Abstract: An installation position calculation device of a relay station according to an embodiment includes: a first identification circuitry that identifies a position of an installed station candidate point at which an LOS region from the relay station is maximized; a next candidate point extraction circuitry that regards the position identified as a transmission point of a radio wave and extracts two or less top next installed station candidate point at which a next relay station maximizes the LOS region; a correction circuitry that corrects the position of each of the installed station candidate points extracted based on a Fresnel zone for the next relay station; and a second identification circuitry that identifies, as an installation position of the next relay station, a position of a next installed station candidate point at which a reflection angle of the radio wave toward the next installed station candidate point extracted is minimized.

Abstract: A terminal includes a receiver that receives a first downlink signal from the first base station and a second downlink signal from the second base station; a transmitter that transmits a first uplink signal to the first base station and a second uplink signal to the second base station; and a processor that establishes a downlink connection with the first base station and an uplink connection with the second base station, in response to detecting a UL-DL imbalance, wherein, upon detecting that an instruction signal from the second base station is received, the processor changes the uplink connection with the second base station to an uplink connection with the second base station via a relay device.

Abstract: An installation position calculation device of a relay station according to an embodiment includes: an identification circuitry configured to identify an installed station candidate point at which an LOS region from the relay station is maximized in an installed station candidate range or among a plurality of installed station candidate points predetermined as installation position candidates; a correction circuitry configured to correct a position of each of the identified installed station candidate points based on a Fresnel zone for the relay station; a storage circuitry configured to store, as an installation position of the relay station, the position of the installed station candidate point at which an LOS region from the relay station is maximized among each of the identified installed station candidate points or the corrected installed station candidate points; and a controller configured to control such that the number of installation positions of the relay station.

Abstract: A relay device controller includes a reception station communication quality collection unit that collects information on communication quality of the reception station, a learning unit that acquires information collected by the reception station communication quality collection unit and calculates a control parameter of the relay device by reinforcement learning using a value based on the communication quality of the reception station as a reward, and a relay device control unit that controls the relay device with the control parameter calculated by the learning unit.

Abstract: A reflection characteristic analysis device analyzes reflection characteristics of a reconfigurable intelligent surface (RIS: Reconfigurable Intelligent Surface). The reflection characteristic analysis device includes a ray trace calculation unit and an electromagnetic field analysis unit. The ray trace calculation unit calculates an incident angle of an electromagnetic wave incident on the reconfigurable intelligent surface by a ray-tracing method. The electromagnetic field analysis unit acquires the incident angle calculated by the ray trace calculation unit, and calculates, based on an electromagnetic field analysis, the reflection characteristics obtained when the electromagnetic wave enters the reconfigurable intelligent surface at the incident angle.

Abstract: A relay system includes: one or more radiation units configured to form a beam in a predetermined direction by radiating radio waves from each of a plurality of elements; a detection unit configured to detect a physical environment on a radio wave propagation path that affects the beam formed by the radiation unit; a direction determination unit configured to determine a direction in which the radiation unit should form the beam based on the physical environment detected by the detection unit; a phase calculation unit configured to calculate a phase of radio wave to be radiated by each of the plurality of elements such that the radiation unit forms a beam in the direction determined by the direction determination unit; and a phase control unit configured to control the phase of the radio wave radiated by each of the plurality of elements based on the phase calculated.

Abstract: A reflection direction control method includes an arrival direction estimation step of estimating an arrival direction of radio waves transmitted by a wireless terminal to one or more reflection units each including a plurality of reflection elements capable of dynamically changing phase characteristics when the radio wave is reflected, a phase control step of controlling a phase of a radio wave reflected by each of the plurality of reflection elements so that the reflection unit reflects, in a predetermined direction, the radio wave transmitted from the estimated arrival direction, and a switching step of switching between an antenna mode in which the reflection unit is caused to receive the radio wave of which the arrival direction is estimated and a reflection mode in which the reflection unit is caused to reflect the radio wave.

