Abstract: A method for monitoring lightpaths in an optical network comprising nodes interconnected by wavelength-multiplexed links is disclosed. Each lightpath is identified by a respective optical signature. A node stores identifiers of optical signatures of lightpaths designated to traverse the node and identifiers of adjacent nodes. Each node also maintains a record of all optical signatures it detects. A command-line interface associated with a selected node tracks a selected lightpath, designated to traverse the selected node, by propagating messages in an upstream direction, a downstream direction, or both, requesting other nodes to provide information pertinent to the selected lightpath. The selected node may also send messages to all its neighboring nodes requesting each to indicated detection, or otherwise, of the selected lightpath.

Abstract: A method and system for identification of a channel in an optical network is provided. The channel is identified by the use of unique combinations of two or more low frequencies, or tones, modulated onto the channel and optionally, a network parameter associated with the channel.

Abstract: The invention describes methods and systems for monitoring the performance of an optical network by marking a group of optical signals with a set of identification tags which are unique to network characteristics. In the preferred embodiments, fiber identification (FID) and bundle identification (BID) tags are encoded into optical signals by marking an optical signal with low frequency dither tones whose frequencies are unique to the fiber section and to a bundle of fibers respectively. Detecting of the FID and BID tones provides more effective and accurate monitoring of performance of the optical network and allows determining of the network topology, e.g. paths of optical channels and traffic load through different fiber sections in the network. Other sets of hierarchically arranged identifiers encoded into optical signals have also been proposed, including band, conduit, city, region, country, etc. identifiers, as well as identifiers related to network security and service characteristics.

Abstract: A method and system for identification of a channel in an optical network is provided. The channel is identified by the use of unique combinations of two or more low frequencies, or tones, modulated onto the channel and optionally, a network parameter associated with the channel.

Abstract: A method and system for compensating for side effects of cross gain modulation in amplified optical networks, which allows reliable identification of expected and unexpected channels in the network is provided. Each optical channel traveling in the optical network is marked with a unique channel signature (expected channel signature), having one or more dither tone modulated onto the optical channel; followed by detecting a spectrum of tones, including said modulated dither tones and ghost tones thereof produced by the cross gain modulation in the optical network, at various locations in the optical network. Amplitudes of the spectrum tones, which belong to the expected channel signature, are compared with a first threshold, while amplitudes of the remaining spectrum tones, which are not the valid tones, are compared with a second threshold, which is lower than the first threshold.

Abstract: A method for the simultaneous graphical display of paths of optical wavelength channels in a telecommunications network together with one or more channel attributes is provided. The graphical display of the network also shows the direction of data flow transported by the channels. An audible or visual alarm for an error condition for a channel attribute on a link in the network can be produced if requires. The operator can also obtain detailed information on a channel by positioning the mouse over a channel.

Abstract: A system and method for operating a plurality of eVOAs in an optical network is provided. The system comprises a number of eVOAs, each eVOA coupled to one or more optical taps and connected to a microcontroller. The microcontroller comprises a monitor signal processing controller for measuring the power of the optical signal at the eVOAs; a scheduler for continuously cycling and checking the eVOAs operating attenuations; a microprocessing controller for determining, setting, adjusting and updating the eVOA operating attenuation and a means for communications between the microprocessor and the other controller within the system. The microcontroller cycles through the plurality of eVOAs and controls one eVOA at a time according to a predetermined method of the eVOA operation. Individual eVOAs may be controlled according to the same or different methods of controlling operations thereof as required.

Abstract: In an optical WDM network, each optical channel is modulated with a respective channel identity. Detectors, conveniently at multiplex ports of optical band filters, detect the channel identities of all of the optical channels in an optical signal at the respective points to produce respective channel lists. A network management system determines channel lists for through ports of the optical band filters, identifies matching pairs of channel lists to determine a topology of each node and to identify optical paths entering or leaving each node, and identifies matching pairs of channel lists for these paths to determine an inter-node topology of the network. The channel identity detector points can alternatively be at the optical paths entering or leaving each node.

