JP7733779B2 - communication equipment - Google Patents

Description

This disclosure relates to a communication device that performs wireless communication, and in particular to a communication device that performs carrier sensing before starting transmission.

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

3GPP Release 15 and Release 16 (NR) specify operation in bands that include multiple frequency ranges, specifically FR1 (410 MHz to 7.125 GHz) and FR2 (24.25 GHz to 52.6 GHz).

In addition, studies are underway on NR, which will support frequencies above 52.6 GHz and up to 71 GHz (Non-Patent Document 1). Furthermore, Beyond 5G, 5G Evolution, and 6G (Release-18 and later) aim to support frequency bands above 71 GHz.

"Study on supporting NR from 52.6 GHz to 71 GHz", RP-193259, 3GPP TSG RAN Meeting #86, 3GPP, December 2019

In unlicensed frequency bands, a process called Listen Before Talk (LBT) is used to perform carrier sensing before starting transmission. Examples of such LBT include Load Based Equipment (LBE) and Frame Based Equipment (FBE). In LBE, carrier sensing is performed according to demand until a carrier that does not interfere with other communication devices is found. In FBE, carrier sensing is performed at predetermined times within a fixed frame period. For example, FBE is applied when it is guaranteed that no communication methods other than those specified by 3GPP (such as WiFi) are present.

Against this background, the possibility of applying FBE processing to high frequency bands such as those above 52.6 GHz has not been considered. After careful consideration, the inventors have discovered the usefulness of applying FBE processing to a second frequency band higher than the first frequency band (e.g., a high frequency band above 52.6 GHz).

The following disclosure has been made in light of this situation, and aims to provide a communication device that can appropriately apply FBE processing in a second frequency band that is higher than the first frequency band.

One aspect of the present disclosure is a communications device comprising a control unit that executes a channel access procedure in an unlicensed frequency band that includes a first frequency band and a second frequency band higher than the first frequency band, and the control unit allows application of a first process that executes carrier sensing at a predetermined timing in a fixed frame period when a first condition is satisfied in the channel access procedure for the first frequency band, and executes a second process that executes carrier sensing at a predetermined timing in a fixed frame period when a second condition is satisfied in the channel access procedure for the second frequency band.

FIG. 1 is a diagram showing the overall configuration of a wireless communication system 10. FIG. 2 is a diagram illustrating the frequency ranges used in the wireless communication system 10. FIG. 3 is a diagram showing an example of the configuration of a radio frame, a subframe, and a slot used in the radio communication system 10. FIG. 4 is a functional block diagram of the communication device 300. FIG. 5 is a diagram for explaining the channel access procedure. FIG. 6 is a sequence diagram showing an example of operation. FIG. 7 is a sequence diagram showing an example of operation. FIG. 8 is a diagram for explaining a channel access procedure according to the first modification. FIG. 9 is a sequence diagram showing an example of operation according to the third modification. FIG. 10 is a diagram illustrating an example of the hardware configuration of the communication device 300.

Embodiments will be described below with reference to the drawings. Note that identical or similar reference symbols will be used to designate identical functions and configurations, and descriptions of these will be omitted where appropriate.

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

Note that the wireless communication system 10 may be a wireless communication system conforming to a standard known as Beyond 5G, 5G Evolution, or 6G.

NG-RAN 20 includes radio base station 100A (hereinafter, gNB100A) and radio base station 100B (hereinafter, gNB100B). Note that the specific configuration of wireless communication system 10, including the number of gNBs and UEs, is not limited to the example shown in Figure 1.

NG-RAN 20 actually includes multiple NG-RAN nodes, specifically gNBs (or ng-eNBs), and is connected to a 5G-compliant core network (5GC, not shown). Note that NG-RAN 20 and 5GC may also be simply referred to as the "network."

gNB100A and gNB100B are 5G-compliant radio base stations that perform 5G-compliant radio communication with UE200. gNB100A, gNB100B, and UE200 are capable of supporting Massive MIMO (Multiple-Input Multiple-Output), which generates a more directional beam (BM) by controlling radio signals transmitted from multiple antenna elements; Carrier Aggregation (CA), which aggregates and uses multiple component carriers (CCs); and Dual Connectivity (DC), which simultaneously communicates on two or more transport blocks between a UE and each of two NG-RAN nodes.

