Nippon Telegraph and Telephone Corporation

Hirantha Abeysekera

Yasushi Takatori

Toshiro Nakahira

Koichi Ishihara

Takafumi Hayashi

Tomoki Murakami

Shoko Shinohara

Masato Mizoguchi

Takeo Ichikawa

Munehiro Matsui

Riichi Kudo

Yasuhiko Inoue

Yusuke Asai

Akiyoshi Inoki

Yoshifumi Morihiro

Keisuke Wakao

Mamoru Akimoto

Takahiro Asai

Akira Yamada

Akira Kishida

Kenichi Kawamura

Yukihiko Okumura

Yasufumi Morioka

Daisuke Goto

Hiroto Yasuda

Riku Omiya

Daisuke Koizumi

In a wireless communication system including a plurality of base stations to which terminal stations are connectable, and a monitoring station which monitors each of the base stations, the monitoring station includes an information collection unit configured to collect wireless environment information including a plurality of information items indicating wireless environments around the base stations and the terminal stations, from each of the base stations, a defect detection unit configured to detect whether or not one or more defects occur based on a combination of the information items, and a defect determination unit configured to determine estimated occurrence probabilities of the defects detected by the defect detection unit based on a combination of the information items.

Wireless communication system, monitoring station, defect detection method, and wireless communication program

Provided is a wireless communication system in which, based on a random access scheme, a transmission opportunity (TXOP) acquired by a wireless access point is granted to a wireless station when performing uplink data transmission from the wireless station to the wireless access point and the TXOP acquired by the wireless station is granted to the wireless access point when performing downlink data transmission from the wireless access point to the wireless station, the system includes a scheduling unit for TXOP granting determining one or more wireless stations having a quality of an uplink data transmission lower than a prescribed value as TXOP responders to which the wireless access point grants the TXOP, and determining one or more wireless stations having a quality of a downlink data transmission lower than the prescribed value as TXOP holders which grant the TXOP to the wireless access point.

Wireless communication system and wireless communication method

A radio communication method of connecting a base station with a plurality of terminal stations, the base station including a plurality of radio communication units compatible with a plurality of communication standards or communication schemes, the method including collecting, from each of the plurality of terminal stations, communication quality information representing a communication quality of the terminal station, collecting, from each of the plurality of terminal stations, communication performance information representing a communication performance of the terminal station, collecting, from each of the plurality of terminal stations, identifier information that identifies the terminal station, calculating, based on the communication quality information, the communication performance information and the identifier information that are collected, a setting policy including a setting for each of the plurality of radio communication units, and a switching policy of setting a condition for switching the plurality of radio communication units, and setting, for each of the plurality of radio communication units, the terminal station to be connected based on the setting policy and the switching policy that are calculated.

Wireless communication method, base station, and wireless communication system

A wireless communication system includes a plurality of base stations to which terminal stations are connectable, and a base station control device controlling each of the base stations. The base station control device includes an information collection unit collecting wireless environment information indicating wireless environments around the base stations and the terminal stations from each of the base stations, and a policy calculation unit calculating a policy for connecting the base stations and the terminal stations based on the wireless environment information. Each of the base stations includes receiver receiving the calculated policy a destination calculation unit calculating a destination to which a terminal station left unaccommodated is to be connected based on the received policy, and a transmitter transmitting the received policy and the calculated destination to the terminal station. Each of the terminal stations determines a connection destination based on the transmitted policy and transition destination.

Wireless communication system, communication control method, and communication control program

A wireless communication system includes a plurality of base stations to which one or more terminal stations are connectable, and a base station control device controlling each of the plurality of base stations. The base station control device includes an information collection unit collecting connection information regarding the terminal stations connected to the base stations from each of the base stations, a list generation unit generating a white list indicating the terminal stations allowed to be connected to the base stations for each of the base stations based on the connection information, and a transmission unit configured to transmit the white list to each of the base stations. Each of the base stations includes a reception unit receiving the white list, and a setting unit performing setting so as to allow or inhibit connection of each of the terminal stations to the base station based on the received white list.

Wireless communication system, base station control device, communication control method, and communication control program

A wireless performance evaluation method for performing wireless performance evaluation of a wireless network including wireless base stations and wireless terminal stations includes: before performing wireless performance evaluation operation based on wireless performance evaluation information generated from wireless performance evaluation conditions, determining whether an existing wireless performance evaluation result of wireless performance evaluation operation that has been performed is substitutable or not; and if the existing wireless performance evaluation result is substitutable, skipping arithmetic processing corresponding to the wireless performance evaluation information and substituting the existing wireless performance evaluation result.

Wireless performance evaluation method and wireless performance evaluation system

A wireless communication system includes a base station to which a plurality of terminal stations are connectable and a control unit that controls the base station. The base station includes a collection unit that collects terminal station information indicating terminal stations each having issued a connection request to the base station, an information processing unit that causes a storage unit to store connected terminal station information indicating, among the terminal stations indicated by the terminal station information, the terminal station currently being connected to the base station, a network communication unit that receives, from the control station, base station control information for controlling a response to the connection request from the terminal station that is not indicated by the connected terminal station information, and a connection determination unit that determines, based on each of the connected terminal station information and the base station control information, whether or not the connection request from the terminal station that is not indicated by the connected terminal station information is to be refused. The control station transmits, when a predetermined condition is satisfied, to the base station, the base station control information indicating that the connection request from the terminal station that is not indicated by the connected terminal station information is to be refused.

