Luminous Networks, Inc.

Oni Systems Corp.

Optical Networks, Inc.

Robert F Kalman

Vinay K Bannai

Jason C Fan

Charles Barry

Prasad Prabhakar Jogalekar

Ronald S Maynard

Robert T Weverka

Inwhan Choi

Sohail Mallick

Robert Stillman

Warren Watts

Seshadri Srinivasan

Atul Shinde

Richard Lindquist

Edward R Silva

The disclosed network includes two rings, wherein a first ring transmits data in a clockwise direction, and the other ring transmits data in a counterclockwise direction. The traffic is removed from the ring by the destination node. During normal operations (i.e., all spans operational), data between nodes flows on the ring that would provide the minimum number of hops to the destination node. Thus, both rings are fully utilized during normal operations. The nodes periodically test the bit error rate of the links (or the error rate is constantly calculated) to detect a fault in one of the links. The detection of such a fault sends a broadcast signal to all nodes to reconfigure a routing table within the node so as to identify the optimum routing of source traffic to the destination node after the fault. Since the available links will now see more data traffic due to the failed link, traffic designated as 'unprotected' traffic is given lower priority and may be dropped or delayed in favor of the 'protected' traffic. Specific techniques are described for identifying a failed link, communicating the failed link to the other nodes, differentiating between protected and unprotected classes of traffic, and updating the routing tables.

Dynamically allocated ring protection and restoration technique

The disclosed network includes two rings, wherein a first ring transmits data in a clockwise direction, and the other ring transmits data in a counterclockwise direction. The traffic is removed from the ring by the destination node. During normal operations (i.e., all spans operational), data between nodes flows on the ring that would provide the minimum number of hops to the destination node. Thus, both rings are fully utilized during normal operations. The nodes periodically test the bit error rate of the links (or the error rate is constantly calculated) to detect a fault in one of the links. The detection of such a fault sends a broadcast signal to all nodes to reconfigure a routing table within the node so as to identify the optimum routing of source traffic to the destination node after the fault. Since the available links will now see more data traffic due to the failed link, traffic designated as &ldquo;unprotected&rdquo; traffic is given lower priority and may be dropped or delayed in favor of the &ldquo;protected&rdquo; traffic. Specific techniques are described for identifying a failed link, communicating the failed link to the other nodes, differentiating between protected and unprotected classes of traffic, and updating the routing tables.

Selecting a routing direction in a communications network using a cost metric

An architecture for transport of multiple services in connectionless packet-based networks is described herein, along with the packet format used for data transport in this architecture. The architecture supports transport of both connectionless packetized data and framed data from synchronous leased lines. The architecture supports transparent packetization of incoming DS1 data. The architecture works for mesh architectures but is optimized for OSI Layer (crossconnect) and Layer (Virtual LAN, or VLAN) services and for ring topologies, since for these services in a ring no path setup is required using a label distribution protocol. In addition, it simultaneously supports OSI Layer , Layer , and Layer services.

Architecture for transport of multiple services in connectionless packet-based communication networks

An optical switch comprises a two-dimensional array of optical inputs, a Fourier transform lens, and a two-dimensional array of optical outputs. Each of the optical inputs emits an optical beam that is transmitted through the Fourier transform lens to one of the optical outputs. A first deflection means gives each of the optical beams a respective direction of incidence upon the Fourier transform lens. The optical output to which a given beam travels depends on the beam's respective direction of incidence. A second deflection means deflects the optical beams after they have been transmitted through the Fourier transform lens and renders the beams parallel, thereby enabling the beams to couple efficiently to the optical outputs. Each of the deflection means preferably comprises at least one Micro-Electro-Mechanical Systems, or MEMS, deflector array. The optical inputs and outputs preferably comprise optical fibers. The Fourier transform lens overcomes diffraction limitations, since the lens causes the spreading optical beams to reconverge.

Fourier optical switch

A method for forming lensed ends on waveguides to within very fine tolerances is applicable to many types of waveguides, including single fibers and POWs. The method uses photolithographic materials and techniques, but uses the waveguides themselves to provide the exposing radiation. Thus a method for forming a lens on the end of a waveguide having a waveguiding region and a cladding region includes the step of coating a first end of the waveguide with a photoresist material having sensitivity to at least light in a particular wavelength range. Light in that particular wavelength range is then injected into a second end of the waveguide so that the light within the waveguiding region preferentially exposes the photoresist that covers the waveguiding region at the first end of the waveguide. The method can be carried out with either positive photoresist (where only the exposed portion is removed by development) or negative photoresist (where only the exposed portion remains after development).

Lensed planar optical waveguides for packaging opto-electronic devices

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Cupertino, CA, United States of America

Robert F Kalman