Visible light communication device, communication system, and communication method

Abstract

This invention provides a visible light communication device, communication system, and communication method that can improve the throughput of deep learning (DL) using VLC while applying a wireless communication network to relay between VLC APs. [Solution] The visible light communication device performs visible light communication using visible light communication signals. The visible light communication device comprises a wireless signal receiving unit that receives wireless communication signals from multiple upstream communication devices via a wireless communication network using radio waves, and a terminal-side visible light transmitting unit that transmits visible light communication signals to a terminal. The wireless signal receiving unit connects to a specific upstream communication device and receives wireless communication signals depending on the communication status with the multiple upstream communication devices.

Description

Technical Field

[0005]

[0001] The present disclosure relates to a visible light communication device, a communication system, and a communication method that support VLC.

Background Art

[0002] Visible Light Communication (VLC) is a technology that transmits information using visible light. VLC is a form of wireless communication that does not use an optical fiber or the like, and data can be transmitted and received using a lighting device such as an LED light. VLC enables extremely broadband and high-speed (for example, exceeding 100 Gbps) communication even when compared with wireless communication using radio waves (electromagnetic waves in the frequency range of 3 Hz to 3000 GHz).

[0003] Therefore, application of VLC to a mobile communication network, which is a wireless network for performing voice calls and data communication using a mobile device such as a mobile phone or a smartphone, has been explored (Non-Patent Documents 1 to 3). For example, a configuration combining a downlink (DL) by VLC and an uplink (UL) by infrared communication (IR) is known.

[0004] Further, for example, applying VLC to DL and relaying between a plurality of VLC access points (APs) via a wireless communication network using radio waves (for example, a mobile communication network or a wireless LAN (Local Area Network, Wi-Fi (registered trademark), etc.)) is also conceivable.

Prior Art Documents

Non-Patent Documents

[0005]

Non-Patent Document 1

[0006] However, because VLC is extremely wideband and high-speed compared to wireless communication networks, applying the aforementioned wireless communication network for relaying between VLC APs raises concerns that bandwidth (communication speed) will be limited, thus restricting the download throughput to terminals (User Equipment, UE) via VLC.

[0007] Therefore, the following disclosure is made in light of these circumstances and aims to provide a visible light communication device, communication system, and communication method that can improve the throughput of DL by VLC while applying a wireless communication network to relay between VLC APs. [Means for solving the problem]

[0008] One aspect of the present disclosure is a visible light communication device (VLC-AP 100) that performs visible light communication using visible light communication signals, comprising: a radio signal receiving unit (radio signal receiving unit 110) that receives radio communication signals from a plurality of upstream communication devices (radio base stations 50) via a radio communication network using radio waves; and a terminal-side visible light transmitting unit (terminal-side visible light transmitting unit 130) that transmits the visible light communication signals to a terminal, wherein the radio signal receiving unit connects to a specific upstream communication device and receives the radio communication signals depending on the communication status with the plurality of upstream communication devices.

[0009] One aspect of the present disclosure is an upstream communication device (wireless base station 50) provided upstream of a visible light communication device (VLC-AP 100) that performs visible light communication with a terminal using visible light communication signals, the upstream communication device comprising a wireless signal transmitting unit (wireless signal transmitting unit 51) that transmits wireless communication signals using radio waves toward the visible light communication device, and a terminal-side wireless communication unit (terminal-side wireless communication unit 53) that transmits and receives wireless communication signals with the terminal, wherein the wireless signal transmitting unit connects to the visible light communication device and transmits the wireless communication signals according to the communication status with the upstream communication device. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a schematic diagram of the overall configuration of the communication system 10. [Figure 2] Figure 2 shows an example of a connection configuration between multiple wireless base stations 50 and a VLC-AP 100. [Figure 3] Figure 3 is a functional block diagram of the VLC-AP 100. [Figure 4]Figure 4 is a functional block diagram of the wireless base station 50. [Figure 5] Figure 5 shows an example sequence of events leading up to the start of visible light communication in the DL direction via the wireless base station 50 and VLC-AP 100. [Figure 6] Figure 6 shows an example of the hardware configuration of the wireless base station 50 and the VLC-AP 100. [Modes for carrying out the invention]

[0011] The embodiments will be described below with reference to the drawings. Note that identical or similar reference numerals are used to denote the same functions and components, and their descriptions will be omitted as appropriate.

[0012] (1) Overall outline of the communication system Figure 1 is a schematic diagram of the overall configuration of the communication system 10 according to this embodiment. The communication system 10 uses a combination of Visible Light Communication (VLC) and radio wave wireless communication technologies. VLC is a form of wireless communication that does not use optical fibers or the like, and can send and receive data using lighting devices such as LED lights. In particular, the VLC according to this embodiment can achieve a high transmission speed (data rate), and enables extremely wideband and high-speed communication (for example, over 100 Gbps) compared to wireless communication using radio waves (electromagnetic waves with frequencies in the range of 3 Hz to 3000 GHz).

[0013] The visible light used in VLCs generally refers to light with wavelengths ranging from approximately 380 nanometers (nm) to 750 nanometers (nm), which corresponds to the range of light visible to the human eye. Visible light does not need to include ultraviolet or infrared light.

[0014] Wireless communication using radio waves can typically be interpreted as wireless communication that utilizes a mobile communication network, which is a wireless network for voice calls and data communication using mobile devices such as mobile phones and smartphones. The mobile communication network may also be referred to as a mobile communication network, a Public Land Mobile Network (PLMN), etc. The frequency bands used by the mobile communication network include a low frequency band: 600 MHz to 1 GHz, a medium frequency band: 3.5 GHz to 4.7 GHz, a high frequency band (millimeter wave): 24 GHz to 40 GHz band, etc. The mobile communication network may conform to the technical specifications of the 3rd Generation Partnership Project (3GPP: registered trademark) such as 4G (LTE), 5G or 6G.

