Fujitsu Corporation

Seiji Miyoshi

Yutaka Awata

Nobukazu Koizumi

Takashi Sasaki

Kazutomo Hasegawa

Hiroyasu Murata

Hidetake Asahina

Yoshito Koyama

Misao Fukuda

Minoru Hirahara

Kazuyoshi Maruyama

Seiichi Yamato

Eiji Miyachika

Takashi Sato

Norio Murakami

Mitsuo Kakuishi

Kenji Takato

Norio Ueno

Masato Takeyabu

Shinji Ohta

Yozo Iketani

Yasuaki Takeuchi

Yuji Kobayashi

Hiroaki Itokawa

Atsushi Manabe

Hiroyuki Ujiie

Masahisa Yoshimi

Takuo Gotoda

Kouji Tokiwa

Kinji Kawada

A power supply device includes: a first supply section that supplies power in accordance with an extent of a load in processing in a processing device by applying a voltage to the processing device which processes data; and a second supply section that supplies, to the processing device, power smaller than the supplying power by the first supply section, in accordance with an extent of a load in processing in the processing device to increase and decrease a voltage with respect to the application voltage by the first supply section.

Method for suppressing a voltage fluctuation applying to a load by a second power section with the same or opposite voltage polarity

A power supply device of the invention includes: a supply section that supplies power to a second processing device which processes data in response to processing execution by a first processing device which processes data; a load detection section that detects a load of processing execution by the first processing device; and a power control section that causes the supply section to increase or decrease power supply according to the magnitude of load detected by the load detection section. The load of processing execution by the first processing device disposed in the upstream side relative to the second processing device is detected, and power supply to the second processing device is increased or decreased according to the detected magnitude of load. Accordingly, even when the amount of processing data sharply increases, sufficient power can be unfailingly supplied to the second processing device.

Power supply device having load detection function and communication apparatus provided with the power supply device

A digital subscriber line communicating system having a central office and a remote terminal connected through a telephone line, the transmitting side comprising a sliding window transmitting unit for transmitting DMT symbols according to the sliding window through the telephone line to the receiving side, and the receiving side comprising a sliding window receiving unit for receiving DMT symbols according to the sliding window from the transmitting side, the sliding window indicating the phase of cross-talk condition due to a TCM-ISDN transmission at the receiving side, whereby TCM cross-talk can be reduced without largely departing from the standard system.

Digital subscriber line communicating system

A digital subscriber line transmission (xDSL), system includes a transmitting side which transmits training symbols by adding some data that is contained in a training symbol sequence onto at least one of the beginning and the end of this symbol sequence and then transmits the training symbol sequence. A receiving side removes the data that has been added onto the training symbol sequence and executes training processing. The length of the training symbol sequence and of a transmit symbol sequence at time of normal communication is set in such a manner that the symbol sequence will not fall within an interval in which effects of near-end crosstalk from a neighboring line are received. The data added to the training symbol sequence specifies an interval in which effects of the crosstalk are received.

Digital subscriber line transmission method, apparatus and system

A digital subscriber line communicating system having a central office and a remote terminal connected through a telephone line, the transmitting side including a sliding window transmitting unit for transmitting DMT symbols according to the sliding window through the telephone line to the receiving side, and the receiving side including a sliding window receiving unit for receiving DMT symbols according to the sliding window from the transmitting side, the sliding window indicating the phase of cross-talk condition due to a TCM-ISDN transmission at the receiving side, whereby TCM cross-talk can be reduced without largely departing from the standard system.

A digital subscriber line transmission (xDSL) system includes a transmitting side which transmits training symbols by adding some data that is contained in a training symbol sequence onto at least one of the beginning and the end of this symbol sequence and then transmits the training symbol sequence. A receiving side removes the data that has been added onto the training symbol sequence and executes training processing. The length of the training symbol sequence and of a transmit symbol sequence at time of normal communication is set in such a manner that the symbol sequence will not fall within an interval in which effects of near-end crosstalk from a neighboring line are received. The data added to the training symbol sequence specifies an interval in which effects of the crosstalk are received.

A digital subscriber line communicating system having a central office and a remote terminal connected through a telephone line, the transmitting side comprising a sliding window transmitting-unit for transmitting DMT symbols according to the sliding window through the telephone line to the receiving side, and the receiving side comprising a sliding window receiving unit for receiving DMT symbols according to the sliding window from the transmitting side, the sliding window indicating the phase of cross-talk condition due to a TCM-ISDN transmission at the receiving side, whereby TCM cross-talk can be reduced without largely departing from the standard system.

