Tokyo, Japan
Tokyo, Japan

NTT DOCOMO, Inc. is the predominant mobile phone operator in Japan. The name is officially an abbreviation of the phrase, "do communications over the mobile network", and is also from a compound word dokomo, meaning "everywhere" in Japanese. Docomo provides phone, video phone , i-mode , and mail services. The company has its headquarters in the Sanno Park Tower, Nagatachō, Chiyoda, Tokyo.Docomo was spun off from Nippon Telegraph and Telephone in August 1991 to take over the mobile cellular operations. It provides 2G PDC cellular services on the 800 MHz band, and 3G FOMA W-CDMA services on the 2 GHz and 800 MHz ) and 1700 MHz ) bands, and 4G LTE services. Its businesses also included PHS , paging, and satellite. Docomo ceased offering a PHS service on January 7, 2008. Wikipedia.


Time filter

Source Type

An audio packet error concealment system includes an encoding unit for encoding an audio signal consisting of a plurality of frames, and an auxiliary information encoding unit for estimating and encoding auxiliary information about a temporal change of power of the audio signal. The auxiliary information is used in packet loss concealment in decoding of the audio signal. The auxiliary information about the temporal change of power may contain a parameter that functionally approximates a plurality of powers of subframes shorter than one frame, or may contain information about a vector obtained by vector quantization of a plurality of powers of subframes shorter than one frame.


Patent
NTT DoCoMo | Date: 2016-10-28

A method for waking up one or more sleeping small cell base stations in a wireless communication system for serving a user equipment is described. The wireless communication system includes a plurality of small cell base stations and one or more macro base stations. A wake up signal configuration is received at a user equipment, and a wake up signal configured in accordance with the received wake up signal configuration is transmitted by the user equipment.


Patent
NTT DoCoMo | Date: 2016-11-29

Transmission/reception timing of a data signal and a control signal through a Uu interface and transmission/reception timing of the data signal through a Ud interface are properly adjusted. A mobile communication method according to the present invention includes: a step A in which a radio base station eNB notifies a mobile station UE#1 and a mobile station UE#2 that an opportunity to transmit and receive the data signal through the Ud interface is allocated through a PDCCH in which an X-RNTI is used; and a step B in which the radio base station eNB transmit direction information, for notifying of a direction in which the data signal should be transmitted in the opportunity, to the mobile station UE#1 and the mobile station UE#2.


Patent
NTT DoCoMo | Date: 2016-12-07

Provided are a receiver, a transmitter and a radio communication method capable of using non-orthogonal multiple access while suppressing cost increase and processing delay. A mobile station 200A receives non-orthogonal signals, also receives a reference signal to be used for interference cancellation, and extracts the non-orthogonal signal addressed to the mobile station 200A from the received non-orthogonal signals by demodulating and cancelling the radio signal addressed to another mobile station. In addition, the mobile station 200A demodulates the extracted non-orthogonal signal addressed to the mobile station 200A on the basis of the reference signal. The reference signal is multiplexed in the same radio resource block as a resource block allocated to the non-orthogonal signals, and is multiplexed in the radio resource block only when at least one signal is scheduled in the radio resource block.


Patent
NTT DoCoMo | Date: 2016-12-07

A mobile communication method includes the steps of transmitting a first control signal including an identifier different from a C-RNTI to the mobile station UE#A through a FDCCH by a radio base station PhNB#10 managing a cell #10 formed by linking multiple small cells, transmitting a second control signal including an identifier to the mobile station UE through a PDCCH by a radio base station eNB#1 managing a cell #1 having a coverage area overlapping with a coverage area of the cell #10, and regarding the first control signal as valid by the mobile station UE#A, when it determines that the identifier included in the first control signal and the identifier included in the second control signal match each other.


Patent
NTT DoCoMo | Date: 2017-01-25

Techniques for transmitting uplink data in dual connectivity efficiently are disclosed. One aspect of the present invention relates to user equipment having a dual connectivity function to communicate with multiple base stations simultaneously, comprising: a transmission buffer configured to store uplink data for transmission; a buffer status management unit configured to manage a data amount stored in the transmission buffer; and a transmission control unit configured to receive splitting trigger information indicative of a threshold for the data amount stored in the transmission buffer and a first base station to transmit the uplink data stored in the transmission buffer when the stored data amount is smaller than or equal to the threshold and select a base station to transmit the uplink data stored in the transmission buffer from the multiple base stations depending on whether the data amount stored in the transmission buffer is smaller than or equal to the threshold.


A mobile station which communicates with a base station using an unlicensed band includes a resource management unit configured to manage information about an uplink transmission resource allocated by the base station; a transmission detection unit configured to detect whether transmission in the unlicensed band is possible before arrival of the allocated uplink transmission resource; and a transmission unit configured to transmit an uplink signal on the allocated uplink transmission resource, when transmission in the unlicensed band is possible.


Patent
NTT DoCoMo | Date: 2017-03-15

A user apparatus in a communication system including a first base station and a second base station that perform communication with the user apparatus by inter-base station carrier aggregation, including: a maximum transmission power holding unit configured to hold a maximum transmission power that is configured beforehand for the first base station; a transmission power determination unit configured to determine whether a transmission power that is used by the user apparatus for performing signal transmission to the first base station reaches the maximum transmission power held by the maximum transmission power holding unit; and a transmission control unit configured, when it is determined that the transmission power reaches the maximum transmission power by the transmission power determination unit, to stop signal transmission to the second base station.


The present invention is designed so that LBT (Listen Before Talk) is performed adequately in a radio communication system (LAA) to run LTE in an unlicensed band. A radio base station to communicate with a user terminal that is capable of using a licensed band and an unlicensed band has a control section that controls the transmission of downlink signals in the unlicensed band using LBT, a selection section that selects the symbol to execute LBT, randomly, with equal probability, from a plurality of candidate symbols, and an acquiring section that acquires a measurement result, in which the received signal intensity in the LBT period is measured, wherein, when the control section judges that the channel of the unlicensed band is in an idle state from the measurement result of received signal intensity, the control section executes control so that a beacon reference signal is transmitted in all of the candidate symbols that follow the symbol in which LBT was executed.


Patent
NTT DoCoMo | Date: 2017-04-12

A module (10) is a communication device capable of performing data communication by connecting with terminals (20, 30) using short-range wireless communication via preset connection destination addresses. The module (10) includes a switching request receiving unit (13) configured to receive, when the module (10) is connected with the terminal (20), a switching request indicating a connection switching to the terminal (30), an address changing unit (14) configured to change the connection destination address using the reception of the switching request by the switching request receiving unit (13) as a trigger, a connection disconnecting unit (15) configured to forcibly disconnect the connection with the terminal (20) when the connection destination address is changed by the address changing unit (14), and a connection process executing unit (16) configured to receive a connection request from the terminal (30) by the connection destination address changed by the address changing unit (14) after the connection with the terminal (20) is disconnected by the connection disconnecting unit (15) and to connect with the terminal (30).

Loading NTT DoCoMo collaborators
Loading NTT DoCoMo collaborators