Abstract: A relay device has the following configuration for quickly and easily acquiring highly accurate terminal position information and controlling the reconfigurable intelligent surface. The reconfigurable intelligent surface dynamically changes the reflection direction of the radio wave. The image sensor captures a use range of a terminal composed of a plurality of regions divided in a lattice shape. A control device controls the reconfigurable intelligent surface. In particular, the control device acquires image data of a use range of the terminal captured by the image sensor. The control device searches for a region where the terminal exists among the plurality of regions from the image data. The control device directs the reflection direction of the reconfigurable intelligent surface to a region where the terminal exists.

Abstract: A wireless communication system includes: a first wireless terminal capable of communicating through both a first communication scheme using a first frequency band and a second communication scheme using a second frequency band higher than the first frequency band; a second wireless terminal that is compatible with communication through the first communication scheme and is not compatible with communication through the second communication scheme; and a base station that is compatible with multi-link and accommodating the first wireless terminal and the second wireless terminal. A carrier sense level during transmission in communication between a base station and the first wireless terminal through the first communication scheme is set to a value less than a predetermined value that is a carrier sense level during transmission in communication between the base station and the second wireless terminal through the first communication scheme.

Abstract: A wireless communication system according to one embodiment is a wireless communication system including: one or more wireless terminals capable of communicating by both a first communication scheme using a first frequency band and a second communication scheme using a second frequency band, which is higher than the first frequency band; and a multi-device compatible base station that accommodates the wireless terminals, and the wireless communication system includes: delay determination circuitry configured to determine whether a delay in communication of the second communication scheme exceeds a predetermined value; and a controller to perform control such that the wireless terminals and the base station communicate by the first communication scheme without using the second communication scheme until a predetermined time elapses in a case where the delay determination circuitry determine that the delay exceeds the predetermined value.

Abstract: The following processing is performed in the learning phase. The base station device transmits a control signal toward the relay device. The relay device dynamically selects a phase weight that determines the beam direction of the reflected wave according to the set value. A channel state of the CH2 is estimated from a low-frequency CH2 reference signal that has arrived at the base station device from the terminal device. The communication quality of the CH1 is measured from the high-frequency CH1 reference signal that has arrived at the base station device from the terminal device. A learning model is generated by learning the set value, the channel state, and the communication quality. In the estimation phase, the latest channel state acquired by the CH2 is applied to the learning model, and an optimum set value predicted to maximize the communication quality under the latest state is estimated.

Abstract: A wireless communication system includes a sensing unit that detects an obstacle currently present between a transmitting station and a receiving station. There is an environment memory that stores information on a detection result of the sensing unit, an environment prediction unit that predicts a variation in a radio wave propagation environment between the transmitting station and the receiving station from the information stored in the environment memory. There is further a simulation calculation unit that simulates an environment in which a communication path between the receiving station and a reflector and a communication path between the transmitting station and the reflector are a line-of-sight environment on the basis of a prediction result of the environment prediction unit and calculates a control parameter of the reflector that achieves the environment. Further, a reflector control unit controls the reflector in accordance with the control parameter calculated by the simulation calculation unit.

Abstract: The wireless communication system includes a plurality of wireless terminals each including a plurality of wireless interfaces corresponding to a plurality of channels in different frequency bands, and a wireless base station device that establishes wireless communication with the wireless terminals. Each of the wireless terminals performs channel sensing, and transmits sensing information including an identifier of a sensed channel, a sensing result of the channel, and an identifier of the wireless terminal. The wireless base station device calculates and stores a sensing time for each of the wireless terminals on the basis of the sensing information, the sensing time being an accumulated value of time required for sensing by the wireless terminal, and allocates a reward according to the sensing time to each of the plurality of wireless terminals.

