Abstract: An apparatus includes an information transmission part that transmits first information including an allocated IP address and a group identifier identifying a group to another apparatus that manages communication by the group, when connecting to the Internet; and a list reception part that receives a list in which IP addresses used for performing intercommunication in the group identified by the group identifier in the first information are listed, as a response to the first information from the computer. A communication part of the apparatus performs communication by using the IP addresses listed in the received list.

Abstract: Upon receipt of a request to connect to an ad-hoc network from an external communication node, an address assigning unit obtains information on an IP address assigned to the external communication node. The address assigning unit determines whether the IP address is already used by any of communication nodes that are connected to the ad-hoc network based on network management information stored in a storage unit. The address assigning unit generates a new IP address that is used none of the communication nodes when the IP address is already used, and transmits the new IP address to the external communication node. The external communication node is assigned the new IP address, and connects to the ad-hoc network.

Abstract: Upon receipt of a request to connect to an ad-hoc network from an external communication node, an address assigning unit obtains information on an IP address assigned to the external communication node. The address assigning unit determines whether the IP address is already used by any of communication nodes that are connected to the ad-hoc network based on network management information stored in a storage unit. The address assigning unit generates a new IP address that is used none of the communication nodes when the IP address is already used, and transmits the new IP address to the external communication node. The external communication node is assigned the new IP address, and connects to the ad-hoc network.

Abstract: A data compression program making a computer perform processing which enables compression of only highly compressible data. First, a transmitter-side device performs compression processing of a portion of data to be compressed. Next, the transmitter-side device compares volumes of the portion of the data before and after the compression processing, and determines whether or not the compression processing is effective. When the data to be compressed is uncompressed data, the volume of the portion of the data is reduced by the compression processing. On the other hand, when the data to be compressed is compressed data, the volume of the portion of the data is not reduced by the compression processing. Therefore, only when it is determined that the compression processing is effective, the transmitter-side device compresses the other portions of the data to be compressed.

Abstract: In a communication system, which continues the communication while a mobile node moves over local networks, mobile IP system is used as a procedure of the mobile node moving over networks, and also the mobile node requests to the server (HA in the mobile IP) for the setting of data sent from the network such as a request for data-receiving time period and a request for compression of the receiving data and the server performs processing such as substitutional receiving of the data and transfer of the compressed data to the mobile node when not in the requested time period.

Abstract: One connection unit is connected to each radio communication line. There are a plurality of radio communication lines. Radio-field intensity of each radio communication line is monitored. A radio communication line whose radio-field intensity is equal to or higher than a threshold is decided and data communication is established using this radio communication line and corresponding connection unit.

Abstract: A technique is provided to facilitate the management and notification of visited location names indicating to which network each mobile terminal currently belongs. A reception means receives address information of a connection network that a mobile terminal is currently visiting. A location identification means identifies a visited location name of the mobile terminal with reference to the received address information, as well as to a visited location name table that stores the address information in association with the visited location name. Based on the identified visited location name, a location management table creation means creates a location management table for managing the location of the mobile terminal. In response to a location data request asking for the location of the mobile terminal, a notification means consults the location management table and thus sends the visited location name.

Abstract: A communication control program which can change quality of received data according to variations in communication conditions associated with change of a network used in communication. In accordance with the communication control program, a terminal detects at least one of a plurality of network interfaces which is currently available for communication, determines a network interface having the highest priority among the at least one of the plurality of network interfaces by referring to an interface information table, and performs data communication through the determined network interface. In addition, the terminal notifies a content server of a bandwidth of the determined network interface. Then, the content server determines quality of content to be delivered to the terminal, generates the content with the determined quality, and transmits the content to the terminal.

Abstract: A data compression program making a computer perform processing which enables compression of only highly compressible data. First, a transmitter-side device performs compression processing of a portion of data to be compressed. Next, the transmitter-side device compares volumes of the portion of the data before and after the compression processing, and determines whether or not the compression processing is effective. When the data to be compressed is uncompressed data, the volume of the portion of the data is reduced by the compression processing. On the other hand, when the data to be compressed is compressed data, the volume of the portion of the data is not reduced by the compression processing. Therefore, only when it is determined that the compression processing is effective, the transmitter-side device compresses the other portions of the data to be compressed.

Abstract: A gateway, a communication terminal equipment, and a communication control program are provided for reducing the number of items to be specified by a user in association with the change of the gateway computer, thereby lessening the user's burden. At first, the gateway computer transmits a message for indicating securement of a security capability to the communication terminal equipment at regular intervals and in a broadcasting manner. Then, the communication terminal equipment obtains an address of the gateway computer having the security capability through a wireless network. Next, the communication terminal equipment communicates data with the gateway computer based on the obtained address and determines an authenticating system and an encrypting and a decrypting rules for data to be communicated. Then, the communication terminal equipment and the gateway computer are operated to communicate data according to the encrypting and the decrypting rules.

Abstract: The present invention relates to the communication between a client and a server. A communication control method has a step for specifying a relay apparatus corresponding to a designated apparatus to be communicated with based on relay definition information which relates information for specifying the apparatus to be communicated with to information for specifying the relay apparatus to relay the communication with the apparatus to be communicated with and a step for establishing a relay connection with the specified relay apparatus.

Abstract: One connection unit is connected to each radio communication line. There are a plurality of radio communication lines. Radio-field intensity of each radio communication line is monitored. A radio communication line whose radio-field intensity is equal to or higher than a threshold is decided and data communication is established using this radio communication line and corresponding connection unit.

Abstract: The present invention operates in a system in which a plurality of workstations are connected via communications lines. When a workstation outputs a message to another workstation, a message output unit identifier is set in an environment variable pertaining to a process which issues a message output request. The process obtains the message output unit identifier set according to the environment variable, and requests the message output workstation to output a message via communications lines. A requested workstation outputs the message on a predetermined unit. Thus, setting a message output unit for an environment variable easily specifies or modifies the message output unit by entering the command, etc. without modifying a program at all.