127 results about "Optical burst switching" patented technology

An optical packet switching system in which transmission quality, reliability, and system management in optical packet switching control are improved. An optical packet switch section includes semiconductor optical amplifiers as gate switches multistage-connected on paths along which optical packets sent from a plurality of input line cards are transmitted and performs optical packet switching by broadcasting the optical packets to a plurality of gate switches, by selecting the optical packets by ON / OFF gating operation of the gate switches, and by absorbing noise signals which flow along non-selected paths by putting gate switches at a final stage into the OFF state. A switch control section exercises ON / OFF drive control over the gate switches in the optical packet switch section on the basis of port connection requests from the plurality of input line cards so as to generate requested paths.

A method and apparatus are provided for low latency loss-free burst switching. Burst schedules are initiated by controllers of bufferless core nodes and distributed to respective edge nodes. In a composite-star network, the burst schedules are initiated by any of a plurality of bufferless core nodes and distributed to respective edge nodes. Burst formation takes place at source nodes and a burst size is determined according to an allocated bitrate of a burst stream to which the burst belongs. An allocated bitrate of a burst stream may be modified according to observed usage of scheduled bursts of a burst stream. A method of control-burst exchange between each of a plurality of edge nodes and each of a plurality of bufferless core nodes enables burst scheduling, time coordination, and loss-free burst switching. Both the payload bursts and control bursts are carried by optical channels connecting the edge nodes and the core nodes. A method and a circuit are provided for generating burst descriptors wherein each burst is associated with a burst stream and each burst stream is allocated a service bitrate. The generated burst descriptors are used in each master controller in each core node to create the burst schedules. In a conventional burst-scheduling process, the burst queues at a master controller of an optical switch receives burst descriptors from the source nodes and schedules the burst switching times. In a distinct departure, according to the present invention the burst descriptors are generated by a master controller of an optical switch in a core node, the switching times of the corresponding bursts are scheduled, and the schedules are distributed to the respective edge nodes. The burst-descriptor generation is based on burst-stream bitrate-allocation defined by the source nodes.

Asynchronous optical data is aligned with synchronous convergence points in an optical packet switching system. The convergence points can be any place where data enters an optical packet switching element, buffer stage, switch fabric, etc. The arrival time for data approaching the convergence point is compared with a reference signal associated with the upcoming convergence point. The comparison is used to identify the amount of time-shift required to align the approaching data with the reference signal. Control information is derived according to the comparison and used to control an optical data aligner that synchronizes the data with the convergence point.

A Wavelength Division Multiplexing (WDM) multi-mode switching system and method and method provides concurrent switching in various switching modes. For example, WDM links may communicate data in various switching modes including, but not limited to, an electronic packet switching (EPS) mode, optical circuit switching (OCS) mode, and optical burst switching (OBS) mode. Edge routers and core routers in the WDM multi-mode switching systems and methods provide switching and processing necessary to handle data provided in the various switching modes. Further, the WDM multi-mode switching systems and methods can also provide dynamic reconfiguration between the various switching modes.

The invention is an unique control method that maintains the bandwidth efficiency of Optical Burst Switched, Labeled Optical Burst Switched, and other burst or packet switched networks. The invention also combines in a novel manner the delayed Reserve-a-Fixed-Duration (RFD) class of switching techniques and special classes of slow Switching Elements.