Communication device, communication method, and program

Abstract

The communication apparatuses (20 and 40) include a sensing unit (241), a communication unit (21 and 41), and a control unit (24 and 45). The sensing unit (241) performs sensing of a channel in an unlicensed band. The communication unit (21 and 41) performs communication based on a result of the sensing. The control unit (24 and 45) selects, as a sensing mode, either a first mode in which sensing is performed a predetermined number of times within a variable period or a second mode different from the first mode, in accordance with a predetermined condition.

Description

Technical Field

[0001] This disclosure relates to communication equipment, communication methods, and procedures. Background Technology

[0002] The 3rd Generation Partnership Project (3GPP) studied radio access methods and radio networks for cellular mobile communications (hereinafter also referred to as "Long Term Evolution (LTE)," "LTE-Advanced (LTE-A)," "LTE-Advanced Pro (LTE-APro)," "5th Generation (5G)," "New Radio (NR)," "New Radio Access Technology (NRAT)," "Evolved Universal Terrestrial Radio Access (EUTRA)," or "Further EUTRA (FEUTRA)"). Note that in the following description, LTE includes LTE-A, LTE-A Pro, and EUTRA, while NR includes NRAT and FEUTRA. In LTE and NR, base station equipment (base stations) is also referred to as evolved NodeB (eNodeB) in LTE and gNodeB in NR, while terminal equipment (mobile stations, mobile station equipment, or terminals) is also referred to as user equipment (UE). LTE and NR are cellular communication systems in which base stations are arranged in a cellular pattern to cover multiple areas. A single base station can manage multiple cells.

[0003] NR is the next-generation radio access method for LTE and is a different radio access technology (RAT) from LTE. NR is an access technology capable of supporting various use cases, including enhanced mobile broadband (eMBB), massive machine-type communication (mMTC), and ultra-reliable low-latency communication (URLLC). This paper studies the technical framework of NR for use cases, requirements, and deployment scenarios.

[0004] The application of cellular communication-based radio access methods in unlicensed and licensed-shared frequency bands has been studied. In such unlicensed frequency bands, coexistence with other nodes or wireless systems is considered important, and for radio access methods such as LTE or NR, functions such as pre-talk listening (LBT) or discontinuous transmission, in which channel sensing occurs before transmission, are required. Details of an NR-based radio access method in an unlicensed frequency band are disclosed in Non-Patent Document 1. Note that unlicensed frequency bands are, for example, 2.4 GHz, 5 GHz, 6 GHz, or 60 GHz. Licensed-shared frequency bands are, for example, 3.5 GHz or 37 GHz.

[0005] Furthermore, considering the need for wider bandwidth, the utilization of a high-frequency band, known as millimeter waves, from 52.6 GHz to 110 GHz, was investigated. Within this band, utilization in various use cases such as high data rate eMBB, mobile data offloading, and vertical industry factory applications was studied. Non-Patent Document 2 discloses research on the utilization of millimeter waves in 3GPP.

[0006] Citation List

[0007] Non-patent literature

[0008] Non-patent literature 1: RP-172021, "Study on NR-based Access to Unlicensed Spectrum," 3GPP TSG RAN Meeting #77, Sapporo, Japan, September 11 to 14, 2017

[0009] Non-patent document 2: 3GPP TR 38.807V0.2.0"3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Study on requirements for NR beyond 52.6GHz (Release 16)" June, 2019 Summary of the Invention

[0010] Technical issues

[0011] In the case of communication in unlicensed frequency bands, the communication device performs a pre-talk listen-to-sense (LBT) to sense the channel before transmitting. During LBT, the communication device waits to transmit. Furthermore, depending on the outcome of the LBT, the communication device may wait further to transmit. As mentioned above, transmitting after performing LBT may result in transmission delays and the wireless communication link may become unstable.

[0012] Therefore, this disclosure provides a communication device, communication method, and program that can further stabilize wireless communication links.

[0013] It should be noted that the above-mentioned problems or objectives are merely one of the many problems or objectives that can be solved or achieved by the various embodiments disclosed in this specification.

[0014] Solution to the problem

[0015] According to this disclosure, a communication device is provided. The communication device includes a sensing unit, a communication unit, and a control unit. The sensing unit senses a channel in an unlicensed frequency band. The communication unit communicates based on the sensing results. The control unit selects, according to predetermined conditions, either a first method of sensing a predetermined number of times within a variable time period or a second method different from the first method as the sensing method. Attached Figure Description

[0016] Figure 1 This is a diagram illustrating an example of the overall configuration of a communication system according to an embodiment of the present disclosure.

[0017] Figure 2 This is a diagram illustrating an example of the structure of a 5G core network.

[0018] Figure 3 This is a diagram used to illustrate Level Before Talk (LBT) Category 1.

[0019] Figure 4 This is a diagram used to illustrate LBT category 2.

[0020] Figure 5 This is a diagram used to illustrate LBT categories 3 and 4.

[0021] Figure 6 This is a diagram used to illustrate the general situation of FBE.

[0022] Figure 7 This is a diagram used to illustrate omnidirectional LBT.

[0023] Figure 8 This is a diagram used to illustrate directional LBT.

[0024] Figure 9 It is a diagram used to illustrate the use of a single beam.

[0025] Figure 10 It is a diagram used to illustrate the use of multiple beams.

[0026] Figure 11 This is a block diagram illustrating an example of the configuration of a base station device according to an embodiment of the present disclosure.

[0027] Figure 12 This is a schematic block diagram illustrating an example of a data antenna configuration according to an embodiment of the present disclosure.

[0028] Figure 13 This is a schematic block diagram illustrating the configuration of a digital antenna according to an embodiment of the present disclosure.

[0029] Figure 14 This is a diagram illustrating an example of the configuration of a terminal device according to an embodiment of the present disclosure.

[0030] Figure 15 This is a diagram illustrating an example of the configuration of a communication control device according to an embodiment of the present disclosure.

[0031] Figure 16 This is a diagram illustrating the relationship between the beam and the contention window according to embodiments of the present disclosure.

[0032] Figure 17 This is a diagram illustrating the relationship between the beam and the contention window according to embodiments of the present disclosure.

[0033] Figure 18 This is a diagram illustrating the relationship between the beam and the contention window according to embodiments of the present disclosure.

[0034] Figure 19 This is a sequence diagram illustrating the communication processing flow according to embodiments of the present disclosure. Detailed Implementation

[0035] Preferred embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. Note that in this specification and the drawings, components that are substantially identical in function are indicated by the same reference numerals, thereby omitting repeated descriptions of these components.

[0036] In this specification and accompanying drawings, components with substantially identical functional configurations can be distinguished by adding different letters after the same reference numerals. For example, multiple components with substantially identical functional configurations may be distinguished when necessary, such as base station equipment 20A and 20B. However, when it is not particularly necessary to distinguish each of the multiple components with substantially identical functional configurations, the same reference numerals are simply assigned. For example, when it is not necessary to specifically distinguish base station equipment 20A and 20B, they are simply referred to as base station equipment 20.

[0037] Each of the one or more embodiments (including examples and variations) described below can be implemented independently. On the other hand, at least some of the embodiments described below can be combined with at least some other embodiments as appropriate. These embodiments may include novel features different from each other. Thus, these embodiments can help achieve or solve different purposes or problems and can produce different effects.

[0038] Note that the explanation will be given in the following order.

[0039] 1. Introduction

[0040] 1.1. Examples of system composition

[0041] 1.2. Channel Access Method

[0042] 1.3. Technical Issues

[0043] 1.4. Related Technologies

[0044] 2. Examples of the composition of each device

[0045] 2.1. Example of Base Station Equipment Configuration

[0046] 2.2. Examples of Terminal Equipment Configuration

[0047] 2.3. Examples of the composition of communication control equipment

[0048] 3. Technical Features

[0049] 3.1. Application conditions of LBT category

[0050] 3.2. Setting LBT parameters

[0051] 4. Communication Processing

[0052] 5. Variations

[0053] 6. Conclusion

[0054] <<1. Introduction>>

[0055] <1.1. Examples of System Structure>

[0056] Figure 1 This is a diagram illustrating an example of the overall configuration of a communication system 1 according to an embodiment of the present disclosure. For example... Figure 1 As shown in the diagram, the communication system 1 includes multiple base station devices 20 (20A and 20B), multiple terminal devices 40 (40A and 40B), a core network 120, and a packet data network (PDN) 130. Note that the number of the corresponding devices is not limited to this; for example, the number of base station devices 20 or the number of terminal devices 40 may be one.

[0057] Base station equipment 20 is a communication device that operates cell 110 and provides wireless communication services to one or more terminal devices 40 located within the coverage area of ​​cell 110. Cell 110 may operate in accordance with any wireless communication method such as LTE or New Radio (NR). Base station equipment 20 is connected to core network 120. Core network 120 is connected to packet data network (PDN) 130 via gateway device (not shown). Note that base station equipment 20 may be implemented by a group of multiple physical or logical devices. For example, in embodiments of this disclosure, base station equipment 20 is classified as multiple devices, including baseband unit (BBU) and radio unit (RU), and may be interpreted as a group of these multiple devices. Alternatively, in embodiments of this disclosure, base station equipment 20 may be one or both of BBU and RU. BBU and RU may be connected via a predetermined interface (e.g., eCPRI). Alternatively, RU may be referred to as remote radio unit (RRU) or radio point (RD). Alternatively, RU may correspond to gNB distributed unit (gNB-DU) described below. Alternatively, the BBU may correspond to the gNB central unit (gNB-CU) described below. Alternatively, the RU may be a device integrally formed with the antenna. The antenna of the base station device 20 (e.g., an antenna integrally formed with the RU) may employ an advanced antenna system and support MIMO (e.g., FD-MIMO) or beamforming. In an advanced antenna system, the antenna of the base station device 20 (e.g., an antenna integrally formed with the RU) may, for example, include 64 transmit antenna ports and 64 receive antenna ports.

[0058] Furthermore, multiple base station devices 20 can be interconnected. One or more base station devices 20 may be included in a radio access network (RAN). That is, base station device 20 may simply be referred to as RAN, RAN node, access network (AN), or AN node. The RAN in LTE is called Enhanced Universal Terrestrial RAN (EUTRAN). The RAN in NR is called NGRAN. The RAN in W-CDMA (UMTS) is called UTRAN. The base station device 20 in LTE is called an evolved Node B (eNodeB) or eNB. That is, EUTRAN includes one or more eNodeBs (eNBs). Furthermore, the base station device 20 in NR is called a gNodeB or gNB. That is, NGRAN includes one or more gNBs. In addition, EUTRAN may include gNBs (en-gNBs) connected to the core network (EPC) in the LTE communication system (EPS). Similarly, NGRAN may include ng-eNBs connected to the core network (5G core (5GC)) in the 5G communication system (5GS). Alternatively, when the base station device 20 is an eNB, gNB, etc., the base station may be referred to as a 3GPP access. Alternatively, if base station equipment 20 is a radio access point, the base station may be referred to as a non-3GPP access point. Alternatively, base station equipment 20 may be an optical feeder device referred to as a Remote Radio Headend (RRH). Alternatively, if base station equipment 20 is a gNB, base station equipment 20 may be referred to as a combination of or any of the aforementioned gNB CU and gNB DU. The gNB CU manages multiple upper layers of the access layer (e.g., Radio Resource Control (RRC), Service Data Adaptation Protocol (SDAP), and PDCP) for communication with the UE. On the other hand, the gNB-DU manages multiple lower layers of the access layer (e.g., RLC, MAC, and PHY). That is, among the messages and information described below, RRC signaling (e.g., various System Information Blocks (SIBs) including the Master Information Block (MIB) and SIB1, RRCSetup messages, and RRCReconfiguration messages) may be generated by the gNB CU, while the downlink control indicator (DCI) and various physical channels (e.g., PDCCH and PBCH) described below may be generated by the gNB-DU. Alternatively, in RRC signaling, some configurations, such as IE:cellGroupConfig, can be generated by the gNB-DU, and the remaining configurations can be generated by the gNB-CU. These configurations can be sent and received via the F1 interface described later. Base station device 20 can be configured to communicate with other base station devices 20. For example, in the case where multiple base station devices 20 are eNBs or a combination of eNB and en-gNB, the base station devices 20 can be connected via the X2 interface.Alternatively, if multiple base station devices 20 are eNBs or a combination of gn-eNBs and gNBs, the devices can be connected via the Xn interface. Alternatively, if multiple base station devices 20 are a combination of gNB CUs and gNB DUs, the devices can be connected via the F1 interface described above. Messages / information (RRC signaling, DCI information, or physical channels) described later can be communicated between multiple base station devices 20 (e.g., via the X2, Xn, or F1 interfaces).