The wireless communication system 10 also supports multiple frequency ranges (FR). Figure 2 shows the frequency ranges used in the wireless communication system 10.

As shown in Figure 2, the wireless communication system 10 supports FR1 and FR2. The frequency bands for each FR are as follows:

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

Note that SCS may also be interpreted as numerology. Numerology is defined in 3GPP TS38.300 and corresponds to one subcarrier spacing in the frequency domain.

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

To solve these problems, when using bands above 52.6 GHz, Cyclic Prefix-Orthogonal Frequency Division Multiplexing (CP-OFDM)/Discrete Fourier Transform - Spread (DFT-S-OFDM) with larger Sub-Carrier Spacing (SCS) may be applied.

In addition to the frequency bands allocated for use by the wireless communication system 10, the wireless communication system 10 also uses unlicensed frequency bands Fu, which are different from the allocated frequency bands. Specifically, the wireless communication system 10 is capable of implementing New Radio-Unlicensed (NR-U), which expands the available frequency bands by using spectrum from unlicensed frequency bands.

The frequency bands allocated for the wireless communication system 10 are frequency bands included within frequency ranges such as FR1 and FR2 mentioned above, and are based on administrative license allocations.

Unlicensed frequency bands (Fu) are frequency bands that do not require government license allocation and can be used without being restricted to specific telecommunications carriers. Examples include frequency bands used for wireless LAN (WLAN) (such as the 2.4 GHz or 5 GHz bands).

In the unlicensed frequency band Fu, wireless stations can be installed regardless of the specific telecommunications carrier, but it is undesirable for signals from nearby wireless stations to interfere with each other and significantly degrade communication performance.

For this reason, in Japan, for example, a requirement for wireless systems using the unlicensed frequency band Fu (e.g., the 5 GHz band) is that the gNB100 performs carrier sensing before starting transmission, and only after confirming that the channel is not being used by other nearby systems is the Listen-Before-Talk (LBT) mechanism applied, which allows transmission within a specified period of time. Carrier sensing is a technology that checks whether a frequency carrier is being used for other communications before emitting radio waves.

The band for LBT in NR-U (LBT sub-band) can be provided within the unlicensed frequency band Fu and may be described as a band for checking whether or not the unlicensed frequency band Fu is in use. The LBT sub-band may be, for example, 20 MHz, half the size (10 MHz), or one-quarter the size (5 MHz).

In an embodiment, the unlicensed frequency band Fu includes a first frequency band (e.g., the 2.4 GHz band or the 5.0 GHz band) and a second frequency band higher than the first frequency band (e.g., the 60 GHz band). The first frequency band may be included in FR1. The second frequency band may be included in FR2x. Note that the unlicensed frequency band Fu shown in Figure 2 is merely an example.

Figure 3 shows an example of the configuration of radio frames, subframes, and slots used in the wireless communication system 10.

As shown in Figure 3, one slot consists of 14 symbols, and the larger (wider) the SCS, the shorter the symbol period (and slot period). The SCS is not limited to the interval (frequency) shown in Figure 3. For example, 480 kHz, 960 kHz, etc. may also be used.

Furthermore, the number of symbols that make up one slot does not necessarily have to be 14 symbols (e.g., 28 or 56 symbols). Furthermore, the number of slots per subframe may differ depending on the SCS.

Note that the time direction (t) shown in Figure 3 may also be referred to as the time domain, symbol period, or symbol time. The frequency direction may also be referred to as the frequency domain, resource block, subcarrier, or bandwidth part (BWP).

(2) Functional Block Configuration of Wireless Communication System Next, a functional block configuration of the wireless communication system 10 will be described. Specifically, a functional block configuration of the communication device 300 will be described. The communication device 300 may be a gNB 100 or a UE 200. As shown in FIG. 4 , the communication device 300 includes a communication unit 310 and a control unit 320.

The communication unit 310 performs communication using licensed frequency bands. Communication using licensed frequency bands includes communication using channels specified by 3GPP. The channels include control channels and data channels.

Control channels include DCCH (Physical Downlink Control Channel), PUCCH (Physical Uplink Control Channel), RACH (Random Access Channel), Downlink Control Information (DCI) including the Random Access Radio Network Temporary Identifier (RA-RNTI), and Physical Broadcast Channel (PBCH).

