Lucent Technologies Inc.

Narasimhan Raghavan

Christopher Alan White

Daniel Charles Kilper

David A Sadler

William A Thompson

Heribert Joseph Blach

Ellen Eng

Mary Socratous

Richard Adleman

Peter L Bartman

Elizabeth O Richey

Claude A Martell

Sydney A Taegar

Yan Shi

A channel-growth plan for an optical transmission system selects channels such that the transients that result in the channels that survive a network failure, such as an upstream fiber cut, are either minimized or effectively handled by some transient-control technique. In one embodiment, the growth plan may try to keep post-transient surviving channel total power gain equal to the pre-transient total power gain. Alternatively, the growth plan may try to distribute the surviving channels uniformly over the pre-transient channel-frequency range. Other manifestations are to keep (1) the average power of the surviving channels substantially equal to the average power of the pre-transient channels or (2) the average power of the post-transient surviving channels substantially equal to the power level of a specified channel. Transient-control can be balanced with conventional low-cost and high-performance goals to provide an effective hybrid channel-growth plan.

Transient-based channel growth for optical transmission systems

A method for the automatic provisioning of a network element (NE) includes receiving a client signal at a tunable optical translator (OT) in the NE, determining the set of channels supported by the OT that are able to correspond to the client signal, eliminating the channels that have connections, that may be present on a line side of the NE in a laser off scan process, or that have not been equipped or otherwise provisioned for transmission, tuning the OT to each of the remaining channels and determining the optical power level of each channel on a line side of the NE in a laser on scan process. Subsequently, the channel with the highest power level is selected to transmit the client signal and associations for a point to point connection for that channel are added for that OT to a database of associations for the NE.

Method, apparatus and system for the automatic provisioning of a network element

In an optical transmission system, operations of certain elements are adjusted in an individualized manner after detecting a change in the total optical power level corresponding to multiple optical channels in a link of the system in order to control transients in those channels. For example, in response to a sudden drop in the number of channels resulting from a fiber cut, the power levels of the optical pumps in a Raman amplifier in an OADM are adjusted to reduce transient gain errors in the surviving channels, where the adjustment to the pump power level for each different optical pump is a function of both the detected change in the total optical power level and at least one specified coefficient for that particular optical pump, in order to handle non-linearities in the response of the Raman amplifier to the sudden drop in the number of optical channels.

Transient control in optical transmission systems

A method and apparatus for controlling the pump powers of a broadband DWDM optical system using Raman amplification which determines pump settings that are advantageously directed to minimizing the peak-to-peak ripple of the channel powers with respect to a given per-channel target. The illustrative method and apparatus first formulates a linear programming optimization problem, and then solves the formulated linear program in order to derive a new set of pump powers to be applied to the Raman amplification pumps. In accordance with the principles of the invention, the formulated linear programming optimization problem advantageously includes one or more 'virtual' channels in addition to the actual channels used in the optical transmission system. The linear program may be solved with use of any conventional linear programming solution technique, such as, for example, the simplex method.

Method and apparatus for controlling pump powers of broadband Raman amplifiers in optical transmission systems incorporating virtual channels to reduce noise

Growing community of inventors

Piscataway, NJ, United States of America

Narasimhan Raghavan