| 摘要 |
<p>Information is transmitted between a subscriber location (12) and a central office (14), when each location is connected to the office by a single loop (16). Bursts of time compressed multiplexed, full duplex digital signals are synchronously transmitted at an information bit rate of between about forty and eighty kilobits per second and burst cycle of between about 0.8 and 4.0 milliseconds. Each burst contains bits defining at least one voice channel, at least one data channel and at least one signalling channel. The burst also has at least one synchronising bit at the front and back. Preferably the burst contains two thirty two bit voice channels, one eight bit medium speed data channel and four onebit low speed data channels. The total length of the burst is eight eight bits. The departure of the bursts from each subscriber location is timed so that those transmitted from the locations for each duplex arrive at the central office simultaneously.</p> |
