Patents
Literature
Patsnap Eureka AI that helps you search prior art, draft patents, and assess FTO risks, powered by patent and scientific literature data.

91 results about "Radio jamming" patented technology

Radio jamming is the deliberate jamming, blocking or interference with authorized wireless communications. In the United States, radio jamming devices (known as "jammers") are illegal and their use can result in large fines.

Unmanned aerial vehicle route planning method for low-altitude airspace unmanned aerial vehicle operation

The invention is suitable for the technical field of unmanned aerial vehicle route planning, and provides an unmanned aerial vehicle route planning method for low-altitude airspace unmanned aerial vehicle operation, which comprises the following steps of: constructing dynamic route networks at different moments based on three-dimensional GIS (Geographic Information System) gridding; evaluating the comprehensive risk of any grid at different moments based on the multi-source heterogeneous data; multiple uncertainties in a flight environment are considered, and a double-layer planning robust optimization model of unmanned aerial vehicle route planning is established according to multiple origin-destination points and time windows of unmanned aerial vehicle tasks; and designing a two-stage distributed algorithm of the bilayer planning robust optimization model for solving the route planning of the unmanned aerial vehicle. On the basis of three-dimensional GIS gridding, factors such as obstacle distribution, wind shear, a dynamic restriction area, radio interference and unmanned aerial vehicle performance are comprehensively considered, targets such as safety, efficiency and green are considered according to origin-destination points and time windows of a plurality of unmanned aerial vehicle tasks, a plurality of unmanned aerial vehicle paths are generated, and the safe and efficient level of low-altitude airspace operation is assisted.
Owner:CIVIL AVIATION UNIV OF CHINA

Radio interference identification method based on electromagnetic spectrum monitoring

The invention discloses a radio interference identification method based on electromagnetic spectrum monitoring, and the method comprises the following steps: S1, collecting spectrum data in an electromagnetic environment through broadband spectrum monitoring equipment, and carrying out the digital sampling processing; s2, adopting a diffusion probability model to automatically remove environmental noise and non-interference signals; s3, automatically generating an expansion data set of edge and small sample interference signals by adopting an attention-enhanced data synthesis expansion technology; s4, extracting multi-dimensional time-frequency domain dynamic correlation characteristics of the spectrum interference signal based on a Transform structure; s5, adopting an attention enhancement self-supervision algorithm to generate a self-supervision soft label of an unknown interference type; s6, dynamic back diffusion iteration is carried out through the diffusion probability model, and an interference classification result is obtained; and S7, constructing a closed-loop dynamic feedback mechanism by using an interference classification result. According to the invention, accurate identification of radio interference signals is realized, and the accuracy, dynamic adaptability and automation degree of interference signal classification are improved.
Owner:WUHAN HAIHUA XINTONG TECH CO LTD

Communication control device, communication device, communication control method, and communication method

Spectrum use efficiency is effectively improved while protected entities are protected from radio interference. A communication control device of the present disclosure includes a processing unit that: determines a first interference margin that is an amount of interference that is acceptable to be given to a protected entity by at least one group of a plurality of communication devices, based on a cumulative acceptable amount of interference of the protected entity; and determines a plurality of second interference margins that are amounts of interference that are acceptable to be given to the protected entity by the plurality of communication devices by allocating the first interference margin among the plurality of communication devices in the group.
Owner:SONY GROUP CORP

Radio system interference processing method and device

The invention discloses a radio system interference processing method and device, and relates to the technical field of radio anti-interference, and the method comprises the following steps: real-time environment monitoring and data acquisition; interference source detection and accurate identification; dynamic prediction and trend analysis of an interference source; generating a multi-dimensional interference avoidance strategy; real-time feedback and intelligent decision optimization are carried out; performing cooperative work and system integration; and finally evaluating and adjusting the performance. The method has the advantages that rapid positioning and accurate avoidance of the radio interference source are achieved through real-time environment monitoring and accurate identification and dynamic prediction of the interference source, compared with a traditional fixed threshold value or energy detection method, dynamic changes such as frequency, bandwidth and power of the interference source can be responded in time, misjudgment and missed judgment are reduced, and the detection accuracy is improved. Blind avoidance or excessive avoidance is avoided, and the accuracy of interference avoidance is improved.
Owner:BEIJING BOHONG KEYUAN INFORMATION TECH CO LTD

