Abstract: In a network system for effecting signal transmission by plural channels, there are provided plural channel alteration units each of which is adapted to receive signals through plural channels and to output each of the signals entered by said plural channels in any of plural channels. Transmission control is executed in such a manner that mutually proximate plural signals, which have to be outputted by a designated same channel among the plural channels from a first one of the plural channel alteration units, are entered through respectively different channels into the first channel alteration unit. As the first channel alteration unit receives the plural signals by different channels, there can be resolved the drawback of a long waiting time for the output of the signals by a desired channel, encountered in case the signals are entered by a signal channel.

Abstract: In a network system, a plurality of terminals are serially connected using a multiplex line and the multiplex line includes at least one first channel for transmitting a cell in a first direction and at least one second channel for transmitting a cell in a second direction, which is opposite to the first direction. In a transmission method to be performed in the network system, a terminal out of the plural terminals, which has a request for writing data in a cell transmitted through the second channel, writes a write request in a cell transmitted through the first channel and having no write request written therein, and sends out this cell. Each of the plural terminals counts the number of a cell or cells having the write request written therein and transmitted through the first channel or channels.

Abstract: A switching device include a buffer for temporarily storing a signal sent by a corresponding input terminal; variable channel transmission units, one of which is provided for each input terminal, for outputting a received signal with one of N different channels; fixed channel reception units, one of which is provided for each output terminal, for receiving the signal carried with a given channel and for outputting a signal with the given channel to a corresponding output terminal, with the given channel not overlapping any other; a variable channel control unit for synchronously altering, in consonance with predetermined patterns, channels with which the variable channel transmission unit outputs a signal, so that two or more variable channel transmission units do not simultaneously output signals with the same channel; and a buffer control unit for synchronously reading from the buffer a signal that is to be output, while altering the channel with which the variable channel transmission unit transmits a sign