Kyushu Institute of Technology

Toyota Infotechnology Center Co. Ltd.

Toyota Jidosha Kabushiki Kaisha

Kazuya Tsukamoto

Onur Altintas

Yuji Oie

Masato Tsuru

Hideaki Tanaka

Koichi Seki

A wireless communication method implemented by a first apparatus constituting a vehicle-to-vehicle communication system, including: receiving vehicle data transmitted on a control channel from a second apparatus; acquiring, from a map information storage unit configured to store map information divided into a plurality of first areas, information relating to a first area including a current position of the first apparatus; determining whether or not to access a DB storing WS information on the basis of position information relating to the first in-vehicle wireless communication apparatus, position information relating to another apparatus, and information relating to the first area; acquiring WS information relating to a vicinity of the current position from the DB after determining to access the DB; and transmitting the WS information acquired from the DB in the querying step to a peripheral apparatus.

Wireless communication method, in-vehicle wireless communication apparatus, and program

There is provided a technique of establishing a communication between a transmitting node and a receiving node by selecting a suitable frequency band for communication without using a predetermined control channel. Firstly, a frequency band to be used as a control channel is selected from among low frequency bands, and information on frequencies and information on application's quality requirements are exchanged between the transmitting node and the receiving node using the control channel. Then, a frequency band to be used as a data channel is determined, and a communication is started. During the communication, frequency use statuses around the transmitting node and the receiving node are notified through the control channel, and when the control channel or data channel being used becomes unusable, the channel is dynamically changed. Since a low frequency band having a long propagation distance is used as the control channel, exchange of information through the control channel can be performed before communication through a data channel in a high frequency band becomes possible, the data channel that meets the quality requirements can be determined quickly.

Frequency band coordination method and radio communication apparatus in cognitive radio system

Provided is a technique that enables quicker detection of usable frequency bands in a cognitive radio system. Each radio communication apparatus in the system has, in common, a hash function used to obtain a frequency range from time information and location information. Each radio communication apparatus detects unused frequency bands while narrowing down a frequency range over which a detection process is performed by obtaining the terminal's own location information and current time information from GPS signals, and input them to the hash function. Since a transmitting node and a receiving node that perform a communication are at locations close to each other at the same time, they perform detection in the same frequency range. Therefore, an unused frequency band(s) that is usable by both of them can be detected. Furthermore, at different locations or at different times, the detection will be performed in different frequency ranges. Therefore efficient frequency utilization can be achieved. It is preferred that the nodes have a plurality of kinds of hash functions in common.

Unused frequency band detection method and radio communication apparatus in cognitive radio system

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Kitakyushu, Japan

Kazuya Tsukamoto