National Institute of Information and Communications Technology, Incorporated

Ha Nguyen Tran

Chen Sun

Yohannes Alemseged Demessie

Hiroshi Harada

Homare Murakami

Kentaro Ishizu

Stanislav Filin

Goh Miyamoto

Gabriel Porto Villardi

A technique that can effectively utilize unused wireless link and realize high-quality wireless communication between a communication terminal and a base station and enables efficient distribution of radio resources over an entire wireless communication system is provided. A wireless communication system in which a base station and a communication terminal can conduct wireless communication by detecting a usable wireless link and changing a wireless link used for the connection is also provided. On the communication network side, in addition to a plurality of wireless communication networks and a base station, a server device is provided. Connection-method reconstruction management means for determining a connection method of the wireless communication on the basis of communication condition information including information on usable wireless link at current locations of the base station and the communication terminal and connection-method reconstruction control means for controlling the connection method of the wireless communication for the corresponding base station are provided.

Wireless communication system and method of wireless communication

Object: To provide a mechanism and a function of a system that can determine a communication method and the like effectively utilizing frequency resources, considering priority of each communication, in a cognitive communication network system of a frequency shared type or the like assuming that a given frequency band is shared by a plurality of systems in use. Solution: In a configuration in which a cognitive communication network system has a plurality of radio access networksand a superior communication networkthat provides a common platform at least to the radio access networks, in a plurality of base stationson at least a part of the radio access network, base-station state obtaining meansthat collect information relating to a state of the base station itself in the base station or a communication state and base-station communication reconfiguration managing meansthat reconfigure at least one of either a selection of the base station to be used in the communication or a communication condition in the base station on the basis of the information collected by the base-station state obtaining means are provided.

Cognitive communication network system and communicating method thereof

Disclosed is a wireless communication system and the like that can avoid interference even if a plurality of networks coexist. The wireless communication system includes a primary user, cluster head equipment, and a secondary user. The cluster head equipment is for providing a local area network to a cluster region containing the abovementioned primary user. Also, the cluster head equipment contains: an acquisition means that acquires one or both&#x2014;of information regarding the primary user and information regarding a primary signal&#x2014;and the like; and a transmission means that transmits information to the secondary user. Then, using this wireless communication system, the secondary user performs cognitive wireless communication or the like on the basis of the information received from the transmission means of the cluster head equipment.

Wireless communication system, cluster head equipment (CHE) installed in wireless communication system, and wireless communication method

Disclosed is a wireless communication system capable of avoiding interference even when a network including a secondary user coexists. The wireless communication system includes a primary user belonging to a first network, a first secondary user belonging to a second network, and a coexistence manager (CM). The coexistence manager (CM) acquires information relating to spectrum holes that are, at least temporarily, not in use by the primary user. In addition, the coexistence manager (CM) determines whether or not usage of the spectrum holes by the first secondary user causes interference. If the determination result is that interference is caused, coexistence manager (CM) notifies to this effect a second secondary user belonging to a third network, which differs from the second network.

Wireless communication system, coexistence manager installed in said system, and method for wireless communication

There is disclosed a channel adjusting method capable of suppressing the occurrence of interference between a cognitive pilot channel (CPC) and an auxiliary control channel (ACS) in cognitive wireless communications. According to the channel adjusting method for use in cognitive wireless communications, initially, a connection using a cognitive pilot channel (CPC) is set up. Thereafter, it is determined whether or not a spectrum sensing channel (ACS) is to be utilized. If yes, it is then determined whether or not any interference occurs between the spectrum sensing channel (ACS) and the set-up cognitive pilot channel (CPC). This allows an adjustment to be performed such that no interference occurs between the cognitive pilot channel (CPC) and the spectrum sensing channel (ACS).