[0015] Note that the wireless network using radio waves does not necessarily have to be a mobile communication network. For example, a network conforming to the technical specifications of other wireless communications such as a wireless LAN (Wi-Fi (registered trademark)) may be used.

[0016] As shown in FIG. 1, the communication system 10 includes a communication network 20. The communication network 20 may include a part of the above-described mobile communication network, and may further include other wireless networks and wired networks.

[0017] The communication system 10 may include a CCU 30 and a radio base station 50 as entities on the mobile communication network side (which may also be called nodes, etc.). The CCU 30 (Central Control Unit) is one of the control elements of the mobile communication network and may also be called a communication control device. The CCU 30 has a function of controlling the mobile communication network (which may include radio resource management (RRM)) and may be realized by an entity (which may also be a Function) constituting a radio access network (RAN) or a core network (CN).

[0018] The radio base station 50 performs wireless communication using radio waves with the terminal 200 (User Equipment 200, hereinafter referred to as UE 200). The radio base station 50 may be called a gNodeB (gNB), an access point (AP), etc. Note that the radio base station 50 may be called a radio access point from the perspective of distinguishing it from the VLC-AP 100.

[0019] The radio base station 50 may support Massive MIMO (Multiple-Input Multiple-Output, mMIMO) that generates a more directional beam by controlling wireless signals transmitted from a plurality of antenna elements, carrier aggregation (CA) that bundles and uses a plurality of component carriers (CC), etc.

[0020] The communication system 10 may include a router 60 and a VLC-AP 100 as VLC-side entities. The router 60 can perform routing, priority control, etc. of packets transmitted and received by the VLC-AP 100. Note that depending on the network configuration, the router 60 may not necessarily be provided.

[0021] The CCU 30 and the router 60 (or the VLC-AP 100) may be directly connected by an optical fiber 40. Of course, the CCU 30 and the router 60 can also communicate via the communication network 20.

[0022] The VLC-AP 100 is an access point (AP) for visible light communication. The VLC-AP 100 can perform visible light communication using a visible light communication signal using visible light toward the UE 200. Thus, the VLC-AP 100 supports visible light communication in the downlink (DL) direction. On the other hand, the mobile communication network (CCU 30 and radio base station 50) may support wireless communication using radio waves in the uplink (UL) and DL directions.

[0023] Furthermore, the VLC-AP 100 may support wireless communication using radio waves. For example, the VLC-AP 100 may send and receive wireless communication signals with the radio base station 50 via a wireless communication network using radio waves. Figure 2 shows an example of a connection configuration between multiple radio base stations 50 and the VLC-AP 100. As shown in Figure 2, the VLC-AP 100 may be connected to multiple upstream radio base stations 50 (#1 to #3). In this embodiment, the radio base station 50 may constitute an upstream communication device provided upstream of the VLC-AP 100 (visible light communication device).

[0024] Multiple wireless base stations 50 may be connected by a wireless communication network. This wireless communication network is assumed to be a mobile communication network, but it may also be a wireless LAN (Wi-Fi®). Any (e.g., #1) or all of the multiple wireless base stations 50 may be connected to the CCU 30.

[0025] The wireless base station 50 connected to the VLC-AP 100 may consist of a CU (Central Unit) and a DU (Distributed Unit), where the DU may be located separately from the CU at a geographically different location. The VLC-AP 100 may be connected to the DU or to the CU.

[0026] The UE 200, also known as user equipment or user device, is a mobile device that can be moved. The UE 200 may be a portable terminal or an IoT (Internet of Things) device such as an in-vehicle terminal.

[0027] The UE 200 has wireless communication capabilities via a mobile communication network, as well as visible light communication capabilities using VLC. Specifically, the UE 200 can transmit and receive radio signals using radio waves via the radio base station 50. In other words, the UE 200 may support DL and UL communication via a mobile communication network.

[0028] Furthermore, the UE 200 can receive visible light communication signals via the VLC-AP 100. In other words, the UE 200 can support DL-direction communication via VLC. Note that the UE 200 (and VLC-AP 100) may also support UL-direction VLC communication, but in this embodiment, it is assumed that UL-direction communication will utilize a mobile communication network.

[0029] (2) Functional block configuration of the communication system 10 Next, the functional block configuration of the communication system 10 will be described. Specifically, the functional block configurations of the wireless base station 50 and the VLC-AP 100 will be described. Figure 3 is a functional block configuration diagram of the VLC-AP 100. Figure 4 is a functional block configuration diagram of the wireless base station 50. Note that Figures 3 and 4 only show the main functional blocks related to the description of the embodiment, and the wireless base station 50 and VLC-AP 100 have other functional blocks (for example, a power supply unit). For convenience, the functional block configuration of the VLC-AP 100 will be described below.

[0030] (2.1) VLC-AP 100 As shown in Figure 3, the VLC-AP 100 comprises the VLC-AP 100 unit, a wireless signal receiving unit 110, a terminal-side visible light transmitting unit 130, and a control unit 140.

[0031] The wireless signal receiving unit 110 receives wireless communication signals via a wireless communication network using radio waves. Specifically, the wireless signal receiving unit 110 may receive wireless communication signals from multiple wireless base stations 50 (upstream communication devices). Alternatively, the wireless signal receiving unit 110 may receive wireless communication signals from a relay device that relays wireless communication signals (for example, a Reconfigurable Intelligent Surface (RIS), Integrated Access and Backhaul (IAB) node) instead of a wireless base station 50.