Unmanned aerial vehicle countering method

The invention provides an unmanned aerial vehicle countering method, which comprises the following steps of: acquiring a radar signal containing an unmanned aerial vehicle reflection signal in a target airspace through a radar detection module, obtaining an unmanned aerial vehicle motion feature through feature extraction, and inputting the unmanned aerial vehicle motion feature into a threat judgment model to determine a threat level. And if the active interception condition is met, controlling the radio interference module to transmit a directional interference beam and activate the physical interception module, and analyzing an interference efficiency parameter to generate a dynamic interception instruction. And finally, combining the target airspace coordinate, the threat level and the interception instruction into a countering control instruction, and sending the countering control instruction to a physical interception module to complete interception. According to the invention, automatic and accurate countering of the urban low-altitude unmanned aerial vehicle can be realized, and the response speed and interception reliability of a security and protection system are improved.
Owner:FUJIAN SOUTHEAST AVIATION TECHNOLOGY CO LTD

Railway radio interference monitoring method, device, equipment and computer readable medium

The embodiment of the invention discloses a railway radio interference monitoring method, device and equipment and a computer readable medium. A specific embodiment of the method comprises the following steps: monitoring frequency spectrum data of a railway radio target frequency band and an associated frequency band in real time to obtain target frequency spectrum data and associated frequency spectrum data; performing spectrum analysis processing on the target spectrum data and the associated spectrum data to determine whether a potential interference signal exists; in response to determining that the interference signal exists, acquiring a same-direction orthogonal signal; determining an interference type by using the same-direction orthogonal signal and a pre-trained railway radio interference identification model; and on the basis of the interference type, generating reporting alarm information, and sending the reporting alarm information to a target terminal. According to the implementation mode, through daily and real-time monitoring, interference signals are intelligently collected and analyzed, problems are found in advance, and major potential safety hazards in the railway operation process are avoided.
Owner:BEIJING SOFTWIN TECHNOLOGY CO LTD

Software defined elevation based non-terrestrial network access

Aspects of the subject disclosure may include, for example, attaching, by a radio circuit, to a terrestrial radio network for radio communications with the terrestrial radio network, monitoring an altitude of the radio circuit relative to a surface of earth, and attaching, by the radio circuit, to a non-terrestrial radio network for subsequent radio communication with the non-terrestrial radio network to limit radio interference on the terrestrial radio network, wherein the attaching to the non-terrestrial radio network is responsive to the altitude of the radio circuit exceeding a first elevation threshold value. Other embodiments are disclosed.
Owner:AT&T INTELLECTUAL PROPERTY I L P +1

Multi-source data fusion water radio interference identification and positioning method and system

The invention relates to the field of radio interference intelligent identification and positioning, in particular to a multi-source data fusion water radio interference identification and positioning method and system, and the method comprises the following steps: collecting multi-source data; performing multi-source data fusion processing; constructing a rule base, and screening out suspected abnormal signals from the frequency spectrum situation map through threshold judgment and rule matching; a support vector machine model is called, multi-dimensional static signal features are used as input, a classification hyperplane is constructed through a radial basis kernel function, and normal signals and abnormal signals are distinguished from suspected abnormal signals; calling a decision tree model, and performing scene judgment on the suspected abnormal signal to identify the abnormal signal; calling a convolutional neural network model, converting the time domain signal into a spectrogram through short-time Fourier transform, and extracting texture features through multilayer convolution to identify an abnormal signal; through the method and the system, real-time identification and high-precision positioning of interference signals can be realized.
Owner:SHANGHAI OCEAN UNIV +1

Interference and jammer cancellation for radios

Methods, systems, and devices for reducing the impact of a jamming signal on wireless communications are described. Generally, the described techniques provide for receiving a first signal at a first antenna and receiving a second signal at a second antenna. An anti-jammer manager may process the first signal and the second signal to obtain a residual signal. The processing may include determining a weighting factor based at least in part on a correlation between the first signal and the second signal, applying the weighting factor to the first signal to create a weighted first signal, and subtracting the weighted first signal from the second signal to obtain the residual signal. A demodulator may demodulate the residual signal to obtain symbol information. A decoder may decode the symbol information to obtain data. The techniques may be used to recover a desired signal portion from a jammed signal.
Owner:VIASAT INC