Data channels include PDSCH (Physical Downlink Shared Channel) and PUSCH (Physical Uplink Shared Channel). Data refers to data transmitted via a data channel. Data channel may also be interpreted as a shared channel.

The communication unit 310 performs communication using the unlicensed frequency band Fu. As described above, the unlicensed frequency band Fu includes a first frequency band and a second frequency band higher than the first frequency band. Communication using the unlicensed frequency band Fu may be used in conjunction with communication using a licensed frequency band. In other words, carriers in the licensed frequency band and carriers in the unlicensed frequency band Fu may be bundled together. Such technology may be referred to as LAA (Licensed-Assisted Access).

The control unit 320 controls the communication device 300. In an embodiment, the control unit 320 executes a channel access procedure in the unlicensed frequency band Fu. The channel access procedure includes a process of performing carrier sensing before starting transmission (hereinafter referred to as LBT; Listen Before Talk). Examples of LBT include LBE (Load Based Equipment) processing and FBE (Frame Based Equipment) processing. In LBE processing, carrier sensing is performed according to demand until a carrier that does not interfere with other communication devices is found. In FBE processing, carrier sensing is performed at predetermined timing within a fixed frame period.

Here, when a first condition is met in the channel access procedure for the first frequency band, the control unit 320 allows the application of a first process that performs carrier sensing at a predetermined timing in a fixed frame period. The first process is an example of FBE process. The first condition is that it is guaranteed that no other technology (e.g., WiFi) different from the wireless communication system 10 exists in the first frequency band. The control unit 320 may perform LBE process instead of FBE process even when the first condition is met.

On the other hand, when a second condition is met in the channel access procedure for the second frequency band, the control unit 320 executes a second process that performs carrier sensing at a predetermined timing in a fixed frame period. The second process is an example of FBE process. The second condition differs from the first condition. For example, the following conditions may be considered as the second condition.

First, the second condition may be that it is predetermined that FBE processing be applied as the channel access procedure for the second frequency band. For example, the second condition may be that a standard such as 3GPP specifies that FBE processing be applied as the channel access procedure for the second frequency band. In other words, FBE processing may be applied as the channel access procedure for the second frequency band, without LBE processing being applied.

Second, the second condition may be that it is confirmed that no other technology (e.g., WiFi) different from the wireless communication system 10 exists in the second frequency band. Here, the "confirmation" in the second condition is a different concept from the "guarantee" in the first condition, and may include a concept that the impact of other technologies is small. The second condition may be that it is notified that no other technology exists in the second frequency band. Such notification may be performed by the gNB100 or by an upper node of the gNB100 (e.g., OAM; Operation, Administration and Maintenance).

Third, the second condition may be that FBE processing is configured to be applied as a channel access procedure for the second frequency band. The application of FBE processing may be configured in the SIM, by the MAC CE, or by the RRC.

(3) Channel Access Procedure Next, the channel access procedure will be described, which is the FBE process described above.

As shown in Figure 5, a fixed frame period (FFP) is defined for FBE processing. For example, possible values for FFP are 1 ms, 2 ms, 2.5 ms, 4 ms, 5 ms, and 10 ms. In FBE processing, carrier sensing is performed at predetermined timing. The predetermined timing includes at least the timing immediately before the FFP. The predetermined timing may also include the timing immediately before the channel occupancy time (hereinafter referred to as COT).

Possible channel access procedures for FBE processing include Type 2A, Type 2B, and Type 2C. Type 2A is a processing in which the time interval (hereinafter referred to as the gap) between other transmissions and the target transmission is 25 μs. Type 2B is a processing in which the gap between other transmissions and the target transmission is 16 μs. Type 2C is a processing in which the gap between other transmissions and the target transmission is shorter than 16 μs. Type 2A and Type 2B are processing in which channel sensing is performed in the gap. Type 2C is a processing in which channel sensing is not performed in the gap. For example, Type 2C is used when sharing COT between the gNB100 and UE200 (e.g., §4.1.2 "Type 2 DL Channel access procedure" and §4.2.1.2 "Type 2 UL channel access procedure" of 3GPP TS37.213 V16.1.0).

