Method and apparatus for sparing communications circuits

A telecommunications circuit comprising:

• splitter circuitry adapted to receive a plurality of telecommunication lines, and to split said telecommunication lines into corresponding primary lines and secondary lines, said primary lines for coupling to primary line interfaces;
• a sparing bus for coupling to a spare line interface;
• a backplane adapted to receive said secondary lines;
• at least one sparing switch connected to said backplane;
• and
• selection circuitry carried on said backplane and adapted to control said at least one sparing switch to connect a group of said secondary lines to said sparing bus in response to a selection control signal;
• wherein telecommunications signals normally handled by a given primary line interface and routed over ran associated group of primary lines are routed to the spare line interface over a corresponding group of secondary lines via said sparing bus;
• and
• wherein said backplane is adapted to permit removal of said backplane without interfering with operation of said primary lines and said primary line interfaces.

A signal line switching card adapted for use in telecommunications line interface equipment that includes splitter circuitry for splitting a number of telecommunication lines into corresponding primary and secondary lines, a sparing bus for coupling a selected group of the secondary signal lines to spare interface circuitry, and selection control circuitry for selecting said selected group of the secondary signal lines, said signal line switching card comprising:

• a first set of connections adapted to receive a number of the secondary signal lines derived from said splitter circuitry;
• a second set of connections for coupling to said sparing bus;
• a plurality of switches adapted to selectively connect respective ones of said first connections with respective ones of said second connections;
• and
• a switch control circuit including a control signal input and adapted to control said switches responsive to a control signal received on said switch control signal input from said selection control circuitry;
• and
• wherein said signal line switching card is associated with a backplane that is adapted to be removed from the telecommunications line interface equipment without interfering with the primary lines.

A switching controller card adapted for use in telecommunications line interface equipment that includes splitter circuitry for splitting a number of telecommunication lines into corresponding primary and secondary lines, a sparing bus for coupling a selected group of the secondary signal lines to spare interface circuitry, and a switching network for selectively connecting a desired group of the secondary signal lines to said sparing bus, said switching controller card comprising:

• a first interface adapted to receive switch selection information;
• a second interface adapted to output a switch control signal for control of said switching network;
• and
• control circuitry comprising a switching controller adapted to generate said switch control signal based on said switch selection information such that said switch control signal operates said switching network to connect said desired group of said secondary signal lines to said sparing bus;
• wherein a communications controller included in the telecommunications line interface equipment determines said switch selection information based on monitoring for failure a number of primary interface circuits adapted to transfer communication signal between the telecommunication lines and the primary interface circuits via the primary signal lines;
• and
• wherein said switching controller card is mounted on a backplane adapted to be removed without interfering with the primary lines of the telecommunications line interface equipment.

A telecommunications apparatus comprising:

• a means for splitting a number of telecommunication lines into corresponding primary and secondary lines;
• a means for coupling said primary lines to a set of primary communications circuits;
• and
• a means for selectively connecting desired ones of said secondary lines to a spare communications circuit when one of said primary communications circuit is unavailable, said desired ones of said secondary lines corresponding to certain ones of said primary lines associated with said unavailable primary communications circuit, said means for selectively connecting associated with a backplane adapted to be removed from the telecommunications apparatus without interfering with the primary lines;
• wherein said telecommunications apparatus is operative to provide a communications function for the telecommunication lines using said primary circuits and said primary lines independent of said spare circuit and said secondary lines.