Ntt Docomo, Inc.

Masashige Shirakabe

Hitoshi Yoshino

Naoto Matoba

Nobuhiko Miki

Akihito Morimoto

Takatoshi Sugiyama

Takahiro Asai

Satoshi Nagata

Yukihiko Okumura

Akihito Hanaki

Kei Kikuiri

Yoshiaki Ofuji

Satoru Fukumoto

Tatsuro Masamura

A radio communication system includes multiple base stations including a first base station and a second base station, and a mobile station. A candidate base station selector selects multiple candidate base stations that are candidates for a radio access point for the mobile station on the basis of the reception powers reported by the mobile station. When the mobile station actually executes wireless communication with the base station, an access-point base station determiner determines, as an access-point base station that is the actual radio access point for the mobile station, a base station corresponding to a best reception quality among reception qualities measured in the protected resource and reception quality measured in the non-protected resource.

Radio communication system, mobile station, base station, and communication control method

A high-power radio base station includes a resource setter configured to determine a ratio of the number of second resources at which the radio communicator should stop radio transmission to the sum of the number of the second resources and the number of first resources at which the radio communicator should execute radio transmission. The resource setter determines the ratio on the basis of a first number and a second number, the first number being the number of mobile terminals that are assumed to be connected with the radio base station, rather than the low-power radio base station, when cell range expansion (CRE) is not applied, but are connected with the low-power radio base station by virtue of application of cell range expansion, the second number being the number of mobile terminals connected with the radio base station when cell range expansion is applied. The resource setter determines the ratio in such a manner that the greater the proportion of the second number to the first number, the smaller the ratio.

Radio communication system and radio base station

A radio communication system includes a first radio base station, second radio base stations, and mobile stations. Each of the mobile stations measures a first reception characteristic value and a second reception characteristic value for respective radio waves. The first radio base station determines the radio base station to which each of the mobile stations should connect, according to the first reception characteristic value, and classifies the mobile stations into a first mobile-station group and a second mobile-station group according to the second characteristic values. The first radio base station specifies a correction value according to the distribution of differences in the first reception characteristic value so as to reduce the sum of the number of mobile stations that belong to the second mobile-station group and that should connect to the first radio base station and the number of mobile stations that belong to the first mobile-station group and that should connect to second radio base stations.

Radio communication system and communication control method

A radio communication system includes a first radio base station that forms a first cell; a plurality of second radio base stations each of which forms a second cell; and a mobile station provided with a radio communication unit that connects, by radio, to each radio base station. The first radio base station specifies a correction value according to the number of the second cells formed in the first cell of the first radio base station and signals the correction value to the mobile station. The mobile station corrects a characteristic value indicating the reception characteristic of radio waves from the second radio base station by using the correction value. Either the first radio base station or the mobile station selects the destination of the mobile station according to the characteristic value of the first radio base station and the corrected characteristic value of the second radio base station.

Radio communication system, radio base station, and communication control method

A wireless resource assigning apparatus for assigning wireless resources to transmission data of a plurality of users is disclosed. The wireless resource assigning apparatus includes a scheduling part configured to start scheduling for all users from a first wireless resource among a plurality of wireless resources prioritized according to a predetermined criterion, and repeat scheduling up to the last wireless resource for users except for users to whom any wireless resource has been assigned.

Wireless resource assigning apparatus and wireless resource assigning method

To provide a radio communication control apparatus and a radio communication control method capable of controlling simultaneous transmission and reception so as not to degrade system throughput. A simultaneous transmission and reception controllerdetermines whether the simultaneous transmission and reception using the same frequency are possible, based on radio spectrum environment information of an opposite party of communication and radio spectrum environment information of a self-apparatus. When the simultaneous transmission and reception using the same frequency are determined to be possible, a control signal transmission sectiontransmits instruction information, indicating that the simultaneous transmission and reception are possible, and a transmission parameter thereof, to the above communication terminal. After the transmission parameter is set, a communication sectionexecutes simultaneous transmission and reception with the above communication terminal using the same frequency, when the simultaneous transmission and reception using the same frequency are determined to be possible.

Radio communication control apparatus and radio communication control method

A radio frequency selection device in a radio communication system in which a radio communication channel is established between a mobile station and a base station by allocating a radio communication frequency band different from other radio communication system frequency bands is disclosed. The radio frequency selection device comprises: a frequency band determining unit that determines a radio control channel frequency band for transmitting control information, among frequency bands allocated to the radio communication system, based on the allocated radio communication channel frequency band; and a radio control channel establishing unit that establishes a radio control channel among the determined radio control channel frequency bands.

Radio frequency selection device, a radio communication system and radio control channel establishing method

A frequency band allocation device is disclosed. The frequency band allocation device comprises a frequency band selection unit for selecting usable frequency bands from a dedicated frequency band, a registered frequency band and an unlicensed frequency band; and a frequency band allocation unit for allocating a frequency band out of the selected usable frequency bands to a user, so as to satisfy user required QoS and maximize system frequency utilization factor.

Frequency band allocation device and method

A transmitter used in the multiband environment includes a frequency allocation unit () configured to select and allocate a frequency band that satisfies a user QoS from among multiple separate frequency bands currently available for the user, a parameter determination unit () configured to determine a transmission parameter required for signal transmission based on the allocated frequency band, and a multi-user scheduling control unit () configured to determine a transmission schedule for multiple users taking into account the frequency bands allocated to the multiple users.

Multiband mobile communication system and transmitter used therein

A frequency selection apparatus, a mobile communications system, and a multi-band resource management method are disclosed. The frequency selection apparatus includes

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Yokohama, Japan

Masashige Shirakabe