Panasonic Corporation

Matsushita Electric Industrial Co., Ltd.

Kazuhide Sawabe

Satoshi Ando

Yuji Shimizu

Takumi Tanabe

Yuichi Kawaguchi

Masao Oomoto

Satoshi Arita

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.

Communication apparatus, authentication apparatus, communication method and authentication method

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.

Content delivery system, content server, content receiver, content delivery method, storage medium and program

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 () acquires priority information contained in a currently transmitting packet. A priority determination section () determines, based on priority information contained in a to-be-sent packet and the priority information acquired by the priority information acquisition section (), which one of the to-be-sent packet and the currently transmitting packet should be given priority. A jam signal generation section () generates a jam signal if it is determined by the priority determination section () that the to-be-sent packet is given priority. A communication section () 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.

Packet communication terminal

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. The contents receiving apparatus includes receiving unit receiving the data of the contents with the additional information that are transmitted from the transmitting unit, received data decision unit deciding a receiving request range of the contents out of consideration for the additional information, and data request transmitting unit transmitting the data request including request range information.

Contents distribution system, contents server, contents receiving apparatus, contents distribution method, program and storage media

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.

Wireless communications system, packet transmission device used in the system, and access point

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.

Growing community of inventors

Fukuoka, Japan

Kazuhide Sawabe