Abstract: A digital subscriber line access multiplexer overlay onto a digital loop carrier system for transporting high speed digital data over an existing backplane which carries voice, data, and test signals between voice line cards and a carrier line. The voice signals are time division multiplexed into frames. The system includes a data bus interface for impressing the high speed data on a subset of existing backplane buses for transport along the backplane and for retrieving high speed digital data from the backplane buses. The system further includes a plurality of data line cards for connecting to the backplane and backplane subset conductors, the data line cards being adapted to couple the high speed data between the subscriber line and the backplane, whereby the high speed digital data can be routed over the backplane subset to any of the digital data line cards without interfering with the voice signals routed to voice line cards.

Abstract: A digital subscriber line access multiplexer overlay onto a digital loop carrier system for transporting high speed digital data over an existing backplane which carries voice, data, and test signals between voice line cards and a carrier line. The voice signals are time division multiplexed into frames. The system includes a data bus interface for impressing the high speed data on a subset of existing backplane buses for transport along the backplane and for retrieving high speed digital data from the backplane buses. The system further includes a plurality of data line cards for connecting to the backplane and backplane subset conductors, the data line cards being adapted to couple the high speed data between the subscriber line and the backplane, whereby the high speed digital data can be routed over the backplane subset to any of the digital data line cards without interfering with the voice signals routed to voice line cards.

Abstract: A system for providing at least one telephone service in a multiservice communication system, the system comprising a combiner for combining a plurality of services for delivery between a source and a user along a common line. A decombiner recovers the plurality of services from the common line, a detector detects a failure condition in at least one of the combiner or the decombiner, and a switch responsive to the detected failure bypasses the failed combiner or decombiner to couple at least one service determined to be critical between the source and the user. This allows an improved response to loss of power than many exiting systems.