[0059] Furthermore, as described above, base station equipment 20 can be configured to manage multiple cells. The cells provided by base station equipment 20 are referred to as serving cells. Serving cells include primary cells (PCells) and secondary cells (SCells). When providing dual connectivity to a UE (e.g., terminal equipment 40) (e.g., EUTRA-EUTRA dual connectivity, EUTRA-NR dual connectivity (ENDC), EUTRA-NR dual connectivity with 5GC, NR-EUTRA dual connectivity (NEDC), or NR-NR dual connectivity), the PCell provided by the primary node (MN) and 0 or more SCells are referred to as a primary cell group. Additionally, serving cells may include primary and secondary cells or primary SCG cells (PSCells). That is, when providing dual connectivity to a UE, the PSCell provided by the secondary node (SN) and 0 or more SCells are referred to as a secondary cell group (SCG). Unless specifically configured (e.g., the Physical Uplink Control Channel (PUCCH) on the SCell), the PUCCH is transmitted by the PCell and PScell, not by the SCell. Radio link faults are detected in PCell and PSCell, but not (and not required to be detected) in SCell. As described above, PCell and PSCell have special roles within the serving cell and are therefore also referred to as special cells (SpCell). One downlink component carrier and one uplink component carrier can be associated with a cell. Furthermore, the system bandwidth corresponding to a cell can be divided into multiple bandwidth portions. In this case, one or more bandwidth portions (BWPs) can be set in the UE, and one bandwidth portion can be used as the active BWP in the UE. Moreover, the radio resources (e.g., frequency bands, parameter sets (subcarrier spacing), and time slot configurations) available to the terminal device 40 can differ for each cell, each component carrier, or each BWP.

[0060] When the core network 120 is an NR core network (5G core (5GC)), the core network 120 may include access and mobility management functions (AMF), session management functions (SMF), user plane functions (UPF), policy control functions (PCF) and unified data management (UDM).

[0061] In the case where the core network 120 is an LTE core network (Evolved Packet Core (EPC)), the core network 120 may include a Mobility Management Entity (MME), Serving Gateway (S-GW), PDN Gateway (P-GW), Policy and Charging Rule Function (PCRF), and Home Subscriber Server (HSS). The AMF and MME are control nodes that process control plane signals and manage the mobility of the terminal equipment 40. The UPF and S-GW / P-GW are nodes that process user plane signals. The PCF / PCRF is a control node that performs policy and charging-related controls, such as Quality of Service (QoS) for PDU sessions or bearers. The UDM / HSS is a control node that processes subscriber data and performs service control.

[0062] Here, we will refer to Figure 2 This explains that core network 120 is the core network of the 4th generation mobile communication system (5G). Figure 2 This is a diagram illustrating an example of the structure of a 5G core network.

[0063] The cellular network system of communication system 1 according to this embodiment includes a radio access network (RAN) and a core network (CN). The RAN is a wireless system between base station equipment 20 and terminal equipment 40. The CN mainly performs licensing and session management when terminal equipment 40 accesses the cellular network. In addition, in 4G and 5G, the CN includes control plane functions and user plane functions.

[0064] As described above, the communication system 1 according to this embodiment includes a 5G core network 120, a base station device (RAN / AN) 20, a terminal device (UE) 40, and a DN node 160.

[0065] The 5G core network 120 is also referred to as the 5G core / next-generation core (5GC / NGC). Below, the 5G core network 120 is also referred to as 5GC / NGC 120. The 5GC / NGC 120 is connected to the user equipment (UE) 40 via RAN / AN 20.

[0066] The 5GC / NGC 120 includes a User Plane Function (UPF) node 150 and a Control Plane Function Group 130.

[0067] UPF Node 150 is an important Network Function (NF) node in the user plane. UPF Node 150 has user plane processing capabilities. UPF Node 150 has the function of routing / forwarding data processed in the user plane.

[0068] Note that UPF node 150 and data network (DN) node 160 can be combined to form a user plane function group. In this case, DN node 160 is included in 5GC / NGC 120. DN node 160 has the capability to enable connectivity with services from cellular service providers, the Internet, or third-party services.

[0069] The control plane function group 130 includes Access Management Function (AMF) node 139, Session Management Function (SMF) node 136, Authentication Server Function (AUSF) node 131, Network Slice Selection Function (NSSF) node 134, Network Open Function (NEF) node 132, Network Repository Function (NRF) node 133, Policy Control Function (PCF) node 135, Unified Data Management (UDM) node 137, and Application Function (AF) node 138.

[0070] AMF node 139 has functions such as registration processing, connection management, and mobility management for UE 40. For example, AMF node 139 can perform handover management for terminal device 40. In addition, AMF node 139 manages the location information of terminal device 40.

[0071] SMF node 136 has functions such as session management and IP allocation and management for UE 40. The main role of SMF node 136 is to establish or release PDU sessions for terminal device 40 and manage PDU sessions. In addition, SMF node 136 assigns IP addresses to terminal device 40.

[0072] UDM node 137 has the function of generating 3GPP AKA authentication information and processing user IDs. AF node 138 has the function of interacting with the core network to provide services.

[0073] AUSF node 131 has authentication capabilities. NSSF node 134 has capabilities related to network slice selection. NEF node 132 has the capability to provide network functionality and events to third parties, AF node 138, and edge computing capabilities.

[0074] NRF node 133 has the ability to discover networks and maintain network profiles. PCF node has policy control capabilities.

[0075] Explanation Return Figure 1Terminal device 40 is a communication device that wirelessly communicates with base station device 20 under the control of base station device 20. For example, terminal device 40 measures downlink signals from base station device 20 and reports measurement information indicating the measurement results to base station device 20. Based on the reported measurement information, base station device 20 controls wireless communication with terminal device 40. Alternatively, terminal device 40 can send uplink signals for measurement to base station device 20. In this case, base station device 20 measures the uplink signals from terminal device 40 and controls wireless communication with terminal device 40 based on the measurement information.

[0076] As described above, base station equipment 20 can send and receive information to each other using an inter-base station interface. In the case of a 5GC core network, the inter-base station interface can be an Xn interface. In the case of an EPC core network, the inter-base station interface can be an X2 interface. For example, base station equipment 20 sends measurement information (e.g., measurement results for a cell managed by the source base station equipment or measurement results for a neighboring cell) related to the terminal equipment 40 that is predicted to undergo handover to other neighboring base station equipment 20. As a result, a stable handover is achieved, thereby ensuring the stability of wireless communication for terminal equipment 40.

[0077] Note that, although not in Figure 1 As illustrated, however, communication equipment may exist around communication system 1 that provides wireless communication services using radio access technologies (RATs) other than cellular communication, such as Wi-Fi (registered trademark) or MulteFire. Such communication equipment is typically connected to PDN 13.

[0078] <1.2. Channel Access Method>

[0079] Assume that NR-Unlicensed (NR-U) not only supports Licensed Assisted Access (LAA) using carrier aggregation, but also supports various use cases such as dual connectivity, stand-alone deployments utilizing only unlicensed frequency bands, and use cases where one of the DL carrier and UL carrier is a licensed frequency band and the other is an unlicensed frequency band (e.g., licensed DL and unlicensed UL).

[0080] To support these use cases, NR-U investigated mechanisms for transmitting physical channels and signals, such as synchronization signals (SS), physical random access channels (PRACH), and physical uplink control channels (PUCCH), that are transmitted in the primary cell (PCell) in unlicensed frequency bands.

[0081] Typically, in unlicensed frequency bands, communication devices sense the channel before transmitting physical channels and / or physical signals, using Loop Pre-Listening (LBT) to determine whether the channel is idle or busy. If the channel is idle (LBT successful), the communication device can transmit physical channels and / or physical signals. Conversely, if the channel is busy (LBT failed), the communication device cannot transmit physical channels and / or physical signals.

[0082] Furthermore, the utilization of the 60 GHz millimeter-wave unlicensed frequency band was investigated. Additionally, other radio access methods such as 802.11ad and 802.11ay were introduced into the millimeter-wave unlicensed frequency band. Considering the coexistence with equipment using these other radio access methods and equipment from other operators, LBT (Local Broadband Access) can be used.

[0083] For channels in unlicensed frequency bands (hereinafter also referred to as unlicensed channels), as described above, wireless devices (base station devices or terminal devices) perform channel access (medium access or LBT) before transmitting signals.

[0084] In channel access, the wireless device performs energy measurements on the channel (carrier sense, sensing, or channel idle assessment (CCA)) and compares the measured energy value of the channel with an energy detection threshold. If the measured energy value of the channel is lower than the energy detection threshold, the channel is determined to be idle; if the measured energy value of the channel is higher than the energy detection threshold, the channel is determined to be busy. If the channel is determined to be idle in all sensing slots, the wireless device can acquire the right to transmit on the channel and transmit signals.

[0085] Furthermore, a channel on which a wireless device has acquired the right to transmit can be used by other wireless devices for transmission. In this case, a license is sent from the wireless device that has acquired the right to transmit to other wireless devices.

[0086] The wireless device that acquires the right to transmit on the channel is called the initiating device. Other wireless devices that use the channel acquired by the wireless device are called responding devices.

[0087] Note that 3GPP defines four LBT categories as carrier sense methods. In channel access, LBT corresponding to one of these LBT categories is performed.

[0088] • LBT Category 1: No LBT

[0089] • LBT Category 2: LBT without random backoff

[0090] • LBT Category 3: LBT with random backoff via a fixed-size contention window

[0091] • LBT Category 4: LBT with random backoff via a variable-sized contention window

[0092] Here, we will refer to Figures 1-3 Explain each LBT category.

[0093] Figure 3 This is a diagram used to illustrate LBT category 1. For example... Figure 3 As illustrated in the diagram, in LBT category 1, wireless devices communicate without performing LBT. Figure 3 In the example, the wireless device transmits at 16-microsecond intervals.

[0094] Figure 4 This is a diagram used to illustrate LBT category 2. For example... Figure 4 As illustrated in the diagram, in LBT category 2, wireless devices communicate by performing LBT without random backoff. Figure 4 In this example, the wireless device performs CCA on a sensing time slot and transmits a signal when it determines that the channel is idle. Here, the length of a sensing time slot is 25 microseconds.

[0095] Figure 5 This is a diagram used to illustrate LBT categories 3 and 4. For example... Figure 5 As illustrated in the diagram, in LBT categories 3 and 4, the wireless device performs a predetermined number of CCAs within the contention window (CW) and transmits a signal only when it is determined that the channel is idle. That is, the wireless device performs CCAs within a predetermined number of sensing time slots and transmits a signal only when it is determined that the channel is idle in all sensing time slots. Figure 5 The diagram illustrates a 9-microsecond sensing slot with 5 CCA (Content Capture and Response) cycles. Note that LBT Category 3 and LBT Category 4 differ in whether the contention window size is fixed or variable. Alternatively, LBT Category 3 and LBT Category 4 differ in whether the contention window size is adjusted.

[0096] <1.3. Technical Issues>

[0097] Only LBT Category 4 is applied to data transmission in the current unlicensed frequency band. Therefore, unnecessary transmission delays may occur.

[0098] Specifically, in low-congestion environments, errors due to link adaptation can lead to unnecessary contention window adjustments and transmission delays. An example of a low-congestion environment, i.e., an environment with a low probability of packet contention, is the 60 GHz band. In the 60 GHz band, communication is achieved through beamforming for both transmission and reception. This reduces the probability of interfering with other links.

[0099] On the other hand, even in highly congested environments, with only LBT Class 4 applied, a minimum contention window is set for the first transmission, leading to frequent contention. This can result in unintentional contention repeating until the contention window is adjusted to an appropriate one, thus reducing bandwidth utilization efficiency.

[0100] As mentioned above, when only one channel access method (e.g., LBT Category 4) is used for data communication in an unlicensed frequency band, transmission delays may occur, and the wireless communication link may become unstable.

[0101] Overview of the proposed technology

[0102] Therefore, this disclosure proposes a mechanism that can further stabilize the wireless communication link. In the proposed technique, the base station device 20 or the terminal device 40 (an example of a communication device) switches between LBT category 3 (an example of a second method) and LBT category 4 (an example of a first method) as a carrier sensing mode. The base station device 20 or the terminal device 40 selects and switches the LBT category, for example, according to notifications from other devices or predetermined conditions such as the surrounding environment. As a result, in the proposed technique, a contention window can be appropriately set, unnecessary transmission delays can be suppressed, and the wireless communication link can be further stabilized.

[0103] <1.4. Related Technologies>

[0104] <Channel Access Procedure for Unlicensed Channels>

[0105] Perform a channel access (LBT) procedure to access an unlicensed channel on which the base station device 20 or terminal device 40 transmits.

[0106] In channel access for a load-based device (LBE), one or more channel sensing operations are performed. Based on the sensing results, a determination is made as to whether the channel is idle (unoccupied, available, or enabled) or busy (occupied, unavailable, or disabled) (occupancy determination). During channel sensing, the channel energy is sensed for a predetermined waiting time.

[0107] Examples of waiting times during the channel access process include the first waiting time (time slot), the second waiting time, the third waiting time (delay period), and the fourth waiting time.

[0108] A time slot is a unit of waiting time for base station equipment 20 or terminal equipment 40 during channel access. A time slot is defined, for example, as 9 microseconds.

[0109] During the second waiting period, a time slot is inserted at the beginning. The second waiting period is, for example, defined as 16 microseconds.

[0110] The delay period includes a second waiting time and multiple consecutive time slots following the second waiting time. The number of consecutive time slots following the second waiting time is determined based on the priority class (channel access priority class) used to satisfy QoS.

[0111] The fourth waiting time includes the second waiting time and a time slot following the second waiting time. The fourth waiting time is defined, for example, as 25 microseconds.

[0112] The base station device 20 or the terminal device 40 senses a predetermined channel within a predetermined time slot. If the power detected by the base station device 20 or the terminal device 40 within the predetermined time slot is less than a predetermined energy detection threshold for at least 4 microseconds, the predetermined time slot is considered idle. Conversely, if the power is greater than the predetermined energy detection threshold, the predetermined time slot is considered busy.