For example, "A" in Figure 5 shows a case where LBT Idle is confirmed by Type 2A or Type 2B carrier sense, and downlink (DL) transmission is performed. "B" in Figure 5 shows a case where LBT Idle is confirmed by Type 2C carrier sense, and uplink (UL) transmission is performed. "C" and "D" in Figure 5 show cases where LBT Idle is confirmed by Type 2A or Type 2B carrier sense, and downlink (DL) and uplink (UL) transmission are performed. LBT Idle means that the channel is not occupied by another communication device 300. MCOT is the maximum channel occupation time.

"E" in Figure 5 shows a case where LBT Busy is confirmed by Type 2A or Type 2B carrier sense, and downlink (DL) and uplink (UL) transmission is performed. Note that LBT Busy means that the channel is occupied by another communication device 300.

"F" in Figure 5 shows a case where LBT Idle is confirmed by Type 2A or Type 2B carrier sense, and downlink (DL) transmission is performed. "G" in Figure 5 shows a case where uplink (UL) transmission is performed without performing carrier sense due to COT sharing.

Here, the content of the second process, which is FBE processing applied in the second frequency band (e.g., 60 GHz band), may be the same as the content of the first process, which is FBE processing applied in the first frequency band (e.g., 5 GHz band). For example, the same FFP as used in the first process may be used in the second process. In other words, the communication device 300 (control unit 320) may use the same FFP in the second process as the FFP in the first process.

(4) Operation Example An operation example of the channel access procedure for the second frequency band will be described below. Here, a case will be described in which the NG-RAN 20 (gNB 200) performs carrier sensing of the FBE process (Type 2A or Type 2B) before DL transmission, and the UE 200 performs carrier sensing of the FBE process (Type 2A or Type 2B) before UL transmission.

First, we will explain the case where it is predetermined that FBE processing will be applied as the channel access procedure for the second frequency band.

As shown in Figure 6, in step S10, NG-RAN 20 performs carrier sensing at a predetermined timing in the FFP.

In step S11, NG-RAN 20 performs DL transmission if the result of carrier sensing is LBT Idle. Note that NG-RAN 20 does not perform DL transmission if the result of carrier sensing is LBT Busy.

In step S12, UE200 performs carrier sensing at a predetermined timing in the FFP.

In step S13, UE200 performs UL transmission if the result of carrier sensing is LBT Idle. Note that UE200 does not perform UL transmission if the result of carrier sensing is LBT Busy.

Figure 6 illustrates a case in which it is predetermined that FBE processing is to be applied as a channel access procedure for the second frequency band. However, the sequence shown in Figure 6 may also be applied to a case in which it has been confirmed that no other technology exists in the second frequency band. The sequence shown in Figure 6 may also be applied to a case in which it has been notified that no other technology exists in the second frequency band.

Secondly, we will explain the case where FBE processing is configured to be applied as the channel access procedure for the second frequency band. In Figure 7, the same steps as in Figure 6 are assigned the same step numbers, so a description of the same processing as in Figure 6 will be omitted.

As shown in FIG. 7, in step S20, NG-RAN 20 transmits to UE 200 a setting to apply FBE processing as the channel access procedure for the second frequency band.

Figure 7 illustrates an example in which the FBE process is applied. However, the sequence shown in Figure 7 may also be applied to a case in which the LBE process is applied. In such a case, in step S20, the NG-RAN 20 transmits to the UE 200 a setting indicating that the LBE process is to be applied as the channel access procedure for the second frequency band. In steps S10 and S12, carrier sensing based on the LBE process may be performed. Carrier sensing based on the LBE process may be referred to as Type 1 (e.g., §4.1.1 "Type 1 DL Channel access procedure" and §4.2.1.1 "Type 1 UL channel access procedure" of 3GPP TS37.213 V16.1.0).

(5) Actions and Effects In the embodiment, attention is focused on a new finding that, while there is a high probability that other technologies (e.g., WiFi compliant with IEEE 802.11a/g/n) different from the wireless communication system 10 will coexist in the first frequency band, there is a low probability that other technologies (e.g., WiFi compliant with IEEE 802.11ad/ay) different from the wireless communication system 10 will coexist in the second frequency band. Based on this new finding, the communication device 300 performs FBE processing in a second frequency band of the unlicensed frequency band Fu that is higher than the first frequency band when a second condition different from the first condition for applying FBE processing in the first frequency band is satisfied. This configuration makes it possible to appropriately apply FBE processing in the second frequency band that is higher than the first frequency band.

