US 6,634,807 B1 · Optical transmission system including performance optimization

Abstract

Vulnerability of an optical network to channel impairments or the like, is addressed by utilizing real-time monitoring and control of prescribed optical channel impairments. The impairments are compensated for by employing an optimization process in the optical network such that the optical signals from the source or sources of the impairments are controllably adjusted at any particular node in the network. The optical signals are attenuated more or less at the source node of the associated optical channel in order to optimize performance of the corresponding optical channel in the network. A variable optical attenuator (VOA) is used at the λ laser source of optical channel having the impairment to obtain the attenuation. The optical signal impairment is measured at a receiving node and the source node of the associated optical channel is determined. Then, a control message is transmitted to the identified source node indicating that a VOA associated with the corresponding optical channel λ laser source is to be adjusted to insert more or less attenuation as the case may be. This process is iterated until the corresponding optical channel yields optimum performance for the impairment being measured. A VOA in a remote node associated with the λ laser source of the associated optical channel is first adjusted. Then, a VOA in the local node associated with the optical channel being monitored is adjusted to further optimize the prescribed metric of the optical channel being monitored. This adjustment is iterated until the performance of the associated channel is optimized.

Claims44

Dependent claims

A method for use in an optical transmission system for optimizing optical channel performance comprising the steps of:

(a) selecting a received prescribed optical channel having a prescribed optical wavelength;
(b) a first step of evaluating a predetermined transmission performance metric of said selected prescribed optical channel;
(c) a first step of determining if said prescribed metric under evaluation is within acceptable criteria;
(d) if not, generating a first control message to adjust at least a first controllable optical power adjustment unit associated with said selected prescribed optical channel;
(e) supplying said first control message to cause said first controllable power adjustment unit to adjust in such a manner as to optimize said prescribed metric of said selected prescribed optical channel;
(f) a second step of evaluating said predetermined transmission performance metric of said selected optical channel;
(g) a second step of determining if said prescribed metric under evaluation is within acceptable criteria, and (h) if not, repeating steps (d) through (h) until said prescribed metric is within acceptable criteria;
(i) determining if said selected prescribed optical channel having been optimized is the last of said one or more optical channels and, if not,
(i) selecting another prescribed optical channel having another prescribed optical wavelength;
and
repeating steps (b) through (i) until step (h) indicates that the last one of said selected prescribed optical channels has been optimized.

8 more elements

A method for use in an optical transmission system for optimizing optical channel performance comprising the steps of:

(a) selecting a received prescribed optical channel having a prescribed optical wavelength;
(b) a first step of evaluating a predetermined transmission performance metric of said prescribed optical channel;
(c) a first step of determining if said prescribed metric under evaluation is within acceptable criteria;
(d) if the result of step (c) is NO, a second step of determining if said predetermined transmission performance metric is substantially within said acceptable criteria;
(e) if the result of step (d) is NO, determining a source node including a laser source for said prescribed optical wavelength of said prescribed optical channel;
(f) generating a first control message to adjust at least a first controllable optical power adjustment unit associated with said determined laser source;
and
(g) transmitting said first control message to said source node to cause said first controllable power adjustment unit to adjust in such a manner as to optimize said prescribed metric of said prescribed optical channel.

5 more elements

A method for use in an optical transmission system for optimizing optical channel performance comprising the steps of:

(a) selecting a received prescribed optical channel having a prescribed optical wavelength;
(b) a first step of evaluating a predetermined transmission performance metric of said prescribed optical channel;
(c) a first step of determining if said prescribed metric under evaluation is within acceptable criteria;
(d) if the result of step (e) is NO, determining a source node including a laser source for said prescribed optical wavelength of said prescribed optical channel;
(e) generating a first control message to adjust a first controllable optical power adjustment unit associated with said determined laser source;
(f) generating a second control message to adjust at least a second controllable optical power adjustment unit associated with said selected received prescribed optical channel;
(g) transmitting said first control message to said source node to cause said first controllable power adjustment unit to adjust in such a manner as to optimize said prescribed metric of said prescribed optical channel;
and
(h) supplying said second control message substantially simultaneously with said transmission of said first control message to adjust said at least second controllable unit in such a manner as to optimize said predetermine metric of said prescribed optical channel.

6 more elements

Apparatus for use in an optical transmission system for optimizing optical channel performance comprising:

an optical demultiplexer for obtaining one or more received prescribed optical channels each having a different optical wavelength;
a monitor for evaluating a prescribed performance metric of said one or more received prescribed optical channels and for determining whether said prescribed performance metric being evaluated for a selected one of said prescribed optical channels is within acceptable criteria;
and
a controller, responsive to an indication from said monitor that said prescribed performance metric is not within said prescribed criteria, for generating a control message to control adjustment of a first controllable optical power adjustment unit associated with said selected prescribed optical channel toward bringing said prescribed metric within said acceptable criteria, and supplying said first control message to said first controllable optical power adjustment unit associated with said selected prescribed optical channel, whereby transmission performance of said selected prescribed optical channel is optimized,
wherein said controller is equipped to determine a source node including a laser source of said prescribed optical wavelength of said selected prescribed optical channel.

2 more elements

Apparatus for use in an optical transmission system including a plurality of nodes for optimizing transmission performance of optical channels being transported in the system comprising:

at a first node
a first optical demultiplexer for obtaining one or more prescribed optical channels each having a different optical wavelength,
a monitor for evaluating a prescribed performance metric of said one or more prescribed optical channels and for determining whether said prescribed performance metric being evaluated for said a prescribed one of said optical channels is within acceptable criteria,
a first controller for determining a source node including a laser source for said prescribed optical wavelength of said prescribed optical channel when said performance metric being evaluated is not within said acceptable criteria and for generating a control message to control adjustment of a first controllable optical power adjustment unit associated with said laser source toward bringing said prescribed metric within said acceptable criteria, and
a first optical multiplexer for multiplexing said first control message into an optical signal to be transmitted to said source node;
and
at said source node
a second optical demultiplexer for obtaining a first control message from an incoming optical signal,
a laser source for generating a prescribed optical wavelength for a prescribed optical channel,
a second controller supplied with said first control message for generating an adjustment control message, and
a first controllable optical power adjustment unit associated with said laser source and being responsive to said control message to adjust output light power from said laser source in a direction toward optimizing a predetermined performance metric for said prescribed optical channel, whereby said performance of said prescribed optical channel is optimized.

8 more elements

Dependencies are inferred from the claim text.

Optical transmission system including performance optimization

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Optical transmission system including performance optimization

Life of this patent

Abstract

Claims44