[0113] The channel access process includes a first channel access process, a second channel access process, and a third channel access process. The first channel access process is performed using multiple time slots and delay periods. The second channel access process is performed using a second waiting time or a fourth waiting time. The third channel access process is performed using a second waiting time.

[0114] Parameters related to channel access are determined based on priority classes. Examples of channel access-related parameters include minimum contention window, maximum contention window, maximum channel occupancy time, and possible contention window values. Priority classes are determined by the value of the QoS Class Identifier (QCI) or 5G QoS Identifier (5QI) used for QoS processing. Table 1 shows the correspondence between priority classes and channel access-related parameters, and Table 2 shows examples of the mapping between priority classes and QCI.

[0115] Table 3 shows an example of the mapping between priority classes and 5QI.

[0116] (Table 1) Example of a mapping table between priority classes and parameters related to channel access.

[0117] (Table 2) Examples of mapping between priority classes and QCI

[0118] Channel access priority class (p) QCI 1 1，3，5,65,66,69,70 2 2，7 3 4,6，8,9 4 other

[0119] (Table 3) Examples of mapping between priority classes and 5QI

[0120] LBT Parameter Index LBT category Contention for window size 1 LBT Category 3 15 2 LBT Category 3 31 3 LBT Category 3 63 4 LBT Category 4

[0121] (Details of the first channel access process)

[0122] The first channel access procedure (Type-1 channel access procedure) is classified as LBT category 3 or LBT category 4.

[0123] The following procedures are performed during the first channel access process.

[0124] (0) Sensing the channel during the delay period. If the channel is idle during the time slot of the delay period, the process proceeds to step (1); otherwise, the process proceeds to step (6).

[0125] (1) Obtain the initial value of the counter. The possible initial value of the counter is an integer between 0 and the contention window CW. The initial value of the counter is randomly determined according to a uniform distribution. Set the initial value of the counter in counter N, and then proceed to step (2).

[0126] (2) If counter N is greater than 0 and counter N is selected for subtraction, subtract 1 from counter N. Then, the process proceeds to step (3).

[0127] (3) Add a time slot and wait. In addition, sense the channel in the added time slot. If the added time slot is idle, the process proceeds to step (4); otherwise, the process proceeds to step (5).

[0128] (4) The process is stopped when the counter N is 0. Otherwise, the process proceeds to step (2).

[0129] (5) Add an additional delay period and wait. Furthermore, sense the channel until it is detected as busy in one of the time slots included in the additional delay period, or until all time slots included in the additional delay period can be detected as idle. Afterward, the process proceeds to step (6).

[0130] (6) If the channel is sensed to be idle in all slots included in the additional delay period, the process proceeds to step (4); otherwise, the process proceeds to step (5).

[0131] After step (4) of the above process is stopped, data such as Physical Downlink Shared Channel (PDSCH) and Physical Uplink Shared Channel (PUSCH) are transmitted on the channel.

[0132] Note that after step (4) of the above process is stopped, transmission does not need to be performed on that channel. In this case, if the channel is idle in all time slots and delay periods immediately preceding the transmission, transmission can be performed without performing the above process. On the other hand, if the channel is not idle in either the time slot or the delay period, the process proceeds to step (1) after the channel is sensed to be idle in all time slots of the additional delay period.

[0133] (Details of the second channel access process)

[0134] The second channel access procedure (Type 2 channel access procedure) is classified as LBT Category 2. During the second channel access procedure, if the channel is determined to be idle after sensing for at least a second or fourth waiting time, transmission can proceed immediately. Conversely, if the channel is determined to be not idle after sensing for at least a second or fourth waiting time, transmission is not performed. The second channel access procedure is applied when the transmission interval is 16 microseconds or 25 microseconds.

[0135] The second channel access procedure using a fourth waiting time is called a type 2A channel access procedure, and the second channel access procedure using a second waiting time is called a type 2B channel access procedure.

[0136] <Details of the Third Channel Access Process>

[0137] The third-channel access procedure (Type 2C channel access procedure) is classified as LBT Category 1. In the third-channel access procedure, channel sensing is not performed before transmission. The third-channel access procedure is applied when the transmission interval is within 16 microseconds.

[0138] <Contending for Window Adaptation Process>

[0139] In LBT category 4, a contention window adaptation process is performed.

[0140] The contention window (CW) used during the first channel access process is determined based on the contention window adaptation process.

[0141] The contention window (CW) is maintained for each priority class. Furthermore, the contention window CW has a value between the minimum and maximum contention window. The minimum and maximum contention windows are determined based on the priority class.

[0142] Prior to step (1) in the first channel access process, the value of the contention window CW is adjusted. If the proportion of NACKs in the Hybrid Automatic Repeat Request (HARQ) responses corresponding to the shared channel of the reference HARQ process in at least the reference subframe (reference time slot or reference period) during the contention window adaptation process is higher than a threshold, the value of the contention window CW is increased. Otherwise, the value of the contention window CW is set to the minimum contention window.

[0143] For example, the value of the contention window CW can be increased based on the equation CW = 2·(CW+1)-1.

[0144] The reference period is defined as either from the beginning of the occupied channel to the end of the first slot containing at least one unicast PDSCH, or to the end of the first transmission burst containing at least one unicast PDSCH. For example, 90% is set as a threshold.

[0145] (Details of the channel access process in the downlink)

[0146] In the case of downlink transmission including PDSCH, Physical Downlink Control Channel (PDCCH) and / or Enhanced Physical Downlink Control Channel (EPDCCH) on an unlicensed channel, the base station device 20 accesses the channel and performs downlink transmission based on the first channel access procedure.

[0147] On the other hand, when downlink transmission including DRS but excluding PDSCH is performed on an unlicensed channel, the base station device 20 accesses the channel based on the second channel access procedure and performs downlink transmission. Note that the downlink transmission period is preferably less than 1 microsecond.

[0148] (Details of the channel access process in the uplink)

[0149] On an unlicensed channel, in the case of a first channel access procedure performed via an uplink grant indication for scheduling PUSCH, terminal device 40 performs the first channel access procedure before uplink transmission including PUSCH.

[0150] Furthermore, in the case of a second channel access procedure performed via an uplink grant instruction for scheduling PUSCH, the terminal device 40 performs the second channel access procedure before uplink transmission including PUSCH.

[0151] Furthermore, for uplink transmissions that do not include PUSCH but include a sounding reference signal (SRS), the terminal device 40 performs a second channel access procedure before uplink transmission.

[0152] Furthermore, if the end of the uplink transmission indicated by the uplink grant is within the uplink duration (UL duration), the terminal device 40 performs a second channel access procedure before the uplink transmission, regardless of the procedure type indicated by the uplink grant.

[0153] Furthermore, when uplink transmission is performed after the downlink transmission from base station device 20 has ended and after a fourth waiting time, terminal device 40 performs a second channel access process before uplink transmission.

[0154] (Targeted LBT)

[0155] refer to Figure 7 and Figure 8 Explain omnidirectional LBT and directional LBT. Figure 7 This is a diagram used to illustrate omnidirectional LBT. Figure 8 This is a diagram used to illustrate oriented LBT. Although Figure 7 and Figure 8 The diagram illustrates the LBT performed by terminal device 40, but base station device 20 can also perform LBT in a similar manner.

[0156] like Figure 7 As illustrated in the diagram, in an omnidirectional LBT, the base station device 200 performs beamforming-free channel sensing. Beamforming-free channel sensing is the sensing of a channel that receives data without controlling its directionality, as described above, or the sensing of a channel without directional information.

[0157] Unlike omnidirectional LBT, methods where channel sensing is directional include directional LBT.

[0158] like Figure 8 As shown in the diagram, in a directional LBT, the received power is measured in a predetermined direction. That is, measurements are not performed in directions other than the predetermined direction.

[0159] As a result, the direction of measurement is restricted, thereby suppressing the frequency of busy activity caused by transmissions from unaffected devices.

[0160] In a directional LBT, physical signals and / or physical channels are transmitted in the direction in which the LBT has been successful.

[0161] (Receiver-assisted LBT)

[0162] Receiver-assisted LBT is an LBT that uses information from the receiving device, in addition to the information originally performed by the transmitting device.

[0163] As an example of receiver-assisted LBT, there exists an LBT that uses feedback from the channel state of the receiving device. The transmitting device adjusts the success or failure of the LBT and the LBT parameters based on the information about the channel state from the receiving device. Examples of channel states include inter-cell interference within the same operator, inter-cell interference between different operators, and interference between different RATs. Examples of LBT parameters to be adjusted include the LBT threshold and contention window.

[0164] Another example of receiver-assisted LBT is an LBT that uses response information from the receiving device.

[0165] After a successful LBT (Level-by-Level Request), the transmitting device sends a physical channel and / or physical signal to the receiving device. The receiving device, having received the physical channel and / or physical signal, then performs a pre-selection of the LBT. If the pre-selection of the LBT is successful, the receiving device sends a response to the transmitting device; otherwise, if the pre-selection of the LBT fails, the receiving device either does not send a response or sends no information to the transmitting device. Based on the response information from the receiving device, the transmitting device determines whether channel occupancy was successful.

[0166] (NR beam application methods)

[0167] In NR, it is assumed that there are two types of beam application methods: methods using a single beam and methods using multiple beams. (Refer to...) Figure 9 and Figure 10 Explain the methods of beamforming. Figure 9 This is a diagram used to illustrate the method of using a single beam. Figure 10 This is a diagram used to illustrate the method of using multiple beams.

[0168] like Figure 9 As illustrated in the diagram, the use of a single beam is a method of applying a single beam to a predetermined cell coverage area. Specifically, a single beam is used to transmit cell-specific physical channels or physical signals within the predetermined cell coverage area. LTE can also be considered an application of a single beam.

[0169] like Figure 10 As illustrated in the diagram, the use of multiple beams is a method of applying one or more beams to a predetermined cell coverage area. Specifically, multiple beams are used to transmit cell-specific physical channels or physical signals. For example, in analog beamforming or hybrid beamforming, a beam in a predetermined direction is transmitted at a predetermined time instance, and it is difficult to transmit beams other than those in the predetermined direction. Therefore, multiple beams in different directions are switched by switching time instances to cover a wider area. That is, a predetermined beam on which a cell-specific physical channel or physical signal is transmitted is transmitted in one time instance (time resource). Different beams are transmitted in different time instances. As described above, in the use of multiple beams, multiple beams are used by switching multiple beams at multiple time instances. For example, in… Figure 10 In the process, the beams are switched in five directions, beams #1-#5. Switching multiple beams across multiple time instances is called beam scanning.

[0170] Note that even in digital antenna configurations, multiple beams can be used.

[0171] Furthermore, beams can be referred to as channels, paths, antennas, antenna ports, etc. That is, transmissions using different beams can be referred to as transmissions using different channels, paths, antennas, or antenna ports. Additionally, beams can also be conceived as virtual cells. Terminal device 40 can treat different beams transmitted from the same cell as different virtual cells or virtual carriers.

[0172] (Appropriate beam selection in NR)

[0173] In NR, communication system 1 preferably selects appropriate beams for each of the downlink and uplink. Specifically, it is preferable to appropriately select each of the downlink transmit beam of base station equipment 20 and the downlink receive beam of terminal equipment 40. Additionally, it is preferable to appropriately select the uplink transmit beam of terminal equipment 40 and the uplink receive beam of base station equipment 20.

[0174] Based on the reports or feedback information received from the terminal device 40, the appropriate downlink transmission beam of the base station device 20 can be obtained. An example of the process for obtaining the appropriate downlink transmission beam is as follows: The base station device 20 transmits a predetermined known signal multiple times using different downlink transmission beams. The terminal device 40 determines the appropriate downlink transmission beam from the multiple transmitted known signals based on received strength, received quality, etc., and reports or provides feedback to the base station device 20 with information corresponding to the appropriate downlink transmission beam. As a result, the base station device 20 is able to identify the appropriate downlink transmission beam. Examples of known signals here include the synchronization signal (SS) / physical broadcast channel (PBCH) block, the channel state information-reference signal (CSI-RS), the demodulation reference signal (DMRS) of the physical downlink control channel (PDCCH), the DMRS of the physical downlink shared channel (PDSCH), and the phase tracking reference signal (PTRS).

[0175] Alternatively, the appropriate downlink transmit beam of the base station device 20 can be obtained based on the appropriate uplink receive beam of the base station device 20.

[0176] Based on reports or feedback information received from base station device 20, the appropriate uplink transmission beam for terminal device 40 can be obtained. An example of the process for obtaining the appropriate uplink transmission beam is as follows: Terminal device 40 transmits a predetermined known signal multiple times using different uplink transmission beams. Base station device 20 determines the appropriate uplink transmission beam from the multiple transmitted known signals based on received strength, received quality, etc., and reports or notifies terminal device 40 of information corresponding to the appropriate uplink transmission beam. As a result, terminal device 40 is able to identify the appropriate uplink transmission beam. Examples of known signals here include the Physical Random Access Channel (PRACH), the Sounding Reference Signal (SRS), the Physical Uplink Control Channel (PUCCH) DMRS, and the Physical Uplink Shared Channel (PUSCH) DMRS.

