| 摘要 |
PURPOSE:To realize variable speed communication easily, by giving the right to assign a channel to both a terminal and an exchange costituting a network. CONSTITUTION:A terminal 17 has plural communication speeds and performs plural communications simultaneously, and this terminal is connected to an exchange 20 by a multiplex subscriber line 25 consisting of (n) (1<=n<=31) information channels 22 (B channel) for transferring user information constituting a user information part and one signal channel 23 (D channel) for transferring a call controll signal. Similarly, terminals 18 and 19 are connected to the exchange 20 by the multiplex subscriber line 25. In a figure, 21 is a signal frame, 24 is a transmitting and receiving circuit, and 26 is an information channel. The frame of a multiplex subscriber consists of a framing bit 27 showing the head F of one frame, plural B channels 22, and a D channel 23. By the framing bit 27, the terminals 17, 18, and 19 extracts a basic clock from the exchange 20 constituting the network individually and transmits and receives signals synchronously with the exchange 20. |
