Abstract: A communication apparatus transmits an authentication frame to an authentication apparatus and receiving a response frame for response to the authentication frame from the authentication apparatus so that an authentication process is performed for the communication apparatus by the authentication apparatus. The communication apparatus includes a receiving section which receives a communication frame transmitted from another apparatus, and an authentication processing section which determines whether the received communication frame is a frame of EAP-response (Extensible Authentication Protocol-response) or not. The authentication processing section discards the received communication frame if it is determined that the received communication frame is the frame of EAP-response.

Abstract: A communication apparatus transmits an authentication frame to an authentication apparatus and receives a response frame for response to the authentication frame from the authentication apparatus so that an authentication process is performed for the communication apparatus by the authentication apparatus. In the communication apparatus, a transmitting section transmits an authentication frame to the authentication apparatus using a multicast address as a transmission destination address, and if a reception determining section determines that the response frame is not received from the authentication apparatus, a transmission destination address changing section changes the transmission destination address from the multicast address to a broadcast address, and the transmitting section transmits the authentication frame that has the transmission destination address changed to the broadcast address to the authentication apparatus.

Abstract: A communication apparatus transmits an authentication frame to an authentication apparatus and receives a response frame for response to the authentication frame from the authentication apparatus so that an authentication process is performed for the communication apparatus by the authentication apparatus. In the communication apparatus, a transmitting section transmits an authentication frame to the authentication apparatus using a multicast address as a transmission destination address, and if a reception determining section determines that the response frame is not received from the authentication apparatus, a transmission destination address changing section changes the transmission destination address from the multicast address to a broadcast address, and the transmitting section transmits the authentication frame that has the transmission destination address changed to the broadcast address to the authentication apparatus.

Abstract: A content delivery system transmits content which is divided into a plurality of content blocks. The system includes a content server having a specifier to specify blocks associated with one or more ranges, and a transmitter to transmit the specified blocks according to a predetermined protocol. Each respective block has additional information attached indicating a common range for an attribute related to the content within the respective block. The system further includes a content receiver having a receiver to receive the content, a request range determiner to determine a request range of the content based on the attached additional information of each block by using block information indicating a length for each of the transmitted blocks, and a requestor to request the content associated with the determined request range from content associated with the one or more ranges.

Abstract: The present invention discloses a communication terminal included in a network system in which a plurality of communication terminals are connected to a single transmission medium. A priority information acquisition section (11) acquires priority information contained in a currently transmitting packet. A priority determination section (13) determines, based on priority information contained in a to-be-sent packet and the priority information acquired by the priority information acquisition section (11), which one of the to-be-sent packet and the currently transmitting packet should be given priority. A jam signal generation section (14) generates a jam signal if it is determined by the priority determination section (13) that the to-be-sent packet is given priority. A communication section (15) sends out the to-be-sent packet on the transmission medium after the jam signal stops and before the currently transmitting packet is sent out again.

Abstract: In a network system for transmitting and receiving contents with one or more pieces of additional information corresponding to an internal attribute of the contents, a contents server can decide the data to be transmitted without regard to a division transfer method supposed for a contents receiving apparatus. The contents server includes storage unit holding one or more contents, contents data acquisition unit receiving a data request including request range information of the contents out of consideration for the additional information and extracting the data of the contents in a requested range out of the storage unit, and transmitting unit transmitting the extracted data of the contents with the additional information.

Abstract: In a network system for transmitting and receiving contents with one or more pieces of additional information corresponding to an internal attribute of the contents, a contents server can decide the data to be transmitted without regard to a division transfer method supposed for a contents receiving apparatus. The contents server includes storage unit holding one or more contents, contents data acquisition unit receiving a data request including request range information of the contents out of consideration for the additional information and extracting the data of the contents in a requested range out of the storage unit, and transmitting unit transmitting the extracted data of the contents with the additional information.

Abstract: Access points for supporting wireless communications, a packet transmission device, and terminals for handing-over between service areas are provided. An existing terminal is provided with respect to this access point for performing a Quality of Source (QoS) guarantee. Accordingly, when a new terminal is handed over to be engaged in wireless communications with this access point, the priority of the packet associated with the existing terminal and/or new terminal is changed.

