Abstract: The wireless communication apparatus, which performs a wireless communication by using one of switchable communication rates, includes quality assurance level specifying means for specifying a quality assurance level that is the minimum communication rate for assuring transfer quality of a streaming data of specified transfer rate; communication rate setting control means for determining an initial setting value that is higher communication rate than the quality assurance level, setting the communication rate to the initial setting value when the communication is started, and changing a setting of the communication rate according to the communication state; and a transmission process unit for performing a modulation process of the streaming data according to the communication rate for transmitting the modulated streaming data.

Abstract: A radio LAN system includes a server configured to hold a file; an access point connected with the server; a LAN terminal connected with the access point by radio; and a client terminal configured to issue a file transfer request to the server. An operation mode between the access point and the LAN terminal is set to a non-compression mode in which compression of the file is not performed, when the file is in a compressed state, and to a compression mode in which compression of the file is performed, when the file is in a non-compressed state. The file is transferred from the server to the client terminal in the operation mode in response to the file transfer request.

Abstract: A router has a function of handling a plurality of sessions and includes, a communication control unit for communicating with a plurality of terminals, and receiving a desired priority level of each session from each terminal at a time of starting communication; a priority adjustment unit for adjusting the desired priority level among terminals when it is determined that simultaneous communication of all sessions cannot be performed and the desired priority level competes among terminals if every desired priority level is permitted as it is without changing; and a priority control unit for assigning a transmission bandwidth to each session according to a determined priority level corresponding to each of the plurality of sessions.

Abstract: The present invention provides a VoIP wireless telephone system utilizing a wireless LAN wherein expansion of an IP wireless extension telephone is realized while ensuring secrecy of talk in a VoIP service. In the system, ID and password for connection to the Internet by PPPoE are set to a wireless LAN terminal; user authentication is executed with the above information upon connection to a BAS through a DSLAM; an ADSL modem transmits, to the BAS, IP frames received from the wireless LAN terminal; and after connection by PPPoE an IP address is given from the BAS to the wireless LAN terminal.

Abstract: The wireless communication apparatus, which performs a wireless communication by using one of switchable communication rates, includes quality assurance level specifying means for specifying a quality assurance level that is the minimum communication rate for assuring transfer quality of a streaming data of specified transfer rate; communication rate setting control means for determining an initial setting value that is higher communication rate than the quality assurance level, setting the communication rate to the initial setting value when the communication is started, and changing a setting of the communication rate according to the communication state; and a transmission process unit for performing a modulation process of the streaming data according to the communication rate for transmitting the modulated streaming data.

Abstract: A radio LAN system includes a server configured to hold a file; an access point connected with the server; a LAN terminal connected with the access point by radio; and a client terminal configured to issue a file transfer request to the server. An operation mode between the access point and the LAN terminal is set to a non-compression mode in which compression of the file is not performed, when the file is in a compressed state, and to a compression mode in which compression of the file is performed, when the file is in a non-compressed state. The file is transferred from the server to the client terminal in the operation mode in response to the file transfer request.

Abstract: The present invention provides a VoIP wireless telephone system utilizing a wireless LAN wherein expansion of an IP wireless extension telephone is realized while ensuring secrecy of talk in a VoIP service. In the system, ID and password for connection to the Internet by PPPoE are set to a wireless LAN terminal; user authentication is executed with the above information upon connection to a BAS through a DSLAM; an ADSL modem transmits, to the BAS, IP frames received from the wireless LAN terminal; and after connection by PPPoE an IP address is given from the BAS to the wireless LAN terminal.

Abstract: The present invention is a load distribution type network fault monitoring system of a broadband router, which is connected to a plurality of client terminals and which has a function of accessing the Internet, the load distribution type network fault monitoring system comprising: a fault monitoring section in the broadband router for monitoring and recording a connection situation between the client terminals and the broadband router, and an abnormality in data communication contents; and a network monitoring machine connected to the Internet to receive collectively the connection situation and the abnormality in data communication contents monitored by the fault monitoring section, at regular intervals, sum up the received data, and ascertain a network state.

Abstract: In an information providing system including an access point, an information providing server, and an accounting server, the access point is supplied from a communication terminal with an information obtaining request and specifying-information specifying desired information and transmits the information obtaining request and the specifying-information to the information providing server. The access point receives and memorizes candidate information transmitted from the information providing server in response to the information providing request and the specifying-information. The access point prepares a list of the received candidate information and sends the list to the communication terminal. The access point receives, from the communication terminal, selection information for selecting particular information in the list and sends, to the communication terminal, the particular information specified by the selection information.

Abstract: In a vertical type heat exchanger including a water chamber delimited by a drum end plate and a header plate on which a large number of heat transfer tubes are arrayed, a novel manipulator for working in the heat exchanger is provided such that a support frame is disposed within the water chamber, a base end portion of a freely extensible and contractible main arm which is rotatable about its base end portion and vertically swingable about a fulcrum at its base end portion, is mounted on the support frame, a base end portion of a sub-arm which is rotatable about its base end portion and vertically swingable about a fulcrum at its base end portion and also which can be positioned in parallel to the header plate, is mounted at the tip end portion of the main arm, a vertically movable clamp shaft which can be inserted into the heat transfer tube is provided coaxially with the rotational axis of the sub-arm, and a position detector for detecting the position of the clamp shaft so as to assist in positioning the c