[0177] Alternatively, the appropriate uplink transmit beam of terminal device 40 can be based on the appropriate downlink receive beam of terminal device 40.

[0178] (Quasi-common addressing (QCL) in NR)

[0179] In NR, a QCL (Quasi-Co-located Channel) is defined to represent channel characteristics. For example, two different signals (physical channel, physical signal, or antenna port) are quasi-co-located (QCL) if it can be assumed that they have the same channel characteristics.

[0180] Examples of channel characteristics represented by QCL include Doppler shift, Doppler spread, average delay, delay spread, and spatial Rx parameter.

[0181] The QCL between antenna ports is defined in the Transmit Configuration Indicator (TCI) state and is defined as the following type.

[0182] -'QCL-TypeA': {Doppler frequency shift, Doppler spread, average delay, delay spread}

[0183] -'QCL-TypeB': {Doppler shift, Doppler spread}

[0184] -'QCL-TypeC': {Doppler spread, average delay}

[0185] -'QCL-TypeD': {Space Rx parameter}

[0186] (Details of the downlink transmit beam in NR)

[0187] In NR, the downlink transmit beam is defined by a predetermined signal index and QCL.

[0188] Examples of pre-defined signals include Synchronization Signal / Physical Broadcast Channel (SS / PBCH) blocks. For instance, multiple SS / PBCH blocks with the same channel but different indices can be transmitted. SS / PBCH blocks with different indices can be transmitted via different transmit beams.

[0189] Additionally, the relationship between the beams of the other reference signals and physical channels is determined based on the TCI state between the SS / PBCH block with a predetermined index and other reference signals and physical channels.

[0190] <2. Examples of the composition of each device>

[0191] <2.1. Example of Base Station Equipment Configuration>

[0192] Next, the composition of base station equipment 20 will be explained. Figure 11 This is a diagram illustrating an example of the configuration of a base station device 20 according to an embodiment of the present disclosure. The base station device 20 is a communication device (wireless system) that wirelessly communicates with a terminal device 40. The base station device 20 is a type of information processing device.

[0193] The base station equipment 20 includes a wireless communication unit 21, a storage unit 22, a network communication unit 23, and a control unit 24. Note that... Figure 11 The configuration shown in the diagram is the functional configuration; the hardware configuration may differ. Furthermore, the functions of base station equipment 20 can be distributed across multiple physically separate devices and implemented therein.

[0194] The wireless communication unit 21 is a wireless communication interface for communicating with other communication devices (e.g., terminal device 40 and other base station devices 20). The wireless communication unit 21 operates under the control of the control unit 24. The wireless communication unit 21 can support multiple radio access methods. For example, the wireless communication unit 21 can support both NR and LTE. The wireless communication unit 21 can support other cellular communication methods such as W-CDMA or cdma2000. Furthermore, in addition to cellular communication methods, the wireless communication unit 21 can also support wireless LAN communication methods. Of course, the wireless communication unit 21 can also support only one radio access method.

[0195] The wireless communication unit 21 includes a receiving processing unit 211, a transmitting processing unit 212, and an antenna 413. The wireless communication unit 21 may include multiple receiving processing units 211, multiple transmitting processing units 212, and multiple antennas 413. Note that when the wireless communication unit 21 supports multiple radio access methods, each unit of the wireless communication unit 21 can be configured separately for each radio access method. For example, if the base station equipment 20 supports NR and LTE, the receiving processing unit 211 and the transmitting processing unit 212 can be configured separately for NR and LTE, respectively.

[0196] The receiving processing unit 211 processes the uplink signal received via the antenna 413. The receiving processing unit 211 includes a wireless receiving unit 211a, a demultiplexing unit 211b, a demodulation unit 211c, and a decoding unit 211d.

[0197] The wireless receiving unit 211a performs down-conversion, removal of unnecessary frequency components, amplification level control, quadrature demodulation, conversion to digital signal, removal of guard interval, and extraction of frequency domain signal through fast Fourier transform on the uplink signal. For example, assuming the radio access method of the base station device 20 is a cellular communication method such as LTE, the demultiplexing unit 211b separates the uplink channel, such as the Physical Uplink Shared Channel (PUSCH) or Physical Uplink Control Channel (PUCCH), and the uplink reference signal from the signal output from the wireless receiving unit 211a. The demodulation unit 211c demodulates the received signal for the modulation symbols of the uplink channel using a modulation scheme such as Binary Phase Shift Keying (BPSK) or Quadrature Phase Shift Keying (QPSK). The modulation scheme used by the demodulation unit 211c can be multi-level QAM such as 16-QAM, 64-QAM, or 256-QAM. Decoding unit 211d decodes the coded bits of the demodulated uplink channel. The decoded uplink data and uplink control information are output to control unit 24.

[0198] The transmission processing unit 212 performs transmission processing of downlink control information and downlink data. The transmission processing unit 212 includes an encoding unit 212a, a modulation unit 212b, a multiplexing unit 212c, and a wireless transmission unit 212d.

[0199] Encoding unit 212a encodes the downlink control information and downlink data input from control unit 24 using encoding methods such as block coding, convolutional coding, or turbo coding. Modulation unit 212b modulates the coded bits output from encoding unit 212a using predetermined modulation methods such as BPSK, QPSK, 16-QAM, 64-QAM, or 256-QAM. Multiplexing unit 212c multiplexes the modulation symbols and downlink reference signals of each channel and maps them to predetermined resource elements. Wireless transmission unit 212d performs various signal processing on the signals from multiplexing unit 212c. For example, wireless transmission unit 212d performs processing such as conversion to the time domain via Fast Fourier Transform, addition of guard intervals, generation of baseband digital signals, conversion to analog signals, quadrature modulation, up-conversion, removal of extra frequency components, or power amplification. The signal generated by transmission processing unit 212 is transmitted from antenna 413.

[0200] Storage unit 22 is a storage device, such as DRAM, SRAM, flash memory, or hard disk, from which data can be read and written. Storage unit 22 serves as the storage device of base station equipment 20.

[0201] The network communication unit 23 is a communication interface used to communicate with other devices (e.g., other base station equipment 20). For example, the network communication unit 23 is a local area network (LAN) interface such as a network interface card (NIC). The network communication unit 23 can be a USB interface including a Universal Serial Bus (USB) host controller, a USB port, etc. Furthermore, the network communication unit 23 can be a wired interface or a wireless interface. The network communication unit 23 functions as a network communication device for the base station equipment 20. The network communication unit 23 communicates with other devices under the control of the control unit 24.

[0202] Control unit 24 is a controller that controls the various units of base station equipment 20. Control unit 24 is implemented, for example, by a processor such as a central processing unit (CPU) or a microprocessor (MPU). For instance, control unit 24 is implemented by a processor that uses RAM or similar memory as its working area to execute various programs stored in storage devices within base station equipment 20. Note that control unit 24 can also be implemented by integrated circuits such as application-specific integrated circuits (ASICs) or field-programmable gate arrays (FPGAs). CPUs, MPUs, ASICs, and FPGAs can all be considered controllers.

[0203] like Figure 11As shown in the diagram, the control unit 24 includes a sensing unit 241 and a determining unit 242. The various blocks contained within the control unit 24 (sensing unit 241 and determining unit 242) are functional blocks that instruct the corresponding functions of the control unit 24. These functional blocks can be software blocks or hardware blocks. For example, each of the aforementioned functional blocks can be a software module implemented in software (including microprograms), or it can be a circuit block on a semiconductor chip (die). Each functional block can, of course, be a processor or an integrated circuit. The method of constructing the functional blocks is arbitrary. Note that the control unit 24 can be composed of functional units different from the aforementioned functional blocks.

[0204] Note that the control unit 45 of the terminal device 40 may have various functional blocks (sensing unit 241 and determining unit 242) included in the control unit 24 of the base station device 20. In this case, the term "base station device 20" appearing in the following description may be referred to as "terminal device 40" as appropriate. The terms "control unit 24", "sensing unit 241" and "determining unit 242" appearing in the following description may also be referred to as "control unit 45" as appropriate.

[0205] (Antenna configuration in NR)

[0206] Here, the antenna configurations in NR will be explained. For antennas in NR, we will consider digital antenna configurations, analog antenna configurations, and hybrid antenna configurations that combine digital and analog antenna configurations.

[0207] A digital antenna configuration is a structure in which the antenna weights of each antenna element are controlled by digital circuits (baseband region).

[0208] Figure 12 This is a schematic block diagram illustrating an example of a digital antenna configuration according to an embodiment of the present disclosure. Figure 12 Diagram Explanation Figure 11 The base station equipment 20 comprises a multiplexing unit 212c, a wireless transmission unit 212d, and an antenna 213. Note that unnecessary details regarding the basic structure have been omitted, but each unit provides... Figure 11 The processing is explained in the text.

[0209] In the configuration of a digital antenna, the multiplexing unit 212c includes a precoding unit. In the precoding unit, each antenna element is multiplied by an antenna weight to form a beam.

[0210] In digital antenna configurations, each antenna element can be flexibly phase-controlled, and different beams can be generated in the frequency domain. On the other hand, this configuration is complex.

[0211] Figure 13This is a schematic block diagram illustrating a digital antenna configuration according to embodiments of the present disclosure. Similar to... Figure 12 , Figure 13 Diagram Explanation Figure 10 The base station equipment 20 comprises a multiplexing unit 212c, a wireless transmission unit 212d, and an antenna 213. Note that unnecessary details regarding the basic structure have been omitted, but each unit provides... Figure 12 The processing is explained in the text.

[0212] In the analog antenna configuration, the wireless transmitting unit 212d includes a phase control unit. The phase control unit rotates the phase in the analog region (RF region) to form a beam.

[0213] Flexible phase control is difficult because the phase is controlled in the analog region, but its configuration is simple. For example, antenna switching configuration is part of analog antenna configuration.

[0214] Hybrid antenna configurations combine digital and analog antenna configurations, including phase control elements in both the analog and digital regions. They offer beamforming performance and structural complexity that are moderate compared to both digital and analog-digital antenna configurations.

[0215] <2.2. Examples of Terminal Device Configuration>

[0216] Next, the composition of terminal device 40 will be explained. Figure 14 This is an illustration illustrating an example of the configuration of a terminal device 40 according to an embodiment of the present disclosure. The terminal device 40 is a communication device (wireless system) that wirelessly communicates with a base station device 20. The terminal device 40 is a type of information processing device.

[0217] Terminal device 40 includes a wireless communication unit 41, a storage unit 42, an input / output unit 44, and a control unit 45. Note that... Figure 14 The configuration shown in the diagram is the functional configuration; the hardware configuration may differ. Furthermore, the functions of the terminal device 40 can be distributed across multiple physically separate components and implemented therein.

[0218] The wireless communication unit 41 is a wireless communication interface for communicating wirelessly with other communication devices (e.g., base station device 20 and other terminal devices 40). The wireless communication unit 41 operates under the control of the control unit 45. The wireless communication unit 41 supports one or more radio access methods. For example, the wireless communication unit 41 supports both NR and LTE. The wireless communication unit 41 may support other radio access methods such as W-CDMA or cdma2000.

[0219] The wireless communication unit 41 includes a receiving processing unit 411, a transmitting processing unit 412, and an antenna 313. The wireless communication unit 41 may include multiple receiving processing units 411, multiple transmitting processing units 412, and multiple antennas 313. Note that when the wireless communication unit 41 supports multiple radio access methods, each unit of the wireless communication unit 41 can be configured separately for each radio access method. For example, the receiving processing unit 411 and the transmitting processing unit 412 can be configured separately for LTE and NR, respectively. The configuration of the receiving processing unit 411 and the transmitting processing unit 412 is similar to that of the receiving processing unit 211 and the transmitting processing unit 212 of the base station device 20.

[0220] Storage unit 42 is a storage device, such as DRAM, SRAM, flash memory, or hard disk, from which data can be read and written. Storage unit 42 serves as the storage device of terminal device 40.

[0221] Input / output unit 44 is a user interface for exchanging information with the user. For example, input / output unit 44 may be an operating device for various user operations, such as a keyboard, mouse, operation keys, or touch panel. Alternatively, input / output unit 44 may be a display device such as a liquid crystal display (LCD) or an organic electroluminescent (EL) display. Input / output unit 44 may be an audio device such as a speaker or buzzer. Furthermore, input / output unit 44 may be a lighting device such as a light-emitting diode (LED) lamp. Input / output unit 44 functions as an input / output device (input device, output device, operating device, or notification device) of terminal device 40.

[0222] Control unit 45 is a controller that controls the various units of terminal device 40. Control unit 45 is implemented, for example, by a processor such as a CPU or MPU. For instance, control unit 45 is implemented by the processor using RAM or the like as its working area to execute various programs stored in a storage device within terminal device 40. Note that control unit 45 can be implemented by an integrated circuit such as an ASIC or FPGA. CPUs, MPUs, ASICs, and FPGAs can all be considered controllers. Note that control unit 45 may have various functional blocks included in control unit 24 of base station device 20.

[0223] <2.3. Examples of the Composition of Communication Control Equipment>

[0224] Communication system 1 may include communication control device 30. Communication control device 30 is a device that manages base station device 20. For example, communication control device 30 is a device that controls the wireless communication of base station device 20. For example, communication control device 30 is a device that determines the communication parameters (also called operating parameters) that base station device 20 will use and grants permission or instructions to base station device 20.

