Ntt Docomo, Inc.

Ntt Mobile Communications Network, Inc.

Junichiro Hagiwara

Motoshi Tamura

Yasuyuki Watanabe

Takaaki Sato

Kazufumi Yunoki

Katsuhiko Yamagata

Yoshiyuki Yasuda

Mutsumaru Miki

Masafumi Hata

Takuya Hamajima

Nobutaka Ishikawa

Nobuhide Uchiyama

Akiko Okamoto

Kenya Kusunose

Akihiro Uchikoshi

Daisuke Igarashi

Yasufumi Morioka

Hideaki Takahashi

Takehiro Nakamura

Hiroshi Kawakami

Seizo Onoe

Akihiro Higashi

Etsuhiro Nakano

Koji Ohno

Masatomo Nakano

Hiroki Morikawa

Hiroyuki Ishii

Hiroto Yasuda

Jinho Kim

Mikio Iwamura

Akira Yamada

Anass Benjebbour

Yusuke Ohwatari

Tomoyuki Ooya

Hitoshi Yoshino

Hiromasa Fujii

Narumi Umeda

Yukihiko Okumura

Yasuhiro Kato

Kazunori Obata

Hidenori Aoki

Akiko Green Gables C-101 12-14 Okamoto

Nobutaka 202 Bell Light Nokendai Ishikawa

A radio communication system is disclosed that includes at least one user equipment and multiple base stations including a first base station configured to execute radio resource control of the user equipment through a control path and a second base station configured not to execute radio resource control of the user equipment. The system includes multiple gateways, including a first gateway connected with the first base station and a second gateway connected with the second base station, and a switching station that controls the establishment of user paths among nodes.

Radio communication system and control method

A radio communication system includes at least one user equipment, a first base station, a second base station, a first gateway, a second gateway, and a switching station. The switching station decides whether or not a gateway through which communication executed by the user equipment should be routed is the second gateway. In a case in which it is decided that the gateway through which communication executed by the user equipment should be routed is the second gateway, the switching station executes control for establishing a first user path for uplink and a second user path that is a radio path. The second base station executes control for establishing a first user path for downlink.

A radio communication system includes a user device, a first base station, a second base station, a switching center, and a gateway device. In a handover operation performed in a situation in which a user-plane path has been established through the first base station, the first base station transmits, to the user device, a radio connection reconfiguration message commanding that a radio bearer be established between the second base station and the user device and receives a radio connection reconfiguration complete message transmitted from the user device. The first base station transmits, to the switching center, a path switching request message requesting that the established user-plane path be changed so as to pass through the second base station.

Radio communication system

The radio communication system has a user equipment, a first base station, a second base station, a serving gateway, and a switching station. The first base station has a control-plane path set to the switching station. The second base station has no control-plane path to the switching station. A path setting determiner determines whether to set a user-plane path, based on measurement information reported from the user equipment. A base station determiner determines, based on identification information obtained by the user equipment, whether a base station to which the user-plane path is to be set is the second base station, the base station corresponding to the obtained identification information.

A radio communication system has a user equipment, a first base station, a second base station, and a gateway device. The first base station is capable of executing radio resource control of the user equipment, whereas the second base station does not execute radio resource control of the user equipment. The first base station, based on a measurement report message, determines whether a user-plane path is to be established between the first base station and the second base station. In a case in which it is determined that a user-plane path is to be established, the first base station establishes a user-plane path between the first base station and the second base station. Also, the first base station controls the user equipment to establish a user-plane path between the user equipment and the second base station.

Radio communication system and base station

A base station generates first setting information commonly used for establishing a logical path for communication with a user apparatus and for establishing a logical path for communication with a relay station, and second setting information used only for establishing the logical path for communication with the relay station, and transmits a second RRC message including the second setting information to the relay station after transmitting a first RRC message including the first setting information to the relay station. The first setting information includes information indicating a priority of a radio bearer in the logical path, information indicating usage of resources in SPS, information indicating resources of SRS, configuration information in a MAC sublayer, and information on change of a security encryption key in handover, and the second setting information includes at least system information and MBSFN information.

Base station, relay station and method in mobile communication system

A relay station includes a signal generation unit configured to generate a signal in the relay station and a receiving unit configured to receive a signal from a first communication station. The relay station further includes a signal generating node identifying unit configured to identify whether a signal to be transmitted to a second communication station is a received signal received from the first communication station or a generated signal generated by the signal generation unit. The relay station further includes a signal transmission unit configured to transmit both or one of the received signal and the generated signal associated with a radio bearer to the second communication station.

Relay station for relaying communication between user apparatus and base station, and relay method

A relay station includes a reception section that receives a first radio frame sent from a base station, and a transmission section that sends a second radio frame that includes a downstream data signal included in the received first radio frame, to a mobile station located in a cell of the relay station. When it is determined that a first identifier of a handover-destination cell, included in a first radio frame, matches a second identifier of the cell of the relay station, included in the second radio frame, and that the transmission timing of the first identifier matches the transmission timing of the second identifier, a time shift section of the relay station shifts the transmission timing of the second radio frame sent from the transmission section so as to make the transmission timing of the first identifier different from the transmission timing of the second identifier.

