Fujitsu Corporation

Yasuo Takami

Masato Hashizume

Tatsuya Oku

Kouji Tanonaka

Hisanori Okano

Tomohisa Furuta

A communication device includes a reception buffer configured to receive a pulse signal cyclically transmitted from a transmission source device via a transmission line; a branch circuit configured to generate a branch pulse signal by branching the pulse signal; a delay circuit configured to add a predetermined delay time to the generated branch pulse signal; and a transmission buffer configured to transmit the branch pulse signal to which the predetermined delay time was added to the transmission source device via the transmission line.

Communication device, pulse signal delay adjustment method and communication system

A disclosed network device includes a plurality of interface cards that receive clock signals and clock signal quality information from other devices via communication lines, respectively being predetermined communication line types corresponding to the plurality of interface cards, a controller that acquires the clock signal quality information and determines one of the clock signals having a highest quality based on this, and a clock processor that generates a synchronization clock signal used for network synchronization the clock processor, based on the determined one of the clock signals, whereby the clock processor includes a frequency measuring instrument that measures a frequency component of the one of the clock signals, and determines the communication line type corresponding to one of the interface cards, and a clock controller that provides a coefficient to a digital filter based on the determined communication line type.

Network device

An SDH transmission system including a container selection unit for selectively extracting a specific virtual container VC-m of a particular hierarchy from among the uppermost layer virtual containers VC-4 obtained from a demapping circuit that is a part of the SDH transmission system, and a path overhead processing unit for processing the path overhead of the specific virtual container VC-m obtained from the container selection means. Whereby, it is possible to extract and check the path overhead of the through path and to facilitate maintenance and inspection.

Growing community of inventors

Kawachinagano, Japan

Yasuo Takami