Abstract: A wireless communication device includes a transmission processing unit communicable with each of multiple communication peer devices through switching between beam directions in a time division manner, and a control unit that allows beam information representing how beams are used by the multiple communication peer devices with which the transmission processing unit is communicable to be shared by the multiple communication peer devices.

Abstract: A voice transmission device has a tandem pass through function in an STM, ATM, IP network, and a noise canceller (21) is provided at a latter stage of an echo canceller (12) in a coding part, and in a case where a multistage connection state does not occur, noise removal is performed to carry out efficient coding, and in a case where a relay is performed in the multistage connection state, switching is performed to stop the operation of the noise canceller (21), and voice deterioration by redundant decoding and coding is prevented, and therefore, even in a cellular phone having no noise cancel function, or the like, and at both a normal time and a time of a tandem pass through state, high quality voice transmission can be performed, and further, since an unvoiced portion in voice data is increased by removing a noise component, a portion subjected to coding becomes small, and transmission amount of the line is reduced.

Abstract: A voice transmission apparatus 100 includes a subscriber-side I/F processing unit 1, a voice signal processing unit 2, a packet processing unit 3, an Ethernet I/F processing unit 4, a device-operation-monitoring-control processing unit 5, an amount of discarded voice packets/packet jitter measuring unit 6, a calling restriction determining unit 7, and an ITU-T Q.50 DLC processing unit 8. An operation monitor control desk 9 and an exchange 10 are connected to the voice transmission apparatus 100. The voice transmission apparatus 100 can impose a calling restriction on the exchange 10 based on the amount of discarded packets and the amount of packet jitter measured by the amount of discarded voice packets/packet jitter measuring unit 6.

Abstract: A voice transmission device has a tandem pass through function in an STM, ATM, IP network, and a noise canceller (21) is provided at a latter stage of an echo canceller (12) in a coding part, and in a case where a multistage connection state does not occur, noise removal is performed to carry out efficient coding, and in a case where a relay is performed in the multistage connection state, switching is performed to stop the operation of the noise canceller (21), and voice deterioration by redundant decoding and coding is prevented, and therefore, even in a cellular phone having no noise cancel function, or the like, and at both a normal time and a time of a tandem pass through state, high quality voice transmission can be performed, and further, since an unvoiced portion in voice data is increased by removing a noise component, a portion subjected to coding becomes small, and transmission amount of the line is reduced.

Abstract: A multiplex transmission apparatus according to the present invention compresses and multiplexes transmission signals, such as a voice signal, a facsimile signal and a data modem signal, then transmits them, wherein a signal input from an exchange side is subjected to compression encoding and facsimile demodulation in a plurality of signal process channels in a signal processing section, and thereafter each of the signal process channels generates and transmits a channel check signal to an opposing multiplex transmission apparatus side, which detects the channel check signal and returns a response signal, whereby abnormality in a signal process channel can be detected.

Abstract: The present invention concerns multiplex transmission equipment that transmits a speech, signal, a facsimile signal, a voice band data signal and similar transmission signals in compressed and multiplexed form. A signaling signal corresponding to the signaling system of each signal transmission system is detected and the operation of an echo canceller during signaling is controlled accordingly. This operation control of the echo canceller permits normal transmission of the signaling signal, and establishes communications between multiplex transmission equipment and the counterpart, allowing signal transmission subsequent to signaling.

Abstract: When there is an error in setting of a companding law of an encoder or a decoder, there is a problem of an error in judgment although it should be originally judged that the continuity of the testing channel does not exist. Therefore, a channel check test system includes a transmitting side DCME for inserting a nonlinear quantized input test pattern into a channel to be tested, and a receiving side DCME.

Abstract: A facsimile signal transmission system which satisfies the stipulation of the signal sending time and the stipulation of the signal time interval for enabling successful facsimile communication even if a detection delay or a sending delay occurs. In a facsimile signal transmission system for transmitting a digital command signal (DCS signal), an echo protect tone signal (EPT signal), a training signal, and a training check signal, if an IDLE message signal output from a transmission part at the end of the DCS signal is received in a reception party, a first timer operated for a first predetermined time is started. When the first predetermined time has elapsed, sending of the EPT signal to the reception facsimile terminal is started. A second timer operated for a second predetermined time is started at the same time as sending of the EPT signal is started. When the second predetermined time has elapsed, sending of the EPT signal is terminated.

Abstract: When there is an error in setting of a companding law of an encoder or a decoder, there is a problem of an error in judgment although it should be originally judged that the continuity of the testing channel does not exist.

Abstract: When there is an error in setting of a companding law of an encoder or a decoder, there is a problem of an error in judgment although it should be originally judged that the continuity of the testing channel does not exist. Therefore, a channel check test system includes a transmitting side DCME for inserting a nonlinear quantized input test pattern into a channel to be tested, and a receiving side DCME.

Abstract: When a frame detection signal is received which indicates that frame data was discarded during transmission, a facsimile signal corresponding to the oldest one of facsimile signals stored in a restored data storage part 30, 41 is output to a modem 22, 33.

Abstract: A reset signal generating part outputs reset signals RV and RD to a signal discriminating part, based on an output from a 2100 Hz detecting part which detects whether or not a tone of 2100 Hz exists in an input signal. When the 2100 Hz tone is detected, the signal discriminating part firstly resets a discrimination state at "speech" and secondly sets the discrimination state at "data" based on the reset signal. Therefore, a signal discrimination apparatus, wherein it is possible to reset the discrimination state at "speech" at the beginning of a facsimile call even when no call control information is received, can be provided.

Abstract: A counter increments a count value every given time period. An adaptive operation control unit selects channels in which adaptive operations are done from all the channels in obedience to the count value to output produced selection signals to AND circuits. Double-talk detection circuits judge the presence/absence of a double-talk state and output detection signals to the AND circuits. The AND circuits operate logical AND of the selection signals and the detection signals and output the logical AND results as control signals to filter coefficient updating circuits. The filter coefficient updating circuits update or do not update filter coefficients stored in FIR filter units according to the control signals. The FIR filter units produce echo replicas by calculating convolutions of the filter coefficients and the receive signals. Subtractors subtract the echo replicas from transmission signals to output residual signals.