[Modification 1]
The following describes a first modification of the embodiment, focusing on differences from the embodiment.

In the embodiment, the content of the second processing, which is FBE processing applied in the second frequency band (e.g., the 60 GHz band), may be the same as the content of the first processing, which is FBE processing applied in the first frequency band (e.g., the 5 GHz band). In contrast, in Modification Example 1, the content of the second processing, which is FBE processing applied in the second frequency band, differs from the content of the first processing, which is FBE processing applied in the first frequency band. For example, the second processing may use an FFP that is shorter than the FFP used in the first processing.

Specifically, as shown in Figure 8, the FFP of the second process applied in the second frequency band (lower row in Figure 8) is shorter than the FFP of the first process applied in the first frequency band (upper row in Figure 8). For example, the FFP of the first process may have values of 1 ms, 2 ms, 2.5 ms, 4 ms, 5 ms, and 10 ms. In contrast, the FFP of the second process may have values of 0.5 ms, 1 ms, 1.25 ms, 2 ms, 2.5 ms, and 5 ms.

As described above, the communication device 300 (control unit 320) may use an FFP in the second process that is shorter than the FFP in the first process.

In such a case, the FFP used in the second process may be predetermined. Alternatively, the FFP used in the second process may be a value obtained by scaling the FFP used in the first process by a scaling factor α. The scaling factor α may be a predetermined value, a value set in the SIM, a value set by the MAC CE or RRC, or a value associated with the SCS.

In Modification Example 1, attention is paid to the fact that the SCS of the second frequency band is wider (larger) than the SCS of the first frequency band. Based on this attention, early channel access can be achieved by making the FFP used in the second frequency band shorter than the FFP used in the first frequency band.

[Modification 2]
The second modification of the embodiment will be described below, focusing on differences from the first embodiment.

In Modification Example 2, the communication device 300 performs carrier sensing on a frequency (e.g., LBT sub-band) basis in the first process applied in the first frequency band. In contrast, the communication device 300 may perform carrier sensing on a beam basis in the second process applied in the second frequency band.

In Modification Example 2, we focus on the fact that in the second frequency band, which is higher than the first frequency band, a large bandwidth and large propagation loss can be accommodated by using a massive antenna with many antenna elements to generate a narrower beam. Based on this focus, by performing carrier sense on a beam basis, it is possible to achieve CCA (Clear Channel Assessment) that is in line with the actual transmission beam. Furthermore, it is possible to suppress interference with other communication devices 300, thereby providing more transmission opportunities.

[Modification 3]
The third modification of the embodiment will be described below, focusing on differences from the first embodiment.

The second condition includes a condition that the UE 200 that can constitute the communication device 300 has the capability to perform the second process. In such a case, the UE 200 transmits an information element indicating whether or not it has the capability to perform the second process to the NG-RAN 20 (gNB 100) as an information element included in the UE Capability.

For example, as shown in FIG. 9, in step S30, UE200 transmits a capability to NG-RAN20 indicating that it has the capability to perform the second process. In FIG. 9, the same steps as in FIG. 6 are assigned the same step numbers, so a description of the same processes as in FIG. 6 will be omitted.

Figure 9 illustrates an example of a case in which UE200 has the capability to perform the second process. However, the sequence shown in Figure 9 may also be applied to a case in which UE200 does not have the capability to perform the second process. In such a case, in step S30, UE200 transmits a capability to NG-RAN20 indicating that UE200 does not have the capability to perform the second process. When notification or configuration has been made to apply the second process (FBE process) in the second frequency band, and UE200 does not have the capability to perform the second process, communication using the second frequency band does not need to be performed.

In Modification Example 3, a case where the ability of UE200 to perform the second process is an optional feature has been illustrated. However, the ability of UE200 to perform the second process may also be a mandatory feature. In such a case, the processing of S30 shown in FIG. 9 may be omitted.

