Mitsubishi Electric Corporation

Daichi Uchino

Noriyuki Fukui

Mitsuru Mochizuki

Tadahiro Shimoda

Kazuaki Ishioka

Fumihiro Hasegawa

Masaaki Kusano

Keijiro Take

Yusuke Kinoshita

Provided is a communication system with low latency and high reliability, etc. Even after transitioning from RRC_CONNECTED to RRC_INACTIVE, a communication terminal device maintains secondary base station configuration information on configuring a secondary base station. Even when at least one of a master base station and a secondary base station is changed during the RRC_INACTIVE, the communication terminal device maintains the secondary base station configuration information. The communication terminal device again transitions to the RRC_CONNECTED using the maintained secondary base station configuration information.

User apparatus, base station and communication system

A communication device is a base station that communicates with mobile terminals by radiating communication beams within a coverage, the communication beams including a first beam and a second beam having a shorter radio wave propagation distance than the first beam at a same transmission power, the coverage including a plurality of virtual cells. The communication device includes: a grouping processing unit that groups the plurality of virtual cells such that virtual cells in which mobile terminals capable of uplink communication using the first beam and incapable of uplink communication using the second beam are located are aggregated; and a beam forming unit that controls a radiation direction of the communication beams such that the communication beams are radiated at a same timing to all virtual cells belonging to a same group.

Communication device, control circuit, and storage medium

A radio communication technology for enabling high reliability, a high transmission rate, and low power consumption is provided. A communication system includes a communication terminal and a base station. The base station includes a plurality of transmitter-receivers configured to perform radio communication with the communication terminal. The base station is configured to perform radio communication with the communication terminal by using a part or all of the plurality of transmitter-receivers. The communication terminal receives a downlink synchronization signal from at least one first transmitter-receiver to be newly connected, and establishes downlink synchronization with the at least one first transmitter-receiver by using the downlink synchronization signal. The communication terminal establishes uplink synchronization with the at least one first transmitter-receiver through random access processing.

A wireless control apparatus controls beamforming performed by a wireless base station apparatus that provides a communication service to a service area which includes a plurality of spots to be irradiated with a beam including a terminal search beam and a communication beam that are not used simultaneously for irradiation, and is irradiated with a plurality of the beams and is not simultaneously covered by the plurality of beams, and the apparatus includes: an arrival direction estimation unit that estimates an arrival direction of a wireless signal transmitted by a terminal communicating with a wireless base station; and a control unit that determines whether there is an active terminal in the spots on the basis of the arrival direction estimated by the arrival direction estimation unit, and, when it is determined that there is no active terminal, controls beamforming performed by the wireless base station apparatus to decrease a frequency of the terminal search beam with which one or more of the spots determined to include no active terminal is irradiated and increases a frequency of a communication beam with which another of the spots in the service area is irradiated.

Wireless control apparatus

A control apparatus for wireless communication system includes: a communication unit to obtain, from a base station, information indicating reception quality, at a terminal device, of a signal transmitted on a directional beam from the base station; and a processing unit to determine whether to remove a spot on the basis of the information obtained by the communication unit, the spot being an area irradiated with a directional beam from the base station. If the processing unit determines that the spot is to be removed, the communication unit sends an instruction to remove the spot to the base station or to a master base station of the base station.

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Tokyo, Japan

Daichi Uchino