A digital subscriber line transmission (xDSL)-, system includes a transmitting side which transmits training symbols by adding some data that is contained in a training symbol sequence onto at least one of the beginning and the end of this symbol sequence and then transmits the training symbol sequence. A receiving side removes the data that has been added onto the training symbol sequence and executes training processing. The length of the training symbol sequence and of a transmit symbol sequence at time of normal communication is set in such a manner that the symbol sequence will not fall within an interval in which effects of near-end crosstalk from a neighboring line are received. The data added to the training symbol sequence specifies an interval in which effects of the crosstalk are received.

A digital subscriber line communicating system for communicating between a transmitting side and a receiving side tough a communication line, the system including a hyperframe counter for periodically counting a predetermined number of continuous transmitting data symbols constituting a hyperframe synchronized with a timing signal, and a decoder for discriminating, based on the count value of the hyperframe counter, whether a transmitting data symbol belongs to a FEXT, or a NEXT. A sequencer is provided for initializing the status during an initialization period before starting usual communication. The initialization period includes an activation and acknowledgement sequence, a transceiver training sequence, a channel analysis sequence, and an exchange sequence. According to a single bitmap mode, the initialization is carried out by transmitting modulated symbols through only inside of the sliding window. According to a dual bitmap mode, the initialization except for an S/N measuring sequence in the channel analysis sequence is carried out by transmitting modulated symbols through only inside of the sliding window, and the S/N measuring sequence is carried out by transmitting modulated symbols through both inside and outside of the sliding window.

Digital subscriber line communicating system and a transceiver in the system

A digital subscriber line communicating system having a central office and a remote terminal connected through a telephone line, the transmitting side having a sliding window transmitting unit for transmitting DMT symbols according to the sliding window trough the telephone line to the receiving side, and the receiving side having a sliding window receiving unit for receiving DMT symbols according to the sliding window from the transmitting side, the sliding window indicating the phase of cross-talk condition due to a TCM-ISDN transmission at the receiving side, whereby TCM cross-talk can be reduced without largely departing from the standard system.

A digital subscriber line communicating system having a central office and a remote terminal connected through a telephone line, the transmitting side including a sliding window transmitting unit for transmitting DMT symbols according to the sliding window through the telephone line to the receiving side, and the receiving side including a sliding window receiving unit for receiving DMT symbols according to the sliding window from the transmitting side, the sliding window indicating the phase of cross-talk condition due to a TCM-ISDN transmission at the receiving side, whereby TCM cross-talk can be reduced

Digital subscriber line communicating system determining signal-to-noise ratios

A digital subscriber line communicating system for communicating between a transmitting side and a receiving side through a communication line, comprising a hyperframe counter for periodically counting a predetermined number of continuous transmitting data symbols constituting a hyperframe synchronized with a timing signal, and a decoder for discriminating, based on the count value of the hyperframe counter, whether a transmitting data symbol belongs to a FEXTor a NEXT. A sequencer is provided for initializing the status during an initialization period before starting usual communication. The initialization period includes an activation and acknowledgement sequence, a transceiver training sequence, a channel analysis sequence, and an exchange sequence. According to a single bitmap mode, the initialization is carried out by transmitting modulated symbols through only inside of said sliding window. According to a dual bitmap mode, the initialization except for an S/N measuring sequence in the channel analysis sequence is carried out by transmitting modulated symbols through only inside of said sliding window, and the S/N measuring sequence is carried out by transmitting modulated symbols through both inside and outside of said sliding window.

A subscriber communication machine is provided with an off-synchronous detector detecting off-synchronization of communication with an office communication machine, a correlation processor, when the off-synchronization is detected, correlatively processing received data received over a communication line and held data having been transmitted from the office communication machine, and a resynchronization controller specifying a synchronous timing by the correlation process in the correlation processor to establish resynchronization in the communication with the office communication machine. When the subscriber communication machine cannot keep synchronization with a transmission cycle in a predetermined transmission system such as TCM in steady communication, it is possible to promptly resume the communication without the necessity for initializing all over again.

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Kawasaki, Japan

Seiji Miyoshi