Abstract: A terminal apparatus specifies, based on capability information of the terminal apparatus, one of a first resource with which an apparatus that is not capable of performing repeated transmission of a message 3 in a four-step random access procedure in consecutive slots can transmit a random access preamble, and a second resource that is different from the first resource and with which an apparatus that is capable of performing repeated transmission of the message 3 in consecutive slots can transmit the random access preamble, as a resource to be used when the terminal apparatus transmits the random access preamble, and transmits the random access preamble to a base station apparatus with the specified resource.

Abstract: A base station device transmits a control signal for causing a transition from an RRC_CONNECTED state to an RRC_INACTIVE state and including connection parameter information to a terminal device. The terminal device performs uplink transmission to the base station device using the connection parameter information included in the control signal in the RRC_INACTIVE state to which the RRC_CONNECTED state has transitioned. The base station device performs uplink reception from the terminal device that is in the RRC_INACTIVE state to which the RRC_CONNECTED state has transitioned using the connection parameter information included in the control signal.

Abstract: A base station device transmits a control signal for causing a transition from an RRC_CONNECTED state to an RRC_INACTIVE state and including connection parameter information to a terminal device. The terminal device performs uplink transmission to the base station device using the connection parameter information included in the control signal in the RRC_INACTIVE state to which the RRC_CONNECTED state has transitioned. The base station device performs uplink reception from the terminal device that is in the RRC_INACTIVE state to which the RRC_CONNECTED state has transitioned using the connection parameter information included in the control signal.

Abstract: The present embodiments relate to multi user detection in distributed antenna systems. A communication system may include a central processing circuitry and a plurality of access points connected to the central processing circuitry via a fronthaul interface. Each access point of the plurality of access points may include a plurality of antennas configured to receive signals from a plurality of UEs, and a local processing circuitry connected to the plurality of antennas. The local processing circuitry may be configured to estimate channel properties of a MIMO channel between the UEs and the antennas of the access point, and determine a subset of the UEs using the channel properties. The local processing circuitry may transmit data associated with the subset of wireless communication devices to the central processing circuitry for use to perform multiuser detection at the central processing circuitry.

Abstract: A communication device capable of connecting to and communicating with another device using a first function operating as a terminal device and a second function operating as a base station device, the communication device acquires a first reception power density of a signal of a downlink received from an upstream device connected by the first function, acquires a second reception power density of a signal of an uplink received from a downstream device connected by the second function, and transmits a transmission power control command for controlling transmission power of the signal of the downlink to the upstream device, based on the first reception power density and the second reception power density.

Abstract: A base station device transmits a control signal for causing a transition from an RRC_CONNECTED state to an RRC_INACTIVE state and including connection parameter information to a terminal device. The terminal device performs uplink transmission to the base station device using the connection parameter information included in the control signal in the RRC_INACTIVE state to which the RRC_CONNECTED state has transitioned. The base station device performs uplink reception from the terminal device that is in the RRC_INACTIVE state to which the RRC_CONNECTED state has transitioned using the connection parameter information included in the control signal.

Abstract: A terminal apparatus that performs communication using a communication path set between the terminal apparatus and a core network via a base station apparatus connected to the core network or via the base station apparatus and a relay apparatus that relays communication with the base station apparatus acquires information regarding candidates of a communication path to which switching should be performed from a first communication used, from the base station apparatus that functions as a serving base station in the first communication path, determines whether or not to perform switching of the communication path from the first communication path, and performs switching from the first communication path to a second communication path included in the candidates without being instructed by the serving base station, in response to the determination to perform the switching after receiving the information regarding the candidates.

Abstract: A terminal apparatus that performs communication using a communication path set between the terminal apparatus and a core network via a base station apparatus connected to the core network or via the base station apparatus and a relay apparatus that relays communication with the base station apparatus acquires information regarding candidates of a communication path to which switching should be performed from a first communication used, from the base station apparatus that functions as a serving base station in the first communication path, determines whether or not to perform switching of the communication path from the first communication path, and performs switching from the first communication path to a second communication path included in the candidates without being instructed by the serving base station, in response to the determination to perform the switching after receiving the information regarding the candidates.

Abstract: A control apparatus that is connected to a plurality of antennas and performs communication of user data with a terminal apparatus using at least one of the plurality of antennas, specifies a reception state of a random access preamble transmitted from the terminal apparatus for establishing connection with the control apparatus, at each of the plurality of antennas, selects an antenna to be used when performing communication of user data with the terminal apparatus, from the plurality of antennas based on the respective reception states at the plurality of antennas, and performs control such that communication of user data is performed with the terminal apparatus using the selected antenna.

Abstract: A control apparatus that wirelessly communicates with a terminal apparatus scrambles, when a random access preamble is received from the terminal apparatus, if the random access preamble is not based on a setting notified by the control apparatus, communication with the terminal apparatus after the random access preamble is received, using a scrambling sequence that is based on second identification information different from first identification information corresponding to the control apparatus.

