National Institute of Information and Communications Technology, Incorporated

Kentaro Ishizu

Hiroshi Harada

Homare Murakami

Stanislav Filin

Ha Nguyen Tran

Goh Miyamoto

Daisuke Inoue

Masahiro Kuroda

Chen Sun

Yohannes Alemseged Demessie

A plurality of consecutive frequency bands are used as a broadband and use efficiency thereof is improved. An available-frequency-band-information-list is retained such that the list is categorized into frequency-band-groups, each of the groups is a series of consecutive frequency bands, and a frequency-band-number-width is given to each of the groups. Determining a necessary-frequency-band-number, one group is selected from the groups whose width match the number as a first-type band group, when any of the width of each of the groups does not match the number, one group is selected from the groups whose width are next larger than the number as a frequency band group to be used, and a series of consecutive frequency bands corresponding to the number is selected from the frequency band group to be used as a second-type band group. Communication is controlled so as to use the first-type or the second-type band group.

Communication device and communication control method

Provided is a management device maintaining communication qualities while accommodating a changeable communication environment. Based on correspondence between each geographical position of plural managed devices and available frequencies thereat, pair available frequencies available in common by arbitrary two managed devices are specified for each pair, and notified to the arbitrary two devices. From managed devices, acquiring pair communication qualities obtained when the pair available frequencies is used, defined is a best pair available frequency capable of obtaining a best pair communication quality. Specifying all of candidate paths connecting the each pair, relaying other managed devices, calculated are, based on the best pair communication quality, path communication qualities in the candidate paths connecting the each pair using the best pair available frequency. Selecting for the each pair a use path having a best quality in the path communication qualities, communication between the each pair is performed by using the use path.

Communication management device and communication management method

Provided are an information transmission device and method thereof allowing a wireless device intended to newly start an operation in a white space to efficiently perform its preparatory operation, the transmission device including: a first retainer retaining first information including at least a list of channels available in each of first-type partial areas obtained when dividing an area at a first fineness; a second retainer retaining second information including at least a list of channels available in each of second-type partial areas obtained when dividing the area at a second fineness finer than the first fineness; a generator generating multiplexed information including the first and the second information so that the first and the second information are repeated at equal frequencies, or the first information is repeated at a frequency higher than that of the second information in the time axis direction; and a transmitter wirelessly transmitting the multiplexed information.

Information transmission device and information transmission method

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

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

The present invention provides a technique capable of processing to automatically and optimally select types of external networks and a communication system, and at the same time, capable of switching network selection upon a user's arbitrary opportunity. A communication connection deviceis provided with: a network communication adaptorconnecting a terminal device; external network communication adaptorscompatible with external networks; a network selection processing portionautomatically selecting a network from the external networks according to profile informationpreviously including at least one of types of networks and a communication system; re-selection processing instruction mechanismsdesigned to cause, as a result of a user's operation, the network selection processing portionto start selection processing.

Communication connection device

The present invention provides a user-carriable mobile communication relay device that relays communication between an internal network and an external network, in which even when the device is moved, the device dynamically selects and connects the external network depending on a surrounding radio wave environment or a communication content. The device is provided with an internal network communication adaptercompatible with the internal network connecting to a specific terminal deviceexternal network communication adapterscompatible with external networks with a mobile telephone network and with a wireless LAN at an installation site; a network selection processing portionautomatically selecting one or more networks to be connected, out of the external networks, according to stored profile informationan internal network connection processing portionestablishing or reconfiguring the connection to an internal network selected for a predetermined opportunity; an external network connection processing portionestablishing or reconfiguring the connection to an external network selected for a predetermined opportunity; and a communication relay processing portionrelay-processing communication between the internal network and the external network.

Mobile communication relay device

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.

Communication terminal device, communication system and method of selecting base station thereof

The present invention provides a technology of effectively avoiding tracing on a terminal performed with an identification number being a target and DoS attack without making any significant changes to a communication system. In the wireless communication system of the present invention, under a control of a control communication processing portionof an access point, a hash function arithmetic operation processing portiongenerates a third identification number to be updated using a current identification number, hash key and random number for any wireless communication terminal, a control communication processing portionsends an update instruction signal containing the random number to the wireless communication terminal and updates the current identification number stored in the identification number storage portionto a second identification number. When the wireless communication terminal receives an update instruction signal, the current identification number is updated to the second identification number and the hash function arithmetic operation processing portion generates a third identification number using the current identification number, hash key and random number stored in the self number storage portion.

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Koganei, Japan

Kentaro Ishizu