Hitachi Telecom Technologies, Ltd

Kimitoshi Takeuchi

Toru Yoshihara

Shinya Suzuki

Makoto Oohashi

Toru Watanabe

Kanichi Satou

Eisuke Atsuumi

Haruyasu Oono

Hiroaki Hashimoto

Tatsuya Suzuki

A communication apparatus connected to a PBX and an ATM network is provided with a DTMF signal detecting portion for detecting whether or not a DTMF signal is contained in a voice signal from the PBX, a DTMF signal monitoring portion, a DTMF cell generating portion for coding and sending out a DTMF signal, a DTMF cell decomposing portion for decoding a coded DTMF signal and a DTMF signal generating portion for generating a DTMF signal on the basis of the information content of a decoded DTMF signal and sending out this DTMF signal to the PBX, and the transmission side communication apparatus codes a DTMF signal in a specified form and transmits the DTMF signal and the reception side communication apparatus decodes the coded DTMF signal and, on the basis of this content information, restores the DTMF signal in a DTMF signal generating portion. By doing so, even in case of transmitting a DTMF signal by way of a communication apparatus performing a voice code compression, it is made possible for a reception side communication apparatus (PBX) to judge/recognize the DTMF signal without error.

DTMF signal transmission method and communication apparatus

When a communication system is constructed by use of a plurality of data relay apparatuses of the present invention, it is possible to control an execution/non-execution of a compression/decompression for voice data so that the compression/decompression is not repeatedly executed regardless of a PBX. An ATM multiplexer sends out a transmission pattern to an apparatus adjacent to the ATM multiplexer via a PBX, and stops the compression/decompression of the voice data to relay the voice data transmissively, only when the ATM multiplexer receives the transmission pattern from the adjacent apparatus via the PBX. In other cases, the ATM multiplexer relays the voice data while executing the compression/decompression operation for the voice data.

Voice data relay apparatus

Arbitration for a bus mastership is performed in accordance with the priority degrees of data which are to be transferred on a bus, by a comparatively simple construction. In a case where interfacessimultaneously output to the busthe priority degrees which correspond to non-ATM linesbeing the reception sources or transmission destinations of the data stored in ATM cells, and where the priority degrees outputted by the interface themselves are the highest, the interfaces transmit to the bus, bus mastership request signals which contain the addresses of the interfaces themselves. A bus control modulereceives the bus mastership request signals on the bus, it determines that one of the interfaces to which the bus mastership is granted, and it outputs to the busa bus mastership grant signal which contains the address of the determined interface.

ATM apparatus, IP apparatus and bus system

A multiplexing equipment included in an ATM network to transmit control line signals for interfacing data communication terminals. The transmission of the control line signals is realized by reserving a field in a payload in a cell format for the control line signal transmission between the data communication terminals, mapping RS/CD, CS, ER/DR, CI of the control line signals at intervals based on a terminal speed, multiplexing the mapped control line signals at the transmission side, and separating the multiplexed control line signals at reception side.

Cell creation method for control line signals of ATM Network and multiplexing equipment

A congestion control method and apparatus that conducts congestion control for a frame relay terminal in real time and without any time lag when a congestion has occurred at an outgoing cell store medium of a fast multiplex unit of an ATM multiplex apparatus. The fast multiplex unit of the ATM multiplex apparatus is provided with a outgoing cell store medium monitor unit monitoring a congestion level of the outgoing cell store medium and generating a congestion reporting signal indicative of the congestion level and a light/heavy congestion indication signal. The time lag which occurs when the congestion reporting is made is eliminated by sending both signals directly to a frame relay interface control unit from the fast multiplex unit.

ATM multiplex apparatus and congestion reporting method

A communication apparatus or connected to a PBX or and an ATM network , is provided with a DTMF signal detecting portion for detecting whether or not a DTMF signal is contained in a voice signal from the PBX or , a DTMF signal monitoring portion , a DTMF cell generating portion for coding and sending out a DTMF signal, a DTMF cell decomposing portion for decoding a coded DTMF signal and a DTMF signal generating portion for generating a DTMF signal on the basis of the information content of a decoded DTMF signal and sending out this DTMF signal to the PBX or , and the transmission side communication apparatus or codes a DTMF signal in a specified form and transmits the DTMF signal and the reception side communication apparatus or decodes the coded DTMF signal and, on the basis of this content information, restores the DTMF signal in a DTMF signal generating portion . By doing so, even in case of transmitting a DTMF signal by means of a communication apparatus performing a voice code compression, it is made possible for a reception side communication apparatus (PBX) to judge/recognize the DTMF signal without error.

Growing community of inventors

Koriyama, Japan

Kimitoshi Takeuchi