Wireless communication system, base station, and wireless communication method

In a wireless communication system wherein wireless stations transmit on a shared frequency band, each of the wireless station includes means for notifying a control device of environmental information that includes information on interference from outside, and for switching from an operational channel to an evacuation channel notified by the control device when interference from outside is detected on the operational channel, and the control device includes means for calculating an evacuation channel for each wireless station according to a predetermined control procedure based on the environmental information collected from the wireless station, and for notifying the wireless station of the evacuation channel.

Wireless communication system, and wireless communication method

Included are a plurality of base stations to which a plurality of terminal stations are connectable and a control station that controls each of the base stations. The control station includes a network communication unit that receives, from each of the base stations, base station information indicating the base station, wireless environment information indicating a reception signal received by the base station from another of the base stations and a signal intensity thereof, and terminal station information indicating the terminal station connected to the base station and a signal intensity and a calculation unit that calculates, based on the base station information, the wireless environment information, and the terminal station information each received from each of the base stations, connection control information for controlling a connection permission from each of the base stations to each of the terminal stations. Each of the base stations includes a connection control unit that controls, based on the connection control information, the connection permission to each of the terminal stations.

Wireless communication system, control station, base station, and wireless communication method

A radio communication method of connecting a base station with a plurality of terminal stations, the base station including a plurality of radio communication units compatible with a predetermined communication standard, the method including collecting additional-line information including information regarding whether each terminal station is compatible with additional communication standard; collecting request information including a request in the predetermined communication standard of each terminal station; collecting identifier information that identifies each terminal station; calculating, based on the additional-line information, the request information and the identifier information that are collected, a setting policy including a setting for each radio communication unit, and a switching policy of setting a condition for switching the plurality of radio communication units; and setting, for each radio communication unit, the terminal station to be connected based on the setting policy and the switching policy that are calculated.

A communication control method for controlling transmission powers transmitted by a plurality of base stations in a coverage area, the coverage area being covered by the plurality of base stations includes setting a transmission power of each base station to a maximum, calculating, for each base station, a percentage of an individual coverage area with respect to the coverage area when the transmission power of each base station is set to the maximum, the individual coverage area serving as a range in which each base station individually accommodates a terminal station, reducing, when a maximum value of the calculated percentages deviates from an average value by a predetermined value or greater, the transmission power of any of the plurality of base stations with the maximum percentage value, newly calculating, for each base station, a percentage of the individual coverage area with respect to the coverage area, and continuing the control until the maximum value of the calculated percentages deviates from the average value by less than the predetermined value.

Communication control method, control station, and communication control program

A method includes collecting, as environment information, a radio environment represented by a signal received at a plurality of radio communication units from another base station, each of the plurality of radio communication units being switchable between a normal mode in which the radio communication unit performs radio communication as a base station and a subordinate mode in which the radio communication unit performs radio communication as a virtual terminal station, calculating test conduct information for each base station based on base station performance information representing a performance of each base station and the environment information, and conducting an operation test of each base station by, based on the test conduct information, setting any of the radio communication units to the normal mode, switching the radio communication units of the other base station to the subordinate mode, and performing radio communication with each other.

Base station operation test method, wireless communication system, and base station

A wireless communication characteristic evaluation method for calculating a wireless communication characteristic of a wireless communication system in which a plurality of wireless communication terminals perform communication by transmitting or exchanging signals includes: an RSSI measurement step of measuring an RSSI measurement used for calculation of the wireless communication characteristic; and a calculation step of calculating the wireless communication characteristic based on the RSSI measurement and correction data of the RSSI measurement according to specifications of the wireless communication terminals or a correction calculation model.

Wireless communication characteristic evaluation method and wireless communication characteristic evaluation device

In a wireless communication system including an intermediate processing device which performs processing between a plurality of base stations to which terminal stations are connectable and a base station control device which controls each of the base stations, the intermediate processing device includes an information collection unit configured to collect wireless environment information which includes information regarding the terminal stations connected to the base stations and which indicates wireless environments around the base stations and the terminal stations, from each of the base stations, a first conversion unit configured to convert the wireless environment information collected by the information collection unit into first information which is equally processable by the base station control device without distinction for each of the base stations, a transmission unit configured to transmit the first information to the base station control device, a reception unit configured to receive a parameter calculated by the base station control device based on the first information, and a second conversion unit configured to convert the parameter received by the reception unit into individual second information in accordance with each of the base stations, and each of the base stations includes a reception unit configured to receive the second information and a setting unit configured to perform setting so as to perform communication with each of the terminal stations based on the second information.

Wireless communication system, intermediate processing device, communication control method, and communication control program

A wireless communication system in which wireless stations perform transmission, a plurality of wireless modules that are operated in a shared frequency band being installed in the wireless stations, wherein the wireless stations each include means for notifying a control device of environment information that includes capacity information regarding the wireless station and information regarding a surrounding wireless environment, the control device includes means for determining an operation mode of each wireless module of each wireless station based on the environment information collected from each wireless station, following a control guideline that is determined in advance, and notifying the wireless stations of the operation modes, and the wireless stations each include means for setting the operation modes in the plurality of wireless modules and changing connection of connection destination wireless stations according to the operation modes of the wireless modules, the wireless stations being notified of the operation modes by the control device.

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Yokosuka, Japan

Hirantha Abeysekera