate elements between two elements that are “connected” or “coupled” with each other. The coupling or connection between elements may be physical, logical, or a combination thereof. For example, “connection” may be replaced with “access.”

[0284] In this disclosure, when two elements are connected, they can be considered to be "connected" or "coupled" to each other using one or more wires, cables, printed electrical connections, etc., and, in some non-exclusive and non-exclusive examples, electromagnetic energy having wavelengths in the radio frequency domain, microwave domain, and optical (both visible and invisible) domain.

[0285] In this 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 "combine" may be interpreted similarly to "different."

[0286] Where the terms “include,” “including,” and variations thereof are used in this disclosure, these terms are intended to be inclusive, as is the term “comprising.” Furthermore, the term “or” as used in this disclosure is not intended to mean exclusive OR.

[0287] In this disclosure, if articles are added by translation, such as a, an, and the in English, this disclosure may include the fact that the noun following these articles is plural.

[0288] In this disclosure, "less than or equal to," "less than," "greater than or equal to," "more than," and "equal to" may be interpreted interchangeably. In addition, in this disclosure, words meaning "good," "bad," "big," "small," "high," "low," "early," "slow," "wide," and "narrow" may be interpreted interchangeably, not limited to the positive, comparative, and superlative degrees. In addition, in this disclosure, words meaning "good," "bad," "big," "small," "high," "low," "early," "slow," "wide," and "narrow" may be interpreted interchangeably, not limited to the positive, comparative, and superlative degrees, by adding "i-th" (where i is any integer) to the expression (for example, "highest" may be interpreted interchangeably with "i-th highest").

[0289] In this disclosure, "of," "for," "regarding," "related to," and "associated with" may be interpreted as being interchangeable.

[0290] In this disclosure, phrases such as "when A, B", "if A, then B", "B upon A", "B in response to A", "B based on A", "B during / while A", "B before A", "B at (the same time as) / on A", "B after A", "B since A", and "B until A" may be interchangeable. Furthermore, A, B, etc., may be replaced with appropriate expressions such as nouns, gerunds, or regular sentences depending on the context. The time difference between A and B may be approximately zero (immediately after or immediately before). Additionally, a time offset may be applied to the time when A occurs. For example, "A" may be interpreted as "before / after the time offset when A occurs". The time offset (e.g., one or more symbols / slots) may be predetermined or determined by the UE based on notified information.

[0291] In this disclosure, timing, time, duration, time instance, any unit of time (e.g., slot, subslot, symbol, subframe), period, occasion, resource, etc., may be interpreted interchangeably.

[0292] Although the invention described herein has been explained in detail above, it will be clear to those skilled in the art that the invention described herein is not limited to the embodiments described herein. The descriptions herein are illustrative and not intended to be restrictive in any way to the invention described herein.

[0293] This application is based on Japanese Patent Application No. 2025-019437, filed on February 7, 2025. All of its contents are included herein.

Claims

1. A terminal having a control unit that autonomously determines whether to connect to a second RAT when communicating using a first radio access technology (RAT), and a receiving unit that measures the second RAT when it is determined that it should connect to the second RAT.

2. The terminal according to claim 1, wherein the determination is based on the amount of traffic or delay related to the application running on the terminal.

3. The terminal according to claim 1, wherein the control unit detects a cell that satisfies specific conditions based on the measurement results of the second RAT.

4. The terminal according to claim 3, wherein the control unit initiates an initial access procedure to the cell.

5. A wireless communication method for a terminal, comprising the steps of: autonomously determining whether to connect to a second radio access technology (RAT) when communicating using a first radio access technology (RAT); and, if it is determined that to connect to the second RAT, measuring the second RAT.

6. A base station having: a receiving unit that autonomously determines whether a terminal communicating using a first radio access technology (RAT) should connect to the second RAT and transmits a signal for the initial access procedure of the second RAT; and a control unit that determines whether the terminal may perform communication using the second RAT.

Images