[0032] The wireless signal receiving unit 110 may connect to a specific wireless base station 50 and receive wireless communication signals depending on the communication status with multiple wireless base stations 50. The specific wireless base station 50 may be one or more. For example, the wireless signal receiving unit 110 may connect to a wireless base station 50 whose load state is below a predetermined threshold. Alternatively, the quality of the wireless link between the wireless base station 50 and the VLC-AP 100 may be used as the criterion. The destination wireless base station 50 may be determined according to control information from the CCU 30 or the wireless base station 50. The load state of the wireless base station 50 may be based on the number of UE 200 connections, the amount of traffic (communication volume) to be processed, the CPU utilization rate, etc.

[0033] Thus, the wireless signal receiving unit 110 may connect to a specific wireless base station 50 (upstream communication device) based on instructions from the CCU 30 (communication control unit). Alternatively, the wireless signal receiving unit 110 may connect to a wireless base station 50 with low communication volume based on instructions from the CCU 30.

[0034] The terminal-side visible light transmitter 130 transmits a visible light communication signal to the UE 200. Specifically, the terminal-side visible light transmitter 130 acquires DL direction data (which may include user data of the user plane and control data of the control plane) contained in the wireless communication signal received by the wireless signal receiver 110, and transmits a visible light communication signal modulated with this data in the visible light band to the UE 200.

[0035] The visible light communication signal is not particularly limited as long as it uses the wavelengths described above, but in this embodiment, it is desirable that the VLC can achieve wireless communication with extremely wide bandwidth and high speed (e.g., over 100 Gbps) compared to the transmission speed achievable by mobile communication networks.

[0036] As mentioned above, the coverage of visible light communication signals is generally significantly narrower than the coverage of the cell (beam) formed by the radio base station 50. The radio signal receiving unit 110 often transmits visible light communication signals using a single visible light communication element, but it may also transmit visible light communication signals using multiple visible light communication elements.

[0037] The control unit 140 controls each functional block that constitutes the VLC-AP 100. Specifically, the control unit 140 may control the wireless signal receiving operation by the wireless signal receiving unit 110 and the visible light communication signal transmission operation by the terminal-side visible light transmitting unit 130.

[0038] For example, the control unit 140 may determine the destination radio base station 50 according to control information from the CCU 30 or the radio base station 50, and control the radio signal receiving unit 110 so that it can receive radio communication signals from the determined radio base station 50. Alternatively, the control unit 140 may control the on / off status and directionality of the transmission of visible light communication signals according to control information from the CCU 30.

[0039] (2.2) Wireless base station 50 As shown in Figure 4, the wireless base station 50 includes a wireless signal transmission unit 51, a terminal-side wireless communication unit 53, a network connection unit 55, and a control unit 57.

[0040] The wireless signal transmission unit 51 transmits a wireless communication signal using radio waves to the VLC-AP 100. Specifically, the wireless signal transmission unit 51 may transmit a wireless communication signal in accordance with the specifications of a mobile communication network. However, as mentioned above, wireless LAN (Wi-Fi®) or the like may be applied.

[0041] The wireless signal transmission unit 51 may connect to the VLC-AP 100 and transmit a wireless communication signal depending on the communication status with the wireless base station 50. Specifically, the wireless signal transmission unit 51 may connect to the VLC-AP 100 and transmit a wireless communication signal based on instructions from the CCU 30. The communication status with the wireless base station 50 may refer to the load status of the wireless base station 50, or the quality of the wireless link between the wireless base station 50 and the VLC-AP 100, as described above.

[0042] The terminal-side wireless communication unit 53 transmits and receives wireless communication signals with the UE 200. Specifically, the terminal-side wireless communication unit 53 may transmit and receive wireless communication signals with the UE 200 in accordance with the specifications of the mobile communication network.

[0043] The terminal-side wireless communication unit 53 may suspend the transmission and reception of wireless communication signals with the UE 200 if the wireless resources required by the wireless signal transmission unit 51 are insufficient. Specifically, if the terminal-side wireless communication unit 53 is also performing wireless communication with the UE 200, and the wireless resources (which may be interpreted as processing capacity or throughput, etc.) required for wireless communication between the wireless base station 50 and the VLC-AP 100 are insufficient, the terminal-side wireless communication unit 53 may suspend wireless communication with the UE 200. Alternatively, the terminal-side wireless communication unit 53 may terminate wireless communication with the UE 200 and prompt the UE 200 to reconnect.

[0044] The network connection unit 55 provides a function to connect to the communication network 20. Specifically, the network connection unit 55 can connect to the communication network 20 via the CCU 30. The network connection unit 55 may also provide a function to connect to other wireless base stations 50. Specifically, the network connection unit 55 may connect to other wireless base stations 50 via a wired interface or a wireless interface.

[0045] The control unit 57 controls each functional block that constitutes the other wireless base station 50. Specifically, the control unit 57 may control the transmission and reception of wireless communication signals by the wireless signal transmission unit 51 and the terminal-side wireless communication unit 53, and the connection with the communication network 20 (or other wireless base station 50) by the network connection unit 55.

[0046] (3) Operation of the communication system 10 Next, the operation of the communication system 10 will be described. Specifically, the operation of resource allocation for visible light communication in the DL direction via the wireless base station 50 and VLC-AP 100 will be described.

[0047] (3.1) Operation overview As shown in Figure 2, each of the multiple radio base stations 50 located upstream of the VLC-AP 100 may tally the number of UEs 200 connected to that radio base station 50 and report it to the CCU 30 (or a specific radio base station 50).

