Fujitsu Corporation

Junichi Sawada

Shinji Takao

Koji Matsunaga

Hidetoshi Amari

Kenichi Ishikawa

Tsuyoshi Matsumoto

Tatsuya Toyozumi

Kazuyuki Inomoto

Hiroaki Shiraishi

Ryu Kobayashi

Kanna Okamura

Yoshinobu Takagi

Kouichi Kitano

Hiroki Tamura

Ichiro Kagami

Masaru Nishida

Masao Mutou

Koichiro Nakayama

Mineo Kotegawa

Yushi Nobayashi

A communication device is connected to an end of a first network of a cascade topology, and also to a second network. This communication device transmits a first list including information of communication devices, in the first network, that are destinations of transmission of frames through the first network, to an opposing communication device, in the second network, located at another end of the first network, and receives, from the opposing communication device, a second list including information of communication devices, in the first network, that are destinations of transmission of frames from the opposing communication device through the first network. The communication device determines in which of the first list and the second list a destination of a frame is included, and when the destination of the frame is included in the second list, transmits the frame to the second network.

Communication system for fault tolerance in cascade topology and ring topology

A video relayer device includes a processing unit and a memory. The processing unit includes: a key information transfer section to transfer first key information to a video content sink upon receiving the first key information from a video content source having a timer, and a timer pausing section to control the timer of the sink to pause upon receiving the first key information from the source. The processing unit is operable to receive second key information and a calculation result from the sink and store the same, respectively in the memory. The processing unit further includes a timer resuming section to control the timer of the source to resume when the second key information and the calculation result have been stored, respectively, in the memory.

Video transmission system and video relayer device

A communication apparatus that is present between each of receiver and sender LANs including a user network and a WAN, and relays a packet exchanged between the sender and receiver LANs through the WAN while correcting an error in the packet. The communication apparatus determines whether to perform error correction on a packet received from the sender LAN. When it is determined not to perform the error correction, the communication apparatus instantly transfers the packet to the receiver LAN.

Communication apparatus, communication control method, and computer product

A generating unit generates an apparatus reference frame phase that becomes a reference in a data multiplexing/demultiplexing apparatus, based on a reception frame phase of the data input to a predetermined reception buffer and a predetermined delay amount. A multiplexing/demultiplexing unit reads data from the reception buffer based on the apparatus reference frame phase generated by the generating unit, and multiplexes or demultiplexes the data.

Method and apparatus for multiplexing and demultiplexing data, and computer product

A method is disclosed for setting a master node of a ring network that has adjacently connected nodes situated on rightward and leftward lines of a bidirectional transmission channel. The method includes the steps of: counting the number of nodes interposed between a designated node and each node other than the designated node on the rightward and leftward lines of the bidirectional transmission channel; and setting one of the nodes as the master node. The master node satisfies a relation of, NHC_L=NHC_R or NHC_L=NHC_R-, wherein NHC_L is the number of interposed nodes counted from the leftward line, and NHC_R is the number of interposed nodes counted from the rightward line.

Method and apparatus for setting master node of ring network

A wireless repeater on a communication line has a structure that includes a plurality of wireless communication media, and a band control unit that changes the first bandwidth of the communications line according to increase and decrease in the number of wireless communication media by an operation dividing the first bandwidth of the communications line into a plurality of second bandwidths and an operation multiplexing a plurality of second bandwidths adjusting to the first bandwidth, responding to the number of the wireless communication media.

Wireless repeater, the method for wireless repeating, and data communications system

A transmission device capable of configuring a communication network over which MC packets are forwarded in a way that does not use bands with futility is disclosed. The transmission device is so configured to transmit, when receiving a multicast packet from a host, to the other transmission device the multicast packet that is to be discarded by the transmission device having no necessity of forwarding the received multicast packet to the next transmission device.

Transmission device

Growing community of inventors

Kawasaki, Japan

Junichi Sawada