Photonic switching

An optical communication arrangement comprising:

• an optical bit stream comprising periodic frames of signal groups, each said signal group comrising a plurality of time slots each having digital information bits and each said signal group being separate in time by a route switching interval;
• processor means for allocating each said signal group for communication of said plurality of time slots to a predetermined destination;
• and
• photonic switch means, controlled during each said route switching interval, for switching each of the allocated signal groups in an optical domain to its respective allocated predetermined destination;
• a source communication system responsive to communication requests for generating said optical bit stream;
• said source communication system comprising processor means for measuring the volume of communications of said communication requests and for generating data messages representing said volume of communications;
• data transmission means for transmitting said data messages to said processor means for allocating;
• said processor means for allocating responsive to said data messages for changing said allocations to reflect the volume of communications represented by said data messages.

An optical communication arrangement comprising:

• an optical bit stream comprising frame synchronizing signals and periodic frames of signal groups, each said signal group comprising a plurality of time slots each having digital information bits and each said signal group being separated in time by a route switching interval;
• a branch node for inserting and removing a proper subset of said signal groups from said optical bit stream;
• means for allocating each said signal group for communication of said plurality of time slots to a predetermined destination;
• and
• photonic switch means, controlled during each said route switching interval, for switching each of the allocated signal groups in an optical domain to its respective allocated predetermined destination wherein said optical bit stream comprises frame synchronizing signals, and said branch node comprises:
• means for detecting said frame synchronizing signals;
• clock means responsive to said means for detecting said frame synchronizing signals;
• and
• adjustable delay means responsive to said clock means for adjustably delaying signals to be inserted into said optical stream.

An optical communication arrangement comprising:

• a plurality of optical bit streams each comprising periodic frames of signal groups, each frame comprising a frame synchronizing signal, each said signal group comprising a plurality of time slots each having digital information bits and each said signal group being separated in time by a route switching interval;
• means for allocating each said signal group for communication of said plurality of time slots to a predetermined destination;
• means for frame synchronizing said plurality of optical bit streams;
• and
• photonic switch means controlled during each said route switching interval for concurrently switching each of the allocated signal groups of each of said frame synchronized plurality of optical bit streams in an optical domain to the respective predetermined destination.

An optical communication arrangement comprising:

• a plurality of optical bit streams each comprising periodic frames of signal gorups, each frame comprising a frame synchronizing signal, each said signal group comprising a plurality of time slots each having digital information bits and each said signal group being separated in time by a route switching interval;
• means for allocating each said signal group for communication of said plurality of time slots to a predetermined destination;
• means for frame synchronizing said plurality of optical bit streams;
• photonic switch means, controlled during each said route switching interval, for switching each of the allocated signal groups of each of said frame synchronized plurality of optical bit streams in an optical domain to its respective allocated predetermined destination;
• and
• a source communication system, comprising:
• communication sources for generating electrical communication signals;
• and
• electrical/optica1 conversion means for converting said electrical communication signals into optical signals of one of said optical bit streams;
• wherein one of said predetermined destinations comprises optical/electrical conversion means for converting the optical signals corresponding to a signal group allocated for communication of said plurality of time slots to said one predetermined destination to corresponding destination electrical signals for said one predetermined destination;
• wherein said electrical/optical conversion means further comprises means for introducing adjustable delay prior to generating said optical signals.

An optical communication arrangement comprising:

• a plurality of optical bit streams each comprising periodic frames of signal groups, each frame comprising a frame synchronizing signal, each said signal group comprising a plurality of time slots each having digital information bits and each said signal group being separate in time by a route switching interval;
• processor means for allocating each said signal group for communication of said plurality of time slots to a predetermined destination;
• means for frame synchronizing said plurality of optical bit streams;
• photonic switch means, controlled during each said route switching interval, for switching each of the allocated signal groups of each of said frame synchronized plurality of optical bit streams in an optical domain to its respective allocated predetermined destination;
• a communication switching system responsive to communication requests for generating said optical bit stream;
• said communication switching comprising processor means for measuring the volume of communications of said communication requests and for generating data messages representing said volume communications;
• data transmission means for transmitting said data messages to said processor means for allocating;
• and
• said processor means for allocating responsive to said data mesages for changing said allocations to reflect the volume of communications represented by said data messages.

