Abstract: There are provided a communication system, a radio LAN base station control device, and a radio LAN base station device capable of increasing the control reliability and improving communication stability and safety between the radio LAN base station control device and the radio LAN base station device. In this communication system (10), a plurality of data tunnels are formed between an AP control device (100) and the radio LAN base station device (200) and the data tunnels are used according to the frame type (control data frame, data frame, etc.) so as to increase the reliability that the AP control frame reaches the radio LAN base station device (200). As a result, control reliability between the AP control device (100) and the radio LAN base station device (200) is increased. Thus, it is possible to improve the communication stability and safety in the communication system (10).

Abstract: There are provided a communication system, a radio LAN base station control device, and a radio LAN base station device capable of increasing the control reliability and improving communication stability and safety between the radio LAN base station control device and the radio LAN base station device. In this communication system (10), a plurality of data tunnels are formed between an AP control device (100) and the radio LAN base station device (200) and the data tunnels are used according to the frame type (control data frame, data frame, etc.) so as to increase the reliability that the AP control frame reaches the radio LAN base station device (200). As a result, control reliability between the AP control device (100) and the radio LAN base station device (200) is increased. Thus, it is possible to improve the communication stability and safety in the communication system (10).

Abstract: An access point control system enables transmission of statistic information on access point devices without communicating extra messages, that is, spending CPU recourses and network band resources unnecessarily. In the system, when the access point devices (101-1 to 101-3) send a session maintenance message to an access point control device (102), the devices report the statistic information to the access point control device (102) at the same time. On receiving the statistic information, the access point control device (102) holds it. On receiving from a network control device (103) a statistic information acquisition request for the statistic information on an access point device, the access point control device (102) reports the statistic information received from the access point device to the network management device (103).

Abstract: There are provided a communication system, a key distribution control device, and Wireless LAN base station device capable of more synchronizing the key configuration time of the Wireless LAN base station device with that of a communication terminal device, thereby reducing the communication cut-off period generated between the Wireless LAN base station device and the communication terminal device. In this communication system, an AP control device (100) can concatenate (encapsulate) an EAPoL-Key frame as first key information used by the communication terminal device (300) and second key information used by the Wireless LAN base station device (200) so as to generate a single frame (a key configuration request frame) and transmit the frame to the Wireless LAN base station device (200). The Wireless LAN base station device (200) separates the received frame into the EAPoL-Key frame as the first key information and the second key information used by the Wireless LAN base station device (200).

Abstract: The present invention provides a carbon-carbon composite material consisting of a matrix carbon and a fibrous reinforcing carbon, said matrix carbon and fibrous carbon consisting substantially of amorphous carbon and forming an interface without an intervening third material, wherein said composite material has a fracture surface showing a uniform vitreous light reflection, but when it is used as an anode and electrolytically etched in sulfuric acid-acidified water, a difference in the degree of etching arises between the matrix carbon and the fibrous carbon, and a method for the preparation thereof. The composite material has a high flexural strength and a very low gas permeability and is useful as a molding material in the fields of high temperature chemistry, the atomic energy industry and medicine.

Abstract: The present invention provides a carbon-carbon composite material consisting of a matrix carbon and a fibrous reinforcing carbon, said matrix carbon consisting substantially of optically anisotropic carbon and said fibrous reinforcing carbon consisting substantially of optically isotropic carbon, and said matrix carbon and fibrous reinforcing carbon forming an interface without an intervening third material, wherein said composite material has a fracture surface showing a uniform vitreous light reflection, and a method for the preparation thereof. The composite material has a high flexural strength and a very low gas permeability and is useful as a molding material in the fields of high temperature chemistry, the atomic energy industry and medicine.

Abstract: Separators for a lead-acid storage battery are provided which are composed of a fibrous structure such as non-woven fabric, paper, woven or knitted fabric which is impregnated with 1 to 50% by weight, based on the weight of the fibrous structure not yet coagulated, of an organopolysiloxane and then cured.