Abstract: A wireless communication device 1 encrypts a passphrase which corresponds to a communication mode after change and which is a character string for authentication by using an encryption key PTK corresponding to a communication mode before change, and transmits the encrypted passphrase to a wireless communication device 2, and also creates an encryption key PTK corresponding to the communication mode after change from the passphrase corresponding to the communication mode after change. The wireless communication device 2 receives the encrypted passphrase transmitted from the wireless communication device 1 and decrypts the encrypted passphrase by using an encryption key PTK corresponding to the communication mode before change, and also creates an encryption key PTK corresponding to the communication mode after change from the decrypted passphrase.

Abstract: Each of wireless communication devices 2A, 2B and 2C is configured in such a way as to transmit information about either a service or an application which the wireless communication device can provide, in accordance with a protocol which makes it possible to perform wireless communications with a wireless communication device 1 regardless of the setting of a communication mode to the wireless communication device 1, and the wireless communication device 1 is configured in such a way as to collect information about an application which is transmitted from each of the wireless communication devices 2A, 2B and 2C. As a result, the wireless communication device 1 can acquire the information about the providable application from each of the wireless communication devices 2A, 2B and 2C existing in the surroundings thereof regardless of the setting of a communication mode.

Abstract: A radio communication system includes a plurality of radio communication apparatuses including an active scan terminal and a passive scan terminal. After transmitting a probe request frame from one frequency channel, the active scan terminal continuously transmits the probe request frame from other frequency channels without waiting for a response frame from the other radio communication apparatuses, thereafter transmits the probe request frame from a response channel, which is a waiting channel, and waits for a response from the passive scan terminal, and superimposes, on the probe request frame, information concerning an offset time to the response and information concerning the response channel, and, after receiving the probe request frame, after the elapse of the offset time to the response, the passive scan terminal transmits a response frame from a frequency channel designated by the response channel information.

Abstract: Each of wireless communication devices 2A, 2B and 2C is configured in such a way as to transmit information about either a service or an application which the wireless communication device can provide, in accordance with a protocol which makes it possible to perform wireless communications with a wireless communication device 1 regardless of the setting of a communication mode to the wireless communication device 1, and the wireless communication device 1 is configured in such a way as to collect information about an application which is transmitted from each of the wireless communication devices 2A, 2B and 2C. As a result, the wireless communication device 1 can acquire the information about the providable application from each of the wireless communication devices 2A, 2B and 2C existing in the surroundings thereof regardless of the setting of a communication mode.

Abstract: A radio communication system includes a plurality of radio communication apparatuses including an active scan terminal and a passive scan terminal. After transmitting a probe request frame from one frequency channel, the active scan terminal continuously transmits the probe request frame from other frequency channels without waiting for a response frame from the other radio communication apparatuses, thereafter transmits the probe request frame from a response channel, which is a waiting channel, and waits for a response from the passive scan terminal, and superimposes, on the probe request frame, information concerning an offset time to the response and information concerning the response channel, and, after receiving the probe request frame, after the elapse of the offset time to the response, the passive scan terminal transmits a response frame from a frequency channel designated by the response channel information.

Abstract: A wireless communication device 1 encrypts a passphrase which corresponds to a communication mode after change and which is a character string for authentication by using an encryption key PTK corresponding to a communication mode before change, and transmits the encrypted passphrase to a wireless communication device 2, and also creates an encryption key PTK corresponding to the communication mode after change from the passphrase corresponding to the communication mode after change. The wireless communication device 2 receives the encrypted passphrase transmitted from the wireless communication device 1 and decrypts the encrypted passphrase by using an encryption key PTK corresponding to the communication mode before change, and also creates an encryption key PTK corresponding to the communication mode after change from the decrypted passphrase.