A photonic transmission communication network comprising:

• a plurality of first nodes;
• a second node comprising photonic switch means;
• a plurality of optical links for transmitting optical signals between each of said first nodes and said second node;
• each of said first nodes comprising electrical/optical conversion means and optical/electrical conversion means connected to one end of one of said plurality of optical links for connection respectively to a plurality of sources of and destinations for electrical digital communication signals;
• said photonic switch means connected to a plurality of said optical links and comprising means for switching optical signals between pairs of said plurality of said connected optical links;
• the optical signals on each of said optical links being grouped in time frames, each frame comprising a plurality of signal groups of adjacent time slots for carrying information signals between a plurality of communication sources and destinations, each said signal group separated in time by a route switching interval;
• and
• means for frame synchronizing the incoming optical signals on the plurality of optical links connected to said optical switch means;
• said information signals of each of said groups of time slots being switched concurrently by said photonic switch means and being communicated between said elctrical/optical conversion means and optical/electrical conversion means of the same pair of first nodes.

A photonic transmission communication network comprising:

• a plurality of first nodes;
• a second node comprising photonic switch means;
• a plurality of optical links for transmitting optical signals between each of said first nodes and said second node;
• each of said first nodes comprises electrical/optical conversion means and optical/electrical conversion means connected to one end of one of said plurality of optical links for connection respectively to a plurality of sources of and destinations for electrical digital communication signals;
• said photonic switch means connected to a plurality of said optical links and comprising means for switching optical signals between pairs of said plurality of connected said optical links;
• and
• the optical signals on each of said optical links being grouped in time frames, each frame comprising a plurality of signal groups of adjacent time slots for carrying information signals between a plurality of communication sources and destinations, each said signal group separated in time by a switching inteval, and said information signals of each of said groups of time slots being communicated between said electrical/optical conversion means and optical/electrical conversion means of the same pair of first nodes;
• wherein said second node further comprises electrical/optical conversion means and optical/electrical conversion means for connection respectively to a plurality of sources of and destinations for electrical digital communication signals;
• wherein said photonic switch means further switches signals between ones of said plurality of optical links and said optical/electrical conversion means of said second node;
• and
• wherein the signals of each of said signal groups are sent between the electrical/optical conversion means of one of said first and second nodes and the optical/electrical conversion means of another of said first and second nodes.

A photonic transmission communication network comprising:

• a plurality of first nodes;
• a second node comprising photonic switch means;
• a plurality of optical links for transmitting optical signals between each of said first nodes and said second node;
• each of said first nodes comprises electrical/optical conversion means and optical/electrical conversion means connected to one end of said plurality of optical links for connection respectively to a plurality of sources of and destinations for electrical digital communication signals;
• said photonic switch means connected to a plurality of said optical links and comprising means for switching optical signals between pairs of said plurality of connected said optical links;
• and
• the optical signals on each of said optical links being grouped in time frames, each frame comprising a plurality of signal groups of adjacent time slots for carrying information signals between a plurality of communication sources and destinations, each said signal group separated in time by a route switching interval, and said information signals of each of said groups of time slots being communicated between said electrical/optical conversion means and optical/electrical conversion means of the same pair of first nodes;
• wherein one of said nodes comprises means for assigning the route associated with each of the plurality of signal groups of each of said plurality of optical links.

Photonic switch apparatus comprising:

• a plurality of optical paths each carrying an optical signal stream comprising periodic frames of signal groups interleaved between control intervals, each said signal group comprising a plurality of time slots each having digital information bits and each signal group, said plurality of optical paths comprising a plurality of optical incoming paths and a plurality of optical outgoing paths;
• synchronizing means for frame synchronizing signals on said plurality of optical incoming paths;
• photonic switch means for establishing optical domain switchable connections from said plurality of optical incoming paths to said plurality of optical outgoing paths;
• and
• control means for operating said photonic switch only during said control intervals to maintain a plurality of switched connections therethrough for communicating in an optical domain successively received signal groups between specified ones of said plurality of input and output paths and for concurrently switching such connections during said control intervals.

