Abstract: A mobile body-mounted communication device mounted in a mobile body such as a vehicle and making difficult the long-time tracking of the moving path of the mobile body. The mobile body-mounted communication device mounted in a mobile body and used for transmitting/receiving packet information is characterized by comprising a borrowing address acquiring section for acquiring lending addresses as borrowed addresses from an address management device managing lending addresses, a borrowing time information acquiring section for acquiring information representing predetermined times during which the borrowing addresses can be used from the address management device, and a transmitting section for transmitting packet information including information on a borrowing address out of the borrowing addresses and the mobile body during the predetermined borrowing times determined for the borrowing addresses.

Abstract: Transmission of transmission packets from communication terminals (20) is executed with a probability based on the total number of communication terminals (20) present within a communication area (NA). It is thus possible to determine when to transmit with simple computation, and promptly transmit information. Since when to transmit can be determined with simple computation, when to transmit can promptly be determined according to continuously changing traffic conditions and the throughput of the communication system can be maintained at a high level when the communication terminals (20) are mounted on vehicles.

Abstract: A mobile unit communication apparatus, including a wireless transceiver, is provided at a mobile unit. At the mobile unit communication apparatus, a surrounding object detection unit detects objects surrounding the mobile unit. The surrounding communication impediment detection unit detects a likelihood of an impediment to communication in the surroundings of the mobile unit from conditions for surrounding objects detected by the surrounding object detection unit. A relay communication unit transmits information received by the wireless transceiver from the wireless transceiver. A relay wait time setting unit sets a time until information received by the wireless transceiver is transmitted by the relay communication unit from the wireless transceiver longer for a larger likelihood of an impediment to communication detected by the surrounding communication impediment detection unit.

Abstract: A mobile body-mounted communication device mounted in a mobile body such as a vehicle and making difficult the long-time tracking of the moving path of the mobile body. The mobile body-mounted communication device mounted in a mobile body and used for transmitting/receiving packet information is characterized by comprising a borrowing address acquiring section for acquiring lending addresses as borrowed addresses from an address management device managing lending addresses, a borrowing time information acquiring section for acquiring information representing predetermined times during which the borrowing addresses can be used from the address management device, and a transmitting section for transmitting packet information including information on a borrowing address out of the borrowing addresses and the mobile body during the predetermined borrowing times determined for the borrowing addresses.

Abstract: More rapid and effective communication is performed between mobile units that cannot communicate directly due to impediments to communication that block signals. A mobile unit communication apparatus (1), including a wireless transceiver (9), is provided at a mobile unit. At the mobile unit communication apparatus (1), a surrounding object detection unit (6) detects objects surrounding the mobile unit. The surrounding communication impediment detection unit (7) detects a likelihood of an impediment to communication in the surroundings of the mobile unit from conditions for surrounding objects detected by the surrounding object detection unit (6). A relay communication unit (16) transmits information received by the wireless transceiver (9) from the wireless transceiver (9).

Abstract: A vehicle communication device mounted to each of vehicles for sending and receiving information among plural vehicles includes a traveling lane detecting device for detecting a vehicle traveling lane on a road surface and an appropriateness of relay determining device for determining an appropriateness of relay on the basis of the vehicle traveling lane detected by the traveling lane detecting device, wherein the vehicle communication device assigns a vehicle to be requested to relay the information on the basis of the result determined by the appropriateness of relay determining device and sends the information to the assigned vehicle.

Abstract: A communication device for a movable body mounted to each of movable bodies for exchanging information among the movable bodies includes a surrounding detecting device for detecting a surrounding of the movable body, an appropriateness of relay determining device for determining an appropriateness of relay, a first transmitting process device for transmitting a first signal, a first receiving process device for receiving the first signal sent by the first transmitting process device, a second transmitting process device for determining whether or not the relay is required, and a second receiving process device for receiving the second signal sent by the second transmitting process device.

Abstract: A mobile communication apparatus is provided, which permits highly efficient communication even between mobile units that cannot communicate directly because of signal-shielding communication obstacles. The mobile communication apparatus 10 includes transmission means 11, reception means 11, surrounding environment detection means 13, 14 for detecting whether or not there are communication obstacles in the surroundings of a mobile unit, communication state decision means 15 for making decisions as to the quality of the communication state of the mobile unit based on detection results of the surrounding environment detection means 13, 14, and control means 16 for controlling transmission, via the transmission means 11, of information received by the reception means 11 based on decision results of the communication state decision means 15.

Abstract: A mobile communication apparatus is provided, which permits highly efficient communication even between mobile units that cannot communicate directly because of signal-shielding communication obstacles. The mobile communication apparatus 10 includes transmission means 11, reception means 11, surrounding environment detection means 13, 14 for detecting whether or not there are communication obstacles in the surroundings of a mobile unit, communication state decision means 15 for making decisions as to the quality of the communication state of the mobile unit based on detection results of the surrounding environment detection means 13, 14, and control means 16 for controlling transmission, via the transmission means 11, of information received by the reception means 11 based on decision results of the communication state decision means 15.

Abstract: A vehicle communication device mounted to each of vehicles for sending and receiving information among plural vehicles includes a traveling lane detecting device for detecting a vehicle traveling lane on a road surface and an appropriateness of relay determining device for determining an appropriateness of relay on the basis of the vehicle traveling lane detected by the traveling lane detecting device, wherein the vehicle communication device assigns a vehicle to be requested to relay the information on the basis of the result determined by the appropriateness of relay determining device and sends the information to the assigned vehicle.

Abstract: A communication device for a movable body mounted to each of movable bodies for exchanging information among the movable bodies includes a surrounding detecting device for detecting a surrounding of the movable body, an appropriateness of relay determining device for determining an appropriateness of relay, a first transmitting process device for transmitting a first signal, a first receiving process device for receiving the first signal sent by the first transmitting process device, a second transmitting process device for determining whether or not the relay is required, and a second receiving process device for receiving the second signal sent by the second transmitting process device.

Abstract: An air compressor includes a suction space, a compression space and a discharge space that are aligned with one another. The compressor also includes one-way valves that function as a suction valve and a discharging valve. The open areas of the suction valve and the discharge valve are sufficiently enlarged since both valves are not formed in the same element. Therefore, both valves can permit a large amount of air flow. Further, the suction space serves as a crank space so that fresh air is always drawn into the crank space to cool the crank space.