Method and system for providing information about a radio-communication channel

A method provides information about a radio-communication channel between a transmitter (11) and a receiver (12) for a target future time instant, while at least one of the transmitter and receiver is moving. Information is inferred from at least one current or past mobility state of the pair formed by said transmitter and receiver, combined with a mobility model function relating to said pair. The method is useful for adjusting parameters of a communication session ongoing between said transmitter and receiver. It may also be useful for a radio-detection system suitable for characterizing radio interference due to a transmitter-equipped carrier (10).
Owner:MITSUBISHI ELECTRIC R&D CENTRE EUROPE BV +1

Wireless repeater suitable for mesh network, control apparatus, and program

To suppress wraparound interference in a wireless repeater used in a mesh network.SOLUTION: A wireless repeater which amplifies radio waves input via a first antenna and outputs the radio waves from a second antenna is configured to: measure first wireless communication quality of signals input via a first beam while the signals input via the first beam set in the first antenna are not amplified or output by the second antenna; measure second wireless communication quality of the signals input via the first beam while the signals input via the first beam are amplified and output via a second beam set in the second antenna; and determine and set a beam to be used for communication in at least one of the first and second antennas, based on the amount of change between the first wireless communication quality and the second wireless communication quality.SELECTED DRAWING: Figure 4
Owner:KDDI CORP

Digital solid mineral resource exploration and data acquisition internet-of-things transmission method and system

The invention discloses a digital solid mineral resource exploration and data acquisition internet-of-things transmission method and system, and the method comprises the steps: carrying out the denoising and normalization processing of multi-source sensing data through an edge calculation node, and guaranteeing the data quality; a low-power wide area network and 5G and LoRa converged communication are combined to construct an efficient transmission channel, and a standby link is switched by detecting radio interference to guarantee the transmission stability; cloud edge collaborative data encryption is utilized, and a block chain technology is combined to record and upload a log, so that data security and traceability are ensured; and finally, performing three-dimensional geologic body modeling and geographic information system analysis based on the traceable data, and generating accurate scheduling instruction data. According to the invention, through the whole process innovation from data processing, transmission optimization, safety guarantee to prediction modeling, the efficiency of geological data processing and the accuracy of metallogenic prediction are significantly improved, and reliable technical support is provided for geological exploration.
Owner:HUNAN RONGTAN INTELLIGENT EQUIPMENT CO LTD

Wireless device, communication system, communication control method, and program

To reduce the influence of radio wave interference that may occur when waiting for connection from an information processing device.SOLUTION: The present invention provides a wireless device capable of wirelessly communicating with an information processing device, wherein the wireless device includes a wireless control unit that waits for connection from the information processing device in both P2P connection and infrastructure connection, and a standby control unit that stops waiting for P2P connection when the wireless control unit is connected to the information processing device via infrastructure connection.SELECTED DRAWING: Figure 11
Owner:RICOH CO LTD

Method and system for detecting and mitigating an interference attack

The invention relates to a method for detecting and mitigating an interference attack by an interference transmitter in a wireless V2X communication network in which a plurality of mobile devices communicate with one another, comprising: analysing received signals with respect to power-related parameters, wherein an interference signal is detected in the event of a deviation from specified power parameters, classifying the interference signal according to whether the interference signal is a genuine interference signal or a false interference signal, wherein an energy pattern of the interference signal is determined on the basis of the estimated parameters, and wherein an AI-based discriminator is used such that after a test with an appropriate probability sequence either the interference signal is detected as a genuine interference signal or the interference signal is detected as a false interference signal, classifying the genuine interference signal for different radio interference attacks such that a mitigation measure of the genuine interference signal takes place, on the basis of the type of interference attack determined, in such a way that the effect of the interference transmitter is weakened. An autonomous vehicle equipped with mobile sensors, particularly drones, which can be operated in both coupled and autonomous modes, wherein said drones can be deployed with reconfigurable intelligent surfaces (RIS) for mitigating interference attacks and defending against cyber threats, such as interference transmitters, to ensure security and efficiency of the V2X wireless communication network.
Owner:HOCHSCHULE HAMM LIPPSTADT

