Abstract: A digital subscriber line (xDSL) communication system (10) is disclosed that allows xDSL communication across a local loop. The system (10) includes a local loop termination point (14) and customer premises equipment (12) connected to a twisted pair telephone line (16). Loop integrity test devices (22, 24) for xDSL communication are located at the local loop termination point (14) and the customer premises equipment (12) and are coupled to the telephone line (16). The loop integrity test devices (22, 24) are respectively operable to transmit test signatures across the telephone line (16), to receive and evaluate test signatures from the telephone line (16), and to indicate whether the telephone line (16) can support xDSL communication based upon evaluation of test signatures.

Abstract: A communication server (58) includes a plurality of pairs of frequency agile modulators (638) and demodulators (640) each set to operate at a unique frequency and associated with a twisted pair data line (54). The communication server (58) also includes a plurality of pairs of demodulators (644) and modulators (646) that each have a designatable operation frequency and are associated with one of a plurality of XDSL modems (648). A mixer (642) operates to combine signals from the frequency agile modulators (638) and provide the combined signal to the demodulators (644). The mixer (642) further operates to combine signals from the modulators (646) and provide the combined signal to the frequency agile demodulators (640). A detector (634) operates to detect a need for data service on a selected twisted pair data line (54).

Abstract: A communication system (10) includes a number of subscribers (12) coupled to a central office (14) using twisted pair subscriber lines (16). The central office (14) includes a telephone switch (56) that provides telephone service to the subscribers (12), and a communication server (58) having a plurality of XDSL modems (160) that provide data service to the subscribers (12). The communication server (58) allows over-subscription of data service to subscribers (12).