Mitsubishi Electric Corporation

Tadahiro Shimoda

Mitsuru Mochizuki

Noriyuki Fukui

Fumihiro Hasegawa

Daichi Uchino

Masayuki Nakazawa

Akinori Taira

Shigeru Uchida

Toshiki Tanaka

Hiroki Iura

A communication system includes a communication terminal, and a serving base station of the communication terminal. The serving base station notifies the communication terminal of an instruction to configure a measurement gap for the communication terminal to measure a positioning signal transmitted from at least one neighboring base station in order to measure a position of the communication terminal, without a request from the communication terminal (Step ST).

Communication system and base station

Provided is a communication system capable of suppressing increase in the power consumption of a communication terminal device, degradation in the communication quality, and reduction in the use efficiency of radio resources. A base station device (gNB) notifies a communication terminal device (UE) of information on the next reception timing. The UE receives, for example, a downlink control signal in a subframe. The UE obtains, from the downlink control signal, information on a piece of user data in the subframe, and the information on the next reception timing. The UE transmits and receives the piece of user data to and from the gNB. The information on the next reception timing indicates a subframe as the next reception timing of the UE. The UE receives a downlink control signal in the subframe.

Communication system, base station and communication terminal

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

Provided is a technology that can increase the robustness of a communication system. A communication system includes: a communication terminal; a first network configured to perform radio communication with the communication terminal; and at least one second network configured to perform communication with the first network. When the first network determines to release connection between the first network and the communication terminal (ST) with the communication terminal being connected to the first network and to the at least one second network through the first network, the communication terminal or the first network instructs the at least one second network to release the connection with the communication terminal (ST).

Communication system, communication terminal, and network

A radio communication technology with small delay 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 transmitter-receiver to be newly connected, and establishes downlink synchronization with the at least one transmitter-receiver by using the downlink synchronization signal. The communication terminal receives a random access start order from the base station, performs random access processing by using the random access start order, and establishes uplink synchronization with the at least one transmitter-receiver.

User apparatus, base station, and communication system

Radio resource management is simplified when a cell is spatially separated by a plurality of radio beams. A cell configured by a base station device is spatially separated by a plurality of radio beams being served by the base station device. The base station device shares, between two or more of the plurality of radio beams, a radio resource control (RRC) parameter to be applied to a communication terminal device.

Communication system

A communication system includes a user apparatus; and base stations respectively configured to wirelessly communicate with the user apparatus. The base stations include a master base station and a secondary base station that configure dual connectivity for the user apparatus. The secondary base station is configured with a grant configuration related to transmission without grant in uplink to the secondary base station.

Communication system, user apparatus, and base station

A communication system that can reduce latency while preventing reduction in a transmission rate. An eNB communicates with a UE #1 using a self-contained subframe including a first downlink signal (DL #1) and a first uplink signal (UL #1), and with a UE #2 using a self-contained subframe including a second downlink signal (DL #2) and a second uplink signal (UL #2). The self-contained subframe for the UE #1 includes a first gap duration (Gap #1) during which neither the DL #1 nor the UL #1 is transmitted, between transmission durations of the DL #1 and the UL #1. The self-contained subframe for the UE #2 includes a second gap duration (Gap #2) during which neither the DL #2 nor the UL #2 is transmitted, between transmission durations of the DL #2 and the UL #2. The Gaps #1 and #2 are set to each UE.

A user apparatus in a communication system includes: a plurality of user apparatuses each of which is configured to transmit a sounding reference signal (SRS); and a base station configured to wirelessly communicate with the plurality of the user apparatuses. The user apparatus receives, from the base station, configuration information related to a wireless resource of the sounding reference signal allocated to another user apparatus.

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 communication system includes a user apparatus; and a base station including a distributed unit (DU) configured to wirelessly communicate with the user apparatus and a central unit (CU) connected to the distributed unit. The base station including the CU and the DU supports packet duplication, and the DU notifies the user apparatus of starting the packet duplication.

A communication system includes a terminal apparatus; and a plurality of base stations respectively configured to wirelessly communicate with the terminal apparatus, the base stations including an MgNB and an SgNB that configures dual connectivity with the terminal apparatus. The terminal apparatus performs small data transmission for the SgNB in an RRC_INACTIVE state.

Communication system, terminal apparatus, and SGNB

Provided is a high-speed communication system with the high reliability and the low latency under New Radio (NR). A base station device includes a plurality of distributed units (DUs,) that transmit and receive radio signals, and a central unit (CU,) that controls the plurality of DUs (). The CU () duplicates a downlink packet addressed to a communication terminal device (), and forwards the duplicated downlink packet to each of at least two DUs () among the plurality of DUs (). Each of the at least two of the DUs () transmits, to the communication terminal device () by the radio signal, the downlink packet obtained from the CU (). Upon redundant receipt of the downlink packets, the communication terminal device () removes a redundant downlink packet in accordance with a predefined downlink packet removal criterion.

A high-speed communication system etc. are provided in New Radio (NR) and LTE. When a secondary base station device detects a data inactive state for all bearers, the secondary base station device notifies a master base station device of occurrence of the data inactive state regardless of absence of an inquiry from the master base station device. The data inactive state is a state in which downlink data for a communication terminal device is inactive. When the master base station device receives the notification about the occurrence of the data inactive state, the master base station device transmits a command to the communication terminal device to transition from an RRC_CONNECTED state to an RRC_INACTIVE state. Based on the command from the master base station device, the communication terminal device transitions to the RRC_INACTIVE state.

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Tokyo, Japan

Tadahiro Shimoda