Relay apparatus, radio communication system, and transmission control method

A relay node of a communication system includes a communication unit that initiates a session by executing an initial connection procedure for retrieving a cell list indicating one or more donor base station candidates from a maintenance node after establishment of an initial communication link among the relay node, a base station, and a switching center, and for establishing a communication link to a donor base station in the cell list and a switching center connected to the donor base station; a storing unit that stores the cell list; and a reconnection control unit that selects, when a radio link with the donor base station is lost, a donor base station satisfying a predetermined criterion in the cell list, and that causes the communication unit to establish a communication link to the selected donor base station and a switching center connected to the selected donor base station.

Relay node and reconnection method

A relay station for relaying a radio signal between a mobile station and a base station includes a relay station information generating unit configured to generate relay station information used by the base station to select a switching center to be connected to the relay station. The relay station also includes a message generating unit configured to generate a message including the relay station information generated by the relay station information generating unit, and a transmitting unit configured to transmit the message generated by the message generating unit to the base station.

Relay station, base station, radio communication system, and method

A coordinated transmission method of the invention has the steps of selecting a directional pattern corresponding to an area in which a radio terminal locates, from among a plurality of directional patterns determined respectively corresponding to a plurality of resources in frequency domains where the plurality of directional patterns is configured so that a plurality of radio base stations surrounding the area transmits, to the area, directional beams of same frequency domain resources to face one another, while not transmitting the directional beams of the same frequency domain resources using the same frequency domain resources to areas adjacent to the area, and of distributing a signal to transmit to the radio terminal according to the selected directional pattern, determining a frequency domain and directions of directional beams regarding the distributed signal, and delivering the signal to each of the plurality of radio base stations that simultaneously transmits the signal to the radio terminal.

Coordinated transmission method, coordinated transmission system, central station and radio base station

When a network pages the temporary user mobile identifier of a mobile station, the mobile station sends a response to the network. Next, the network checks the authenticity of the user using a ciphering key, corresponding to the temporary user mobile identifier and a random number. If the temporary user mobile identifier is authenticated, a normal incoming call acceptance procedure is executed. If the mobile station is authenticated although the temporary user mobile identifier is wrong, the network reassigns a new temporary user mobile identifier to the mobile station and stops the current communication. In communication, the network and the mobile station mutually notify encipherment-onset time and negotiate about encipherment manner with each other. In addition, diversity handover is commenced upon a call attempt. Furthermore, if a branch replacement is necessary, the current branch is replaced by new branches capable of executing the diversity handover. Additionally, when a new call occurs to or from the mobile station capable of treating a plurality of calls simultaneously, the mobile station uses the same branch structure and the same communication frequency band for all of calls. Additionally, when a new call occurs to or from the mobile station capable of treating a plurality of calls simultaneously, a branch structure and a communication frequency band, which can continue all of the calls, are selected and used. Therefore, the mobile communications system is suitable for transmission of various sorts of data in accordance with the development of multimedia.

Method and system for mobile communications

The present invention is to provide a communication channel with a low inter-cell interference while suppressing variation in the amount of inter-cell interference. Provided is a base station arranged in a radio communication system configured to implement a frequency division multiple access method by using a frequency division multiplexing method as a modulation method, and configured of cells each divided into an inner region and an outer region. The base station includes an allocation controller configured to perform subchannelization using a perfectly-orthogonal channel in the outer region of the cell, and to perform subchannelization using a quasi-orthogonal channel in the inner region of the cell.

Radio communication apparatus and radio communication method

A disclosed radio communication apparatus transmits a radio signal to multiple users via multiple transmit antenna groups at appropriate transmit power levels, each of the transmit antenna groups including one or more transmit antennas, the transmit antenna groups having respective transmit power constraints. The apparatus includes a precoding unit configured to perform precoding on signals modulated for individual users and generate transmit weights, an optimum transmit power calculation unit configured to receive the transmit weights from the precoding unit and use components of the transmit weights and respective transmit power limit values for the transmit antenna groups to calculate an initial value for a transmit power optimization problem for calculation of the appropriate transmit power levels for the users, and a transmission unit configured to transmit radio signals at the calculated transmit power levels.

When a new call occurs to or from the mobile station capable of treating a plurality of calls simultaneously, the mobile station uses the same branch structure and the same communication frequency band for all of calls. Additionally, when a new call occurs to or from the mobile station capable of treating a plurality of calls simultaneously, a branch structure and a communication frequency band, which can continue all of the calls, are selected and used.

Growing community of inventors

Yokohama, Japan

Junichiro Hagiwara