Portable frequency interferometer and wireless signal shielding system

The invention discloses a portable frequency interferometer and a wireless signal shielding system. The portable frequency interferometer comprises an interferometer host used for generating a radio interference signal; the at least one antenna assembly is used for transmitting the radio interference signal; and a movable connecting piece. The interferometer host is movably connected with the at least one antenna assembly through the movable connecting piece, so that the antenna assembly can move relative to the interferometer host, and the antenna assembly and the interferometer host can be fixed. According to the portable frequency interferometer, the antenna assembly is movably connected to the interferometer host, integration of the antenna assembly and the interferometer host is achieved, the overall size of the portable frequency interferometer is more compact, miniaturization of the portable frequency interferometer is facilitated, and the appearance of the portable frequency interferometer is simpler and more attractive.
Owner:SHENZHEN AWP TECH CO LTD

Network node and method therein

A method performed by a first network node for reducing radio interference in a wireless communications network is provided. The first network node obtains a first traffic profile of a first User Equipment (UE). The first traffic profile is indicative of a first traffic pattern of the first UE in a communication direction. The first network node obtains a second traffic profile of a second UE. The second traffic profile is indicative of a second traffic pattern of the second UE in a second communication direction. Based on the obtained first and second traffic profiles, the first network node determines one or more transmission parameters for scheduling communication for the first UE in the first communication direction. Based on the one or more transmission parameters, the first network node schedules communication for the first UE in a first cell of the first network node.
Owner:TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

Railway radio interference analysis method based on machine learning

The invention discloses a railway radio interference analysis method based on machine learning. The method comprises the following steps: step 1, acquiring radio signal data in a railway communication scene; 2, performing signal preprocessing on the radio signal data; 3, extracting the interference structure characteristics of railway radio through the improved RepLKNet network, and generating an interference structure characteristic pattern; 4, constructing a training sample set based on the interference structure feature map; 5, inputting the training sample set into the improved TimesNet network to execute supervised training, and obtaining a railway radio interference analysis model; step 6, loading the railway radio interference analysis model, performing interference analysis on the radio signal data to be analyzed, and outputting an interference analysis result; and 7, outputting an interference analysis result. According to the invention, through the improved RepLKNet network and the improved Times Net network, the accuracy and stability of railway radio interference analysis are improved.
Owner:GUANGZHOU GUANGYUAN ELECTRONIC TECH CO LTD

Communication method, apparatus, system, storage medium and program product

Embodiments of the present application provide a communication method, device, system, storage medium and program product, the method comprising: a first terminal device receiving first information, the first information being used for indicating a radio interference map, the radio interference map comprising at least one interference region, the interference region being obtained based on at least one transmission layer of at least one terminal device; and the first terminal device further sending second information, the second information being determined based on the first information, the second information comprising at least one of the following: an identifier of a first interference region, first interference channel information. Wherein the at least one interference region comprises the first interference region, the first interference region corresponding to at least one transmission layer of the first terminal device, and the first interference channel information corresponding to the first terminal device. The first terminal device feeds back the second information based on the first information, so as to facilitate the network device to perform scheduling, avoid pairing users subjected to strong interference, and improve the signal-to-interference-and-noise ratio and spectral efficiency.
Owner:HUAWEI TECH CO LTD

Interference and jammer cancellation for radios

Methods, systems, and devices for reducing the impact of a jamming signal on wireless communications are described. Generally, the described techniques provide for receiving a first signal at a first antenna and receiving a second signal at a second antenna. An anti-jammer manager may process the first signal and the second signal to obtain a residual signal. The processing may include determining a weighting factor based at least in part on a correlation between the first signal and the second signal, applying the weighting factor to the first signal to create a weighted first signal, and subtracting the weighted first signal from the second signal to obtain the residual signal. A demodulator may demodulate the residual signal to obtain symbol information. A decoder may decode the symbol information to obtain data. The techniques may be used to recover a desired signal portion from a jammed signal.
Owner:VIASAT INC

A radio interference source automatic positioning and troubleshooting system and method thereof

The application provides a radio interference source automatic positioning and troubleshooting system and method thereof, the radio interference source automatic positioning and troubleshooting system comprises a front-end hardware enhancement module, a core algorithm optimization module and a system-level cooperative positioning module, the radio interference source automatic positioning and troubleshooting method comprises hardware deployment and preprocessing, spatial domain beamforming and subarray combination, digital domain multipath elimination and signal recovery and the like, the radio interference source automatic positioning and troubleshooting system and method thereof provided by the application effectively solve the problem that the traditional equipment cannot distinguish the direct wave from the reflected wave, so that the direction finding result is seriously deviated or even points to the wrong direction, and greatly improve the accuracy and reliability of the direct wave identification of the signal.
Owner:SHENZHEN RADIO DETECTION TECH RES INST

