Abstract: Provided is a radio communication technology with high reliability. A communication system includes a communication terminal, base stations, and a host device of the base stations. A serving base station of the communication terminal or the host device selects, from among the base stations, a positioning base station transmitting a positioning signal for measuring a position of the communication terminal. The positioning base station transmits the positioning signal, and the communication terminal receives the positioning signal.

Abstract: The present invention has an object to prevent failure of communication due to leaving of a communication terminal from a radiation range of a beam selected by the communication terminal. A communication system according to the present invention includes: a base station configured to transmit a plurality of directional beams being different from each other; and a communication terminal configured to perform radio communication with the base station by using a beam for communication selected from the plurality of directional beams. A system information block transmitted by the base station includes, regarding each of the plurality of directional beams, neighboring beam information indicating neighboring beams being adjacent to each of the plurality of directional beams. The communication terminal selects the beam for communication, based on the neighboring beam information.

Abstract: Provided is a radio communication technology with low latency and high reliability. A communication system includes a communication terminal, and a plurality of communication apparatuses configured to perform radio communication with the communication terminal. When the communication terminal switches a communication apparatus to which the communication terminal is connected from a first communication apparatus to a second communication apparatus, the communication terminal corrects a time of the communication terminal, based on a timing reference to be transmitted from the second communication apparatus and timing advance of the second communication apparatus.

Abstract: A communication system includes a base station device and at least one terminal device. The base station device is configured to control a plurality of base station beams having different beam directions. The base station device transmits a reference signal through a corresponding base station beam. The reference signal is specific to each of the plurality of base station beams used by the at least one terminal device to measure reception quality of a signal from the base station device. The at least one terminal device notifies the base station device of terminal beam related information. The terminal beam related information concerns at least one terminal beam formed by the at least one terminal device. The base station device controls transmission of the reference signal through the plurality of base station beams, based on the terminal beam related information.

Abstract: An antenna device 10 comprises azimuthal range (“sector”) antennas in which an upward directivity antenna 21 is paired with a downward directivity antenna 22, and different sector antennas in which an upward directivity antenna 23 is paired with a downward directivity antenna 24. The upward directivity antennas 21 and 23 are the antennas upwardly directed toward a tilt-angle range, and the downward directivity antennas 22 and 24 are the antennas downwardly directed toward a tilt-angle range. The sector antennas are the antennas for transmitting and receiving radio signals from azimuthal ranges (sectors) being a fill sweep divided into three or more, and the two pairs each are disposed horizontally in an individual sector. By providing these configurations, while efficiently utilizing their installation space, effectiveness of diversity can be enhanced.

Abstract: On the ground plate uprightly mounted in the vertical direction, a plurality of short patch antennas are provided at mutually adjacent positions, and also a pair of non-powered elements are mounted, wherein each of the non-powered elements is disposed between the plurality of short patch antenna elements in such a manner as to extend in the vertical direction and is electrically insulated from the ground plate. Due to this construction, the radiation pattern in the horizontal direction of the plurality of short patch antennas can be greatly improved.

Abstract: The non-powered short-patch antenna element is disposed on a ground plate below a plurality of flat antenna elements provided in an indoor-type antenna device, wherein the distance between the uppermost portion of the short-patch antenna element and that of the flat antenna element is set to the length of ½ wavelength. Due to this construction, the communication quality between the base plate and a mobile station at a remote place from the base plate can be greatly improved without interference caused otherwise by the electromagnetic wave below the antenna device.