Kddi Corporation

Kddi Research, Inc.

Kosuke Yamazaki

Issei Kanno

Takeo Ohseki

Masaaki Ito

Shunsuke Kamiwatari

Naoto Tsumachi

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.

Communication device, control method and computer-readable storage medium for executing transmission power control in relay transmission

A terminal device that comprises a plurality of antennas notifies a network to which the terminal device belongs of information according to which it is possible to specify at least one of, among the plurality of antennas, a second antenna having a predetermined characteristic in common with a first antenna included in the plurality of antennas, and a third antenna not having the predetermined characteristic in common with the first antenna.

Terminal device, network node, and control method for communication control with consideration given to antenna arrangement

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.

Control apparatus selectively using plurality of antennas, control method, and computer-readable storage medium

A control apparatus may wirelessly communicate with a terminal apparatus. 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, the control apparatus may scramble 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.

Control apparatus selectively using plurality of antennas, terminal apparatus communicating with control apparatus, and communication method

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.

Terminal apparatus for executing two-step random access procedure, base station apparatus, and control method

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.

Terminal device executing random access procedure, base station device, control method, and computer-readable storage medium

A wireless communication terminal and a communication system selection method are capable of selecting a communication system having high battery usage efficiency by keeping battery remaining time long and satisfying throughput required by the application depending on scenes. The wireless communication terminalcapable of selecting plural communication systems comprises an application information acquisition unitfor acquiring a type of used application; an evaluation amount calculation unitfor changing a communication system selection criterion in response to the type of application thus acquired and calculating an evaluation amount with respect to time adding predetermined time to communication system switching time; and a system selection unitfor comparing the evaluation amounts thus calculated and selecting any one of communication systems. Therefore, it is possible to select/switch to the communication system having high battery usage efficiency among plural systems in response to a real-time requirement of the application.

Wireless communication terminal and communication system selection method

Provided are a wireless communication terminal that can select a power-efficient wireless communication system while keeping a data rate at a fixed level, and a communication system selection method. A wireless communication terminal is designed to be able to operate selectively according to a plurality of communication systems, and is configured to include: a required data rate calculation section that calculates a required data rate as a data rate needed to be satisfied in accordance with a remaining level of power and a communication history; and a communication system selection section that selects which communication system to be used through a comparison between a data rate of each of the communication systems to be determined based on a measured quality of communication service, and the calculated required data rate. This accordingly enables to select a power-efficient communication system while keeping a data rate at a standard level determined by a remaining level of power and a communication history. For example, the communication system can be used adaptively depending on the remaining level of battery, i.e., when the remaining level of battery is high, selected will be a communication system with a high data rate, and when the remaining level of battery is low, selected will be a communication system with a low data rate.

Growing community of inventors

Fujimino, Japan

Kosuke Yamazaki