Switching complex architecture and operation

A system operable to communicate a plurality of signals having various signal formats including time-division multiplexed signals, the system comprising:

• an interface card operable to receive a plurality of incoming signals, to format the incoming signals into transport signals, to route the transport signals to at least one of a plurality of switching fabrics, to receive switched transport signals from at least one of the switching fabrics, and to facilitate transmission of the switched transport signals;
• a primary rate switching fabric operable to receive a first plurality of transport signals and to switch the first plurality of transport signals at a first level;
• a sub-rate switching fabric operable to receive a second plurality of transport signals carrying time-division multiplexed information and to switch the second plurality of transport signals at second level that is a more granular level than the first level;
• a signal distributor operable to receive the first and second pluralities of transport signals and to communicate each of the pluralities of transport signals to its associated switching fabric
• a signal selector operable to receive switched transport signals from the primary rate switching fabric and the sub-rate switching fabric and to facilitate transmission of the switched transport signals to external network elements;
• and
• wherein the signal selector comprises:
• a third time slot interchange operable to receive switched transport signals from the sub-rate switching fabric and to associate the switched transport signals with time slots on which the transport signals were originally received in the second time slot interchange;
• and
• a multiplexer operable to receive switched transport signals from the primary rate switching fabric and the third time slot interchange, and to select a set of switched transport signals for transmission.

An interface card operable to interface a communication system having a switching complex operable to receive and process a plurality of transport signals carrying time-division multiplexed information, wherein the switching complex comprises:

• a primary rate switching fabric operable to receive a first plurality of transport signals and to switch the first plurality of transport signals at a first level;
• sub-rate switching fabric operable to receive a second plurality of transport signals carrying time-division multiplexed information and to switch the second plurality of transport signals at second level that is a more granular level than the first level;
• a signal distributor operable to receive the first and second pluralities of transport signals and to communicate each of the pluralities of transport signals to its associated switching fabric
• a signal selector operable to receive switched transport signals from the primary rate switching fabric and the sub-rate switching fabric and to facilitate transmission of the switched transport signals to external network elements;
• and
• wherein the signal selector comprises:
• a third time slot interchange operable to receive switched transport signals from the sub-rate switching fabric and to associate the switched transport signals with time slots on which the transport signals were originally received in the second time slot interchange;
• and
• a multiplexer operable to receive switched transport signals from the primary rate switching fabric and the third time slot interchange, and to select a set of switched transport signals for transmission.

A method of communicating time-division multiplexed information using a single switching complex, the method comprising:

• receiving at the switching complex a plurality of transport signals comprising:
• a first transport signal comprising pass-through traffic requiring primary rate switching;
• and
• a second transport signal comprising sub-rate traffic requiring sub-rate switching;
• communicating each transport signal to a switching fabric operable to perform a switching function associated with that signal;
• performing primary rate switching on the first transport signal;
• performing sub-rate switching on the second transport signal;
• wherein communicating each transport signal comprises:
• duplicating the transport signals;
• communicating a first set of transport signals to the primary rate switching fabric;
• communicating a second set of transport signals to the sub-rate switching fabric;
• and
• wherein communicating the second set of transport signals comprises:
• communicating the second set of transport signals to a second time slot interchange;
• associating the second plurality of transport signals with a first range of time slots associated with the sub-rate switching fabric;
• and
• transmitting the second plurality of transport signals to the sub-rate switching fabric.