A communication arrangement for interconnecting a plurality of signal sources and signal destinations comprising:

• a plurality of optical paths each carrying an optical signal stream comprising periodic signal groups of optical information time slots with each said group being separated in time by a route switching interval;
• means for allocating each of said groups of time slots for communication of optical information signals therein to a route from one of said signal sources to one of said signal destinations;
• photonic switch means for switching, in an optical domain, information signals in time slots of each of the allocated groups, said photonic switch means operated during said route switching intervals to maintain switched connections therethrough during each of said groups of time slots for the communication of information signals in said time slots of each of said allocated groups over said route from source to destination and for concurrently switching such connections during said control intervals;
• and
• means for synchronizing the optical streams entering said photonic switch means to within an interval less than said route switching interval.

An optical communication arrangement comprising:

• a first and a second optical stream each comprising periodic information signals comprising groups of optical information time slots each of said groups being separated in time by a route switching interval;
• photonic switch means for switching information signals in said optical streams in an optical domain and in said groups of time slots from a plurality of sources to a plurality of destinations without any conversion of optical information signals to an electrical domain in its said communication from said source to said destination, said photonic switch means being operable during said route switching interval to maintain switch connections therethrough during said groups of time slots and for concurrently switching such connections during said control intervals;
• means for synchronizing said optical streams entering said photonic switch means to within an interval less than said route switching interval;
• and
• means for allocating each of said groups of time slots for a communication of optical information signals therein between a predetermined source and a predetermined destination.

Photonic switching apparatus comprising:

• photonic switch means for establishing optical domain switchable connections from a plurality of incoming paths for carrying incoming optical signal streams to a plurality of outgoing paths for carrying outgoing optical signal streams, each of said incoming optical signal streams comprising periodic frames of signal groups, each said signal group comprising a plurality of time slots each having digital information bits and each said signal group being separated in time by a route switching interval;
• means for frame synchronizing said optical streams entering said photonic switch means to within an interval less than said route switching interval;
• processor means for generating control signals to determine the switched connections to be established in said photonic switch means;
• and
• control means responsive to said control signals for controlling during said route switching intervals the concurrent switching of connections of said photonic switch means.

A method of transmitting information signals in an optical communication network comprising the steps of:

• allocating information signals for communication of a plurality of time slots to each of a plurality of predetermined destinations to each of a plurality of periodic signal groups;
• generating first and second optical bit streams each comprising periodic frames of ones of said plurality of periodic signal groups and a synchronizing signal for each frame, each said group being separated in time by a route switching interval;
• frame synchronizing said first and said second optical bit streams;
• and
• concurrently switching in an optical domain during said route switching intervals individual ones of said allocated plurality of periodic signal groups to their respective allocated predetermined destinations.

A method for transmitting information signals in an optical communication network comprising the steps of:

• allocating information signals for communication of a plurality of time slots to each of a plurality predetermined destinations to each of a plurality of periodic signal groups;
• generating first and second optical bit streams each comprising periodic frames of said plurality of periodic signal groups and a synchronizing signal for each frame, each said group being separated in time by a switching interval;
• frame synchronizing said first and said second optical bit streams;
• switching in an optical domain individual ones of said allocated plurality of periodic signal groups to their respective allocated predetermined destinations;
• converting at least one of said optical bit streams into an electrical signal;
• adjustably delaying said electrical signal;
• reconverting said adjustably delayed electrical signal to an optical bit stream.

A method of transmitting information signals in an optical communication network comprising the steps of:

• allocating information signals for communication of a plurality of time slots to each of a plurality predetermined destinations to each of a plurality of periodic signal groups;
• generating first and second optical bit streams each comprising periodic frames of said plurality of periodic signal groups and a synchronizing signal for each frame, each said group being separated in time by a switching interval;
• frame synchronizing said first and said second optical bit streams;
• switching in an optical domain individual ones of said allocated plurality of periodic signal groups to the respective predetermined destination;
• wherein said synchronizing step further comprises the step of deriving a clock signal from said second optical bit stream;
• and
• synchronizing said first optical bit stream to said derived clock.