[0225] In this case, the communication control device 30 can be a network manager that integrates the control of wireless devices in the network. For example, according to ETSI EN 303 387 or IEEE 802.19.1-2014, the communication control device 30 can be a control device such as a spectrum manager / coexistence manager that performs radio wave interference control between wireless devices. Furthermore, a Registered Location Security Server (RLSS) as defined in IEEE 802.11-2016 can also act as the communication control device 30. Additionally, in a frequency-sharing environment, a database (database server, device, or system) such as a Geographic Location Database (GLDB) or a Spectrum Access System (SAS) can also act as the communication control device 30.

[0226] Note that when communication system 1 is a cellular communication system, communication control device 30 can be a device constituting core network 120. Core network 120 is, for example, an evolved packet core (EPC) or a 5G core network (5GC). When core network 120 is an EPC, communication control device 30 can be, for example, a device functioning as a mobility management entity (MME). Furthermore, when core network 120 is a 5GC, communication control device 30 can be, for example, a device functioning as an access and mobility management function (AMF) or a session management function (SMF). Note that even when communication system 1 is a cellular communication system, communication control device 30 does not necessarily have to be a device constituting core network 120. For example, communication control device 30 can be a device functioning as a radio network controller (RNC).

[0227] Note that the communication control device 30 may function as a gateway. For example, if the core network 120 is an EPC, the communication control device 30 may function as a Serving Gateway (S-GW) or a Packet Data Network Gateway (P-GW). Furthermore, if the core network 120 is a 5GC, the communication control device 30 may function as a User Plane Function (UPF). Additionally, the communication control device 30 may be an SMF, PCF, UDM, etc. The core network 120 may include SMF, PCF, UDM, etc.

[0228] Note that the communication control device 30 does not necessarily have to be a component of the core network 120. For example, suppose the core network 120 is a Wideband Code Division Multiple Access (W-CDMA) or Code Division Multiple Access 2000 (CDMA2000) core network. In this case, the communication control device 30 can function as a Radio Network Controller (RNC).

[0229] The communication control device 30 can be connected to each of the multiple base station devices 20. For example, in the case of 5GC, there is an N2 reference point between the AMF and NG-RAN, and the AMF and NG-RAN are logically interconnected via the NG interface.

[0230] The communication control device 30 manages the communications of the base station device 20. For example, the communication control device 30 manages the location of each terminal device 40 in units of an area that includes multiple cells (e.g., a tracking area, a RAN notification area). Note that for each terminal device 40, the communication control device 30 can know and manage which base station device 20 (or which cell) the terminal device 40 is connected to, and in which base station device 20 (or which cell) the terminal device 40 exists, etc.

[0231] Basically, the communication control device 30 controls the base station device 20, but it can also control the terminal devices 40 subordinate to the base station device 20. Furthermore, the communication control device 30 can control multiple secondary systems. In this case, the communication system 1 can be considered as a system comprising multiple secondary systems.

[0232] Furthermore, multiple communication control devices 30 can exist in a communication system 1. For example, the communication control devices 30 can be distributed. In this case, the multiple communication control devices 30 can exchange information about the base station equipment 20 they manage and perform necessary frequency allocation or interference control calculations.

[0233] Furthermore, the communication control device 30 can be a so-called master-slave device, where one communication control device centrally controls multiple communication control devices. In such a system, the master communication control device can control multiple slave communication control devices for centralized decision-making. Additionally, the master communication control device can delegate or relinquish decision-making authority to each slave communication control device for purposes such as load distribution (load balancing).

[0234] Note that the communication control device 30 can also obtain necessary information from entities other than the base station device 20 and the terminal device 40 to complete its tasks. Specifically, the communication control device 30 can, for example, obtain information required for protection, such as the location information of the main system, from databases managed and operated by national or regional radio wave administrative agencies (regulatory databases). Examples of regulatory databases include the Universal License System (ULS) operated by the Federal Communications Commission of the United States. Other examples of information required for protection may include out-of-band emission (OOBE) limits, adjacent channel leakage ratio (ACLR), adjacent channel selectivity, fading margin, and / or protection ratio (PR). For these examples, it is ideal to use these values ​​where they are fixed in the law.

[0235] Furthermore, as another example, it can be assumed that the communication control device 30 obtains radio wave sensing information from a radio wave sensing system installed and operated for radio wave sensing in the main system. As a specific example, the communication control device 30 can obtain the main system's radio wave sensing information from a radio wave sensing system such as the Environmental Sensing Capability (ESC) in the US CBRS. Additionally, if the communication device or terminal has sensing capabilities, the communication control device 30 can obtain the main system's radio wave sensing information from the communication device or terminal.

[0236] The communication control device 30 is a device that controls the wireless communication of the base station device 20. The communication control device 30 can control the wireless communication of the terminal device 40 either via the base station device 20 or directly. The communication control device 30 is a type of information processing device.

[0237] Figure 15 This is a diagram illustrating an example of the configuration of a communication control device 30 according to an embodiment of the present disclosure. The communication control device 30 includes a communication unit 31, a storage unit 32, and a control unit 33. Note that... Figure 15 The configuration shown in the diagram is the functional configuration; the hardware configuration may differ. Furthermore, the functionality of the communication control device 30 can be distributed across and implemented in multiple physically separate components. For example, the communication control device 30 may include multiple server devices.

[0238] The communication unit 31 is a communication interface for communicating with other communication devices (e.g., base station device 20, terminal device 40, and other communication control devices 30). The communication unit 31 operates under the control of the control unit 33.

[0239] Communication unit 31 can support multiple radio access methods. For example, communication unit 31 supports both NR and LTE. Communication unit 31 can also support other radio access methods such as W-CDMA or cdma2000. In this case, the configuration of communication unit 31 is similar to that of wireless communication unit 41 of base station equipment 20.

[0240] Alternatively, the communication unit 31 can be a network interface or a device connection interface. For example, the communication unit 31 can be a local area network (LAN) interface such as a network interface card (NIC). The communication unit 31 can be a USB interface that includes a Universal Serial Bus (USB) host controller, a USB port, etc. In addition, the communication unit 31 can be a wired interface.

[0241] Storage unit 32 is a storage device, such as DRAM, SRAM, flash memory, or hard disk, from which data can be read and written. Storage unit 32 serves as the storage device of communication control device 30.

[0242] Control unit 33 is a controller that controls the various units of communication control device 30. Control unit 33 is implemented, for example, by a processor such as a CPU or MPU. For instance, control unit 33 is implemented by a processor that uses RAM or the like as its working area to execute various programs stored in a memory device within communication control device 30. Note that control unit 33 can also be implemented by an integrated circuit such as an ASIC or FPGA. CPUs, MPUs, ASICs, and FPGAs can all be considered controllers.

[0243] <<3. Technical Features>>

[0244] As mentioned above, LBT Category 4 is currently used for data transmission in unlicensed frequency bands. This can lead to unnecessary transmission delays.

[0245] Therefore, in the communication system 1 according to this embodiment, a channel access procedure different from the first channel access procedure (e.g., an LBT other than LBT category 4) is applied as the LBT for channel occupancy.

[0246] In communication system 1, communication is performed by switching between a first channel access procedure and a channel access procedure different from the first channel access procedure according to predetermined conditions.

[0247] The first channel access procedure and channel access procedures different from the first channel access procedure differ in at least one or more of the following LBT parameters.

[0248] -Contending for window size

[0249] - Methods for resizing contention windows

[0250] - Value of the backoff counter

[0251] -Sensing time slot length

[0252] - Cyclic prefix (CP) extension length

[0253] - Timing of the start or end of sensing

[0254] -LBT method

[0255] - Maximum channel occupancy time

[0256] -Energy detection threshold

[0257] -Preamble detection threshold

[0258] The following will illustrate the differences between the first channel access procedure and channel access procedures that are different from the first channel access procedure.

[0259] As an example, the difference between the first channel access procedure and a channel access procedure different from the first channel access procedure is the LBT category. The first channel access procedure is LBT category 4, while the channel access procedure different from the first channel access procedure is an LBT category other than LBT category 4. More specifically, in communication system 1, communication is performed by switching between LBT category 4 and LBT categories other than LBT category 4 (e.g., LBT category 3) according to predetermined conditions. The category other than LBT category 4 can be LBT category 1 or LBT category 2. Alternatively, LBT methods defined in categories other than LBT categories 1-3 can be used.

[0260] As an example, the difference between the first channel access procedure and a channel access procedure different from the first channel access procedure is the adjustment of the contention window size. The first channel access procedure is an LBT with contention window size adjustment, while the channel access procedure different from the first channel access procedure is an LBT without contention window size adjustment. More specifically, in communication system 1, communication is performed by switching between an LBT with contention window size adjustment and an LBT without contention window size adjustment according to predetermined conditions.

[0261] As an example, the difference between the first channel access procedure and a channel access procedure different from the first channel access procedure is the backoff value. The first channel access procedure is an LBT with random backoff, while the channel access procedure different from the first channel access procedure is an LBT with fixed backoff value. More specifically, in communication system 1, communication is performed by switching between an LBT with random backoff and an LBT with fixed backoff value according to predetermined conditions.

[0262] Note that LBT Category 4 and LBT Category 3 will be described below, but even if examples of differences between the first channel access procedure and channel access procedures different from the first channel access procedure are applied, the technical features and equivalent effects can be achieved.

[0263] <3.1. Application Conditions of LBT Category>

[0264] The following will explain the conditions for selecting LBT category 3, in other words, the conditions for switching between LBT category 3 and LBT category 4.

[0265] (law)

[0266] For example, LBT Category 3 can be selected under the condition that other radio access technologies are guaranteed not to be used in the long term through laws, standards, etc.

[0267] Specifically, LBT category 4 is applied to the transmissions of the initiating device (base station device 20 or terminal device 40) unless it is guaranteed that no other radio access technologies (e.g., wireless LAN) will exist in the long term. On the other hand, LBT category 3 can be applied to the transmissions of the initiating device (base station device 20 or terminal device 40) unless it is guaranteed that no other radio access technologies will exist in the long term.

[0268] Here, a long-term guarantee against the use of other radio access technologies is provided, for example, through legal guarantees that no other radio access technologies will be used in the frequency band (channel or component carrier).

[0269] Alternatively, if the application of an LBT other than LBT category 4 is determined by law, the determined LBT category shall be selected.

[0270] For example, if the application of LBT Category 3 is determined by law, the transmission of the initiating device (base station device 20 or terminal device 40) is subject to LBT Category 3.

[0271] Because laws vary by frequency band, the LBT category to be applied may also vary by frequency band.

[0272] Specifically, for example, in the 60 GHz unlicensed frequency band, LBT category 3 can be applied to the transmission of the initiating device, while in the 5 GHz and 6 GHz unlicensed frequency bands, LBT category 4 can be applied to the transmission of the initiating device.

[0273] Furthermore, since laws vary from country to country, the application of LBT categories may differ from country to country.

[0274] Specifically, for example, in Europe, LBT category 4 can be applied to the transmission of the initiating device, while in the United States, LBT category 3 can be applied to the transmission of the initiating device.

[0275] As an example, location information can be used to determine the country of application. The country of application can be specified based on the coordinates (latitude and longitude) of the base station device 20 or the terminal device 40. Methods for obtaining coordinates include, for example, using a Global Navigation Satellite System (GNSS).

[0276] As an example, a Public Land Mobile Network (PLMN) identifier can be used to determine the country of use. The PLMN identifier is broadcast from base station equipment 20 via information related to cell access contained in SIB1. Terminal equipment 40 can determine the country of use based on the Mobile Country Code (MCC) contained in the PLMN identifier.

[0277] As described above, communication using an LBT different from LBT category 4 (e.g., LBT category 3) is conducted, provided that no other communication devices using other radio access technologies are present, that is, no other communication devices sensing the channel in the same way as LBT category 4 are present.

[0278] (Instructions from higher level)

[0279] Core network

[0280] For example, base station device 20 or terminal device 40 can select LBT category 3 or 4 based on instructions from the core network 12, which is the upper layer. In this case, the LBT category of base station device 20 and terminal device 40 is determined based on instructions from the core network 12 related to LBT parameter control.

[0281] Instructions related to LBT parameter control can be generated by any one of AMF 139, SMF 136, NEF 132, NRF 133, UDM 137, AUSF 131, PCF 135, AF 138, and UPF 150 (see [link to documentation]). Figure 2 Alternatively, new functions for controlling LBT parameters can issue commands related to LBT parameter control.

[0282] As an example, we will illustrate the case where LBT parameters are controlled based on location information from the terminal's AMF 138, which is responsible for mobility management. Here, we assume that AMF 139 determines the LBT category 3 to be selected based on the location information of terminal device 40. In this case, for example, if terminal device 40 moves to a predetermined area, it instructs base station device 20 or terminal device 40 to apply LBT category 3. On the other hand, if terminal device 40 exists in an area other than the predetermined area, it instructs base station device 20 or terminal device 40 to apply LBT category 4.

[0283] ·OAM

[0284] Alternatively, base station device 20 or terminal device 40 can select LBT category 3 or 4 based on instructions, for example, from an Operation, Management and Administration (OAM) function (not shown) at the higher level. In this case, the LBT category of base station device 20 and terminal device 40 is determined based on instructions from OAM related to LBT parameter control. Note that the OAM function is a maintenance, operation, and management function in the network. The OAM function can be implemented in the core network (EPC or NG core), base station device 20, or other communication control devices (e.g., communication control device 30).

