Abstract: The design of telecommunication networks is such that there is provision of end-to-end path protection to multiple demands under a single link or node failure in the networks. Restoration routes are provided on Preconfigured Virtual Cycles (PVC's), where each demand is assigned one restoration route and specific restoration wavelengths on a segment of one cycle. Multiple demands may share restoration wavelengths, and the number of restoration wavelengths may vary among the PVC links. First, a plurality of candidate PVC's are generated where each demand may be assigned to multiple candidates. Assignment of demands with common failure scenarios are allowed, under certain conditions, to the same PVC. Next, a set of PVC's is selected from among the candidates, while minimizing total reserved restoration capacity and ensuring that all demands are protected. Next duplicate assignments are eliminated. Finally, conflicts of wavelength assignments are resolved. The invention focuses primarily on optical networks.

Abstract: A computer implemented fault diagnosis method employing both probabilistic models and statistical learning that diagnoses faults using probabilities and time windows learned during the actual operation of a system being monitored. In a preferred embodiment, the method maintains for each possible root cause fault an a-priori probability that the fault will appear in a time window of specified length as well as maintaining—for each possible resulting symptom(s)—probabilities that the symptom(s) will appear in a time window containing the fault and probabilities that the alarm will not appear in a time window containing the fault. Consequently, the method according to the present invention may advantageously determine—at any time—the probability that a fault has occurred, and report faults which are sufficiently likely to have occurred. These probabilities are updated based upon past time windows in which we have determined fault(s) and their cause(s).

Abstract: The design of telecommunication networks is such that there is provision of end-to-end path protection to multiple demands under a single link or node failure in the networks. Restoration routes are provided on Preconfigured Virtual Cycles (PVC's), where each demand is assigned one restoration route and specific restoration wavelengths on a segment of one cycle. Multiple demands may share restoration wavelengths, and the number of restoration wavelengths may vary among the PVC links. First, a plurality of candidate PVC's are generated where each demand may be assigned to multiple candidates. Assignment of demands with common failure scenarios are allowed, under certain conditions, to the same PVC. Next, a set of PVC's is selected from among the candidates, while minimizing total reserved restoration capacity and ensuring that all demands are protected. Next duplicate assignments are eliminated. Finally, conflicts of wavelength assignments are resolved. The invention focuses primarily on optical networks.

Abstract: The design of telecommunication networks is such that there is provision of end-to-end path protection to multiple demands under a single link or node failure in the networks. Restoration routes are provided on Preconfigured Virtual Cycles (PVC's), where each demand is assigned one restoration route and specific restoration wavelengths on a segment of one cycle. Multiple demands may share restoration wavelengths, and the number of restoration wavelengths may vary among the PVC links. First, a plurality of candidate PVC's are generated where each demand may be assigned to multiple candidates. Assignment of demands with common failure scenarios are allowed, under certain conditions, to the same PVC. Next, a set of PVC's is selected from among the candidates, while minimizing total reserved restoration capacity and ensuring that all demands are protected. Next duplicate assignments are eliminated. Finally, conflicts of wavelength assignments are resolved. The invention focuses primarily on optical networks.

Abstract: A computer implemented fault diagnosis method employing both probabilistic models and statistical learning that diagnoses faults using probabilities and time windows learned during the actual operation of a system being monitored. In a preferred embodiment, the method maintains for each possible root cause fault an a-priori probability that the fault will appear in a time window of specified length as well as maintaining—for each possible resulting symptom(s)—probabilities that the symptom(s) will appear in a time window containing the fault and probabilities that the alarm will not appear in a time window containing the fault. Consequently, the method according to the present invention may advantageously determine—at any time—the probability that a fault has occurred, and report faults which are sufficiently likely to have occurred. These probabilities are updated based upon past time windows in which we have determined fault(s) and their cause(s).

Abstract: The design of telecommunication networks is such that there is provision of end-to-end path protection to multiple demands under a single link or node failure in the networks. Restoration routes are provided on Preconfigured Virtual Cycles (PVC's), where each demand is assigned one restoration route and specific restoration wavelengths on a segment of one cycle. Multiple demands may share restoration wavelengths, and the number of restoration wavelengths may vary among the PVC links. First, a plurality of candidate PVC's are generated where each demand may be assigned to multiple candidates. Assignment of demands with common failure scenarios are allowed, under certain conditions, to the same PVC. Next, a set of PVC's is selected from among the candidates, while minimizing total reserved restoration capacity and ensuring that all demands are protected. Next duplicate assignments are eliminated. Finally, conflicts of wavelength assignments are resolved. The invention focuses primarily on optical networks.

Abstract: The present invention relates to a method and system for design and routing in telecommunications networks having transparent elements such as photonic switches. Transparent optical networks transmit signals optically, performing both switching and amplification photonically. As a result, transparent networks may be more economical than conventional “opaque” optical networks that convert signals to electronic form at each network node because they do not require as much equipment for performing optical-electrical conversion. However, transparent networks pose new operational challenges. Physical-layer impairments that are repaired by optical-electrical-optical (OEO) regeneration can accumulate along (transparent) connection paths. To effectively deploy and utilize transparency, mechanisms to assure that impairment-feasible paths exist and can be identified in the network are required.

Abstract: A system and method for modeling and evaluating resource requirements of services is disclosed. The system and method in one aspect enable describing an application session in a software model, for example, as a sequence of events in a sequence diagram, annotating the sequence diagram with information and using the sequence diagram and the information to create a mathematical model such as a Markov model that represents the application session. Once in Markov form the service can be analyzed.

Abstract: The present invention relates to a method and system for design and routing in telecommunications networks having transparent elements such as photonic switches. Transparent optical networks transmit signals optically, performing both switching and amplification photonically. As a result, transparent networks may be more economical than conventional “opaque” optical networks that convert signals to electronic form at each network node because they do not require as much equipment for performing optical-electrical conversion. However, transparent networks pose new operational challenges. Physical-layer impairments that are repaired by optical-electrical-optical (OEO) regeneration can accumulate along (transparent) connection paths. To effectively deploy and utilize transparency, mechanisms to assure that impairment-feasible paths exist and can be identified in the network are required.