Wavelength division multiplexing combined with time division multiplexing using a common time reference
AssigneeSynchrodyne Networks, Inc.
InventorYoram Ofek
Life of this patent
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Abstract
A switching method operates with very high-speed wavelength division multiplexing (WDM) links, i.e., with multiple lambdas. An efficient time frame switching method is based on pre-defined switching schedules that are responsive to a global common time reference, where the global common time reference is divided into a plurality of contiguous periodic time frames. The plurality of data packets contained in each of the time frames can be switched from any incoming WDM channel to any subset of outgoing WDM channels. The outcome of this switching method is called fractional lambda switching.
Claims80
A switch controller system, for use with a switching fabric comprising a plurality of selectable input ports (i) each receiving data packets over a plurality of incoming channels (j), and a plurality of output ports (k) each sending data packets over a plurality of outgoing channels (l), wherein a Common Time Reference (CTR) is divided into a plurality of contiguous periodic super cycles (SC) each comprised of at least one contiguous time cycle (TC) each comprised of at least one contiguous time frame (TF), said system comprising:
- a controller for logically mapping selected incoming channels to selected outgoing channels for each of the time frames, and for storing the mapping,
- wherein for each of the time frames a respective logical mapping is provided for at least one selected one of the outgoing channels to be connected to at most one of the incoming channels;
- means to provide control signals responsive to the CTR and the logical mapping for each of the time frames within each of the TCs and within each of the SCs;
- and
- means for scheduling the transfer of data packets, wherein during each of the time frames, each of the outgoing channels is connectable to at most one of the incoming channels, responsive to control signals.
A switch controller system comprising:
- a switching fabric comprising a plurality of selectable input ports (i) each receiving data packets over a plurality of incoming channels (j), and a plurality of output ports (k) each sending data packets over a plurality of outgoing channels (l), wherein a Common Time Reference (CTR) is divided into a plurality of contiguous periodic super cycles (SCs) each comprised of at least one contiguous time cycle (TC) each comprised of at least one contiguous time frame (TF);
- a controller for logically mapping selected incoming channels to selected outgoing channels for each of the time frames, and for storing the mapping;
- wherein for each of the time frames a respective logical mapping is provided for at least one selected one of the outgoing channels to be connected to at most one of the incoming channels;
- means to provide control signals responsive to the CTR and the logical mapping for each of the time frames within each of the time cycles and within each of the super cycles;
- and
- means for scheduling the transfer of data packets, wherein during each of the time frames, each of the outgoing channels is connectable to at most one of the incoming channels, responsive to control signals.
A controller system, for switching a plurality of data packets from a plurality of uniquely addressable input ports, each receiving data packets over a plurality of incoming optical channels, to a plurality of uniquely addressable output ports, each sending data packets over a plurality of outgoing optical channels, the controller system comprising:
- a memory comprising storage organized as a plurality of defined arrays representative of a plurality of respective switching matrices;
- a switching fabric for connecting selected ones of the incoming optical channels to selected ones of the outgoing optical channels responsive to the memory;
- and
- a common time reference (CTR);
- wherein the CTR is coupled to the controller system;
- wherein the CTR is divided into a successive sequence of predefined super cycles (SCs);
- wherein each of the predefined super cycles is divided into a successive sequence of at least one predefined time cycle (TC);
- wherein each of the predefined time cycles is divided into a successive sequence of at least one predefined time frame (TF);
- wherein each of the predefined time frames is further divided into a successive sequence of at least one predefined time slot (TS);
- wherein each of the switching matrices specifies which of the incoming optical channels should be connected to which of the outgoing optical channels;
- and
- wherein a selected one switching matrix of the plurality of switching matrices is used in each of the time slots within each of the time frames within each of the time cycles and within each of the super cycles.
A controller system, for switching a plurality of data packets from a plurality of uniquely addressable input ports to a plurality of uniquely addressable output ports, the controller system comprising:
- a memory comprising storage organized as a plurality of defined arrays representative of a plurality of respective switching matrices;
- a switching fabric for connecting selected ones of the input ports to selected ones of the output ports responsive to the memory;
- and
- a common time reference (CTR);
- wherein the CTR is coupled to the controller system;
- wherein the CTR is divided into a successive sequence of predefined super cycles (SCs);
- wherein each of the predefined super cycles is divided into a successive sequence of at least one predefined time cycle (TC);
- wherein each of the predefined time cycles is divided into a successive sequence of at least one predefined time frame (TF);
- wherein each of the predefined time frames is further divided into a successive sequence of at least one predefined time slot (TS);
- wherein each of the plurality of the switching matrices specifies which input port should be connected to which output port;
- wherein each of the plurality of the switching matrices is used in a selected one of the time slots within a selected one of the time frames within a selected one of the time cycles and within a selected one of the super cycles.
A control system for coupling data packets from an input source to an output destination on a time scheduled basis, via a switch comprising a plurality of addressable input ports each with an associated input port number, and a plurality of addressable output ports each with an associated output port number, wherein there is a time frame and time cycle associated with each input to the input port and with each time for switching and with each output to the output port, the system comprising:
- means for providing an output structured as a Common Time Reference (CTR) divided into a plurality of contiguous periodic super cycles (SCs) each comprised of at least one contiguous time cycle (TC) each comprised of at least one contiguous time frame (TF);
- a mapping subsystem for storing data representative of a mapping of a switching structure defining scheduling of movement of the data packets from at least one of the input ports to at least one of the output ports, comprising means for storing as a mapping a correlation of a respective input port number and a respective input port time frame, time cycle, and super cycle versus a respective associated output port number, an associated switching time frame, time cycle, and super cycle and an associated output port time frame, time cycle, and super cycle.
A switching system, comprising:
- a Common Time Reference (CTR), divided into a plurality of contiguous periodic super cycles (SCs) each comprised of at least one contiguous periodic time cycle (TC) each comprised of at least one contiguous periodic time frame (TF);
- a plurality of multiplexed input streams, each comprised of a plurality of channels (j) of data packets, wherein communication of the data packets over any respective one of the channels is periodic with reference to the CTR and is phase independent of the CTR;
- a plurality of input ports (i), each comprised of a demultiplexer for demultiplexing the input streams into a plurality of separate channels;
- a plurality of alignment subsystems, each respectively associated with one of the respective channels,
- wherein each one of the alignment subsystems comprises a plurality of queues, wherein each one of the queues is associated with a respective one of the time frames;
- and
- wherein each one of the alignment subsystems further comprises means for selectively storing respective ones of the data packets and providing selective delay of output of the stored data packets to provide phase alignment of the timing of the output from the alignment subsystem relative to the CTR.
A switching control method for switching a plurality of data, the method comprising:
- providing a Common Time Reference (CTR), that divides time into a plurality of contiguous periodic super cycles each comprised of at least one contiguous time cycle (TC) each comprised of at least one contiguous time frame (TF);
- providing a plurality of input ports, each with a plurality of input channels for receiving data;
- providing a plurality of output ports, each with a plurality of output channels for transmitting data;
- providing a switch controller coupled to the CTR, for coupling the input channels and the output channels;
- and
- providing a switch fabric coupled to and responsive to the switch controller, for coupling selected ones of the input channels to selected ones of the output channels;
- scheduling connection to the switch fabric via the switch controller from a respective one of the input ports, on a respective one of the input channels during a respective one of the time frames responsive to the CTR;
- and
- defining the coupling via the switch controller from each one of the input ports received during any one of the time frames, on a respective one of the input channels, for output during a predefined time frame to at least one selected one of the output ports on at least one selected one of the output channels.
Dependencies are inferred from the claim text.