| 摘要 |
A communication system includes plurality of subscribers having a telephone set and different types of home modems coupled using twisted pairs to a local server that includes plurality of downstream repeaters, a central office coupled to a local server using twisted pair subscriber lines. The central office includes a telephone switch that provides telephone service to the subscribers and a concentrator that connects a plurality of upstream repeaters with a number of office modems that provide data service to the subscriber. A communication system uses CAP or DMT line signals with time division. The line signal transmits with different time framing. Every subscriber line can work in one of three operation modes: Asymmetrical mode, Half-Asymmetrical mode, Symmetrical mode. An office modem changes the operation mode of subscribers line and downstream/upstream bit rate depending on the type of an information source and the type of the subscriber home modem that is connected to the office modem in the current transmit cycle. |
