Abstract: 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 ST1417).

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Better communication is provided. A communication system includes a communication terminal, and a base station configured to perform radio communication with the communication terminal. The communication terminal or the base station determines whether the base station supports a desired slice that is a Radio Access Network slice that the communication terminal desires to use.

Abstract: 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, 802) that transmit and receive radio signals, and a central unit (CU, 801) that controls the plurality of DUs (802). The CU (801) duplicates a downlink packet addressed to a communication terminal device (804), and forwards the duplicated downlink packet to each of at least two DUs (802) among the plurality of DUs (802). Each of the at least two of the DUs (802) transmits, to the communication terminal device (804) by the radio signal, the downlink packet obtained from the CU (801). Upon redundant receipt of the downlink packets, the communication terminal device (804) removes a redundant downlink packet in accordance with a predefined downlink packet removal criterion.

Abstract: A communication system includes a communication terminal, and a plurality of networks configured to perform radio communication with the communication terminal. A priority of at least one of a paging timing and a paging type is assigned to a paging to be transmitted from each of the plurality of networks. The communication terminal selects a corresponding one of the pagings to be received, based on the priority.

Abstract: Satisfactory SL communication is provided. A communication system includes: a first communication terminal; a second communication terminal configured to perform inter-terminal communication with the first communication terminal; and a third communication terminal configured to perform inter-terminal communication with the first communication terminal. The third communication terminal reports resource information for the inter-terminal communication between the first communication terminal and the second communication terminal to the first communication terminal via an interface for the inter-terminal communication between the first communication terminal and the third communication terminal.

Abstract: Provided is a communication system, etc. with low latency and high reliability, under New Radio (NR). A communication system includes a communication terminal device, and a plurality of nodes configured to be connected to the communication terminal device for radio communication and to provide a split bearer for the communication terminal device. The communication terminal device is configured to perform uplink transmission to an uplink transmission node among the plurality of nodes. The uplink transmission node is determined by an uplink transmission node determination process in which a node that provides the uplink transmission from the communication terminal device with lower latency among the plurality of nodes is determined as the uplink transmission node.

Abstract: In a communication system with redundant paths which can ensure the reliability and maintain time-sensitive communications (TSC), a first host and a second host communicate through a plurality of communication paths. In the event of a past or current communication failure in any of the plurality of communication paths, mobility of communication terminals in communication paths other than the any of the plurality of communication paths is restricted.

Abstract: A terminal device having a relay function of relaying a signal received from a first peripheral terminal among peripheral terminals, which are other terminal devices available for direct communication with the terminal device, to a second peripheral terminal among the peripheral terminals, the terminal device including: a detection unit that detects the peripheral terminals; a storage unit that holds peripheral terminal information that is information on each of the peripheral terminals detected by the detection unit; and an information notification unit that transmits a notification message for notifying the other terminal devices of information on the terminal device, the notification message including the peripheral terminal information held by the storage unit.

Abstract: In the SL communication, the QoS required for each service is maintained, and the reliability of the service is enhanced. A communication system includes a base station, and a plurality of communication terminals configured to perform communication with the base station and perform Device-to-Device communication. A first communication terminal transmits, to a third communication terminal, a scheduling request for performing the Device-to-Device communication with a second communication terminal. The third communication terminal transmits, to the base station, the scheduling request received from the first communication terminal. In response to the scheduling request received from the third communication terminal, the base station generates scheduling information on the Device-to-Device communication between the first communication terminal and the second communication terminal, and transmits the scheduling information to the third communication terminal.

Abstract: Provided is a communication system, etc. with low latency and high reliability, under New Radio (NR). A communication system includes a communication terminal device, and a plurality of nodes configured to be connected to the communication terminal device for radio communication and to provide a split bearer for the communication terminal device. The communication terminal device is configured to perform uplink transmission to an uplink transmission node among the plurality of nodes. The uplink transmission node is determined by an uplink transmission node determination process in which a node that provides the uplink transmission from the communication terminal device with lower latency among the plurality of nodes is determined as the uplink transmission node.

Abstract: A highly reliable communication system is provided, for example. A communication system includes a communication terminal device, and a plurality of base stations configured to perform radio communication with the communication terminal device. The plurality of base stations include a master base station and a secondary base station configuring dual connectivity with respect to the communication terminal device. When failure occurs in a secondary cell group (SCG) used for communication between the communication terminal device and the secondary base station, the master base station acquires latest SCG configuration.

Abstract: Provided is a communication system capable of suppressing decrease in a transmission rate. An eNB communicates with a UE using a self-contained subframe. The self-contained subframe includes a downlink signal to be transmitted from the eNB to the UE, and an uplink signal to be transmitted from the UE to the eNB in response to the downlink signal. The uplink signal has a structure including an uplink control signal indicating information for controlling transmission of the uplink signal, and uplink user data to be transmitted before and after the uplink control signal. The eNB notifies the UE of a structure of the uplink signal. The eNB may predetermine scheduling for retransmission to retransmit the downlink signal, before performing initial transmission of the downlink signal.

Abstract: Provided is a technology for implementing a service using Device-to-Device communication such as the V2X communication. A communication system includes: a base station configured to perform communication with a core network; and a communication terminal configured to perform radio communication with the base station. The base station supports a Non-Public Network. The communication terminal is configured to implement a service using Device-to-Device Communication. The communication terminal determines whether the base station is accessible, based on information indicating in which Non-Public Network various services using the Device-to-Device Communication are available.

Abstract: A technology that enables prompt NW connection is provided. A communication system includes: a communication terminal; and a plurality of networks configured to perform radio communication with the communication terminal. The communication terminal determines whether or not there is paging causing collision among a plurality of pagings respectively transmitted to the communication terminal from the plurality of networks. When the communication terminal detects the collision of the paging, the communication terminal notifies at least one of the plurality of networks that transmits the paging causing the collision of the paging about the collision of the paging.