Abstract: The system and method of the present invention provide restoration of coincident line and facility failures. The system of the present invention includes light termination equipment (LTE) that is capable of detecting failures, determining the type of component that failed, determining which restoration facility to use based on the type of component that failed, and providing restoration. The system of the present invention also includes spare capacity for restoration, including protect channels and an optical restoration network. In addition, the system of the present invention includes an optical cross connect switch (OCCS) that is capable of switching electrical signals to the optical restoration network. The method of the present invention is involves detecting a failure, determining the type of component that failed, and sending an alarm to a centralized management center.

Abstract: The system and method of the present invention provide restoration of coincident line and facility failures. The system of the present invention includes light termination equipment (LTE) that is capable of detecting failures, determining the type of component that failed, determining which restoration facility to use based on the type of component that failed, and providing restoration. The system of the present invention also includes spare capacity for restoration, including protect channels and an optical restoration network. In addition, the system of the present invention includes an optical cross connect switch (OCCS) that is capable of switching electrical signals to the optical restoration network. The method of the present invention is involves detecting a failure, determining the type of component that failed, and sending an alarm to a centralized management center.

Abstract: A method of monitoring performance of an optical communications system measures (i) sub-carrier signal-to-noise ratio, (ii) optical signal signal-to-noise ratio, and (iii) measuring optical signal bit error rate, and diagnoses a system component failure based upon measured sub-carrier signal-to-noise ratio, optical signal signal-to-noise ratio, and optical signal bit error rate.

Abstract: A method and system for detecting optical signal degradation or loss within the optical domain of a fiber network. Optical cross-connect switches (OCCS) are provided at network nodes. Optical data traffic is conducted between nodes via a fiber link. The fiber link extends between respective ports of the optical cross-connect switches at each network node. Dedicated signals for detecting faults are introduced and removed within the optical domain of the fiber communication network. In one embodiment, transmitter/receiver units are coupled directly to the fiber link for broadcasting optical signals for fault detection. In another embodiment, transmitter/receiver units are coupled to the fiber link through one or more dedicated ports within optical cross-connect switches (OCCS) at network nodes. Optical signals for fault detection are then broadcast or switched through working and/or spare fibers. Distinctive optical fault detection signals are used when the signals are broadcast or switched over working fibers.

Abstract: A dual-band optical amplifier uses a single pump source, such as a YAG solid-state laser emitting a pump light at a wavelength of 1047 nm, to provide amplification in both the 1550 nm and 1310 nm bands which are commonly encountered in the optical telecommunications environment. The pump light is fed into a fiber doped with praseodymium fluoride having Pr atoms in a +3 ionization state. These ions exhibit a ground state absorption that includes the 1047 nm wavelength. The same pump light is also coupled to a separate amplification fiber doped with trivalent erbium ions and ytterbium. This combination of ions also can be pumped to a metastable excited state by a 1047 nm wavelength source. Accordingly, when photon emission is generated, there is signal amplification in both fibers results.

Abstract: An optical telecommunication network has a plurality of optical cross-connect switching nodes linked together by optical cables to form transmission paths for traffic between sending and destination stations. A centralized operation support system (OSS) is coupled to each node for receiving failure alarms and port status messages for failed cables from the switching nodes and terminal sites. The collected data is used to select alternate routes through the network using the spare capacity of the optical cross-connect switches and available wavelengths within the network. Any connection(s) to put into effect an alternate routing plan is broadcast to the affected nodes or terminal sites. A Real-Time Multiple Wavelength Routing (RMWR) algorithm is used by the OSS or by decentralized switching nodes to select, coordinate and route traffic among selected paths to bypass the failed cable such that wavelength collisions or adjacent cross-talk do not degrade the network performance.

Abstract: An optical interface device dynamically reconfigures a telecommunications network. The device includes an optically switched backplane connected between two stages of an optical tapped amplifier. Various modules may be plugged into the backplane for performing selective processing of the optical signal without any signal conversion to electrical domain. The modules are electrically controlled by a controller, which is also a module, overseeing the operations upon the optical signal by other modules.