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.

Abstract: An in-vehicle apparatus that is a radio communication apparatus includes: a radio communication unit capable of performing radio communication using at least a 5-GHz band; a present-position detecting unit that detects a present position of the own apparatus; and a radio-communication-zone predicting unit that determines, when the radio communication unit is performing communication, whether switching of a channel of the radio communication unit is necessary on a basis of interference data, which is information concerning a coverage of a radio wave transmitted from another system that uses a 5-GHz band and transmits and receives a radio wave in a stationary state, map data, and the present position detected by the present-position detecting unit, and, when switching is necessary, further selects a switching destination channel or causes the radio communication unit to select the switching destination channel.

Abstract: A composite wireless device including a WLAN device and a BT device. The composite wireless device includes a wireless-channel control unit that determines usable FH channels that can be used for frequency hopping of the BT device, based on communication quality information of the WLAN channel, and notifies the BT device of the usable frequency bands, and a BT-communication control unit that acquires communication quality information of an extended frequency band, which is a frequency band other than the usable frequency bands, as extended communication quality information. The wireless-channel control unit adds the FH channels in the WLAN channel, which are determined as being unused based on the extended communication quality information, as the usable FH channels.

Abstract: An in-vehicle apparatus that is a radio communication apparatus includes: a radio communication unit capable of performing radio communication using at least a 5-GHz band; a present-position detecting unit that detects a present position of the own apparatus; and a radio-communication-zone predicting unit that determines, when the radio communication unit is performing communication, whether switching of a channel of the radio communication unit is necessary on a basis of interference data, which is information concerning a coverage of a radio wave transmitted from another system that uses a 5-GHz band and transmits and receives a radio wave in a stationary state, map data, and the present position detected by the present-position detecting unit, and, when switching is necessary, further selects a switching destination channel or causes the radio communication unit to select the switching destination channel.

Abstract: A composite wireless device including a WLAN device and a BT device. The composite wireless device includes a wireless-channel control unit that determines usable FH channels that can be used for frequency hopping of the BT device, based on communication quality information of the WLAN channel, and notifies the BT device of the usable frequency bands, and a BT-communication control unit that acquires communication quality information of an extended frequency band, which is a frequency band other than the usable frequency bands, as extended communication quality information. The wireless-channel control unit adds the FH channels in the WLAN channel, which are determined as being unused based on the extended communication quality information, as the usable FH channels.

Abstract: When prohibiting data transmission by a radio communication terminal, such as a radio communication terminal L-STA, a terminal control apparatus generates radio data including information about a data transmission prohibition time interval in an L-SIG which is a header region which each radio communication terminal can recognize in common, and, if a use state checking unit 21 has checked to see that a channel CH_a is being not used, transmits the radio data to the radio communication terminal L-STA and so on in the form of frames which the radio communication terminal L-STA can recognize by using the channel CH_a.

Abstract: A wireless communication apparatus includes a BT-apparatus unit configured to perform wireless communication using frequency hopping, a WLAN-apparatus unit configured to perform wireless communication in a system different from a system of the BT-apparatus unit using a band including at least a part of a band used by the BT-apparatus unit and using a WLAN-antenna whose directionality is controllable, and an information managing unit configured to, upon detecting simultaneous communication of the BT-apparatus unit and the WLAN-apparatus unit, instruct the WLAN-apparatus unit to perform communication while adjusting a beam direction of the WLAN-antenna and instruct the BT-apparatus unit to measure a communication quality, determine a directionality setting value of the WLAN-antenna based on the communication quality measurement by the BT-apparatus unit, and instruct the WLAN-apparatus unit to perform communication using the determined directionality setting value.

Abstract: A coverage map for a wireless network is generated. The network includes a server communicating with clients in a coverage area. The clients are mobile devices. At the server, location and reliability information from each client is received. The server then constructs and maintains the coverage map according to the location and reliability information. The coverage map is used to deliver telematic information from the server to the clients in response to requests by the clients.

