Mitsubishi Electric Corporation

Tcl Communication Technology Holdings Limited

Mitsubishi Denki Kabushiki Kaisha

Ntt Docomo, Inc.

Tetsuya Mishuku

Noriyuki Fukui

Shigenori Tani

Ryoichi Fujie

Mitsuru Mochizuki

Miho Maeda

Yasushi Iwane

Michiaki Takano

Masaaki Kusano

Akira Okubo

Keiko Tada

Keisuke Ozaki

Hidehiko Oyane

Takahisa Yamauchi

Tatsuro Yajima

Genya Kotani

A mobile terminaljudges whether or not the mobile terminal is able to make a transition to a DTX period during Active, and, when judging that the mobile terminal is able to make a transition to a DTX period during Active, notifies a base stationto that effect. If the base stationjudges that the mobile terminal is able to make a transition to a DRX period during Active when triggered by the notification from the mobile terminal, the base station temporarily stops supply of electric power to the data transmission processing units and the data reception processing units of the mobile terminal

Mobile communications system and mobile terminal

Since OFDM (Orthogonal Frequency Division Multiplexing), which is a downlink access scheme used for an LTE (Long Term Evolution) communication system, is weak at interference, it is preferable that the number of base stations for transmitting the same E-MBMS (Evolved Multimedia Broadcast Multicast Service) data base not excessive. Thus, the mobile terminal performs: processing of obtaining measurement quality values by measuring reception quality of each base station; processing of deciding on whether the measurement quality value of a serving base station exceeds a certain receiving level; processing of adding measurement quality values of other base stations to the measurement quality value of the serving base station until the sum exceeds the certain receiving level; and processing of notifying the serving base station of the serving base station and other base stations as candidates for an active set for E-MBMS. This makes it possible to select as the active set for E-MBMS an appropriate number of base stations that make it compatible to maintain good reception quality and to prevent interference.

Data communication method and mobile communication system

Since OFDM (Orthogonal Frequency Division Multiplexing), which is a downlink access scheme used for an LTE (Long Term Evolution) communication system, is weak at interference, it is preferable that the number of base stations for transmitting the same E-MBMS (Evolved Multimedia Broadcast Multicast Service) data be not excessive. Thus, the mobile terminal performs: processing of obtaining measurement quality values by measuring reception quality of each base station; processing of deciding on whether the measurement quality value of a serving base station exceeds a certain receiving level; processing of adding measurement quality values of other base stations to the measurement quality value of the serving base station until the sum exceeds the certain receiving level; and processing of notifying the serving base station of the serving base station and other base stations as candidates for an active set for E-MBMS. This makes it possible to select as the active set for E-MBMS an appropriate number of base stations that make it compatible to maintain good reception quality and to prevent interference.

A terminal switching method for switching terminals, in a communication system in which HARQ processing is performed, to which a base station grants a transmission permission, from a terminal A to a terminal B includes notifying the terminal B of aborting of the transmission permission, setting a time point at which an HARQ process whose state of the HARQ processing is a retransmission waiting state with the terminal A is performed as a virtual starting point, setting a retransmission waiting window having a predetermined window length with the virtual starting point being regarded as its starting point, and notifying the terminal B of the transmission permission when there is no HARQ process having the retransmission waiting state with the terminal A, wherein the virtual starting point setting and the window setting are repeated until there is no HARQ process having the retransmission waiting state with the terminal A.

Terminal switching method, base station, and communication system

In a communications system including a base station capable of altering a frequency bandwidth which is used for transmitting broadcast data for providing point-to-multipoint broadcasting communications service and which is used for transmitting individual communications data for providing point-to-point individual communications service, and a mobile terminal capable of altering a receivable bandwidth which is used for receiving at least the broadcast data and the individual communications data transmitted from the base station, decision processing of making a decision as to whether the mobile terminal can receive reception-desired content it desires to receive among contents provided by the broadcasting communications service is executed in accordance with a frequency occupying bandwidth used for transmitting the reception-desired content. Thus, the mobile terminal becomes able to make a decision as to whether it can receive particular E-MBMS content considering its own UE position.

Data communications method and mobile communications system

A base station divides a packet into a plurality of wireless transfer blocks, determines a priority of a wireless transfer block based on a delivery acknowledged amount accumulated value, allocates wireless resources to the wireless transfer blocks based on determined priority, and transmits generated wireless transfer blocks by using allocated wireless resources. A mobile station transmits a delivery acknowledgement to the base station when the wireless transfer block is properly received and a re-transmission request when the wireless transfer block is not properly received, and reproduces the packet from received wireless transfer blocks.

Communication system, base station, and mobile station

A mobile terminal judges whether or not the mobile terminal is able to make a transition to a DTX period during Active, and, when judging that the mobile terminal is able to make a transition to a DTX period during Active, notifies a base station to that effect. If the base station judges that the mobile terminal is able to make a transition to a DRX period during Active when triggered by the notification from the mobile terminal, the base station temporarily stops supply of electric power to the data transmission processing units and the data reception processing units of the mobile terminal.

A data-transmission control method is implemented when transmitting data after dividing the data into a plurality of blocks and performing error correction when performing data transmission. The method includes obtaining additional information indicating a result of error correction process of received data and a result of data transmission (ACK/NACK) from a reception station, and deciding a data length of data to be retransmitted when NACK is obtained as the result of data transmission so that a rate of occurrence of transmission errors upon retransmission is minimized, based on a number of blocks in which error correction has failed indicated by the additional information.

Data-transmission control method and transmission device

A base station assigns a most appropriate carrier from wide frequency bands in response to a re-request for channel establishment received from a mobile station, even if a same slot as a slot last assigned is assigned. Furthermore, a frequency management table is managed in which carriers that form a radio channel and are grouped by a specific number thereof so as to be distributed over wide frequency bands. Priorities used to search groups are individually provided for base stations that form a system. This allows neighboring base stations to distribute carriers over the wide frequency bands.

Growing community of inventors

Tokyo, Japan

Tetsuya Mishuku