Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: PER when a wireless apparatus is connected with a predetermined wireless access point is estimated on the basis of three parameters of the received signal strength, the interference signal strength, and the interference adjacency, which have been transmitted from the wireless access point, then the communication throughput is calculated by using the estimated PER, and the connection with a wireless access point expected to have highest communication efficiency is performed. As a result, it is possible to select a wireless access point having high communication efficiency with good precision, as compared with a method, in the related art, of simply performing a connection with a wireless access point having high received signal strength or a method of simply performing a connection with a wireless access point where an interference wave is strong.

Abstract: PER when a wireless apparatus is connected with a predetermined wireless access point is estimated on the basis of three parameters of the received signal strength, the interference signal strength, and the interference adjacency, which have been transmitted from the wireless access point, then the communication throughput is calculated by using the estimated PER, and the connection with a wireless access point expected to have highest communication efficiency is performed. As a result, it is possible to select a wireless access point having high communication efficiency with good precision, as compared with a method, in the related art, of simply performing a connection with a wireless access point having high received signal strength or a method of simply performing a connection with a wireless access point where an interference wave is strong.

Abstract: In a wireless communication system where a fixed radio bandwidth is used, a wireless communication apparatus and a usage bandwidth determination method that guarantee the QoS of real time application data without changing the configurations of the existing base station apparatus and IP network. A wireless resource control section (170) negotiates with a base station apparatus (20) when a wireless communication terminal apparatus (10) changes over from an idle mode to a communication mode, to determine a usable radio bandwidth. A bandwidth estimation section (180) estimates the available bandwidth for the non-real time application from the usable radio bandwidth and the required bandwidth for the real time application. An awnd estimation section (190) estimates the maximum awnd that shows the maximum amount of the packet that can be received in the wireless communication terminal apparatus (10) from the available bandwidth for the non-real time application.