Fujitsu Corporation

Kouji Tanonaka

Akira Yamamoto

Tomoyuki Sakata

Koji Bato

Yasuo Takami

Tomohisa Furuta

A wavelength-multiplexing optical transmission apparatus includes an optical-wavelength-information storing unit that stores optical wavelength information on an optical wavelength of an optical signal to be output from a transponder, and an optical-wavelength-information transmitting unit that transmits the stored optical wavelength information to the transponder via a connection cable. The transponder includes an optical-wavelength control unit that controls an optical wavelength of an optical signal to be input to a wavelength multiplexing unit based on the optical wavelength information received from the optical-wavelength-information transmitting unit.

Wavelength-multiplexing optical transmission system and wavelength-multiplexing optical transmission method

An apparatus which depends on one of a plurality of master clocks as a timing source includes a timing-dependency-direction-identifier-extraction unit which detects an identifier indicative of a direction of timing dependency from a received signal with respect to each of the master clocks, a timing-quality-information-extraction unit which detects a code indicative of a timing quality from the received signal with respect to each of the master clocks, and a synchronization unit which selects the timing source based on the code indicative of a timing quality, and identifies a direction of timing dependency of the timing source based on the identifier indicative of a direction of timing dependency.

Apparatus depending on timing source for synchronization

An SDH transmission unit which processes various classes of digital bitstreams regardless of their levels of the SDH multiplexing hierarchy, harmonizing the signal formats handled in its integral cross-connect facilities. High-order group transmission units are installed in their dedicated high-order group slots on a mounting rack, and through the wiring on a backplane, they are connected to high-order group ports of a cross-connect unit installed in the same rack. Similarly, low-order group transmission units are installed in dedicated low-order group slots on the mounting rack, and connected to low-order group ports of the cross-connect unit through the backplane. Both high-order and low-order group transmission units are designed to send and receive multiplexed signals at a predetermined level of the SDH multiplexing hierarchy. Because of this harmonized signal format, the high-order and low-order group transmission units seamlessly interface with the cross-connect unit, no matter what level of multiplexed signals they process in their internal activities.

SDH transmission apparatus with flexible system configuration

A synchronization control method for a synchronous digital hierarchy system includes the steps of: at a first selecting unit, selecting a given number of timing sources, from among a plurality of first timing sources within a main shelf, in accordance with user setting data, and outputting the given number of the selected timing sources; at a first quality data generating unit, outputting quality data of one or more of the selected timing sources when the one or more of the selected timing sources have no quality data; at a second selecting unit, selecting one or more timing sources from among a plurality of second timing sources within a slave shelf when any timing sources set by the user setting data are included in the second timing sources within the slave shelf, and transmitting the selected one or more timing sources to the main shelf; at a second quality data generating unit, outputting the quality data of the one or more timing sources supplied from the second selecting unit, and transmitting the quality data to the main shelf; and at a first quality selecting unit, selecting a timing source having the highest quality value among the quality data from the first and second quality data generating units, from among the given number of the timing sources, and outputting the selected timing source to the main shelf as equipment clock, and transmitting the equipment clock to the slave shelf.

Method of transmitting sync clock and sync data between shelves of a

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

Kawasaki, Japan

Kouji Tanonaka