Fujitsu Corporation

Akira Oshima

Masato Hori

Takashi Sasaki

Kumiko Maruo

Yasuhiro Arai

Yoichi Ueda

Kentaro Fukushima

Noriyasu Suzuki

Prior to the initialization, CPU of information processing equipment makes a decision about whether a communication line has been connected to a connector or not. When the two are connected, the CPU does not carry out the initialization and shifts xDSL modem to lower power consumption mode. The connection is checked as follows. A test signal is transmitted through the xDSL modem. This signal is reflected by the connector and reflection is received by hybrid circuit. When the energy of this echo is large it means that the communication line it not connected to the connector, when the energy is small it means that the two are connected.

Information processing equipment, signal transformation equipment, method of communications, and computer product

An xDSL transceiver comprising a transmission unit for transmitting a DMT-modulated signal through a subscriber line as a transmission path and a receiving unit for receiving the DMT-modulated signal from the subscriber line. The xDSL transceiver further comprises an echo signal suppression unit for suppressing the echo signal from the transmission unit to the receiving unit by matching the phase between the frame of the transmission signal and the frame of the receiving signal.

xDSL transceiver

An ADSL modem connected to the telephone line is disclosed, which even in the case where a plurality of ADSL modems are connected to a single telephone line installed in a SOHO application or in the home of an ordinary user, a stable high-speed data communication can be realized without superposing the signals between the ADSL models or without causing any impedance mismatch. An ADSL band signal detector ( ) detects whether the ADSL frequency band is occupied by another ADSL modem connected to the telephone line or not. Upon detection that the ADSL frequency is so occupied, a control unit ( ) suppresses the application of the signal energy to the ADSL frequency band.

ADSL modem

Growing community of inventors

Kawasaki, Japan

Akira Oshima