[0048] The CCU 30 may assign a radio base station 50 with available radio resources to wireless communication with the VLC-AP 100 based on the communication status (load status, etc.) of multiple radio base stations 50. Here, multiple radio base stations 50 may be assigned to this wireless communication, and by bundling the radio resources between the radio base stations 50 and the VLC-AP 100, broadband, high-speed visible light communication is supported. In addition, mMIMO may be applied to the wireless communication between the radio base stations 50 and the VLC-AP 100.

[0049] If the radio resources between the radio base station 50 and the VLC-AP 100 cannot meet the throughput required for visible light communication in the DL direction, the radio base station 50 may disconnect the radio link with a particular UE 200 and reallocate the radio resources reserved for that radio link to the radio resources between the radio base station 50 and the VLC-AP 100.

[0050] Furthermore, the wireless base station 50 may disconnect wireless links with low throughput (communication capacity). The UE 200 to be disconnected may be determined by scheduling to ensure fairness among the UE 200s. This can ensure the throughput necessary for visible light communication in the DL direction while reducing the impact on wireless communication with the UE 200. In addition, applying a distributed mMIMO transmission scheme between the wireless base station 50 and the VLC-AP 100 can contribute to improving the efficiency of frequency utilization.

[0051] (3.2) Example of operation Figure 5 shows an example sequence of events leading up to the start of visible light communication in the DL direction via the wireless base station 50 and VLC-AP 100. As shown in Figure 5, UE 200 may receive a visible light communication signal from VLC-AP 100. Here, it is assumed that UE 200 is located within the communication area (coverage) of the visible light communication signal transmitted by VLC-AP 100. VLC-AP 100 may periodically transmit a visible light communication signal that includes its identification number.

[0052] UE 200 receives the visible light communication signal and measures the received power and SNR, etc. If the reception status of the visible light communication signal satisfies predetermined conditions (for example, if the quality of the visible light communication signal is above a predetermined threshold), UE 200 transmits a VLC communication request, including the identification number of VLC-AP 100, to CCU 30 using UL via the radio base station 50 (Radio AP).

[0053] Based on the VLC communication request received from the UE 200, the CCU 30 performs coordination with a plurality of radio base stations 50 located upstream of the VLC-AP 100 associated with the identification number. This coordination may include, as described above, reporting the number of UEs 200 connected to the radio base stations 50, determining which radio base stations 50 can connect to the VLC-AP 100, and securing radio resources between the radio base stations 50 and the VLC-AP 100 based on the communication status (load status, etc.) of the radio base stations 50.

[0054] Furthermore, if the radio resources between the radio base station 50 and the VLC-AP 100 cannot meet the throughput required for visible light communication in the DL direction, as described above, in the coordination, the radio base station 50 may disconnect the radio link with a specific UE 200 and reallocate the radio resources that were reserved for that radio link to the radio resources between the radio base station 50 and the VLC-AP 100.

[0055] Furthermore, the CCU 30 may instruct the relevant radio base station 50 to establish a wireless link (DL) with the VLC-AP 100, and instruct the VLC-AP 100 to transmit DL using VLC. The transmission path for DL ​​data may go through the CCU 30, or it may bypass the CCU 30 and go through the communication network 20, multiple radio base stations 50, and the VLC-AP 100.

[0056] (4) Other embodiments Although embodiments have been described above, it will be obvious to those skilled in the art that the invention is not limited to those embodiments described and that various modifications and improvements are possible.

[0057] For example, in the above description, configure, activate, update, indicate, enable, specify, and select may be interpreted as interchangeable. Similarly, link, associate, correspond, and map may be interpreted as interchangeable, and allocate, assign, monitor, and map may also be interpreted as interchangeable.

[0058] Furthermore, "specific," "dedicated," "UE specific," and "UE individual" may be interpreted interchangeably. Similarly, "common," "shared," "group-common," "UE common," and "UE shared" may be interpreted interchangeably.

[0059] In this disclosure, terms such as "precoding," "precoder," "weight (precoding weight)," "quasi-co-location (QCL)," "transmission configuration indication state (TCI state)," "spatial relation," "spatial domain filter," "transmit power," "phase rotation," "antenna port," "antenna port group," "layer," "number of layers," "rank," "resource," "resource set," "resource group," "beam," "beam width," "beam angle," "antenna," "antenna element," and "panel" may be used interchangeably.

[0060] Furthermore, the block diagrams (Figures 3 and 4) used in the description of the embodiments above show functional units. These functional blocks (components) are realized by any combination of at least one of hardware and software. Moreover, the method of realizing each functional block is not particularly limited. That is, each functional block may be realized using one device that is physically or logically coupled, or it may be realized using two or more physically or logically separated devices that are directly or indirectly connected (for example, using wired or wireless connections). A functional block may also be realized by combining the above one device or the above multiple devices with software.

[0061] Functions include, but are not limited to, judgment, decision, judgment, calculation, calculation, processing, derivation, investigation, exploration, confirmation, reception, transmission, output, access, resolution, selection, selection, establishment, comparison, assumption, expectation, assumption, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating (mapping), and assigning. For example, a functional block (configuration part) that enables transmission is called a transmitting unit or transmitter. In any case, as mentioned above, the method of implementation is not particularly limited.

[0062] Furthermore, the aforementioned wireless base station 50 and VLC-AP 100 (the device) may function as a computer that processes the wireless communication method of this disclosure. Figure 6 shows an example of the hardware configuration of the device. As shown in Figure 6, the device may be configured as a computer device including a processor 1001, memory 1002, storage 1003, communication device 1004, input device 1005, output device 1006, and bus 1007.

[0063] In the following explanation, the term "device" can be replaced with "circuit," "device," "unit," etc. The hardware configuration of the device may include one or more of the devices shown in the diagram, or it may be configured to omit some of the devices.