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

In the embodiments, the case where FBE processing is applied in the channel access procedure for a second frequency band higher than the first frequency band has been mainly described. However, the embodiments are not limited to this. For example, in cases where it has not been confirmed that other technologies do not exist in the second frequency band, where it has not been notified that other technologies do not exist in the second frequency band, or where it has not been configured to apply FBE processing as the channel access procedure for the second frequency band, processing other than FBE processing may be applied in the channel access procedure for the two frequency bands. Processing other than FBE processing may include LBE processing and ATPC (Automatic Transmission Power Control).

The block diagram (Figure 4) used to explain the above-mentioned embodiment shows functional blocks. These functional blocks (components) are realized by any combination of hardware and/or software. Furthermore, there are no particular limitations on how each functional block is realized. That is, each functional block may be realized using a single device that is physically or logically coupled, or may be realized using two or more physically or logically separated devices that are connected directly or indirectly (e.g., using a wired or wireless connection) and these multiple devices. A functional block may also be realized by combining software with the single device or multiple devices.

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

Furthermore, the above-described communication device 300 (the device) may function as a computer that performs processing of the wireless communication method of the present disclosure. Figure 10 is a diagram showing an example of the hardware configuration of the device. As shown in Figure 10, the device may be configured as a computer device including a processor 1001, memory 1002, storage 1003, a communication device 1004, an input device 1005, an output device 1006, and a bus 1007.

In the following explanation, the term "apparatus" can be interpreted as a circuit, device, unit, etc. The hardware configuration of the apparatus may be configured to include one or more of the devices shown in the diagram, or may be configured to exclude some of the devices.

Each functional block of the device (see Figure 4) is realized by one of the hardware elements of the computer device, or a combination of those hardware elements.

Furthermore, each function of the device is realized by loading specific software (programs) onto hardware such as the processor 1001 and memory 1002, causing the processor 1001 to perform calculations, control communications via the communication device 1004, and control at least one of reading and writing data from and to the memory 1002 and storage 1003.

The processor 1001, for example, runs an operating system to control the entire computer. The processor 1001 may be configured as a central processing unit (CPU) that includes interfaces with peripheral devices, a control unit, an arithmetic unit, registers, etc.

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

Memory 1002 is a computer-readable recording medium and may be composed of, for example, at least one of Read Only Memory (ROM), Erasable Programmable ROM (EPROM), Electrically Erasable Programmable ROM (EEPROM), Random Access Memory (RAM), etc. Memory 1002 may also be called a register, cache, main memory (primary storage device), etc. Memory 1002 can store a program (program code), software module, etc. that can execute a method according to one embodiment of the present disclosure.

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

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

The communication device 1004 may be configured to include high-frequency switches, duplexers, filters, frequency synthesizers, etc. to realize, for example, at least one of Frequency Division Duplex (FDD) and Time Division Duplex (TDD).

The input device 1005 is an input device (e.g., a keyboard, mouse, microphone, switch, button, sensor, etc.) that accepts input from the outside. The output device 1006 is an output device (e.g., a display, speaker, LED lamp, etc.) that outputs to the outside. Note that the input device 1005 and the output device 1006 may be integrated into one device (e.g., a touch panel).

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

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

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

Each aspect/embodiment described in this disclosure may be applied to at least one of systems using Long Term Evolution (LTE), LTE-Advanced (LTE-A), SUPER 3G, IMT-Advanced, 4th generation mobile communication system (4G), 5th generation mobile communication system (5G), Future Radio Access (FRA), New Radio (NR), W-CDMA (registered trademark), GSM (registered trademark), CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, Ultra-WideBand (UWB), Bluetooth (registered trademark), or other suitable systems, and next-generation systems enhanced based on these. Furthermore, multiple systems may be combined (e.g., a combination of at least one of LTE and LTE-A with 5G).

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

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

Information, signals (information, etc.) can be output from a higher layer (or lower layer) to a lower layer (or higher layer). They may also be input and output via multiple network nodes.

Input and output information may be stored in a specific location (e.g., memory) or managed using a management table. Input and output information may be overwritten, updated, or appended. Output information may be deleted. Input information may be sent to another device.

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

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

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

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

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

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

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

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

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

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

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

The terms "cell" or "sector" refer to part or all of the coverage area of a base station and/or base station subsystem that provides communication services within that coverage area.

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

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

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

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

Similarly, the mobile station in this disclosure may be interpreted as a base station. In this case, the base station may be configured to have the functions of a mobile station.

