Abstract: The present disclosure describes methods and systems for the hierarchical mesh restoration of connections in an ASON or the like. These methods and systems provide a mesh restorable OTN server layer that carries an aggregate of mesh restorable SONET/SDH SNCs, without designating SONET/SDH/OTN hand-off ports or work/protect lines. Server layer SNCs are terminated on Virtual Trail Termination Points (VTTPs) on the NEs. These VTTPs maintain all of the attributes of physical Trail Termination Points (TTPs). The server routing protocol creates physical TTP interfaces at the server layer, and the server layer advertises bandwidth to the client layer routing protocol. A failure in the server layer results in the mesh restoration of an aggregate line, holding off the release of the individual client SNCs. Only when the server layer cannot restore are these individual client SNCs released.

Abstract: In various exemplary embodiments, the present invention provides methods for maintaining software/hardware backward compatibility across multiple versions in a modular and scalable manner. More specifically, the present invention provides, stacked hardware abstraction layer methods for maintaining software/hardware backward compatibility for networking equipment and the like.

Abstract: The present invention provides a timing recovery architecture and circuit for recovering the clock timing from a received signal in critically-timed transport applications. The present invention further relates to a timing recovery architecture and circuit for removing network-induced clock jitter and wander that occurs in a transport network during asynchronous mapping techniques, bit and/or byte-stuffing techniques, or traditional pointer adjustment schemes associated with traditional PDH (pleisiosynchronous digital hierarchy), SDH (synchronous digital hierarchy), and packet-based networks. The timing recovery circuit may be implemented in a logic circuit such as programmable, digital FPGA (field programmable gate array) logic, or alternatively in standard cell or gate-array ASIC (application-specific integrated circuit) technology, or like logic circuit design.

Abstract: A method and apparatus for executing narrow channel spaced dense wavelength division multiplexing (“DWDM”) includes an optical multiplexor/demultiplexor with channel add/drop having a first circulator and a second circulator. A first fiber Bragg grating couples with the first circulator and the second circulator. A second fiber Bragg grating couples with the second circulator. The fiber Bragg gratings separate optical signals in an interleaved manner. The optical multiplexor/demultiplexor with channel add/drop further includes at least one optical filter in communication with the first circulator. The system can further include at least one optical filter in communication with the second circulator as well. The optical filters are spaced apart a greater distance with respect to channel spacing than the channels passing through the system. However, the unique combination of the circulators and fiber Bragg gratings allow the filters to function at the wider spacing to add/drop channel signals.

Abstract: A method and apparatus for amplifying an optical signal is provided. In accordance with one example embodiment of the invention, the optical amplification system includes an optical signal traveling through the system. At least one module of the optical amplification system is suitable for one of selectively separating and combining one or more individual sub-bands of the optical signal. At least one amplifier is disposed to separately amplify each of the one or more individual sub-bands.

Abstract: A method and apparatus for amplifying an optical signal is provided. In accordance with one example embodiment of the invention, the optical amplification system includes an optical signal traveling through the system. At least one module of the optical amplification system is suitable for one of selectively separating and combining one or more individual sub-bands of the optical signal. At least one amplifier is disposed to separately amplify each of the one or more individual sub-bands.

Abstract: A method and apparatus for executing narrow channel spaced dense wavelength division multiplexing (“DWDM”) includes an optical multiplexor/demultiplexor with channel add/drop having a first circulator and a second circulator. A first fiber Bragg grating couples with the first circulator and the second circulator. A second fiber Bragg grating couples with the second circulator. The fiber Bragg gratings separate optical signals in an interleaved manner. The optical multiplexor/demultiplexor with channel add/drop further includes at least one optical filter in communication with the first circulator. The system can further include at least one optical filter in communication with the second circulator as well. The optical filters are spaced apart a greater distance with respect to channel spacing than the channels passing through the system. However, the unique combination of the circulators and fiber Bragg gratings allow the filters to function at the wider spacing to add/drop channel signals.