Multirate, sonet-ready, switching arrangement

Apparatus for switching connections having a hierarchy of data rates comprising a lowest rate corresponding to one time slot of a time-division multiplex (TDM) frame of time slots and at least one higher rate corresponding to a plurality of time slots within said TDM frame, said apparatus comprising:

• means, responsive to a command to establish a given connection having a higher rate of said at least one higher rate, said command specifying only one time slot within said TDM frame and a data rate for said given connection, for determining from said specified time slot and data rate a set of a plurality of time slots within said TDM frame for said given connection;
• control memory means having locations corresponding to said TDM frame of time slots;
• means coupled to the means for determining a set of a plurality of time slots for said given connection, for determining locations in said control memory means that correspond to determined said set of a plurality of time slots;
• means coupled to the means for determining a set of a plurality of time slots for said given connection, for writing information defining said given connection into determined said locations of said control memory means;
• and
• switching means responsive to reading of said connection-defining information written into said determined locations of said control memory means for establishing said given connection having said higher rate.

A time-slot interchanger comprising:

• data memory means;
• control memory means having a plurality of locations each corresponding to a different one of a plurality of time slots of a time-division multiplex frame;
• means responsive to a request for a connection comprising multiple time slots of the time-division multiplex frame, said request specifying only one input time slot and one output time slot and a data rate of said connection, for determining, from specified said time slots and specified said data rate, other input time slots and output time slots for use for said connection comprising multiple time slots;
• means coupled to the determining means, for writing into locations of said control memory means which correspond to said one output time slot and determined said other output time slots, information identifying said one input time slot and determined said other input time slots;
• and
• said data memory means being responsive to said control memory means for transmitting information, stored from said one input time slot and said determined other input time slots, in said one output time slot and said determined other output time slots.

A time-multiplexed space switch comprising:

• a plurality of first ports;
• a second port;
• control memory means having a plurality of locations each corresponding to a different one of a plurality of time slots of a time-division multiplex frame;
• means responsive to a request for a connection comprising multiple time slots of the time-division multiplex frame, said request specifying a first port and only one output time slot of said switch and a data rate for said connection, for determining, from specified said first port and one output time slot and data rate, other output time slots of said switch for use for said connection comprising multiple time slots;
• means for writing into locations of said control memory means which correspond to said one output time slot and determined said other output time slots, information defining said first port;
• and
• means responsive to said control memory means for transmitting information from input time slots of one of defined said first port and said second port, in said one output time slot and said determined other output time slots of the other of said defined first port and said second port.

Apparatus for switching connections having a hierarchy of data rates comprising a lowest rate corresponding to one time slot of a time-division frame of time slots, said hierarchy comprising at least one higher rate corresponding to a plurality of time slots of predefined spacing within said time-division frame, said apparatus comprising:

• means responsive to a request to establish a given connection having said higher rate for determining a set of time slots of said predefined spacing within said time-division frame for said given connection;
• control memory means for defining switched connections having said lowest rate and said at least one higher rate, said control memory means including a different control memory location for each time slot of said time-division frame of time slots wherein contents of each control memory location indicate which input time slot is to be connected to an output time slot corresponding to said memory location during every occurrence of said output time slot that corresponds to said control memory location;
• means for determining locations in said control memory means that correspond to determined said set of time slots;
• means for writing information defining said given connection into determined said locations of said control memory means, including
• means for detecting each occurrence of a switching element output time slot corresponding to said given connection within said time-division frame, and
• means coupled to the detecting means and to the control memory means and responsive to each detection for writing, into the control memory location that corresponds to the detected output time slot, information specifying one of said input time slots that is to be connected to said detected output time slot during each occurrence of said output time slot that corresponds to said control memory location that corresponds to the detected output time slot;
• and
• switching means responsive to reading of connection information written into said determined locations of said control memory means for establishing said connection having said higher rate.

A method of switching connections having a hierarchy of data rates comprising a lowest rate corresponding to one time slot of a time-division multiplex (TDM) superframe of time slots and at least one higher rate corresponding to at least one time slot of a predetermined frame of time slots within said TDM superframe, said switching method comprising the steps of:

• during each time slot of said TDM superframe, reading a different control memory location of a programmable control memory means that defines switched connections having said lowest rate and a higher rate of said at least one higher rate, said control memory means including a different control memory location for each time slot of said TDM superframe, wherein contents of each control memory location indicate which one of a plurality of first ports is to be connected to a second port during every occurrence of a switching element output time slot that corresponds to said control memory location;
• in response to contents of said control memory locations, connecting said second port to ones of said first ports during first time-slot intervals to effect connections having said lowest rate and for connecting said second port to ones of said first ports during second time-slot intervals to effect connections having said higher rate;
• and
• reprogramming said control memory means to define an individual switched connection corresponding to a selected rate of the hierarchy and including the steps of
• detecting occurrence of a switching element output time slot corresponding to the individual switched connection within each frame that corresponds to the selected rate in a switching element output TDM superframe, and
• in response to each detection, writing into the control memory location that corresponds to the detected output time slot, information specifying one of said first ports that is to be connected to said second port during each occurrence of said output time slot that corresponds to said control memory location that corresponds to the detected output time slot.

A method of controlling a switching element for switching connections having a hierarchy of data rates comprising a lowest rate corresponding to one time slot of a time-division multiplex (TDM) frame of time slots and at least one higher rate corresponding to a plurality of time slots within said TDM frame, said method comprising the steps of:

• in response to a command to establish a given connection through said switching element having a higher rate of said at least one higher rate, said command specifying only one time slot within said TDM frame and a data rate for said given connection, determining from specified said one time slot and specified said data rate a set of a plurality of time slots within said TDM frame for said given connection;
• determining locations in a control memory that correspond to determined said set of a plurality of time slots;
• storing in determined said locations of said control memory information defining said given connection;
• and
• operating said switching element in response to reading of stored said connection information from said control memory to establish said given connection having said higher rate.

A method of controlling a time-slot interchanger having a data memory and a control memory that includes a plurality of locations each corresponding to a different one of a plurality of time slots of a time-division multiplex frame, the method comprising the steps of:

• in response to a request for a connection comprising multiple time slots of the time-division multiplex frame, said request specifying only one input time slot and one output time slot and a data rate of said connection, determining, from specified said time slots and specified said data rate, other input time slots and output time slots for use for said connection comprising multiple time slots;
• writing into locations of said control memory which correspond to said one output time slot and determined said other output time slots, information identifying said one input time slot and determined said other input time slots;
• and
• in response to contents of said control memory, transmitting information stored from said one input time slot and said determined other input time slots, in said one output time slot and said determined other output time slots.

A method of controlling a time-multiplexed space switch having a plurality of first ports, a second port, and a control memory having a plurality of locations each corresponding to a different one of a plurality of time slots of a time-division multiplex frame, the method comprising the steps of:

• in response to a request for a connection comprising multiple time slots of the time-division multiplex frame, said request specifying a first port and only one output time slot of said switch and a data rate for said connection, determining, from specified said first port and one output time slot and data rate, other output time slots of said switch for use for said connection comprising multiple time slots;
• writing into locations of said control memory which correspond to said one output time slot and determined said other output time slots, information defining said first port;
• and
• in response to contents of said control memory, transmitting information from input time slots of one of defined said first port and said second port, in said one output time slot and said determined other output time slots of the other of said defined first port and said second port.