摘要 |
<p>One of the transmission facilities of a TASI system is used as an order wire, via which channel signalling information and assignment information are transmitted. Signalling information is transmitted periodically in frames on the order wire for only some of the channels, connected to the system, at any one time. Accordingly, the assignment information consists of both channel-to-facility assignment information, relating to the assignment of channels to the other facilities, and channel signalling assignment information, relating to the assignment of channels to signalling bit time channels in the frames on the order wire. One assignment can be transmitted in each frame, and frames not used for transmitting assignment information can be used for transmitting commands and messages. The system avoids the need to transmit multi-tone signals preceding speech bursts on the transmission facilities and avoids lengthy delays in the transmission of channel signalling information.</p> |