Intelligent power supply device based on solar cell

The invention relates to a converter technology, which can be used for efficiently extracting electric energy of a solar panel, converting the obtained energy, transmitting the converted energy to an industrial power grid and providing load service for consumers. The invention discloses a power supply device based on solar cells. Comprising a solar cell panel unit, a current and voltage sensor unit of the solar cell panel unit, a DC / DC voltage converter, a DC bus, an inverter, a current and voltage sensor unit at the output end of the converter, a DC / DC converter control unit, an inverter control unit and a control and switch microcontroller which are connected with one another. The device comprises a solar cell panel, a DC / DC converter, a current and voltage sensor unit of a DC bus, an LC filter, a radio interference filter, a current and voltage sensor unit for a load, and a voltage pulse unit installed between the solar cell panel and the DC / DC converter. The technical result obtained by using the proposed intelligent device is that more energy is obtained from the solar panel device, and the reliability of supplying power to users is improved.
Owner:SUN WORLD LLC

Power transmission tower structure with embedded ground conductor for improving lightning performance and method for determining location and effect of embedded conductor

Power line conductors are normally shielded from direct lightning strikes by appropriately placed overhead ground wires. However, even when such overhead ground wires work as intended and intercept a strike, for a short period of time, typically a few microseconds, the shield wire is exposed to an impulse type potential rise. This could be sufficient to cause flashover of one or more line insulator strings. This is called backflash. The present invention solves this problem by providing a power transmission tower structure with an embedded ground conductor positioned in order to optimize the coupling factors to all conductors and reduce stress on all insulator strings through increased electromagnetic coupling. Use of a streamer-inhibited conductor avoids adverse effects such as radio interference and audible noise due to induced charges and improves electromagnetic coupling as a result of the reduced surge impedance of the conductor.
Owner:RIZK FAROUK A M +1

Radio interference prediction method based on meteorological information granularity reduction and least squares support vector machine

A radio interference prediction method based on granular reduction of meteorological information and a least squares support vector machine (LSSVM) algorithm comprises the following steps: Step 1: obtaining radio interference values ​​and corresponding meteorological information from a measured city over the past three years as a total data set based on actual transmission line measurements; Step 2: determining and filtering out data sets within extreme weather intervals from the total data set based on temperature criteria, and dividing the total data set into a training set and a validation set with a ratio of 9:1. This invention provides a radio interference prediction method based on granular reduction of meteorological information and a least squares support vector machine algorithm, which can relatively accurately predict radio interference values ​​and has good adaptability to extreme weather conditions, providing insights for the research of radio interference value prediction methods in practical engineering projects.
Owner:CHINA THREE GORGES UNIV +2

Method and system for providing information about a radio-communication channel

PCT designated stageWO2025215892A1Baseband system detailsNetwork topologiesInterference (communication)Mobility model
A method provides information about a radio-communication channel between a transmitter (11) and a receiver (12) for a target future time instant, while at least one of the transmitter and receiver is moving. Information is inferred from at least one current or past mobility state of the pair formed by said transmitter and receiver, combined with a mobility model function relating to said pair. The method is useful for adjusting parameters of a communication session ongoing between said transmitter and receiver. It may also be useful for a radio-detection system suitable for characterizing radio interference due to a transmitter-equipped carrier (10).
Owner:MITSUBISHI ELECTRIC R&D CENTRE EUROPE BV +1

Methods and devices for radio interference on sensing signals

An apparatus of a communication device, the apparatus may include: an interface configured to transmit a sensing signal and receive a reflected sensing signal; and a processor configured to: determine a sensing signal configuration of a further communication device;estimate a sensing interference of the further communication device based on the sensing signal configuration; and perform an interference cancellation on the reflected sensing signal using the sensing interference.
Owner:INTEL CORP