[0285] OAM functions, for example, acquire information about the communication environment from base station equipment 20 and / or terminal equipment 40, and determine the LBT parameters to be applied by each base station equipment 20 and / or each terminal equipment 40. The OAM function instructs the base station equipment 20 and / or terminal equipment 40 to perform settings related to the LBT parameters.

[0286] For example, the OAM function instructs base station equipment 20 and terminal equipment 40 with less interference to apply LBT category 3, and instructs base station equipment 20 and terminal equipment 40 with more interference to apply LBT category 4.

[0287] Application layer

[0288] Alternatively, base station device 20 or terminal device 40 may select LBT category 3 or 4 based on instructions, for example, from the application layer, which is the upper layer.

[0289] For example, in data transmission for operations with high urgency, LBT category 3 (or LBT category 2) with low latency is applied. For example, in data transmission for information with low urgency, LBT category 4 with high latency is applied.

[0290] (Instructions from the communication control device)

[0291] For example, base station device 20 or terminal device 40 can select LBT category 3 or 4 based on instructions from communication control device 30. In this case, the LBT category of base station device 20 and terminal device 40 is determined based on instructions from communication control device 30 related to LBT parameter control.

[0292] (Instructions from base station equipment)

[0293] For example, terminal device 40 (or relay station) can select LBT category 3 or 4 based on instructions from base station device 20.

[0294] In this scenario, base station device 20 issues instructions related to LBT parameter control, for example, based on RRC signaling. Base station device 20 indicates the LBT category via parameters related to the LBT category in the RRC. When configured or reconfigured via RRC, the parameters related to the previous LBT category are overwritten.

[0295] Alternatively, base station device 20 may, for example, issue instructions related to LBT parameter control based on DCI. Base station device 20 indicates the LBT category using LBT category-related parameters included in the DCI. Base station device 20 may notify the DCI using the PDCCH of each terminal device 40. Alternatively, base station device 20 may group multiple terminal devices 40 together and notify the DCI using a PDCCH shared by the group. The PDCCH of each terminal device 40 is arranged in a user-specific search space (USS), and the PDCCH shared by the group is arranged in a common search space (CSS).

[0296] For example, base station device 20 can issue commands related to LBT parameter control based on MAC CE. Base station device 20 indicates the LBT category through parameters related to the LBT category included in the MAC CE.

[0297] Base station device 20 can, for example, issue instructions regarding LBT parameter control based on the SIB. Base station device 20 indicates the LBT category using LBT category-related parameters included in the SIB. Note that the LBT category parameters notified via the SIB can be overwritten via RRC signaling.

[0298] For example, base station device 20 can issue commands related to LBT parameter control based on a predetermined signal sequence. Base station device 20 indicates the LBT category through parameters related to the LBT category corresponding to the signal sequence of the predetermined signal. Examples of the predetermined signal include SS / PBCH blocks, CSI-RS, DMRS of PDCCH, preamble signals transmitted at the beginning of transmission, reserved signals, etc.

[0299] Note that base station device 20 can issue instructions regarding LBT parameter control by combining the above signaling. For example, base station device 20 can notify the set of parameters related to the LBT category via RRC and indicate a parameter in that set via DCI. Alternatively, base station device 20 can notify the set of parameters related to the LBT category via RRC and indicate a parameter in that set via MAC CE.

[0300] For example, base station device 20 specifies the LBT category, contention window size adjustment method, and / or contention window size as information regarding LBT parameter control. As a method of issuing explicit instructions, for example, base station device 20 specifies the LBT category and contention window size in association with parameters (fields) related to channel access.

[0301] As an example, base station device 20 specifies the LBT category by indicating the value (index of LBT parameter) of a predetermined field that specifies the LBT category, contention window size adjustment method, and / or contention window size. Specifically, base station device 20 specifies the LBT category, contention window size adjustment method, and / or contention window size according to Table 4. Terminal device 40 performs LBT before the transmission of physical signals / physical channels by using the LBT category indicated by the predetermined field.

[0302] (Table 4)

[0303]

[0304]

[0305] As another example of specifying the LBT category, the application / non-application of the contention window adjustment process can be cited. For example, this field is specified for uplink configuration grant PUSCH transmission, PRACH transmission, MsgA (PRACH and PUSCH) transmission, semi-persistent PUCCH transmission, sidelink physical signal / physical channel transmission, etc.

[0306] Additionally, as another example of specifying an LBT category, there are instances where the LBT category for uplink PUSCH transmission is specified in association with the ChannelAccess-CPext field or ChannelAccess-CPext-CAPC field included in the uplink grant (e.g., DCI format 0_0 or DCI format 0_1). For example, base station devices 20 may notify each other of the ChannelAccess-CPext field or ChannelAccess-CPext-CAPC field and the LBT category, contention window size adjustment method, and / or contention window size. After receiving the uplink grant, terminal device 40 performs LBT before PUSCH transmission by using the LBT category indicated in the ChannelAccess-CPext field or ChannelAccess-CPext-CAPC field.

[0307] As another example of specifying an LBT category, there are instances where the LBT category for uplink PUCCH transmission is specified in association with the ChannelAccess-CPext field contained in the downlink grant (e.g., DCI format 1_0 or DCI format 1_1). For example, base station device 20 notifies the ChannelAccess-CPext field in association with the LBT category, contention window size adjustment method, and / or contention window size. After receiving the downlink grant, terminal device 40 performs LBT before PUCCH transmission by using the LBT category indicated in the ChannelAccess-CPext field.

[0308] As a method of issuing implicit instructions, the base station device 20 specifies the LBT category and contention window size in association with other parameters (fields) and physical parameters.

[0309] For example, base station device 20 specifies LBT parameters in association with an index of the control resource set (CORESET) used for PCDDH transmission. In other words, LBT parameters are set individually for each of the downlink transmissions and corresponding uplink transmissions with different CORESETs. As a specific example, different contention window sizes are set for different CORESETs. Different contention window sizes are applied for PDCCH transmissions and corresponding uplink transmissions with different CORESETs.

[0310] For example, base station device 20 specifies LBT parameters in association with the index of the search space in which PDCCHs are arranged. In other words, LBT parameters are set individually for each of the downlink transmissions and corresponding uplink transmissions with different search spaces. As a specific example, different contention window sizes are set for different search spaces. Different contention window sizes are applied for PDCCH transmissions and corresponding uplink transmissions with different search spaces. Furthermore, for example, LBT parameters differ between CSS and USS. Beamforming-based LBT is not applied for CSS, but beamforming-based LBT is applied for USS.

[0311] For example, base station device 20 specifies LBT parameters based on the type of the Radio Network Temporary Identifier (RNTI) of the PDCCH. In other words, LBT parameters are set individually for each of the downlink transmissions and corresponding uplink transmissions with different RNTIs. As a specific example, different contention window sizes are set for different RNTIs. Different contention window sizes are applied to PDCCH transmissions and corresponding uplink transmissions with different RNTIs.

[0312] Base station equipment 20 can indicate LBT parameters other than LBT categories. Examples of LBT parameters include the following information.

[0313] -Information about contention window resizing methods

[0314] - Value of the backoff counter

[0315] -Sensing time slot length

[0316] - Cyclic prefix (CP) extension length

[0317] -Send start timer

[0318] - Timing of the start or end of sensing

[0319] -LBT method (beamforming-based LBT or receiver-assisted LBT)

[0320] - Information used to specify whether dynamic channel access or semi-static channel access is performed.

[0321] -Channel access priority class

[0322] - Maximum channel occupancy time

[0323] -Energy detection threshold

[0324] -Preamble detection threshold

[0325] Examples of information regarding contention window size adjustment methods include the length of the contention window (contention window size), possible values ​​for the contention window, reference time periods, etc. For LBT category 3, the length of the contention window indicates the contention window size used in a fixed manner. On the other hand, in the case of LBT category 4, the initial value of the contention window size, the maximum value of the contention window size, the amount by which the contention window is increased, etc., are specified.

[0326] Possible values ​​for the contention window, which represent the increment of the contention window, follow, for example, the formula CW = 16·(n+1)⁻¹ (where n is the number of times the contention window value is updated). As a specific example, {15,31,47,63} is used. Note that the base station device 20 may indicate a value obtained from this formula, or it may indicate the formula described above.

[0327] Base station device 20 can specify the location of the reference time period and the length of the time period. Note that if no settings are made related to the reference time period, the default reference time period is applied (i.e., the first time slot of at least one unicast PDSCH is included in the channel occupancy time).

[0328] The value of the backoff counter can be used, for example, to indicate the value of a counter applied during the first channel access process. Additionally, the length of the sensing time slot can be used, for example, to indicate the length of the first, second, third, and / or fourth waiting times.

[0329] As a CP extension length, it indicates, for example, the length of the CP for PUSCH and / or PUCCH. As a transmit start timing, it indicates, for example, the transmit start timing for PUSCH and / or PUCCH. Furthermore, as a sensing timing, it indicates, for example, the sensing start timing.

[0330] As an LBT method, for example, it refers to an application that indicates a channel access procedure different from the first, second, and third channel access procedures. Here, different channel access procedures include, for example, beamforming-based LBT, receiver-assisted LBT, etc.

[0331] Dynamic channel access or semi-static channel access can be indicated from base station device 20. Furthermore, as a channel access priority class, for example, it can indicate a channel access priority class that can be transmitted from base station device 20. Alternatively, it can indicate a channel access priority class that cannot be transmitted from base station device 20.

[0332] For example, the base station device 20 may indicate the maximum channel occupancy time, a power threshold applied to signal detection, and a power threshold applied to preamble detection. Information regarding the power thresholds may be communicated in conjunction with information about the transmit power of the base station device 20 (reference SignalPower). Alternatively, the terminal device 40 may determine the thresholds using the transmit power of the base station device 20, the transmit power of the terminal device 40, and / or the information regarding the power thresholds, and use these thresholds for LBT.

[0333] (Testing Information)

[0334] For example, base station device 20 or terminal device 40 can select LBT category 3 or 4 based on the detected information. In this case, base station device 20 or terminal device 40 detects the information required to determine the LBT category and determines the LBT category based on the detected information. Note that although the case of base station device 20 determining the LBT category will be described below, terminal device 40 can determine the LBT category in a similar way.

[0335] For example, base station equipment 20 determines the LBT category based on whether the presence of other devices has been detected. Other devices are devices that use other radio access technologies, such as wireless devices that comply with 802.11ad or 802.11ay as other radio access technologies.

[0336] Base station equipment 20 detects the presence of other devices, for example, by using signal detection methods such as received power strength or decoding. More specifically, for example, if the received power strength of a predetermined signal exceeds a threshold, base station equipment 20 determines that the predetermined signal has been detected and that the presence of other devices has been detected. Alternatively, if the predetermined signal is successfully decoded, base station equipment 20 determines that the predetermined signal has been detected and that the presence of other devices has been detected.

[0337] Base station equipment 20 selects LBT category 4 if the presence of other equipment has been detected, and selects LBT category 3 if the presence of other equipment has not been detected.

[0338] Alternatively, base station equipment 20 can determine the LBT category based on whether the presence of a device applying LBT category 4 to it has been detected. A device applying LBT category 4 to it is, for example, a device conforming to 802.11ad or 802.11ay.

[0339] For example, if a preamble signal is detected from a wireless device conforming to 802.11ad or 802.11ay, the base station device 20 determines that the presence of a device applying LBT category 4 to it has been detected. The base station device 20 selects LBT category 4 if the presence of a device applying LBT category 4 to it has been detected, and selects LBT category 3 if the presence of a device applying LBT category 4 to it has not been detected.

[0340] Alternatively, for example, if an IEEE 802.11 WLAN Received Signal Strength Indicator (RSSI) equal to or greater than a predetermined value is detected, the base station device 20 determines that the presence of a device applying LBT category 4 has been detected. The base station device 20 selects LBT category 4 if the presence of a device applying LBT category 4 has been detected, and selects LBT category 3 if the presence of a device applying LBT category 4 has not been detected. IEEE 802.11 WLAN RSSI is, for example, an RSSI measured from beacons, DMG beacons, FILS discovery frames, probe response frames, etc.

[0341] Alternatively, base station equipment 20 can determine the LBT category based on whether the presence of an NR-U device has been detected.

[0342] For example, if an NR-U-specific physical signal and / or physical channel has been detected, the base station device 20 determines that the presence of another NR-U device has been detected. For example, if an SS / PBCH block or CSI-RS has been detected, the base station device 20 determines that the presence of another NR-U device has been detected. Or, for example, if an SRC or PUCCH has been detected, the base station device 20 determines that the presence of another NR-U device has been detected.

[0343] If the presence of other NR-U devices is detected, the base station device 20 determines the LBT parameters (such as LBT category) applied by the other NR-U devices. For example, the base station device 20 selects LBT category 4 if other NR-U devices apply LBT category 4, and selects LBT category 3 if other NR-U devices apply LBT category 3.

[0344] Alternatively, base station equipment 20 can determine the LBT category based on information from other equipment. This information could be carried, for example, by a broadcast channel / broadcast signal or a sidelink physical channel / physical signal.

[0345] For example, base station device 20 determines the LBT category based on information related to LBT parameters, which is information from other devices. Examples of information related to LBT parameters include information about the LBT category, contention window size, etc. In this case, base station device 20 selects the detected LBT parameters.

