Fujitsu Corporation

Victor Company of Japan, Limited

Koichi Sugama

Yukio Katayanagi

Takashi Kaiga

Ryuji Kayama

Tomohiro Ueno

Masashige Kawarai

Tsutomu Chikazawa

Kenichi Yajima

Hiroyuki Ishii

Kenichi Hasegawa

Masahiro Shioda

Hideo Abe

Yuichi Nagaki

Hiroshi Kato

Noboru Shimizu

Hiromitsu Yanaka

Shoji Kikunaga

Yoshihiro Onoda

Toshikazu Yamakawa

A transmission apparatus includes a network-side interface unit configured to receive a signal transmission frame into which a client signal is arranged from each of a working line and a protection line of a network, and extract the client signal from the received signal transmission frame, a client-side interface unit configured to transmit the extracted client signal to a client transmission path by using a generated clock, based on frequency adjustment information of the client signal included in the signal transmission frame, a protection-line-side memory configured to store the frequency adjustment information of the client signal included in the signal transmission frame received from the protection line, and a switch controller configured to control to generate a clock by using the frequency adjustment information of the client signal stored in the protection-line-side memory when the signal transmission frame fails to be received from the working line.

Transmission apparatus and transmission method

A transmission device includes a receiver receiving a signal transmission frame from a network, where a client signal is mapped to the signal transmission frame; a separator separating the client signal from the signal transmission frame; a phase synchronizer generating a clock based on a frequency adjustment information set of the client information included in the signal transmission frame; a transmitter transmitting the client signal to a client transmission path by using the clock generated by the phase synchronizer; a memory storing the frequency adjustment information set included in the signal transmission frame in response to receiving the signal transmission frame from the network by the receiver; and a switch controller causing the phase synchronizer to generate a clock based on the frequency adjustment information set stored in the memory in response to not receiving the signal transmission frame from the network by the receiver.

Transmission device and transmission method

A transmission device in which a bus of a central processing unit is used to synchronize timing signals between units, thereby restraining enlargement in scale of wiring. A reference signal generator generates a reference signal. A reference signal receiver is mounted on a unit set as an active or standby unit and receives the reference signal. A timing signal generator divides the frequency of the received reference signal by means of a frequency divider/counter to generate a timing signal. A count holder holds the count value of the frequency divider/counter. The bus connects the units and the central processing unit. A count receiver receives, via the bus, the count value from the count holder of the active unit. A count updater updates the count value of the frequency divider/counter to the count value received by the count receiver.

Device for synchronizing between an active unit and a standby unit

In a power supply monitoring device, a power supply voltage monitoring portion always monitors a power supply voltage supplied to a monitored circuit and outputs a voltage reduction signal when detecting that the power supply voltage is reduced below a predetermined threshold (e.g. a second voltage higher than a voltage guaranteeing a normal operation of the monitored circuit and lower than a rated voltage). A monitoring controller having received the voltage reduction signal determines whether or not an operational malfunction has occurred in the monitored circuit by comparing operation data of the monitored circuit with reference data of the monitoring controller itself. Also, the monitoring controller executes recovery processing (reset processing or reference data overwrite processing) suitable for the monitored circuit referring to a prestored recovery processing type specific to the monitored circuit when detecting an operational malfunction of the monitored circuit.

Power supply monitoring device

A traffic shaping control device for an ATM communication network which permits downscaling of hardware and eliminates a delay of cells that is caused by performing a delay process on cells which need not be subjected to the delay process. The flow rate of cells of each of connections is checked with the use of flow rate calculating unit, and a cell exceeding a predetermined reference flow rate is circulated through a delay loop, which is constituted by delay-controlled cell detecting unit, delay-passed cell detecting unit, number-of-repetitions monitoring unit and delay unit, a number of times corresponding to an initial number of repetitions determined for each connection. Such a cell is therefore delayed so that the flow rate may eventually become lower than or equal to the predetermined reference flow rate. The cell flow rate is thereafter again checked by the flow rate calculating unit, and the above operation is repeated until the flow rate is reduced to the predetermined reference flow rate or below.

Traffic shaping device for ATM communication network

A head drum construction for use in a magnetic recording and reproducing apparatus such as a VTR apparatus comprises a rotatable drum having first and second axially opposite surfaces, a recording magnetic transducer such as a recording magnetic head mounted on the rotatable drum for recording information signals on a magnetic tape, a playback monitoring magnetic transducer such as a reproducing magnetic head mounted on the rotatable drum for reproducing, with a time delay, the information signals recorded on the magnetic tape by the recording magnetic transducer, a first signal transmission path connected to the recording magnetic transducer and disposed on the first surface, and a second signal transmission path connected to the playback monitoring magnetic transducer and disposed on the second surface.

Head drum construction including magnetically shielded record and

Growing community of inventors

Kawasaki, Japan

Koichi Sugama