Constraint-based design of optical transmission systems

A method of designing an optical transmission system, the method comprising the steps of:

• obtaining a set of one or more demands and a set of optical transmission system elements wherein elements may be consecutively coupled via a span:
• obtaining at least one constraint on the design of the optical transmission system, wherein the at least one constraint comprises one of:
• (i) a signal loss in a span should not exceed a given maximum signal loss;
• (ii) a signal loss in a span should not exceed a given maximum signal loss and a span should be longer than a given minimum span length;
• (iii) a signal loss in a span should not exceed a given first maximum signal loss and a span should be longer than a given minimum span length, however, at most one in m contiguous spans can have a loss up to a given second maximum signal loss, wherein the second maximum signal loss is greater than the first maximum signal loss;
• and (iv) a signal loss in a span should not exceed a given maximum signal loss and a span should be longer than a given minimum span length, and an average span loss of any m consecutive spans should not exceed a given average loss, wherein the average loss is less than the given maximum signal loss;
• and
• computing a least-cost configuration for the optical transmission system based on at least a portion of the set of one or more demands and the set of one or more optical transmission system elements such that the at least one constraint is satisfied;
• wherein the step of computing the least-cost configuration based on constraint (ii) further comprises traversing element locations from a source to a destination such that increasingly longer solutions are computed.

A method of designing an optical transmission system, the method comprising the steps of:

• obtaining a set of one or more demands and a set of optical transmission system elements wherein elements may be consecutively coupled via a span;
• obtaining at least one constraint on the design of the optical transmission system, wherein the at least one constraint comprises one of:
• (i) a signal loss in a span should not exceed a given maximum signal loss;
• (ii) a signal loss in a span should not exceed a given maximum signal loss and a span should be longer than a given minimum span length;
• (iii) a signal loss in a span should not exceed a given first maximum signal loss and a span should be longer than a given minimum span length, however, at most one in m contiguous spans can have a loss up to a given second maximum signal loss, wherein the second maximum signal loss is greater than the first maximum signal loss and (iv) a signal loss in a span should not exceed a given maximum signal loss and a span should be longer than a given minimum span length, and an average span loss of any m consecutive spans should not exceed a given average loss, wherein the average loss is less than the given maximum signal loss;
• and
• computing a least-cost configuration for the optical transmission system based on at least a portion of the set of one or more demands and the set of one or more optical transmission system elements such that the at least one constraint is satisfied;
• wherein the step of computing the least-cost configuration based on constraint (iii) further comprises generating solutions for element locations H1 . . . Hj from solutions for H1 . . . Hj1 knowing the nearest extra loss span having a loss up to the given second maximum signal loss from Hj-1 in the latter.

A method of designing an optical transmission system, the method comprising the steps of:

• obtaining a set of one or more demands and a set of optical transmission system elements wherein elements may be consecutively coupled via a span;
• obtaining at least one constraint on the design of the optical transmission system, wherein the at least one constraint comprises one of:
• (i) a signal loss in a span should not exceed a given maximum signal loss;
• (ii) a signal loss in a span should not exceed a given maximum signal loss and a span should be longer than a given minimum span length;
• (iii) a signal loss in a span should not exceed a given first maximum signal loss and a span should be longer than a given minimum span length, however, at most one in m contiguous spans can have a loss up to a given second maximum signal loss, wherein the second maximum signal loss is greater than the first maximum signal loss;
• and (iv) a signal loss in a span should not exceed a given maximum signal loss and a span should be longer than a given minimum span length, and an average span loss of any m consecutive spans should not exceed a given average loss, wherein the average loss is less than the given maximum signal loss;
• and
• computing a least-cost configuration for the optical transmission system based on at least a portion of the set of one or more demands and the set of one or more optical transmission system elements such that the at least one constraint is satisfied;
• wherein the step of computing the least-cost configuration based on constraint (iv) further comprises:
• computing all possible configurations having m−1 spans that are valid under constraint (iii) starting from every element location and all the configurations having m−1 or less spans starting from location H1;
• and
• using each such configuration Cij equal to Hi. . . Hj, computing an optimal configuration from locations H1 . . . Hj that includes Cij, for increasing values of i;
• wherein the overall solution results when Cij includes the destination location.

