Kokusai Denshin Denwa Co., Ltd.

Kokusai Denshin Denwa Kabushiki Kaisha

Hiromichi Mori

Jun Matsumoto

Masanobu Fujioka

Yoshikazu Ikeda

Tatsuo Maruyama

A time division speech path switch for an electronic exchange system has a plurality of speech path memories for each input highway, and an input highway information is stored simultaneously in all of said speech path memories. The number of said input highway memories is equal to number of output highways, and each speech path memory can store at least one frame information of an input highway. A holding memory is provided at each output highway. A switched output signal is read out of one of said speech path memories according to content of the holding memory coupled with the output highway. According to the invention which has a plurality of input speech path memories and a plurality of holding memories, instead of a single speech path memory and a single holding memory of a prior art, an operational speed of a speech path memory and a holding memory may be slow as compared with that of a prior art. And, a large capacity of exchange system may be designed by using a low speed memory device.

Time division speech path switch

A distributed switching system is disclosed which includes a plurality of simple-function switching units interconnected by speech path links, each unit having a speech-path switch, a plurality of processing units connected to speech-paths for use in signal and call processing, and an inter-unit bus for the connection between the switching units and the processing units, and functions as a single large switching system as a whole.

Distributed switching system

A speech path switching system in time-divisional electronic telephone switching system for the full availably switching between k number of incoming highways and k number of outgoing highways and each highway having n number of telephone channels comprises (a) k number of speech path memories for temporarily storing telephone signals, provided for each incoming highway, (b) k number of input counters provided for each speech path memory for designating the input address of said speech path memory, said input counter being circularly incremented synchronized with the frame phase of the corresponding incoming highway, (c) k number of holding memories provided for each outgoing highway for designating the read out address of said speech path memory to substantially connect an incoming channel to an outgoing channel, and (d) k number of output counters provided for each holding memory for designating the read out address of the holding memory.

Speech path switching system in time-divisional electronic telephone

In a telephone switching system having a main-speech-path switch, connected to a plurality of subscribers and a plurality of board trunks, the connection in the main-speech-path switch is controlled as follows. In the first mode, the connection between a calling channel and one of the board trunks and the connection between a called channel and the board trunk are established through the main-path-switch, so as to selectively enable speech between an operator connected to said board trunk and one of a calling subscriber and a called subscriber. In the second mode, the connections between the calling channel and the called channel is directly established in the main-speech-path switch, while simultaneously connecting the two channels to the board trunk through the main-speech-path switch, so as to enable to monitor the speech between the calling subscriber and the called subscriber by the telephone operator. In the third mode, the main-speech-path switch effects only the connection between the calling channel and the called channel, while clearing the connection between said two channels and said board trunk. Thus, the main-speech-path switch is free from the board trunk except for the monitoring and the initial connection operation, and can increase the exchange capability.

Call processing system with an operator assistance in a telephone

In a transmission station, the information from each channel is sampled and encoded to a PCM form having a predetermined length of bits. The group of said bits together with line number bits is called a signal block. Only significant signal blocks from all the channels are transmitted to a receiving station through a buffer memory provided at a transmission station and a common transmission line. The receiving station receives the signal blocks through a buffer memory provided at the receiving station and inserts an idle signal to the portion where the transmission station removes a signal block due to an insignificant signal block. The received signal blocks are distributed to each receiving channel, thus, the original signal is reproduced at the receiving station.

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Kawasaki, Japan

Hiromichi Mori