| 摘要 |
PURPOSE:To limit dialing by detecting a DLC signal in a PCM signal outputted from a DCME by a control procedure recommended by the CCITT.Q50 and sending a busy tone to a caller subscriber based on the detected DLC signal. CONSTITUTION:A SYD 2, FTSD 3 detect a DLC signal in a PCM signal outputted from a DCME in compliance with a control procedure recommended by the CCITT.Q50 and an SW 6 selects a busy tone from a BTG 5 based on the detected DLC signal and the tone is sent to a caller subscriber. Thus, a problem that a voice signal cannot be sent in the overload state and the voice is intermitted or the talking is entirely not available because a voiced sound of the call requiring a channel number exceeds a threshold level in a conventional system between a PCM terminal station equipment and a DCME is avoided. |
