Fujitsu Corporation

Sumie Okada

Takashi Nara

Takashi Hatano

Yutaka Kawato

Yasuo Tanaka

Kenji Tsutsumi

Yasunori Ogawa

Ryoji Shimozono

A digital subscriber line formed by terminal equipment, a network control device including a plurality of the terminal equipment, and an exchange terminal. In a waiting state of the digital subscriber line, the network control device is placed in a state which can only receive a signal. A sending portion of the network control device is driven when, at a call from the terminal equipment, the terminal control device receives a line activation signal from the exchange equipment and when, at an incoming state from the state from the exchange terminal, the terminal control device receives a line activation from the exchange equipment. The synchronization pattern signal is sent from the sending portion to the exchange terminal so that the synchronization of the exchange terminal is established.

System for controlling network activation sequence

A digital subscriber line formed by terminal equipment, a network control device including a plurality of the terminal equipment, and an exchange terminal. In a waiting state of the digital subscriber line, the network control derive is placed in a state which can only receive a signal. A sending portion of the network control device is driven when, at a call from the terminal equipment, the terminal control device receives a line activation signal from the exchange equipment and when, at an incoming state from the state from the exchange terminal, the terminal control device receives a line activation from the exchange equipment. The synchronization pattern signal is sent from the sending portion to the exchange terminal so that the synchronization of the exchange terminal is established.

A digital exchange system including exchange terminals, a digital network, and a bit rate conversion unit located therebetween. The bit rate conversion unit operates to match low bit-rate channel signals with high bit-rate channel signals acceptable by the digital network, by multiplexing a plurality of the outgoing low bit-rate channel signals. The bit-rate conversion unit operates, on the other hand, to demultiplex the incoming multiplexed low bit-rate channel signals.

Growing community of inventors

Yokohama, Japan

Sumie Okada