Abstract: In a network system for transmitting and receiving contents with one or more pieces of additional information corresponding to an internal attribute of the contents, a contents server can decide the data to be transmitted without regard to a division transfer method supposed for a contents receiving apparatus. The contents server includes storage unit holding one or more contents, contents data acquisition unit receiving a data request including request range information of the contents out of consideration for the additional information and extracting the data of the contents in a requested range out of the storage unit, and transmitting unit transmitting the extracted data of the contents with the additional information.

Abstract: An address management apparatus includes a storage unit for storing a table showing the correspondence between data link layer and network layer addresses, a first search unit for searching the table for an unused data link layer address, a second search unit for searching the table for a network layer address corresponding to a specified data link layer address, and an instruction unit for transmitting an instruction including the unused data link layer address to a terminal specified by the detected network layer address. The apparatus also includes an updation unit for updating the correspondence between the data link layer and the network layer addresses on the table according to the instruction, a detection unit for detecting the instruction to obtain the data link layer address, and a setting unit for setting the data link layer address obtained by the detection unit in the self terminal.

Abstract: The present invention discloses a communication terminal included in a network system in which a plurality of communication terminals are connected to a single transmission medium. A priority information acquisition section 11 acquires priority information contained in a currently transmitting packet. A priority determination section 13 determines, based on priority information contained in a to-be-sent packet and the priority information acquired by the priority information acquisition section 11, which one of the to-be-sent packet and the currently transmitting packet should be given priority. A jam signal generation section 14 generates a jam signal if it is determined by the priority determination section 13 that the to-be-sent packet is given priority. A communication section 15 sends out the to-be-sent packet on the transmission medium after the jam signal stops and before the currently transmitting packet is sent out again.

Abstract: A content delivery method is provided of transmitting a content which is divided into a plurality of content blocks so that the attribute of the content does not change within one content block. The content server transmits a specified content block by attaching additional information according to attribute of the content for every content block. And the content receiver determines a request range of the content, and requests the content within that determined request range on the condition that additional information according to attribute of the content for every content block is attached by utilizing the content block information, including at least the length of all content blocks.

Abstract: A method for reserving communication resources in a gang of apparatus that include a terminal “T1” operable to transmit packets, relays “X0” to “X4” operable to relay the packets, and a receiver “T2” operable to receive the packets. The method comprises defining a link for interconnecting respective interfaces of two apparatus selected from the gang of apparatus, defining a path between the transmitter and the receiver as an assembly of the links, checking all of the links that form the path to see how the links are connected together, and reserving the resources in accordance with the content of requested reservation when all of the links that form the path are found connected together in accordance with the content of the requested reservation.

Abstract: The invention comprises a data dividing unit for dividing input data into a plurality of pieces, a divided data replicating unit for replicating divided data, an additional information embedding unit for embedding additional information into replicated data, an encrypting unit for encrypting the data embedded with the additional information, and a sending unit for sending the encrypted data by means of multicast communications, further comprises a decoding unit for decoding the encrypted data which is received, and an assembling unit for assembling the decoded data.

Abstract: Access points for supporting wireless communications, a packet transmission device, and terminals for handing over between service areas are provided and an existing terminal is provided with respect to this access point for performing QoS guarantee, so that when a new terminal is handed over to be engaged in wireless communications with this access point, the priority of the packet associated with the existing terminal and/or new terminal is changed.

Abstract: An address management apparatus comprises a data link layer address storage unit for storing a data link layer address table showing the correspondences between data link layer addresses and network layer addresses; a data link layer address search unit for searching the address table for an unused data link layer address; a corresponding network layer address search unit for searching the address table for a network layer address corresponding to a specified data link layer address; a data link layer address assignment instruction unit for transmitting a data link layer address assignment instruction which includes, as information, at least the unused data link layer address, to a terminal specified by the network layer address detected by the corresponding network layer address search unit; a data link layer address updation unit for updating the correspondence between the data link layer address and the network layer address on the address table, according to the data link layer address assignment instruct