A method of designing an optical transmission system, the method comprising the steps of:

• obtaining a set of one or more demands and a set of optical transmission system elements wherein elements may be consecutively coupled via a span;
• obtaining at least one constraint on the design of the optical transmission system, wherein the at least one constraint comprises one of:
• (i) a signal loss in a span should not exceed a given maximum signal loss;
• (ii) a signal loss in a span should not exceed a given maximum signal loss and a span should be longer than a given minimum span length;
• (iii) a signal loss in a span should not exceed a given first maximum signal loss and a span should be longer than a given minimum span length, however, at most one in m contiguous spans can have a loss up to a given second maximum signal loss, wherein the second maximum signal loss is greater than the first maximum signal loss;
• and (iv) a signal loss in a span should not exceed a given maximum signal loss and a span should be longer than a given minimum span length, and an average span loss of any m consecutive spans should not exceed a given average loss, wherein the average loss is less than the given maximum signal loss;
• and
• computing a least-cost configuration for the optical transmission system based on at least a portion of the set of one or more demands and the set of one or more optical transmission system elements such that the at least one constraint is satisfied;
• wherein the step of computing the least-cost configuration is bi-directionally solved when span losses are identical in both directions by computing a solution for the uni-directional case and applying the resulting solution to the reverse direction by shifting elements by one element location.

A method of designing an optical transmission system, the method comprising the steps of:

• obtaining a set of one or more demands and a set of optical transmission system elements wherein elements may be consecutively coupled via a span;
• obtaining at least one constraint on the design of the optical transmission system, wherein the at least one constraint comprises one of:
• (i) a signal loss in a span should not exceed a given maximum signal loss;
• (ii) a signal loss in a span should not exceed a given maximum signal loss and a span should be longer than a given minimum span length;
• (iii) a signal loss in a span should not exceed a given first maximum signal loss and a span should be longer than a given minimum span length, however, at most one in m contiguous spans can have a loss up to a given second maximum signal loss, wherein the second maximum signal loss is greater than the first maximum signal loss;
• and (iv) a signal loss in a span should not exceed a given maximum signal loss and a span should be longer than a given minimum span length, and an average span loss of any m consecutive spans should not exceed a given average loss, wherein the average loss is less than the given maximum signal loss;
• and
• computing a least-cost configuration for the optical transmission system based on at least a portion of the set of one or more demands and the set of one or more optical transmission system elements such that the at least one constraint is satisfied;
• wherein the step of computing the least-cost configuration is bi-directionally solved when span losses are not identical in both directions by at least one of:
• taking the distance in both directions into account;
• letting a cost of an element cij be the cost of the elements for both dij and dj,i;
• computing extra loss spans in both directions;
• and, at the end of the computation, shifting the elements in the reverse direction by one element location.

A method of designing an optical transmission system, the method comprising the steps of:

• obtaining a set of one or more demands and a set of optical transmission system elements wherein elements may be consecutively coupled via a span;
• obtaining at least one constraint on the design of the optical transmission system, wherein the at least one constraint comprises one of:
• (i) a signal loss in a span should not exceed a given maximum signal loss;
• (ii) a signal loss in a span should not exceed a given maximum signal loss and a span should be longer than a given minimum span length;
• (iii) a signal loss in a span should not exceed a given first maximum signal loss and a span should be longer than a given minimum span length, however, at most one in m contiguous spans can have a loss up to a given second maximum signal loss, wherein the second maximum signal loss is greater than the first maximum signal loss;
• and (iv) a signal loss in a span should not exceed a given maximum signal loss and a span should be longer than a given minimum span length, and an average span loss of any m consecutive spans should not exceed a given average loss, wherein the average loss is less than the given maximum signal loss;
• and
• computing a least-cost configuration for the optical transmission system based on at least a portion of the set of one or more demands and the set of one or more optical transmission system elements such that the at least one constraint is satisfied;
• wherein the step of computing the least-cost configuration further comprises ignoring computed configurations that place a splice at an optical add-drop multiplexer location.