A radio frame may be composed of one or more frames in the time domain. Each of the one or more frames in the time domain may be called a subframe.

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

Numerology may be a communication parameter that applies to at least one of the transmission and reception of a signal or channel. Numerology may indicate, for example, at least one of the following: subcarrier spacing (SCS), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI), number of symbols per TTI, radio frame structure, specific filtering operations performed by the transceiver in the frequency domain, and specific windowing operations performed by the transceiver in the time domain.

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

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

Radio frame, subframe, slot, minislot, and symbol all represent time units for transmitting signals. Other names may also be used for radio frame, subframe, slot, minislot, and symbol.

For example, one subframe may be called a transmission time interval (TTI), multiple consecutive subframes may be called a TTI, or one slot or one minislot may be called a TTI. In other words, at least one of the subframe and the TTI may be a subframe (1 ms) in existing LTE, a period shorter than 1 ms (e.g., 1-13 symbols), or a period longer than 1 ms. Note that the unit used to express the TTI may be called a slot, minislot, etc., instead of a subframe.

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

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

Note that when one slot or one minislot is referred to as a TTI, one or more TTIs (i.e., one or more slots or one or more minislots) may be the smallest time unit for scheduling. Furthermore, the number of slots (minislots) that make up the smallest time unit for scheduling may be controlled.

A TTI with a time length of 1 ms may be referred to as a regular TTI (TTI in LTE Rel. 8-12), normal TTI, long TTI, regular subframe, normal subframe, long subframe, slot, etc. A TTI shorter than a regular TTI may be referred to as a shortened TTI, short TTI, partial TTI (partial or fractional TTI), shortened subframe, short subframe, minislot, subslot, slot, etc.

Note that a long TTI (e.g., a normal TTI, subframe, etc.) may be interpreted as a TTI having a time length of more than 1 ms, and a short TTI (e.g., a shortened TTI, etc.) may be interpreted as a TTI having a TTI length of 1 ms or more but less than the TTI length of a long TTI.

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

Furthermore, the time domain of an RB may include one or more symbols and may be one slot, one minislot, one subframe, or one TTI in length. One TTI, one subframe, etc. may each be composed of one or more resource blocks.

Note that one or more RBs may also be referred to as a physical resource block (PRB), a sub-carrier group (SCG), a resource element group (REG), a PRB pair, an RB pair, etc.

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

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

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

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

The structures of the radio frames, subframes, slots, minislots, and symbols described above are merely examples. For example, the number of subframes included in a radio frame, the number of slots per subframe or radio frame, the number of minislots included in a slot, the number of symbols and RBs included in a slot or minislot, the number of subcarriers included in an RB, as well as the number of symbols within a TTI, the symbol length, and the cyclic prefix (CP) length can be varied in various ways.

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

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

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

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

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

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

In this disclosure, where articles are added by translation, such as a, an, and the in English, this disclosure may include the noun following these articles being plural.

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

In this disclosure, the term "A and B are different" may mean "A and B are different from each other." It should be noted that the term may also mean "A and B are each different from C." Terms such as "separate" and "combined" may also be interpreted in the same way as "different."

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

10. Wireless communication systems
20 NG-RAN
100 gNB
200 UE
300 Communication Equipment
310 Communications Department
320 Control Unit
1001 processor
1002 memory
1003 Storage
1004 Communication equipment
1005 Input Device
1006 Output Device
1007 Bus

Claims (3)

a communication unit that communicates using an unlicensed frequency band including a first frequency band and a second frequency band that is a frequency band higher than the first frequency band;
a control unit that performs carrier sense at a fixed frame period using the unlicensed frequency band;
Equipped with
The control unit
performing the carrier sense using the first frequency band when a first condition is satisfied, and performing the carrier sense using the second frequency band when a second condition different from the first condition is satisfied ;
performing the carrier sense using the second frequency band at a fixed frame period that is shorter than that of the carrier sense using the first frequency band;
Communication equipment. the control unit performs the carrier sense using the second frequency band on a beam basis.
The communication device according to claim 1 . the second condition includes a condition that a terminal constituting the communication device has the capability to perform the carrier sense using the second frequency band.
The communication device according to claim 1 .