Abstract: A BT apparatus unit configured to perform Bluetooth (registered trademark) communication, a WLAN apparatus unit configured to perform WLAN communication, and an information managing unit configured to acquire a WLAN communication frequency band, which is a frequency band used for the WLAN communication, from the WLAN apparatus unit, determine an unusable frequency band based on the acquired WLAN communication frequency band, and notify the BT apparatus unit of the determined unusable frequency band. The BT apparatus unit performs frequency hopping using a frequency band excluding the unusable frequency band.

Abstract: A base station of a radio communication system emits a radio wave having the same frequency by time division toward a plurality of specific areas from a plurality of antenna elements by using a multiple-beam antenna to form a plurality of spot beams, and transmits broadcast information through a plurality of beacon channels. Upon reception of the broadcast information, a terminal that exists in any one of the plurality of specific areas selects an optimum beacon channel, and transmits a communication establishment request and a bandwidth request to the base station through a request channel corresponding to information for identifying the antenna element, which is included in the broadcast information received through the selected optimum beacon channel. Upon reception of the requests, the base station schedules, when a channel is to be allocated, a channel allocation time including downlink and uplink data bandwidths and the like.

Abstract: A first wireless terminal station transmits beam transmission direction identification information in all directions. A second wireless terminal station receives the transmission direction identification information, combines reception direction identification information and the transmission direction identification information, and transmits directivity direction combination information to a wireless base station. The first and the second wireless terminal stations form directional beams in directions indicated by the directivity direction combination information to thereby perform a direct communication.

Abstract: A combination-information creating unit creates combination information for determining a maximum number of combinations or a maximum frame length according to a usable radio band and a modulation method and combination possibility information for indicating that a combination of frames is possible. A frame combining unit combines a plurality of frames received from an outside access line, based on the combination information, the combination possibility information, and predetermined packet information. A frame dividing unit divides a combined frame included in a received radio signal into individual frames.

Abstract: The radio-tag reading system includes a radio-tag reader and a radio tag storing therein radio tag information. In the radio-tag reader, a radio-tag detection processor transmits via the communication unit a search signal at a predetermined time interval, and detects that the radio tag enters into the communication area of the communication unit based on a response signal to the search signal. A radio-tag information communication processor reads the radio tag information from the radio tag upon receiving the response signal from the radio tag. In the radio tag, a response processor transmits, upon receiving a signal from the radio-tag reader, a response signal in response to the signal.

Abstract: A radio tag is arranged in each of a plurality of radio tag areas. The radio tag areas can be parking lots. A radio tag reader is configured to perform radio communications with the radio tags. The radio tag reader performs radio communications with each radio tag and based on the radio communication determines whether an object, which can be a vehicle, is present in the radio tag area corresponding to the radio tag.

Abstract: A communication method for a CSMA network including a radio terminal and a base station supporting RTS/CTS, includes: the base station transmitting an RTS frame to the radio terminal during a transmission-suspend-period in which the radio terminal suspends transmission to prevent a collision of packets; the radio terminal transmitting an RTR frame to the base station after the transmission-suspend-period has elapsed; and the base station transmitting a data frame to the radio terminal in response to the RTR frame.

Abstract: Upon receiving a frame from a transmitting radio device, a propagation attenuation calculator calculates a propagation attenuation amount from information in the received frame and registers a propagation attenuation amount for each transmission rate in a table. When transmitting a frame, a transmission power controller, selects optimum transmission power to the transmission destination radio device from the table and sends the frame at the selected optimum transmission power, and detects whether there is a value smaller than the selected optimum transmission power in the optimum transmission power at a minimum transmission rate of a radio device different from a transmission destination radio device registered in the optimum transmission power table.

Abstract: A first wireless terminal station transmits beam transmission direction identification information in all directions. A second wireless terminal station receives the transmission direction identification information, combines reception direction identification information and the transmission direction identification information, and transmits directivity direction combination information to a wireless base station. The first and the second wireless terminal stations form directional beams in directions indicated by the directivity direction combination information to thereby perform a direct communication.