Protection switching mechanism

A protection switching mechanism comprising:

• a multiplexer having an input coupled to receive an input signal and a plurality of outputs to output a plurality of output signals;
• a transmission path for each output of the multiplexer, each transmission path coupled to receive an associated output signal from the multiplexer, the transmission paths further including one or more redundant transmission paths, wherein signals directed to a faulty transmission path are redirected to an associated redundant transmission path;
• a remote circuit to selectively switch a redundant transmission path for a faulty transmission path at a subscriber;
• wherein the input signal is a digital signal 3 (DS3 signal) and the output signals are digital signals (DS1 signals);
• a line unit for each transmission path to provide an asynchronous DS1 interface with the DSL;
• a remote unit for each transmission line to provide an interface from DSL back to DS1 at a customer's premise and
• a management unit coupled to control the multiplexer and the remote circuit, the management unit having a memory to store switching information.

A protection switching transmission path device comprising:

• a central office including,
• a multiplexer having an input and a plurality of outputs, and
• a management unit coupled to control the multiplexer;
• a remote circuit including,
• a plurality of relays and
• a controller card coupled to control the plurality of relays, wherein the control card is coupled to receive control signals from the management unit,
• a plurality of standard transmission paths, each standard transmission path coupled between an output of the multiplexer and an associated relay;
• and
• a plurality of redundant transmission paths, each redundant transition path is coupled between an output of the multiplexer and an associated relay, each redundant transmission path is further associated with a group of standard transmission paths, wherein if a standard transmission path in a group of transmission paths is detected as being faulty the management unit directs the multiplexer and the controller card to switch an associated redundant transmission path for the faulty standard transmission path.

A protection switching device comprising:

• a plurality of standard transmission paths coupled between a central office and a remote circuit;
• a redundant transmission path selectively coupled to replace one in a group of the plurality of standard transmission paths;
• the remote circuit having a switch relay for each standard transmission path, each switch relay is coupled to an associated standard transmission path, each switch relay having a first position to provide a connection to a subscriber and a second position to provide a connection to the redundant transmission path, wherein when one of the plurality of standard transmission paths is found to be faulty its associated relay is positioned to the second position;
• and
• the remote circuit having a redundant relay for the redundant transmission path, the redundant transmission path is coupled to an associated redundant relay, each redundant relay having a first position to provide a current loop path and a second position to provide an open circuit, wherein when one of the plurality of standard transmission paths in a group of standard transmission paths is found to be faulty a redundant relay coupled to an associated redundant transmission path is placed in its second position so signals in the redundant transmission path are routed to the subscriber.

A protection switching mechanism comprising:

• a multiplexer having an input coupled to receive an input signal and a plurality of outputs to output a plurality of output signals;
• a plurality of line units, each line unit is coupled to selectively receive an associated output of the multiplexer;
• one or more redundant line units, each redundant line unit is selectively coupled to receive an output of the multiplexer associated with a line unit that is coupled to a faulty transmission line;
• a remote unit for each line unit, each remote unit is coupled to an associated line unit;
• a redundant remote unit for each redundant line unit, each redundant remote unit coupled to an associated redundant line unit;
• a relay for each remote unit and each redundant remote unit, each relay for each remote unit is coupled an associated remote unit and each relay for each redundant remote unit is coupled to an associated redundant remote unit;
• and
• a management unit to control the output of the multiplexer and the relays, wherein when the management unit detects a line unit coupled to a faulty transmission line an output of the multiplexer assigned to the line unit coupled to the faulty transmission line is directed to an associated redundant line unit instead and a relay coupled to the faulty transmission line as well as a redundant relay associated with the redundant line unit are switched to provide an alternate signal path around the faulty transmission line.

A remote circuit comprising:

• a remote shelf enclosure having a plurality of remote unit slots, a protection remote unit slot, a protection switching controller slot and a power supply module slot;
• an automatic protection switching (APS) bus coupled between the protection remote unit slot and the protection switching controller slot;
• a remote unit card having a remote unit removably coupled in each remote unit slot;
• a protection remote unit card having a protection remote unit removably coupled in the protection remote unit slot;
• a protection switching controller card having a protection switching controller removable coupled in the protecting switching controller slot;
• and
• a power supply module card having a power supply module removably coupled in the power supply module card slot.

A remote circuit comprising:

• a remote shelf enclosure having a plurality of remote unit slots, a protection remote unit slot, a protection switching controller slot and a power supply module slot, wherein the protection switching controller slot is positioned adjacent the protection remote unit slot;
• and further wherein the protection switching controller slot receives its power from the protection remote unit slot;
• a remote unit card having a remote unit removably coupled in each remote unit slot;
• a protection remote unit card having a protection remote unit removably coupled in the protection remote unit slot;
• a protection switching controller card having a protection switching controller removable coupled in the protecting switching controller slot;
• and
• a power supply module card having a power supply module removably coupled in the power supply module card slot.

A method of operating a transmission path network, the method comprising:

• grouping a plurality of transmission paths with an associated redundant transmission path;
• coupling an output signal from a multiplexer addressed to a faulty transmission path in the group of transmission paths to the redundant transmission path;
• coupling the redundant transmission path to replace the faulty transmission path at a subscriber;
• and
• replacing the faulty transmission path at the subscriber with a plurality of relays at a remote circuit.

A method of switching transmission paths, the method comprising:

• grouping a plurality of standard transmission paths in separate groups;
• monitoring each standard transmission path for errors by sending a test signal from a central office to a remote circuit and back;
• detecting errors in a standard transmission path in one of the standard transmission paths in a group of standard transmission paths;
• outputting signals directed to the standard transmission path with errors from a multiplexer in the central office to a redundant transmission path associated with the group of standard transmission paths instead of the standard transmission path with errors;
• and
• coupling the redundant transmission path to an end portion of the standard transmission path with errors at the remote circuit, wherein signals directed to the standard transmission path with errors are routed around the standard transmission path.

A method of operating a remote shelf enclosure, the method comprising:

• selectively coupling a plurality of remote units in associated remote units slots;
• selectively coupling a protection remote unit in a protection remote slot;
• selectively coupling a protection switching controller in a protection switching controller slot;
• selectively coupling a power supply module in a power supply slot;
• coupling a standard transmission path to each of the remote units;
• coupling a protection transmission path to the protection remote unit;
• monitoring the standard transmission paths for errors;
• and
• when errors are detected in a standard transmission path, switching an output of the standard transmission path with the errors for an output of the protection transmission path.