[0064] Each functional block of the device (see Figures 3 and 4) is implemented by any hardware element of the computer device, or a combination of such hardware elements.

[0065] Furthermore, each function in the device is realized by loading predetermined software (programs) onto hardware such as the processor 1001 and memory 1002, which allows the processor 1001 to perform calculations, control communication by the communication device 1004, and control at least one of data reading and writing in the memory 1002 and storage 1003.

[0066] The processor 1001 controls the entire computer, for example, by running an operating system. The processor 1001 may consist of a central processing unit (CPU) that includes interfaces with peripheral devices, control units, arithmetic units, registers, and so on.

[0067] Furthermore, the processor 1001 reads programs (program code), software modules, data, etc., from at least one of the storage 1003 and the communication device 1004 into the memory 1002 and executes various processes accordingly. The program used is one that causes the computer to execute at least a part of the operations described in the above embodiment. Moreover, the above-mentioned various processes may be executed by one processor 1001, or by two or more processors 1001 simultaneously or sequentially. The processor 1001 may be implemented by one or more chips. The program may be transmitted from a network via a telecommunications line.

[0068] Memory 1002 is a computer-readable recording medium and may consist of at least one of the following: Read Only Memory (ROM), Erasable Programmable ROM (EPROM), Electrically Erasable Programmable ROM (EEPROM), Random Access Memory (RAM), etc. Memory 1002 may also be called a register, cache, main memory, etc. Memory 1002 can store a program (program code), software modules, etc., that can execute a method according to one embodiment of this disclosure.

[0069] Storage 1003 is a computer-readable recording medium and may consist of at least one of the following: an optical disc such as a Compact Disc ROM (CD-ROM), a hard disk drive, a flexible disk, a magneto-optical disk (e.g., a compact disc, a digital multipurpose disc, a Blu-ray® disc), a smart card, flash memory (e.g., a card, a stick, a key drive), a floppy® disk, a magnetic strip, etc. Storage 1003 may also be called an auxiliary storage device. The recording medium described above may also be, for example, a database, server, or other suitable medium including at least one of memory 1002 and storage 1003.

[0070] The communication device 1004 is hardware (transceiver / receiver device) for communicating between computers via at least one of a wired network and a wireless network, and is also referred to as a network device, network controller, network card, communication module, etc.

[0071] The communication device 1004 may be configured to include, for example, a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc., in order to implement at least one of frequency division duplex (FDD) and time division duplex (TDD).

[0072] The input device 1005 is an input device that accepts input from an external source (e.g., a keyboard, mouse, microphone, switch, button, sensor, etc.). The output device 1006 is an output device that outputs to an external source (e.g., a display, speaker, LED lamp, etc.). The input device 1005 and the output device 1006 may be configured as an integrated unit (e.g., a touch panel).

[0073] Furthermore, each device, such as the processor 1001 and the memory 1002, is connected by a bus 1007 for communicating information. The bus 1007 may be configured using a single bus, or different buses may be configured for each device.

[0074] Furthermore, the device may include hardware such as a microprocessor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a programmable logic device (PLD), and a field-programmable gate array (FPGA), and some or all of each functional block may be implemented by such hardware. For example, processor 1001 may be implemented using at least one of these hardware components.

[0075] Furthermore, notification of information is not limited to the embodiments / models described herein and may be carried out by other means. For example, notification of information may be carried out by physical layer signaling (e.g., Downlink Control Information (DCI), Uplink Control Information (UCI)), upper layer signaling (e.g., RRC signaling, Medium Access Control (MAC) signaling, broadcast information (Master Information Block (MIB), System Information Block (SIB))), other signals, or combinations thereof. RRC signaling may also be called RRC messages, and may be, for example, RRC Connection Setup messages, RRC Connection Reconfiguration messages, etc.

[0076] Each aspect / embodiment described herein may be applied to at least one of systems utilizing Long Term Evolution (LTE), LTE-Advanced (LTE-A), SUPER 3G, IMT-Advanced, 4th generation mobile communication system (4G), 5th generation mobile communication system (5G), 6th generation mobile communication system (6G), xth generation mobile communication system (xG) (where x is, for example, an integer or decimal), Future Radio Access (FRA), New Radio (NR), W-CDMA®, GSM®, CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi®), IEEE 802.16 (WiMAX®), IEEE 802.20, Ultra-WideBand (UWB), Bluetooth®, and other appropriate systems, as well as next-generation systems extended based thereon. Furthermore, multiple systems may be applied in combination (for example, a combination of at least one of LTE and LTE-A with 5G).

[0077] The processing procedures, sequences, flowcharts, etc., of each aspect / embodiment described herein may be reordered, provided they are consistent with each other. For example, the methods described herein present various step elements in an exemplary order and are not limited to that specific order.

[0078] The specific operations described in this disclosure as being performed by a base station may, in some cases, be performed by its upper node. In a network consisting of one or more network nodes having a base station, it is clear that various operations performed for communication with a terminal can be performed by the base station and at least one other network node (for example, an MME or S-GW, but not limited to these). Although the above example illustrates the case where there is one other network node besides the base station, it may also be a combination of multiple other network nodes (for example, an MME and an S-GW).

[0079] Information and signals (such as data) can be output from a higher layer (or lower layer) to a lower layer (or higher layer). Input and output may occur via multiple network nodes.

[0080] 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 to. Output information may be deleted. Input information may be sent to other devices.

[0081] The determination may be made by a value represented by 1 bit (0 or 1), by a boolean value (true or false), or by a numerical comparison (for example, a comparison with a predetermined value).

