Ntt Docomo, Inc.

Ntt Mobile Communications Network, Inc.

Shinya Tanaka

Takehiro Nakamura

Koichi Okawa

Hiroyuki Ishii

Anil Umesh

Akihito Hanaki

Yoshimasa Imamura

Masafumi Usuda

Mamoru Sawahashi

Kenichi Higuchi

Hidehiro Ando

Yoshinori Miki

Tomoki Sao

A target base station transmits a traffic assignment signal a plurality of times to a control station for notifying a traffic amount of downlink data that can be processed by the target base station, after a notified cell change timing in which the mobile station changes a communicating base station.

Base station, mobile communication system, and mobile communication control method

The present invention relates to a packet transmission control device which controls transmission of packets to a plurality of mobile stations. A scheduling unit of the packet transmission control device according to the present invention is configured to schedule the packets to each of the plurality of mobile stations, based on an average transmission rate, a minimum guaranteed transmission rate, a scheduling frequency and capability information.

Packet transmission control device and packet transmission control method

A packet transmission control apparatus is configured to perform transmission control of packets to a plurality of mobile stations. The packet transmission control apparatus includes an acquirer configured to acquire a scheduling frequency which shows a frequency of scheduling of packets to each mobile station in a predetermined period, and a scheduler configured to control scheduling of packets to each mobile station in accordance with an acquired scheduling frequency.

Packet transmission control apparatus and packet transmission control method

A packet transmission control apparatus which performs transmission control of packets to a plurality of mobile stations includes an acquirer configured to acquire an average transmission rate of packets to each of the mobile stations and a guaranteed transmission rate of the packets; and a scheduler configured to perform scheduling to transmit packets to a specific mobile station preferentially, when an average transmission rate of the packets to the specific mobile station approaches the guaranteed transmission rate.

The object of the present invention to provide a directional beam communication system whereby the beam width of a directional beam to be transmitted is reduced by sharing an array antenna among a plurality of adjacent sectors so as to increase the interference suppression effect. The directional beam communication system is configured to communicate with a mobile station MS located in a service area formed by a plurality of sectors Sand Susing a directional beam which is transmitted by an array antenna A including a plurality of antenna elements a. The array antenna A for transmitting the directional beam is shared among at least two adjacent sectors Sand S

Directional beam communication system, directional beam communication method, base station and controller

A method for connecting the radio link between a mobile station and a base station is provided to improve quality of received signals at the base station and the mobile station. A radio network controller (RNC) monitors the difference between the reception power of signals from the source base station BSand the destination base station BS. If the base station BSis incapable of directional beam signal transmission and reception, and when the reception power difference becomes smaller than a first handover threshold, the radio network controller adds the base station BSas a radio link connection destination of the mobile station. If the base station BSis capable of directional beam signal transmission and reception, and when the reception power difference becomes smaller than a second handover threshold, which is larger than the first handover threshold, the radio network controller adds the base station BSas a radio link connection destination of the mobile station.

Base station connection method, radio network controller, and mobile station

The object of the present invention is to improve the accuracy of channel estimation and increase downlink capacity when a base station transmits an individual channel using directional beams. The base stationaccording to the present invention comprises an individual channel transmitterconfigured to transmit an individual channel into which pilot symbols are inserted; and an individual channel format creatorconfigured to create a format of the individual channel. The individual channel format creatorchanges between a format of an individual channel which is to be transmitted using directional beams and a format of an individual channel which is to be transmitted using non-directional beams.

Radio communication method, base station and mobile station

A base station is configured to transmit a downlink signal to a mobile station located in a sector managed by the base station. The downlink signal is spread using a scrambling code. The base station has a monitor configured to monitor a change of a reception condition of an uplink common channel of the mobile station in the sector, a DOA estimator configured to estimate a direction of arrival of an uplink signal transmitted from the mobile station, in response to the change, an area border setter configured to separate the sector into a plurality of areas, by setting an area border in the sector in accordance with the estimated direction, a scrambling code assigner configured to assign a different scrambling code to each of the separated areas and a spreader configured to spread the downlink signal using the assigned scrambling code in each of the separated areas.

Radio communication method and base station

A base station comprises a directional antenna configured to transmit a directional beam to a mobile station, an omnidirectional antenna configured to transmit an omnidirectional beam to the mobile station, and an antenna controller configured to determine whether or not the mobile station is capable of receiving the directional beam, and select the directional antenna as an antenna for transmitting individual data in a case of being capable of receiving the directional beam, or select the omnidirectional antenna as an antenna for transmitting the individual data in a case of being incapable of receiving the directional beam.

Base station, mobile communication system, and communication method

The object of the present invention is to avoid disconnection of a radio link between the radio base station and the mobile station even when the mobile station moves while transmitting no up signals in a case where the radio base station transmits the directional beam. The radio base station according to the present invention comprises an array antennato transmit/receive the directional beam, an transceiverto receive an up signal from a mobile stationand to generate a directional beam pattern for each mobile station according to an antenna weight, a up signal interval measurerto measure elapsed time from reception of the up signal, and a antenna weight generatorto change the antenna weight based on a result of measuring by the up signal interval measurer

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Yokohama, Japan

Shinya Tanaka