A method of designing an optical transmission system, the method comprising the steps of:

• obtaining a set of one or more demands and a set of optical transmission system elements wherein elements may be consecutively coupled via a span;
• obtaining at least one constraint on the design of the optical transmission system, wherein the at least one constraint comprises one of:
• (i) a signal loss in a span should not exceed a given maximum signal loss;
• (ii) a signal loss in a span should not exceed a given maximum signal loss and a span should be longer than a given minimum span length;
• (iii) a signal loss in a span should not exceed a given first maximum signal loss and a span should be longer than a given minimum span length, however, at most one in m contiguous spans can have a loss up to a given second maximum signal loss, wherein the second maximum signal loss is greater than the first maximum signal loss;
• and (iv) a signal loss in a span should not exceed a given maximum signal loss and a span should be longer than a given minimum span length, and an average span loss of any m consecutive spans should not exceed a given average loss, wherein the average loss is less than the given maximum signal loss;
• and
• computing a least-cost configuration for the optical transmission system based on at least a portion of the set of one or more demands and the set of one or more optical transmission system elements such that the at least one constraint is satisfied;
• wherein the step of computing the least-cost configuration further comprises constructing a new element location.

Apparatus for designing an optical transmission system, comprising:

• a memory;
• and
• at least one processor coupled to the memory and operative to:
• obtain a set of one or more demands and a set of optical transmission system elements wherein elements may be consecutively coupled via a span;
• obtain at least one constraint on the design of the optical transmission system, wherein the at least one constraint comprises one of:
• (i) a signal loss in a span should not exceed a given maximum signal loss;
• (ii) a signal loss in a span should not exceed a given maximum signal loss and a span should be longer than a given minimum span length;
• (iii) a signal loss in a span should not exceed a given first maximum signal loss and a span should be longer than a given minimum span length, however, at most one in m contiguous spans can have a loss up to a given second maximum signal loss, wherein the second maximum signal loss is greater than the first maximum signal loss;
• and (iv) a signal loss in a span should not exceed a given maximum signal loss and a span should be longer than a given minimum span length, and an average span loss of any m consecutive spans should not exceed a given average loss, wherein the average loss is less than the given maximum signal loss;
• and
• compute a least-cost configuration for the optical transmission system based on at least a portion of the set of one or more demands and the set of one or more optical transmission system elements such that the at least one constraint is satisfied;
• wherein the operation of computing the least-cost configuration based on constraint (ii) further comprises traversing element locations from a source to a destination such that increasingly longer solutions are computed.

An article of manufacture for designing an optical transmission system, comprising a machine readable medium containing one or more programs which when executed implement the steps of:

• obtaining a set of one or more demands and a set of optical transmission system elements wherein elements may be consecutively coupled via a span;
• obtaining at least one constraint on the design of the optical transmission system, wherein the at least one constraint comprises one of:
• (i) a signal loss in a span should not exceed a given maximum signal loss;
• (ii) a signal loss in a span should not exceed a given maximum signal loss and a span should be longer than a given minimum span length;
• (iii) a signal loss in a span should not exceed a given first maximum signal loss and a span should be longer than a given minimum span length, however, at most one in m contiguous spans can have a loss up to a given second maximum signal loss, wherein the second maximum signal loss is greater than the first maximum signal loss;
• and (iv) a signal loss in a span should not exceed a given maximum signal loss and a span should be longer than a given minimum span length, and an average span loss of any m consecutive spans should not exceed a given average loss, wherein the average loss is less than the given maximum signal loss;
• and
• computing a least-cost configuration for the optical transmission system based on at least a portion of the set of one or more demands and the set of one or more optical transmission system elements such that the at least one constraint is satisfied;
• wherein the step of computing the least-cost configuration based on constraint (ii) further comprises traversing element locations from a source to a destination such that increasingly longer solutions are computed.