Abstract: The present invention provides a terminal device comprising: transmission unit configured to transmit a first message including user data to a base station device in a random access procedure in a mobile communication network; and control unit configured to control the transmission unit to: in a case where a predetermined condition to transition from an inactive state to a connected state is satisfied, transmit the first message that includes predetermined information for notifying the base station device that the terminal device needs to transition to the connected state; and in a case where the predetermined condition is not satisfied, transmit the first message that does not include the predetermined information.

Abstract: A terminal apparatus transmits a predetermined message to a base station apparatus based on a two-step random access procedure, upon receiving one signal that is transmitted from the base station apparatus in response to the predetermined message, and includes pieces of upper layer control information for the terminal apparatus and another terminal apparatus in a multiplexed manner, specifies a first radio resource for transmitting a first response signal indicating whether or not succeeded in receiving control information that is for the terminal apparatus and is included in the one signal, and is different from a second radio resource for transmitting a second response signal for the other terminal apparatus, based on at least one of a control signal that is used for transmitting the one signal and the one signal, and transmits the first response signal using the first radio resource.

Abstract: A terminal apparatus transmits message 1 of a 4-step random access procedure using information of a first beam among a plurality of beams formed by a base station apparatus in order to connect to the base station apparatus, receives, from the base station apparatus, message 2 of the random access procedure as a response to the message 1, and transmits, in response to the message 2, message 3 of the random access procedure including information of a second beam as a beam serving a candidate for switching from the first beam based on radio qualities measured for the plurality of beams after transmitting the message 1.

Abstract: A terminal apparatus, which executes a two-step random access procedure or a four-step random access procedure to establish a connection with a base station apparatus, executes control such that, in a case where a first message of the two-step random access procedure including a preamble and predetermined information for connection establishment is transmitted and a number of unsuccessful attempts to receive the first message by the base station apparatus exceeds a predetermined number, the terminal apparatus transmits a second message to be transmitted from the terminal apparatus to the base station apparatus in the four-step random access procedure.

Abstract: A terminal apparatus that establishes, on the basis of a two-step random access procedure, an initial connection with a base station apparatus by transmitting a first message to the base station apparatus and receiving a second message, which is a reply to the first message, from the base station apparatus, is provided. The first message includes a preamble to be transmitted using one sequence selected from a plurality of sequence candidates and predetermined information for initial access, each one of the plurality of sequence candidates is associated with a radio resource to be used for transmitting the predetermined information, wherein a first radio resource associated with a first candidate of the plurality of sequence candidates is different from a second radio resource associated with a second candidate of the plurality of sequence candidates.

Abstract: A terminal apparatus, which is able to establish a connection with a base station apparatus via a two-step random access procedure by transmitting a first signal including a random access preamble and predetermined information to the base station apparatus and receiving a second signal as a reply to the first signal from the base station apparatus, acquires a random access-radio network temporary identifier (RA-RNTI) on the basis of a radio resource having been used to transmit the predetermined information with the first signal, and executes reception processing of the second signal using the RA-RNTI.

Abstract: A communication apparatus, which is capable of performing, in a predetermined frequency band to be used by a first radio communication system configured to periodically transmit a reference signal with a predetermined frequency spacing, communication using a second radio communication system that is different from the first radio communication system, performs communication of the second radio communication system while the base station apparatus of the first radio communication system operates in a mode in which periodic transmission of the reference signal is stopped for a predetermined period, based on information relating to a timing at which a base station apparatus of the first radio communication system is to operate in the mode.

Abstract: A base station device transmits a control signal for causing a transition from an RRC_CONNECTED state to an RRC_INACTIVE state and including connection parameter information to a terminal device. The terminal device performs uplink transmission to the base station device using the connection parameter information included in the control signal in the RRC_INACTIVE state to which the RRC_CONNECTED state has transitioned. The base station device performs uplink reception from the terminal device that is in the RRC_INACTIVE state to which the RRC_CONNECTED state has transitioned using the connection parameter information included in the control signal.

Abstract: A terminal comprises a function capable of operating in a plurality of states that include a first state in which a connection with a base station has been established, and a second state in which a connection with a base station has not been established, but the base station holds information regarding the terminal device. After starting operation in the second state from a state in which the terminal operates with a first base station in the first state, if predetermined information that enables communication with the first base station in the second state and that has been acquired from the first base station in the first state is held, the terminal determines whether a signal transmission target has changed from the first base station to a second base station device, and performs communication according to a result of the determination.

Abstract: A terminal operable in a first state where connection with a base station is established and a second state where connection with the base station is not established but the base station holds information regarding the terminal is provided. The terminal receives, from the base station, information regarding whether to establish time synchronization when a signal is to be transmitted to the base station in the second state, determines, based on the information, as to whether to establish time synchronization when transmitting a signal to the base station in the second state, and transmits a signal to the base station in the second state, with executing processing for establishing time synchronization with the base station if time synchronization is to be established, and without executing the processing if time synchronization is not to be established.