[0346] Alternatively, base station device 20 may determine the LBT category based on device type-related information, which is information from other devices. Examples of device type-related information include information used for RAT notification. In this case, base station device 20 selects the LBT category to be applied in the notified RAT. For example, if the notified RAT is 802.11ad or 802.11ay, base station device 20 selects LBT category 4.

[0347] (Measurement Information)

[0348] For example, base station device 20 or terminal device 40 can select LBT category 3 or 4 based on the measured information. Note that although the case of base station device 20 determining LBT category will be described below, terminal device 20 can similarly determine LBT category.

[0349] (1) Communication Status

[0350] For example, base station equipment 20 determines the LBT category based on the communication status.

[0351] (1-1) HARQ-ACK Results

[0352] Base station device 20 determines the LBT category, for example, based on the HARQ-ACK result. Base station device 20 determines the LBT category, for example, based on the ACK / NACK ratio, which is a result of HARQ-ACK. Specifically, base station device 20 determines the LBT parameters, for example, based on the ACK / NACK ratio of the PDSCH. Alternatively, base station device 20 determines the LBT parameters based on the ACK / NACK ratio of the PUSCH.

[0353] For example, base station equipment 20 selects LBT category 3 when the proportion of ACKs is equal to or greater than a predetermined value, and selects LBT category 4 when the proportion of ACKs is less than a predetermined value. Alternatively, base station equipment 20 selects LBT category 3 when the proportion of NACKs is less than a predetermined value, and selects LBT category 4 when the proportion of NCKs is equal to or greater than a predetermined value.

[0354] Alternatively, base station device 20 may determine the LBT category, for example, based on the number of consecutive ACKs or NACKs. Specifically, base station device 20 may determine LBT parameters, for example, based on the number of consecutive ACKs or NACKs of the PDSCH. Alternatively, base station device 20 may determine LBT parameters based on the number of consecutive ACKs or NACKs of the PUSCH.

[0355] In this way, base station device 20 selects the LBT category based on the ACK / NACK ratio and the number of consecutive ACK / NACK signals. Note that once a NACK is received, base station device 20 can retransmit the signal. In this case, it can also be said that base station device 20 selects the LBT category based on the number of retransmissions.

[0356] For example, base station equipment 20 selects LBT category 3 when the number of consecutive ACKs is equal to or greater than a predetermined value, and selects LBT category 4 when the number of consecutive ACKs is less than a predetermined value. Alternatively, base station equipment 20 selects LBT category 3 when the number of consecutive NACKs is less than a predetermined value, and selects LBT category 4 when the number of consecutive NCKs is equal to or greater than a predetermined value.

[0357] (1-2) Sensing Results

[0358] Base station equipment 20 determines the LBT category, for example, based on sensing results. Base station equipment 20 determines the LBT category, for example, based on the number of times the sensing results indicate "idle" and the number of times the sensing results indicate "busy".

[0359] Specifically, base station equipment 20 determines LBT parameters, for example, based on the ratio of "idle" to "busy". For example, base station equipment 20 selects LBT category 3 when the "idle" ratio is equal to or greater than a predetermined value, and selects LBT category 4 when the "idle" ratio is less than a predetermined value. Alternatively, base station equipment 20 selects LBT category 3 when the "busy" ratio is less than a predetermined value, and selects LBT category 4 when the "busy" ratio is equal to or greater than a predetermined value.

[0360] Alternatively, base station equipment 20 may determine the LBT category based, for example, on the frequency of busy periods (e.g., the number of consecutive results indicating "busy"). For example, base station equipment 20 may select LBT category 3 if the number of consecutive results indicating "busy" is less than a predetermined value, and select LBT category 4 if the number of consecutive results indicating "busy" is equal to or greater than the predetermined value.

[0361] Alternatively, base station device 20 may determine the LBT category based, for example, on the power value detected by sensing. For instance, base station device 20 may select LBT category 3 if the detected power value is less than a predetermined value, and select LBT category 4 if the detected power value is equal to or greater than the predetermined value.

[0362] (2) Measurement information or measurement feedback information

[0363] For example, base station device 20 or terminal device 40 determines the LBT category based on measurements. For example, terminal device 40 determines the LBT category based on CSI measurement results. Base station device 20 determines the LBT category, for example, based on feedback CSI measurement results. For example, base station device 20 selects LBT category 3 if the channel quality is high (e.g., the Channel Quality Indicator (CQI), Layer Indicator (LI), Rank Indicator (RI), L1-RSRP, or L1-SINR indicates a predetermined value or above) as a result of CSI measurements, and selects LBT category 4 if the channel quality is low (e.g., CQI, LI, RI, L1-RSRP, or L1-SINR indicates a value less than a predetermined value).

[0364] Alternatively, terminal device 40 may determine the LBT category, for example, based on RLM measurement results. For instance, terminal device 40 may select LBT category 3 if the channel quality is high (the radio link quality indicator measured within a predetermined time period is at or above a predetermined value) based on RLM measurement results, and select LBT category 4 if the channel quality is low (the radio link quality indicator measured within a predetermined time period is less than a predetermined value). Note that terminal device 40 may send the RLM measurement results (i.e., radio link quality) to base station device 20, which may determine the LBT category through a similar operation to terminal device 40.

[0365] Base station equipment 20 or terminal equipment 40 may determine the LBT category based, for example, on RRM measurement results. For instance, terminal equipment 40 determines the LBT category based on RRM measurement results (SS-RSRP, CSI-RSRP, SS-RSRQ, CSI-RSRQ, SS-SINR, CSI-SINR, etc.). Base station equipment 20 determines the LBT category based on RRM measurement results reported from terminal equipment 40. If the channel quality is high (RRM measurement results indicate a predetermined value or higher), LBT category 3 is selected; if the channel quality is low (RRM measurement results indicate a value less than a predetermined value), LBT category 4 is selected.

[0366] Base station device 20 or terminal device 30 may determine the LBT category, for example, based on RSSI and / or channel occupancy results measured in the RRSI Measurement Timing Configuration (RMTC). For example, terminal device 40 may determine the LBT category based on RSSI and / or channel occupancy results measured in the RMTC. Base station device 20 determines the LBT category based on RSSI and / or channel occupancy measured in the RMTC as reported by terminal device 40. LBT category 3 is selected when channel quality is high (RSSI indicates a value less than a predetermined value, and channel occupancy results indicate a value less than a predetermined value), and LBT category 4 is selected when channel quality is low (RSSI indicates a value or higher than a predetermined value, and channel occupancy results indicate a value less than a predetermined value). Channel occupancy is defined by the proportion of samples where the RSSI exceeds a set value (channelOccupancyThreshold).

[0367] Furthermore, base station equipment 20 can determine the LBT category based, for example, on CLI measurement results. For instance, terminal equipment 40 determines the LBT category based on CLI-RSSI. For example, base station equipment 20 determines the LBT category based on CLI-RSSI reported from terminal equipment 40. If the channel quality is high (CLI-RSSI indicates a value less than a predetermined value), LBT category 3 is selected; if the channel quality is low (CLI-RSSI indicates a predetermined value or higher), LBT category 4 is selected.

[0368] Based on measurement feedback information, base station equipment 20 selects LBT category 3 when the channel quality is high, that is, when the number of other devices acting as interference sources is small, and selects LBT category 4 when the channel quality is low, that is, when the number of other devices acting as interference sources is large.

[0369] (other)

[0370] Apart from the examples above, base station equipment 20 or terminal equipment 40 may preferably select LBT category 4.

[0371] For example, if terminal device 40 determines the LBT category according to instructions / settings from base station device 20, and no instructions / settings are generated from base station device 20, terminal device 40 selects LBT category 4. On the other hand, if instructions / settings are generated from base station device 20, terminal device 40 selects the LBT category according to the instructions / settings from base station device 20.

[0372] For example, if the base station device 20 determines the LBT category according to the instructions / settings from the communication control device 30, and no instructions / settings are generated from the communication control device 30, the base station device 20 selects LBT category 4. On the other hand, if instructions / settings are generated from the communication control device 30, the base station device 20 selects the LBT category according to the instructions / settings from the communication control device 30.

[0373] Thus, base station equipment 20 or terminal equipment 40 will default to using LBT category 4.

[0374] Furthermore, for example, if terminal device 40 determines the LBT category according to instructions / settings from base station device 20, and no new instructions / settings are generated from base station device 20 before a predetermined time period (timer) has elapsed, terminal device 40 selects LBT category 4. The timer may start, for example, from the timing of generating instructions / settings related to LBT parameters, or from the timing of applying instructions / settings related to LBT parameters.

[0375] <3.2. Setting LBT Parameters>

[0376] LBT parameters can be set for each communication device, such as base station device 20 or terminal device 40, or LBT parameters can be set for each communication parameter.

[0377] (QoS level)

[0378] For example, LBT parameters can be set separately for QoS level (5G QoS identifier (5QI)) or channel access priority class.

[0379] For example, base station device 40 and terminal device 40 maintain separate contention window values ​​relative to the channel access priority class. Terminal device 40 can apply different contention window values ​​for different channel access priority classes.

[0380] Similarly, for the contention window adjustment process, base station device 40 and terminal device 40 can also apply different contention window adjustment procedures for different channel access priority classes. For example, for data with a delay request of 0.5 milliseconds or less, or data with an equivalent delay request, a new channel access priority class (e.g., channel access priority class 0) is defined. A new 5QI index specifying a predetermined delay request value is classified as channel access priority class 0. For channel access priority class 0, LBT category 3 or LBT category 2 can be applied.

[0381] (beam)

[0382] For example, in the case of beamforming-based LBT (directional LBT), LBT parameters can be set individually for each beam.

[0383] Here, the receiving beam in a beamforming-based LBT is defined, for example, by the following definition.

[0384] - The receiving beam corresponding to the transmitting beam of the terminal device 40

[0385] - Receive beam corresponding to the downlink receive beam

[0386] - The direction of the main lobe (elevation and azimuth) and the half-power angle of the main lobe.

[0387] -AoA (Angle of Incidence) / AoD (Angle of Exit)

[0388] - Beam mode set by terminal device 40

[0389] As the receiving beam corresponding to the transmitting beam of the terminal device 40, for example, a receiving beam is formed pointing in the same direction as the transmitting beam, such as PUSCH, PUCCH, PRACH, or SRS, or a receiving beam wider than the transmitting beam. When an uplink transmission command has been generated, the terminal device 40 performs beamforming-based LBT by using the receiving beam pointing in the same direction as the transmitting beam.

[0390] The receive beams corresponding to the downlink receive beams include the receive beams corresponding to the SS / PBCH block or CSI-RS. The receive beam corresponding to the SS / PBCH block or CSI-RS is the receive beam with the highest received power (RSRP) of the SS / PBCH block or CSI-RS, or the receive beam with a received power (RSRP) equal to or greater than a predetermined value. When an SS / PBCH block index or CSI-RS index is specified, the terminal device 40 performs beamforming-based LBT by using the receive beams corresponding to the SS / PBCH block or CSI-RS.

[0391] The received beam is defined, for example, by the direction (elevation and azimuth) of the main lobe and the half-power angle of the main lobe. The direction of the main lobe is represented by the elevation and azimuth angles from a reference point, and the beamwidth is represented by the half-power angle. The reference point can be a direction determined by the base station device 20 or the terminal device 40, the location of the base station device 20, or a direction specified by the base station device 20. The terminal device 40 performs beamforming-based LBT according to the direction (elevation and azimuth) of the main lobe and the half-power angle of the main lobe.

[0392] Regarding the beam pattern set by the terminal device 40, for example, the terminal device 40 forms multiple patterns of predetermined receive beams and / or predetermined transmit beams. These multiple patterns are reported to the base station device 20, for example, as capability information. The base station device 20 assigns an index corresponding to the receive beam pattern or transmit beam pattern to the terminal device 40, thereby controlling the receive beam applied in the beamforming-based LBT of the terminal device 40.

[0393] • Strive to use the window

[0394] For example, base station equipment 20 and terminal equipment 40 can set a contention window value for each beam. This will refer to... Figures 16-18 illustrate. Figures 16-18 This is a diagram illustrating the relationship between the beam and the contention window according to an embodiment of the present disclosure.

[0395] This will explain the first control method for contention for a window. For example... Figure 16 As shown in the diagram, the base station device 40 and the terminal device 40 can set the contention window size individually for each direction (beam). Figure 16 In the example, the base station device 40 and the terminal device 40 set the contention window size CW=15 for beam #1, the contention window size CW=31 for beam #2, and the contention window size CW=63 for beam #3.

[0396] Therefore, different contention window sizes can be applied for different directions and beamwidths. That is, the value of the contention window CW is specifically controlled for each beam. Specifically, the value of the contention window CW is controlled as CW... p,b Where the index of the channel access priority class is p, and the index of the beam is b. In this case, the maximum value of the contention window (CW) is also specifically defined for each beam. min,p and the minimum contention window (CW) max,p Specifically, the maximum and minimum values ​​of the contention window for each beam are represented as CW. min,p,b and CW max,p,b .

[0397] This will explain the second control method for contention windows. For example... Figure 17As shown in the diagram, the base station device 40 and the terminal device 40 can set the same contention window size for each direction (beam). Figure 17 In the example, the base station device 40 and the terminal device 40 set the contention window size CW=15 for beams #1-#3.