Abstract: A method and system for compensating for side effects of cross gain modulation in amplified optical networks, which allows reliable identification of expected and unexpected channels in the network is provided. Each optical channel traveling in the optical network is marked with a unique channel signature (expected channel signature), having one or more dither tone modulated onto the optical channel; followed by detecting a spectrum of tones, including said modulated dither tones and ghost tones thereof produced by the cross gain modulation in the optical network, at various locations in the optical network. Amplitudes of the spectrum tones, which belong to the expected channel signature, are compared with a first threshold, while amplitudes of the remaining spectrum tones, which are not the valid tones, are compared with a second threshold, which is lower than the first threshold.

Abstract: A method to trace, detect, discover and monitor the nodes traversed by a light path from its source to its destination in an Optical Communication Network (OCN) is provided. In accordance with the embodiment of the invention, the system examines various provisioned and discovered optical nodes either sequentially or in parallel to determine whether a unique signature (wavekey) associated with the light path is present. Connectivity and mis-fibering problems are detected by sequentially examining provisioned nodes in the light path to determine if the wavekey associated with the light path can be observed. Control Network topology information is utilized to contact all nodes in the network to trouble-shoot mis-fibering problems.

Abstract: A system and method for operating a plurality of eVOAs in an optical network is provided. The system comprises a number of eVOAs, each eVOA coupled to one or more optical taps and connected to a microcontroller. The microcontroller comprises a monitor signal processing controller for measuring the power of the optical signal at the eVOAs; a scheduler for continuously cycling and checking the eVOAs operating attenuations; a microprocessing controller for determining, setting, adjusting and updating the eVOA operating attenuation and a means for communications between the microprocessor and the other controller within the system. The microcontroller cycles through the plurality of eVOAs and controls one eVOA at a time according to a predetermined method of the eVOA operation.

Abstract: A method and system for identification of a channel in an optical network is provided. The channel is identified by the use of unique combinations of two or more low frequencies, or tones, modulated onto the channel and optionally, a network parameter associated with the channel.

Abstract: A method and system for identification of a channel in an optical network is provided. The channel is identified by the use of unique combinations of two or more low frequencies, or tones, modulated onto the channel and optionally, a network parameter associated with the channel.

Abstract: A method for the simultaneous graphical display of paths of optical wavelength channels in a telecommunications network together with one or more channel attributes is provided. The graphical display of the network also shows the direction of data flow transported by the channels. An audible or visual alarm for an error condition for a channel attribute on a link in the network can be produced if requires. The operator can also obtain detailed information on a channel by positioning the mouse over a channel.

Abstract: The invention describes methods and systems for monitoring the performance of an optical network by marking a group of optical signals with a set of identification tags which are unique to network characteristics. In the preferred embodiments, fiber identification (FID) and bundle identification (BID) tags are encoded into optical signals by marking an optical signal with low frequency dither tones whose frequencies are unique to the fiber section and to a bundle of fibers respectively. Detecting of the FID and BID tones provides more effective and accurate monitoring of performance of the optical network and allows determining of the network topology, e.g. paths of optical channels and traffic load through different fiber sections in the network. Other sets of hierarchically arranged identifiers encoded into optical signals have also been proposed, including band, conduit, city, region, country, etc. identifiers, as well as identifiers related to network security and service characteristics.

Abstract: In an optical WDM network, each optical channel is modulated with a respective channel identity. Detectors, conveniently at multiplex ports of optical band filters, detect the channel identities of all of the optical channels in an optical signal at the respective points to produce respective channel lists. A network management system determines channel lists for through ports of the optical band filters, identifies matching pairs of channel lists to determine a topology of each node and to identify optical paths entering or leaving each node, and identifies matching pairs of channel lists for these paths to determine an inter-node topology of the network. The channel identity detector points can alternatively be at the optical paths entering or leaving each node.