[0082] Each aspect / embodiment described herein may be used individually, in combination, or switched between as needed during implementation. Furthermore, notification of specific information (e.g., notification that "X is") is not limited to explicit notification, but may also be implicit (e.g., by not providing such notification).

[0083] Software should be broadly interpreted to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, and so on, whether they are called software, firmware, middleware, microcode, hardware description languages, or by any other name.

[0084] Furthermore, software, instructions, information, etc., may be transmitted and received via a transmission medium. For example, if software is transmitted from a website, server, or other remote source using at least one of wired technology (such as coaxial cable, fiber optic cable, twisted pair, or Digital Subscriber Line (DSL)) and wireless technology (such as infrared or microwave), then at least one of these wired and wireless technologies is included in the definition of a transmission medium.

[0085] The information, signals, etc. described in this disclosure may be represented using any of the various different technologies. For example, the data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description may be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

[0086] In addition, terms used in this disclosure and terms necessary for understanding this disclosure may be replaced with terms having the same or similar meanings. For example, at least one of the channel and symbol may be a signal (signaling). Also, a signal may be a message. Furthermore, a component carrier (CC) may be called a carrier frequency, cell, frequency carrier, etc.

[0087] The terms “system” and “network” as used in this disclosure are interchangeable.

[0088] Furthermore, the information, parameters, etc., described in this disclosure may be expressed using absolute values, relative values ​​from a given value, or other corresponding information. For example, wireless resources may be indicated by an index.

[0089] The names used for the parameters described above are not restrictive in any way. Furthermore, the formulas and other expressions using these parameters may differ from those expressly disclosed in this disclosure. Since various channels (e.g., PUCCH, PDCCH, etc.) and information elements can be identified by any suitable name, the various names assigned to these various channels and information elements are not restrictive in any way.

[0090] In this disclosure, terms such as "Base Station (BS)," "wireless 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.

[0091] A base station can house one or more (e.g., three) cells (also called sectors). If a base station houses multiple cells, the entire coverage area of ​​the base station can be divided into multiple smaller areas, each of which can also be provided with communication services by a base station subsystem (e.g., a small indoor base station (Remote Radio Head: RRH)).

[0092] The terms "cell" or "sector" refer to a portion or all of the coverage area of ​​at least one of the base stations and base station subsystems that provide communication services in this coverage.

[0093] In this disclosure, the transmission of information by a base station to a terminal may be interpreted as the base station instructing the terminal to perform information-based control or operation.

[0094] In this disclosure, terms such as "Mobile Station (MS)," "user terminal," "User Equipment (UE)," and "terminal" may be used interchangeably.

[0095] 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 appropriate term.

[0096] At least one of the base station and the mobile station may be called a transmitting device, a receiving device, a communication device, etc. At least one of the base station and the mobile station may also be a device mounted on a mobile body, the mobile body itself, etc. The mobile body refers to a movable object, and its speed of movement is arbitrary. This also includes the case when the mobile body is stationary. The mobile body includes, but is not limited to, vehicles, transport vehicles, automobiles, motorcycles, bicycles, connected cars, excavators, bulldozers, wheel loaders, dump trucks, forklifts, trains, buses, handcarts, rickshaws, ships and other watercraft, airplanes, rockets, satellites, drones (registered trademark), multicopters, quadcopters, balloons, and items mounted on them. The mobile body may also be a mobile body that moves autonomously based on operation commands. It 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). Furthermore, at least one of the base station and the mobile station may include devices that do not necessarily move during communication operations. For example, at least one of the base station and the mobile station may be an IoT (Internet of Things) device such as a sensor.

[0097] Furthermore, the term "base station" in this disclosure may be interpreted as "mobile station" (user terminal, hereinafter the same). For example, the various 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), Vehicle-to-Everything (V2X), etc.). In this case, the mobile station may have the functions that a base station has. Also, terms such as "uplink" and "downlink" may be interpreted as terms corresponding to terminal-to-terminal communication (for example, "side"). For example, uplink channel, downlink channel, etc. may be interpreted as side channel (or side link).

[0098] Similarly, the term "mobile station" in this disclosure may be interpreted as "base station." In this case, the base station may be configured to have the functions that a mobile station has.

[0099] A wireless frame may consist of one or more frames in the time domain. Each of these one or more frames in the time domain may be called a subframe. A subframe may further consist of one or more slots in the time domain. A subframe may have a fixed time length (e.g., 1 ms) that is independent of numerology.

[0100] Numerology may be communication parameters applied to at least one of the transmission and reception of a signal or channel. Numerology may include, for example, at least one of the following: subcarrier spacing (SCS), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI), number of symbols per TTI, radio frame configuration, specific filtering processes performed by the transceiver in the frequency domain, and specific windowing processes performed by the transceiver in the time domain.

[0101] A slot may consist of one or more symbols in the time domain (such as an Orthogonal Frequency Division Multiplexing (OFDM) symbol or a Single Carrier Frequency Division Multiple Access (SC-FDMA) symbol). A slot may also be a time unit based on neurology.

[0102] A slot may include multiple minislots. Each minislot may consist of one or more symbols in the time domain. Minislots may also be called subslots. Minislots may consist of fewer symbols than a slot. A PDSCH (or PUSCH) transmitted in a time unit larger than a minislot may be called a PDSCH (or PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using a minislot may be called a PDSCH (or PUSCH) mapping type B.

[0103] Wireless frames, subframes, slots, minislots, and symbols all represent units of time when transmitting a signal. Different names may be used for each of these terms.

[0104] For example, one subframe may be called a Transmit 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 a subframe and a TTI may be a subframe (1 ms) in existing LTE, a period shorter than 1 ms (e.g., 1-13 symbols), or a period longer than 1 ms. Note that the unit representing the TTI may be called a slot, minislot, etc., instead of a subframe.