Abstract: A wireless communication system includes a multi-device-compatible base station to mixedly accommodate one or more first wireless terminals capable of performing simultaneous communication by a plurality of different communication schemes. There is a control device configured to control the base station. The control device includes a collection unit that collects scheme information regarding the communication schemes by which the first wireless terminals are able to perform communication and scheme information regarding the communication schemes by which the second wireless terminals are able to perform communication. There is also a distribution control unit that controls distribution of traffic.

Abstract: The wireless communication system includes a plurality of wireless terminals each including a plurality of wireless interfaces corresponding to a plurality of channels in different frequency bands, and a wireless base station device that establishes wireless communication with the wireless terminals. Each of the wireless terminals performs channel sensing, and transmits sensing information including an identifier of a sensed channel, a sensing result of the channel, and an identifier of the wireless terminal. The wireless base station device calculates and stores the number of sensing channels for each of the wireless terminals on the basis of the sensing information, the number of sensing channels being the number of channels sensed by the wireless terminal, and allocates a reward according to the number of sensing channels to each of the plurality of wireless terminals.

Abstract: A wireless communication system according to one embodiment is a wireless communication system including: one or more wireless terminals capable of communicating by both a first communication scheme using a first frequency band and a second communication scheme using a second frequency band, which is higher than the first frequency band; and a multi-device compatible base station that accommodates the wireless terminals, and the wireless communication system includes: number-of-times measurement circuitry configured to measure the number of retries for attempting communication by the second communication scheme; and a controller to perform control such that the base station performs wireless communication by the first communication scheme without using the second communication scheme until a predetermined time elapses with respect to a wireless terminal in which the number of times measured by the number-of-times measurement circuitry exceed a predetermined number of times.

Abstract: A wireless communication system includes: a first wireless terminal capable of communicating through both a first communication scheme using a first frequency band and a second communication scheme using a second frequency band higher than the first frequency band; a second wireless terminal that is compatible with communication through the first communication scheme and is not compatible with communication through the second communication scheme; and a multi-link compatible base station that accommodates the first wireless terminal and the second wireless terminal. A contention window value during transmission in communication between the base station and the first wireless terminal through the first communication scheme is set to a value greater than a predetermined value that is a contention window value during transmission in communication between the base station and the second wireless terminal through the first communication scheme.

Abstract: A base station according to an embodiment is a base station that performs wireless communication with a terminal using a directional antenna within a predetermined area, the base station including: acquisition circuitry configured to acquire data from a database that holds data indicating an antenna directivity suitable for each state of a terminal or each arrival direction of a radio wave from the terminal measured in a scale model in which a structure within a predetermined area is reduced at a predetermined scale factor; collection circuitry configured to collect a state of a terminal or an arrival direction of a radio wave from the terminal in practice within a predetermined area; and controller configured to control directivity of the directional antenna with respect to the terminal in practice within a predetermined area based on the state of the terminal or the arrival direction and data.

Abstract: In a wireless communication system, a base station device communicates with a terminal device via any relay device (reconfigurable intelligent surface). The base station device stores a CSI when passing through the relay device in association with the object arrangement information. When the current object arrangement information is similar to the stored past object arrangement information, the base station device determines a relay device to be used at the present time on the basis of each CSI stored in association with the past object arrangement information. According to this, it is possible to reduce overhead for acquiring the CSI, and simultaneously execute the use determination of the plurality of reconfigurable intelligent surfaces, by re-using the CSI.

Abstract: The amusement device according to the present disclosure includes: a laser irradiation unit 1 that emits a laser beam; a reflector 3 that reflects the laser beam emitted from the laser irradiation unit 1; and a laser light receiving unit 2 that serves as a target onto which the laser beam emitted from the laser irradiation unit 1 is incident. The amusement device according to the present disclosure further includes an obstacle 5 that can block the laser beam emitted from the laser irradiation unit 1. The laser irradiation unit 1 is configured to enable the emission direction of the laser beam to be changed by an operation by a user. The reflector 3 is configured to enable the direction of a reflection surface to be changed by an operation by the user. The obstacle 5 is configured to be movable by an operation by the user.