Method for adjusting channels in cognitive wireless communication, and cognitive wireless communication system capable of implementing the method

Provided is a power control method, etc., in cognitive radio communication, by which power control can be effectively performed without a large indirect cost. In the power control method, a target value of SNR is estimated on the basis of the control information relating to interference. Subsequently, communication power used for the cognitive radio communication is adjusted on the basis of the estimated target value of SNR. Thereby, power control can be effectively performed without a large indirect cost.

Power control method in cognitive radio communication, cognitive radio communication system, and radio communication device

In a cognitive radio communication device, before a communication link for the cognitive radio communication is established, a control channel which is a common channel which can be used by a plurality of cognitive radio communication devices is detected. By exchanging sensing information and sensing control information among the plurality of radio communication devices using the detected common channel, the information is shared. The plurality of cognitive radio communication devices share the sensing information and the sensing control information, and use the information for determining a channel used for spectrum monitoring and data communication, and the like.

Information sharing method in cognitive radio communication, cognitive radio communication device, and cognitive radio communication system

Provided is a wireless communication system capable of increasing safety in the aviation industry, and applicable to the aviation industry. The wireless communication system comprises a control device and a spectrum sensor. The spectrum sensor performs spectrum sensing using a measurement SAP, receives a signal from a wireless communication device, and transmits information relating to the received signal as sensing information through a communication SAP. On the other hand, the control device receives the sensing information from the spectrum sensor through the communication SAP. Subsequently, the sensing information is analyzed using an application SAP. Thereby, whether or not the signal from the wireless communication device interferes with the radio waves of the airband used in the aviation industry is specified.

Wireless communication system applied to aviation industry and airband interference detection method

Provided is a spectrum sensor for cognitive wireless communication whereby it is possible to improve communication efficiency. In a cognitive wireless communication system, a spectrum sensor senses spectra in multiple frequency bands. A spectrum sensor is configured to be able to operate in one operation mode selected from among a spectrum sensing mode for sensing spectra, and a communication mode for communicating with a wireless communication device. Further, the spectrum sensor is provided with a controller for controlling the operation mode. The controller switches between the above-mentioned operation modes during the symbol period of an ultra-wideband physical layer (UWB PHY).

Spectrum sensor for cognitive wireless communication and method for cognitive wireless communication

Embodiments of the invention enable a large number of wireless communication networks to be efficiently used while the size of a device operated by a user is reduced and power is saved by providing a communication terminal whose connection with different wireless communication networks can be dynamically reconfigured. A communication terminal whose connection with a plurality of wireless communication networks can be dynamically reconfigured is provided with a data communication aggregation device, a communication application executing device, and a local communication path therebetween. The data communication aggregation device interfaces with the plurality of wireless communication networks and communicates with the communication application executing device through the local communication path. The communication application executing device executes an application for communicating with an outside communication network.

Communication terminal and communication network system

To reduce power consumption for scanning and maintain communication quality by reducing the time for scanning or connection when a wireless communication terminal switches between networks or base stations. A wireless communication terminalenabling connection with a plurality of base stations disposed in different positions which includes a base station scanning unitdetecting and scanning a base station capable of communication at the current position of the wireless communication terminal, a simultaneous detection base station recording unitrecording simultaneously detected base stations as simultaneous detection information in a storage unit, a connection candidate extraction unitand a first communication unitperforming communication by connection with the extracted connection candidate base station. Based on the simultaneous detection information, the connection candidate extraction unitextracts a base station having the possibility of simultaneous detection with the currently connected base station as a connection candidate base station.

Wireless communication terminal and wireless communication system

To provide a method of selecting an optimal base station for each application when accumulating communication quality in response to an application type for a base station and a communication terminal switches base stations. A communication quality databaseis prepared by assigning a current location of a communication terminal device, a currently running application program and a communication quality when executing an application program. When making a new connection with a base station, the current application and location is used to select a base station having an optimal communication quality from the communication quality database. This mechanism may be provided in the communication terminal device or may be provided as a communication system including a server device.

Growing community of inventors

Koganei, Japan

Ha Nguyen Tran