[0105] Here, TTI refers to, for example, the smallest unit of time for scheduling in wireless communication. For example, in an LTE system, the base station schedules each user terminal to allocate wireless resources (such as the frequency bandwidth and transmission power available to each user terminal) in TTI units. However, the definition of TTI is not limited to this.

[0106] TTI may be a transmission time unit for channel-encoded data packets (transport blocks), code blocks, code words, etc., or it may be a processing unit for scheduling, link adaptation, etc. Given a TTI, the actual time interval (e.g., number of symbols) to which the transport block, code block, code word, etc. are mapped may be shorter than the given TTI.

[0107] Furthermore, if one slot or one mini-slot is referred to as TTI, then one or more TTIs (i.e., one or more slots or one or more mini-slots) may constitute the minimum time unit of scheduling. In addition, the number of slots (number of mini-slots) that constitute this minimum time unit of scheduling may be controlled.

[0108] A TTI with a time length of 1ms may also be called a normal TTI, long TTI, normal subframe, long subframe, slot, etc. A TTI shorter than a normal TTI may also be called a shortened TTI, short TTI, partial or fractional TTI, shortened subframe, short subframe, mini slot, sub slot, slot, etc.

[0109] Furthermore, long TTIs (e.g., normal TTIs, subframes, etc.) may be interpreted as TTIs with a time length exceeding 1 ms, and short TTIs (e.g., shortened TTIs, etc.) may be interpreted as TTIs with a TTI length less than that of a long TTI but 1 ms or more.

[0110] A resource block (RB) is a resource allocation unit in the time domain and frequency domain, and in the frequency domain, it may contain one or more consecutive subcarriers. The number of subcarriers in an RB may be the same regardless of the neurology, for example, 12. The number of subcarriers in an RB may be determined based on the neurology.

[0111] Furthermore, the time domain of the RB may contain one or more symbols and may be the length of one slot, one minislot, one subframe, or one TTI. One TTI, one subframe, etc., may each consist of one or more resource blocks.

[0112] One or more RBs may also be called a Physical RB (PRB), Sub-Carrier Group (SCG), Resource Element Group (REG), PRB pair, RB pair, etc.

[0113] Furthermore, a resource block may consist of one or more resource elements (REs). For example, one RE may be a radio resource area comprising one subcarrier and one symbol.

[0114] A Bandwidth Part (BWP), also known as a partial bandwidth, may represent a subset of consecutive common resource blocks (RBs) for a given neurology on a given carrier. Here, the common RBs may be identified by an index of the RBs relative to the carrier's common reference point. PRBs may be defined and numbered within a BWP.

[0115] A BWP may include BWPs for UL (UL BWP) and BWPs for DL ​​(DL BWP). One or more BWPs may be set within a single carrier for a UE.

[0116] At least one of the configured BWPs may be active, and the UE does not need to assume that it will send or receive a given signal / channel outside of the active BWP. In this disclosure, terms such as "cell" and "carrier" may be read as "BWP".

[0117] The structures described above, such as wireless frames, subframes, slots, minislots, and symbols, are merely illustrative. For example, the number of subframes included in a wireless frame, the number of slots per subframe or wireless frame, the number of minislots included in a slot, the number of symbols and RBs included in a slot or minislot, the number of subcarriers included in an RB, and the number of symbols, symbol length, and cyclic prefix (CP) length within the TTI can be varied in various ways.

[0118] The terms “connected,” “coupled,” or any variation thereof, mean 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” with each other. The coupling or connection between elements may be physical, logical, or a combination thereof. For example, “connection” may be reinterpreted as “access.” As used in this disclosure, two elements may be considered to be “connected” or “coupled” with each other using at least one of one or more wires, cables, and printed electrical connections, and, in some non-limiting and non-exclusive examples, electromagnetic energy having wavelengths in the radio frequency domain, microwave domain, and optical (both visible and invisible) domain.

[0119] The reference signal can also be abbreviated as Reference Signal (RS), and may be called a pilot depending on the applicable standard.

[0120] In this disclosure, the phrase "based on" does not mean "based solely on" unless otherwise specified. In other words, the phrase "based on" means both "based solely on" and "based at least on."

[0121] In the configuration of each of the above devices, "means" may be replaced with "part," "circuit," "device," etc.

[0122] Any reference to elements using designations such as “First,” “Second,” etc., as used in this disclosure does not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient way to distinguish between two or more elements. Accordingly, references to the First and Second elements do not imply that only two elements may be employed therein, or that the First element must precede the Second element in any way.

[0123] Where the terms “include,” “including,” and variations thereof are used in this disclosure, these terms are intended to be inclusive, as is the term “comprising.” Furthermore, the term “or” as used in this disclosure is not intended to mean exclusive OR.

[0124] In this disclosure, if articles are added through translation, such as a, an, and the in English, this disclosure may include the fact that the noun following these articles is plural.

[0125] The terms “determining” and “determining” as used in this disclosure may encompass a wide variety of actions. “Determining” and “determining” may include, for example, judging, calculating, computing, processing, deriving, investigating, looking up, searching, or inquiring (e.g., searching in a table, database, or other data structure), or ascertaining. “Determining” and “determining” may also include, for example, receiving (e.g., receiving information), transmitting (e.g., sending information), inputting, outputting, or accessing (e.g., accessing data in memory). Furthermore, "judgment" and "decision" can include considering something as having "judgmented" or "decided" after resolving, selecting, choosing, establishing, comparing, etc. In other words, "judgment" and "decision" can include considering something as having "judgmented" or "decided" about some action. Also, "judgment (decision)" can be reinterpreted as "assuming," "expecting," or "considering."