[0398] This allows a common contention window size to be applied across all directions and beamwidths. That is, the value of the contention window CW is controlled collectively for each beam. Specifically, the value of the contention window CW is controlled to be CW. p The index of the channel access priority class is p.

[0399] This will explain the second control method for contention windows. For example... Figure 18 As shown in the diagram, terminal device 40 can divide multiple beams into groups comprising one or more beams and set a contention window size for each group. Figure 18 In this process, terminal device 40 sets the contention window size individually for different directions, while setting a common contention window size when only the beamwidth differs. More specifically, terminal device 40, for example, groups beams #1, #2, and #12 together and sets the contention window size CW = 15. Then, terminal device 40 groups beam #3 together and sets the contention window size CW = 63.

[0400] This allows for the configuration of beam groups with a common contention window size. This configuration can be performed, for example, in the same manner as the LBT category configuration described above. Alternatively, common beam groups can be defined within the implementation. In this case, the terminal device 40 can report the beam relationships of the groups to the communicating partner.

[0401] The relationship between the SS / PBCH block and CSI-RS is an example of beamgrouping. CSI-RS quasi-co-located with the SS / PBCH block can be considered part of the same group. Figure 18 In the example, beam #12 is defined by the index of the SS / PBCH block, beams #1 and #2 are defined by the index of the CSI-RS, and beam #3 is defined by the index of either the SS / PBCH block or the CSI-RS.

[0402] The application of the contention window control methods described above can be modified according to conditions. Example conditions include physical channels / physical signals. For example, the first or third control method is applied to unicast transmission (unicast PDSCH, unicast PUSCH, USS PDCCH, etc.), the second control method is applied to broadcast transmission (PBCH, including SIB PDSCH, CSS PDCCH), and the third control method is applied to reference signal transmission (CSI-RS or SRS).

[0403] Beams can also be associated with other physical parameters. A CORESET is an example of such association. It can be assumed that different CORESETs are transmitted by different beams. That is, within each CORESET, each contention window is controlled independently, and the value of the contention window is maintained. Furthermore, the above control method can be set individually for each CORESET. For example, a second control method for the contention window can be applied to the PDCCH and corresponding PDSCH of CORESET#0, while a first control method for the contention window can be applied to the PDCCH and corresponding PDSCH of another CORESET.

[0404] Other examples of related parameters include search space, RNTI, DCI, PRACH timing, RACH preamble, PUCCH format, etc., which can also be associated with beam and contention window.

[0405] The LBT parameters that can be set for each beam are not limited to the contention window size. For example, as other LBT parameters, the contention window size adjustment method, backoff counter, sensing slot length, CP extension length, LBT mode (whether receiver-assisted LBT can be used, or whether semi-static channel access can be used), and maximum channel occupancy time can also be set for each beam. In this case, similar to the contention window size, for different directions and beamwidths, the contention window size adjustment method, backoff counter, sensing slot length, CP extension length, LBT mode (whether receiver-assisted LBT can be used, or whether semi-static channel access can be used), and maximum channel occupancy time can be applied. Alternatively, contention window size adjustment methods, backoff counters, sensing slot lengths, CP extension lengths, LBT modes (whether receiver-assisted LBT can be used, or whether semi-static channel access can be used), and maximum channel occupancy time can be applied for all directions and beamwidths. Furthermore, contention window size adjustment methods, backoff counters, sensing slot lengths, CP extension lengths, LBT modes (whether receiver-assisted LBT can be used, or whether semi-static channel access can be used), and maximum channel occupancy time can be applied for each group.

[0406] • Energy detection threshold

[0407] Alternatively, for example, an energy detection threshold can be set for each beam. In this case, similar to contention window size, different energy detection thresholds can be applied for different directions and beamwidths. Alternatively, a common energy detection threshold can be applied for all directions and beamwidths, or an energy detection threshold can be applied for each group. As an example, the calculation of the energy detection threshold can also include values ​​related to the beam gain and / or beamwidth of the corresponding beam. For energy detection prior to transmission of a predetermined beam, energy detection is performed using a calculated threshold that includes values ​​related to the beam gain and / or beamwidth of the predetermined beam. Examples of values ​​related to beam gain and / or beamwidth include half-power angle, information about the antenna (antenna configuration, number of antenna ports, or number of antenna elements), etc.

[0408] <<4. Communication Processing>>

[0409] The communication process according to embodiments of this disclosure will then be described. Reference will be made here. Figure 19 This explains how the communication control device 30 determines LBT parameters, including LBT categories, based on measurement information from the base station device 20 and the terminal device 40. Figure 19 This is a sequence diagram illustrating the communication processing flow according to embodiments of the present disclosure.

[0410] like Figure 19 As shown in the diagram, terminal device 40 measures the communication environment (step S101) and reports the communication environment information as a measurement result to base station device 20 (step S102). Base station device 20 measures the communication environment (step S103) and reports the communication environment information of terminal device 40 and the communication environment information as a measurement result of base station device 20 to communication control device 30 (step S104).

[0411] Based on the reported communication environment information, the communication control device 30 determines LBT parameters, including LBT categories (step S105). The communication control device 30 notifies the base station device 20 and the terminal device 40 of the determined LBT parameters (step S106).

[0412] The base station device 20, having received the notification, notifies the terminal device 40 of the LBT parameters (step S107) and communicates by applying the LBT parameters (step S108). The terminal device 40, having received the notification, communicates by applying the LBT parameters (step S109).

[0413] <<5. Variations>>

[0414] The terminal device or base station device in this embodiment can be implemented using a dedicated computer system or a general-purpose computer system.

[0415] For example, a communication program for performing the above operations is stored on and distributed on a computer-readable recording medium such as an optical disc, semiconductor memory, magnetic tape, or floppy disk. Then, for example, the control device is implemented by installing the program in a computer and performing the above processing. In this case, the control device can be a terminal device 40, a base station device 20, or other external device (e.g., a personal computer). Furthermore, the control device can be a device internal to the terminal device 40 and the base station device 20 (e.g., various control units).

[0416] Furthermore, the communication program can be stored on a disk device contained in a server device on a network such as the Internet and downloaded to the computer. Additionally, the above functions can be achieved through cooperation between the operating system (OS) and application software. In this case, parts other than the OS can be stored on media and distributed, or parts other than the OS can be stored on a server device and downloaded to the computer.

[0417] Furthermore, in the various processes described in the above embodiments, all or some processes described as automatically can be performed manually. Alternatively, all or some processes described as manually can be automatically performed using known methods. Additionally, unless otherwise stated, the processing procedures, specific names, and information including various data and parameters illustrated in the specification and drawings can be arbitrarily changed. For example, the various information illustrated in the drawings is not limited to the information illustrated in the drawings.

[0418] Furthermore, the components shown in the diagrams for each device are functional concepts and do not necessarily have the physical configuration shown in the diagrams. That is, the specific distribution and integration patterns of the devices are not limited to those shown in the diagrams. Depending on various loads or usage conditions, all or some of the devices can be functionally or physically distributed / integrated in any unit.

[0419] Furthermore, the above embodiments can be appropriately combined as long as the processing content does not contradict each other.

[0420] <<6. Conclusion>>

[0421] As described above, preferred embodiments of the present disclosure have been detailed with reference to the accompanying drawings; however, the scope of the present disclosure is not limited to such examples. It will be apparent to those skilled in the art that various modifications or alterations can be conceived within the scope of the technical concept set forth in the claims, and it should be understood that such modifications or alterations are all within the scope of the present disclosure.

[0422] Furthermore, the processes described in the flowcharts and sequence diagrams in this specification do not necessarily have to be performed in the order shown in the diagrams. Some processing steps can be performed in parallel. In addition, additional processing steps may be used, and some processing steps may be omitted.

[0423] Furthermore, the effects described in this specification are merely illustrative or exemplary, and not restrictive. That is, in addition to or in lieu of the effects described above, the technology disclosed herein can exhibit other effects that will be apparent to those skilled in the art, based on the description herein.

[0424] Note that the following components are also within the technical scope of this disclosure.

[0425] (1) A communication device, comprising:

[0426] A sensing unit that senses the channel in an unlicensed frequency band;

[0427] A communication unit that communicates based on the sensing results; and

[0428] The control unit selects, according to predetermined conditions, either a first mode of sensing that is performed a predetermined number of times within a variable time period or a second mode that is different from the first mode, as the sensing mode.

[0429] (2) The communication device according to (1), wherein the second mode is the mode of performing the sensing a predetermined number of times within a fixed time period.

[0430] (3) The communication device according to (1) or (2), wherein the control unit selects the first mode when there are other communication devices in the vicinity that perform the sensing in the first mode.

[0431] (4) The communication device according to (3), wherein the control unit selects the sensing method based on a notification from the other communication device.

[0432] (5) The communication device according to any one of (1)-(4), wherein the control unit selects the sensing mode based on measurement information obtained by measuring the quality of communication with the communication counterpart.

[0433] (6) The communication device according to any one of (1)-(5), wherein the control unit selects the sensing mode according to the number of retransmissions.

[0434] (7) The communication device according to any one of (1)-(6), wherein the control unit selects the sensing method based on the result of the sensing.

[0435] (8) The communication device according to (7), wherein the control unit selects a first mode as the sensing mode when the frequency of being busy is equal to or greater than a predetermined value as a result of the sensing.

[0436] (9) A communication device according to any one of (1)-(8), wherein the control unit selects the sensing mode according to instructions from other devices.

[0437] (10) The communication device according to any one of (1)-(9), wherein

[0438] The communication unit communicates using one of a plurality of beams, and

[0439] The control unit sets parameters related to the sensing for each of the plurality of beams.

[0440] (11) The communication device according to (10), wherein the control unit divides the plurality of beams into one or more beam groups containing at least one of the beams and sets different parameters for each beam group.

[0441] (12) A communication method, comprising:

[0442] Sensing the channel in unlicensed frequency bands;

[0443] Communication is performed based on the results of the sensing; and

[0444] According to predetermined conditions, one of the first sensing method and the second sensing method, which are different from the first sensing method, is selected as the sensing method by performing the sensing a predetermined number of times within a variable time period.

[0445] (13) A program that causes a computer to perform:

[0446] Sensing the channel in unlicensed frequency bands;

[0447] Communication is performed based on the results of the sensing; and

[0448] According to predetermined conditions, one of the first sensing method and the second sensing method, which are different from the first sensing method, is selected as the sensing method by performing the sensing a predetermined number of times within a variable time period.

[0449] List of reference numerals

[0450] 120 core network

[0451] 20 base station equipment

[0452] 21 Wireless Communication Units

[0453] 24,45 Control Unit

[0454] 30 Communication control equipment

[0455] 40 terminal devices

[0456] 41 Wireless Communication Unit

Claims

1. A communication device as a terminal device, comprising: A sensing unit that senses the channel in an unlicensed frequency band; A communication unit that communicates based on the sensing results; and The control unit selects either a first mode or a second mode different from the first mode as the sensing mode, which is performed a predetermined number of times within a variable time period, based on whether the presence of other communication devices using other radio access technologies has been detected, such that if the presence of the other communication devices has been detected, one of the first mode and the second mode corresponding to the sensing mode applied by the other communication devices is selected as the sensing mode.

2. The communication device according to claim 1, wherein the second mode is the mode of performing the sensing a predetermined number of times within a fixed time period.

3. The communication device according to claim 1, wherein the control unit selects the sensing method based on a notification from the other communication device.

4. The communication device according to claim 1, wherein the control unit selects the sensing method based on measurement information obtained by measuring the quality of communication with the communication counterpart.

5. The communication device according to claim 1, wherein the control unit selects the sensing mode according to the number of retransmissions.

6. The communication device according to claim 1, wherein the control unit selects the sensing method based on the sensing result.

7. The communication device according to claim 6, wherein the control unit selects a first mode as the sensing mode when the frequency of busy activity is equal to or greater than a predetermined value as a result of the sensing.

8. The communication device according to claim 1, wherein the control unit selects the sensing mode according to instructions from other devices.

9. The communication device according to claim 1, wherein The communication unit communicates using one of a plurality of beams, and The control unit sets parameters related to the sensing for each of the plurality of beams.

10. The communication device according to claim 9, wherein the control unit divides the plurality of beams into one or more beam groups including at least one of the beams, and sets different parameters for each beam group.

11. A communication method executed by a terminal device, comprising: Sensing the channel in unlicensed frequency bands; Communication is based on the results of the sensing; and Depending on whether the presence of other communication devices using other radio access technologies has been detected, one of a first mode of sensing, which is performed a predetermined number of times within a variable time period, and a second mode different from the first mode, is selected as the sensing mode, such that if the presence of the other communication devices has been detected, one of the first mode and the second mode corresponding to the sensing mode applied by the other communication devices is selected as the sensing mode.

12. A computer-readable recording medium storing a program, which, when executed by a computer, causes the computer to perform: Sensing the channel in unlicensed frequency bands; Communication is based on the results of the sensing; and Depending on whether the presence of other communication devices using other radio access technologies has been detected, one of a first mode of sensing, which is performed a predetermined number of times within a variable time period, and a second mode different from the first mode, is selected as the sensing mode, such that if the presence of the other communication devices has been detected, one of the first mode and the second mode corresponding to the sensing mode applied by the other communication devices is selected as the sensing mode.

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