Abstract: A workflow management apparatus that manages a plurality of processes constituting a workflow, comprises: an I/O information acquisition unit 13 that acquires I/O information defining, in each of the processes, output data obtained as a processing result and input data serving as the data related to processing; a process management unit 14 that allows each of the processes to perform processing based on input data of a currently acquired version number; a version number acquisition unit 15 that acquires information related to version numbers of the input and output data handled in each of the processes; and a state registration unit 11 that registers the state of each of the processes, wherein when the output data in any of the processes is updated, the state registration unit resisters the state of the process including the updated output data in the input data thereof as “Being executed” based on the information related to the acquired I/O information and version number.

Abstract: 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.

Abstract: 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.

Abstract: When training carried out prior to data communication is performed in digital subscriber line transmission (xDSL), the side which transmits training symbols adds some data that is contained in a training symbol sequence onto at least one of the beginning and end of this symbol sequence and then transmits the training symbol sequence. The 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.

Abstract: When training carried out prior to data communication is performed in digital subscriber line transmission (xDSL), the side which transmits training symbols adds some data that is contained in a training symbol sequence onto at least one of the beginning and end of this symbol sequence and then transmits the training symbol sequence. The 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.

Abstract: A matched filter able to reduce the size of a circuit is disclosed that includes a shift register, a spreading code storage unit, a multiplier, an accumulator, a spreading code generator, and an accumulation and storage unit. The shift register has a number of sixteen taps, which equals the square root of the spreading factor 256, and holds and bit-shifts received data. The spreading code generator generates spreading codes divided by the number of the taps at a calculation rate roughly sixteen times higher than a data rate of the received data of 3.84 MHz. The spreading code storage unit stores the divided spreading codes generated in the spreading code generator sequentially at the calculation rate. The multiplier 15 multiplies the received data stored in the shift register with the divided spreading codes stored in the spreading code storage unit at the calculation rate. The accumulator sums the products from the multiplier at the calculation rate.

Abstract: 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 through 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.

Abstract: 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 FEXTR or a NEXTR. 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.

Abstract: An optical amplification device is disclosed that performs feedback control to maintain an amplification gain to be a constant based on measured power of input light and power of output light. The device includes a feedback control coefficient switching unit configured to, when performing the feedback control on a difference from an object amplification gain, distinguish a state of increasing or decreasing the number of frequencies of the input light and a steady state by making comparison and determination whether an amplitude of at least one of the power of the input light and the power of the output light is in a predetermined range, and switch the feedback control coefficient. Therefore, it is possible to reduce variation of the power of the output light caused by noise in the steady state without affecting operations of increasing and decreasing a number of frequencies of a light signal.

Abstract: An optical amplifier is provided with a controlling unit for controlling a gain of the optical amplifier based on input light power and output light power of the optical amplifier, as well as a gain control amount variable unit for changing the gain control amount of the optical amplifier by the controlling unit according to at least one of the input light power and the output light power. Thereby, optical communication, which can follow the change in the input power of the optical amplifier in high speed and also is stable, can be realized, without causing the occurrence of an oscillation phenomenon, the large size of the optical amplifier, and the increase in power consumption and heating.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A data transmission system which trains its internal equalizers both in an initialization phase and in a normal communication session. In a transmitter unit, a modulation unit modulates a data signal to be transmitted. This signal is sent out to a telephone subscriber line by a transmitter after being added a cyclic prefix by a prefixing unit. A receiver unit accepts the data signal at its receiver portion. The received signal, however, has been impaired because of non-ideal transmission characteristics of the subscriber line. The receiver unit employs a processor which serves as an equalizer to confine the signal impairment within a period of cyclic prefix of each symbol. The receiver unit further comprises a target channel which provides reference characteristics for use in adapting the processor to the current line characteristics. At an initialization stage, a first training unit performs training by tuning both the target channel and processor.

Abstract: A processing apparatus includes a memory capable of storing data, a butterfly arithmetic unit for performing butterfly computation processes, and a bit-reversed order shuffle processing unit for writing results obtained by butterfly computation processes performed by the butterfly arithmetic unit at addresses in the memory after bit-reversed order shuffle instead of writing the results at addresses in the memory in processing order. The data written by the bit-reversed order shuffle processing unit are discrete fast Fourier transform results.

Abstract: A digital subscriber line communicating system and a transceiver therein are disclosed. The system or the transceiver comprises: a unit for calculating a bitmap which defines the number of transmissible bits for each carrier signal in each of periodical noise durations and a rate converter for converting a constant rate of an input transmitting data into a rate determined by the bitmap, and for adding, in a predetermined number of the periodical noise durations, dummy bits to the data having the converted rate. The bitmap calculating unit includes: a line quality measuring unit for measuring the quality of the communication line in each of the periodical noise durations, a transmission bit number converter for calculating the number of transmissible bits to be allocated to each carrier to form the bitmap, and a bitmap optimizing unit for minimizing the dummy bits by decreasing the number of the transmissible bits allocated to each carrier signal of the symbols.