[0126] In this disclosure, the term "A and B are different" may mean "A and B are different from each other." The term may also mean "A and B are each different from C." Terms such as "separate" and "combine" may be interpreted similarly to "different."

[0127] (Note) The above disclosure may also be expressed as follows: The first feature is a visible light communication device that performs visible light communication using visible light communication signals, comprising a wireless signal receiving unit that receives wireless communication signals from a plurality of upstream communication devices via a wireless communication network using radio waves, and a terminal-side visible light transmitting unit that transmits the visible light communication signals to a terminal, wherein the wireless signal receiving unit connects to a specific upstream communication device and receives the wireless communication signals depending on the communication status with the plurality of upstream communication devices.

[0128] The second feature is that, in the first feature, the wireless signal receiving unit connects to a specific upstream communication device based on instructions from the communication control device.

[0129] The third feature is that, in the first or second feature, the wireless signal receiving unit connects to the upstream communication device with low communication volume based on instructions from the communication control device.

[0130] The fourth feature is an upstream communication device provided upstream of a visible light communication device that performs visible light communication with a terminal using visible light communication signals, comprising a wireless signal transmitting unit that transmits wireless communication signals using radio waves toward the visible light communication device, and a terminal-side wireless communication unit that transmits and receives wireless communication signals with the terminal, wherein the wireless signal transmitting unit connects to the visible light communication device and transmits the wireless communication signals according to the communication status with the upstream communication device.

[0131] The fifth feature is that, in the fourth feature, the wireless signal transmitting unit connects to the visible light communication device and transmits the wireless communication signal based on instructions from the communication control device.

[0132] The sixth feature is that, in the fourth or fifth feature, the terminal-side wireless communication unit will cease sending and receiving the wireless communication signal with the terminal if the wireless signal transmission unit lacks the necessary wireless resources. [Explanation of Symbols]

[0133] 10 Communication Systems 20 Communication Networks 30 CCU 40 Optical Fibers 50 Wireless base stations 51 Wireless signal transmission unit 53 Terminal-side wireless communication unit 55 Network connection section 57 Control Unit 60 routers 100 VLC-AP 110 Wireless signal receiving unit 130 Terminal-side visible light transmission unit 140 Control Unit 200 UE 1001 Processor 1002 memory 1003 Storage 1004 Communication device 1005 Input device 1006 Output device 1007 Bus

Claims

1. A visible light communication device that performs visible light communication using visible light communication signals, A wireless signal receiving unit that receives wireless communication signals from multiple upstream communication devices via a wireless communication network using radio waves, A terminal-side visible light transmission unit that transmits the visible light communication signal toward the terminal, and Equipped with, The wireless signal receiving unit is a visible light communication device that connects to a specific upstream communication device and receives the wireless communication signal, depending on the communication status with the plurality of upstream communication devices.

2. The visible light communication device according to claim 1, wherein the wireless signal receiving unit connects to a specific upstream communication device based on instructions from a communication control device.

3. The visible light communication device according to claim 2, wherein the wireless signal receiving unit connects to the upstream communication device with low communication volume based on instructions from the communication control device.

4. An upstream communication device provided on the upstream side of a visible light communication device that performs visible light communication with a terminal using visible light communication signals, A wireless signal transmission unit that transmits wireless communication signals using radio waves toward the visible light communication device, The terminal and a terminal-side wireless communication unit that transmits and receives wireless communication signals Equipped with, The wireless signal transmitting unit is an upstream communication device that connects to the visible light communication device and transmits the wireless communication signal according to the communication status with the upstream communication device.

5. The upstream communication device according to claim 4, wherein the wireless signal transmitting unit connects to the visible light communication device and transmits the wireless communication signal based on instructions from the communication control device.

6. The upstream communication device according to claim 4, wherein the terminal-side wireless communication unit discontinues sending and receiving wireless communication signals with the terminal if the wireless signal transmission unit lacks the necessary wireless resources.

7. A communication system comprising a visible light communication device that performs visible light communication using visible light communication signals, and an upstream communication device provided upstream of the visible light communication device, The visible light communication device is A wireless signal receiving unit that receives wireless communication signals from multiple upstream communication devices via a wireless communication network using radio waves, A terminal-side visible light transmission unit that transmits the visible light communication signal toward the terminal, and Equipped with, The upstream communication device is, A wireless signal transmission unit that transmits the wireless communication signal toward the visible light communication device, The terminal and a terminal-side wireless communication unit that transmits and receives wireless communication signals Equipped with, The wireless signal receiving unit connects to a specific upstream communication device and receives the wireless communication signal, depending on the communication status with the plurality of upstream communication devices. The wireless signal transmitting unit is a communication system that connects to the visible light communication device and transmits the wireless communication signal according to the communication status with the visible light communication device.

8. A communication method in a visible light communication device that performs visible light communication using visible light communication signals, The steps include receiving wireless communication signals from multiple upstream communication devices via a wireless communication network using radio waves, The steps include transmitting the visible light communication signal to the terminal and Includes, A communication method for receiving the wireless communication signal, wherein, in the step of receiving the wireless communication signal, the method connects to a specific upstream communication device and receives the wireless communication signal, depending on the communication status with the plurality of upstream communication devices.

9. A communication method in an upstream communication device provided upstream of a visible light communication device that performs visible light communication with a terminal using visible light communication signals, The steps include transmitting a wireless communication signal using radio waves to the visible light communication device, The steps of sending and receiving wireless communication signals with the aforementioned terminal and Includes, A communication method that, in the step of transmitting the wireless communication signal, connects to the visible light communication device and transmits the wireless communication signal, depending on the communication status with the visible light communication device.

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