Methods and apparatuses for data transmission

Receiving, by a terminal device, a configuration for radio interface measurements. Determining an indication, wherein the indication is associated with the configuration for the radio interface measurements, for adjusted-schedule data transmission for at least part of data obtained by the radio interface measurements. In the case memory capacity is used, transmitting the at least part of the data according to transmission information in the configuration and in the case the memory capacity is not used, storing the at least part of the data and transmitting the at least part of the data as adjusted-schedule data transmission data. The adjusted-schedule data transmission data may comprise data obtained in one measurement data instance associated with a configuration for radio interference measurements with an indication for adjusted-schedule transmission. The indication for the adjusted-schedule data transmission may contain a priority indication of a secondary priority.
Owner:NOKIA TECHNOLOGIES OY

External interference measurement method and system of corona cage radio interference test system

The invention discloses a corona cage radio interference test system external interference measurement method and system. The method comprises the following steps: determining field arrangement parameters of a corona cage test wire and a voltage divider; and connecting a non-shielding layer of the voltage divider with a high-voltage coupling loop through a metal wire, connecting the high-voltage coupling loop with radio interference measurement equipment through a shielding coaxial cable, and determining the radio interference on the basis of the field arrangement parameters and the parameters of the corona cage test wire model. Determining the electric field intensity Edf of a corona cage test wire in the high-voltage coupling loop at the non-screen part of the voltage divider and the radio interference Esf of a water pump in a test area at the non-screen part of the voltage divider through the radio interference measurement equipment; and determining an induced electric field Em of the radio interference measurement equipment based on the electric field intensity Edf and the radio interference Esf.
Owner:CHINA ELECTRIC POWER RESEARCH INSTITUTE CO LTD +4

System for obtaining annual statistical value of corona effect of high-altitude alternating-current transmission line through quarterly observation

The invention discloses a system for obtaining the annual statistical value of the corona effect of a high-altitude AC power transmission line through quarterly observation, and the system comprises an audible noise measurement device which comprises at least one outdoor microphone disposed at a preset position, and an analyzer; the radio interference measuring device comprises an antenna and a receiver which are arranged at preset positions of the power transmission line; the meteorological equipment is used for measuring and distinguishing weather and rainy days; the computer is in communication connection with the audible noise measuring device, the radio interference measuring device and the meteorological equipment, and is used for synchronously controlling the start and stop of the equipment and collecting and storing data; wherein the audible noise measurement device, the radio interference measurement device and the meteorological equipment form an all-weather synchronous measurement system which is configured to acquire data through synchronous observation of three consecutive months in autumn, and the data are classified and counted by the computer according to weather conditions; and obtaining a rainy day audible noise L50 value capable of representing a year-round statistical result, and a radio interference average value in rainy days and good weather.
Owner:CHINA ELECTRIC POWER RESEARCH INSTITUTE CO LTD +2

Radio interference signal detection circuit and method

The invention discloses a radio interference signal detection circuit and method, and relates to the field of interference signal detection, a first switch tube is used for being switched on when no voltage signal is zero so as to output a first low level signal, and is switched off when the voltage signal is greater than a preset voltage threshold; the first pull-up resistor is used for pulling up the control end of the second switch tube to a first high-level signal when the first switch tube is switched off; the second switch tube is used for being switched on when the first switch tube outputs the first low-level signal so as to output a second high-level signal, and is switched off when the first switch tube is switched off; and the signal processing module is used for processing the level signal of the first end of the signal processing module and outputting a detection signal to the signal identification module, so that the signal identification module detects the radio interference signal. According to the invention, the voltage signal is converted into the detection signal through the first switch tube, the first pull-up resistor, the second switch tube and the signal processing module, thereby achieving the detection of the radio interference signal.
Owner:HOLLEY METERING LTD

Telecommunications apparatus and methods

Although not part of the telecommunications system 400 itself, also shown in FIG. 4 are some other devices which are operable to wirelessly communicate with one another and which are operating within the radio environment of the telecommunications system 400. In particular, there is a pair of wireless access devices 416 communicating with one another via radio link 418 operating in accordance with a Wi-Fi standard and a pair of Bluetooth devices 420 communicating with one another via radio link 422 operating in accordance with a Bluetooth standard. These other devices represent a potential source of radio interference for the telecommunications system 400. It will be appreciated that in practice there will typically be many more such devices operating in the radio environment of the wireless telecommunications system 400, and only two pairs of devices 416, 420 are shown in FIG. 4 for simplicity.
Owner:SONY GROUP CORP