^{1}

This paper develops a new scalable and efficient model for the design of

WDM (wavelength division multiplexing) mesh networks are preferred as next generation optical core networks [

Different kinds of protection approaches have been proposed for WDM optical mesh networks to ensure survivability from any single failure. Among them,

So far, however, very few papers have explored

To design

In this paper, we explore

The rest of the paper is organized as follows. Section

In this section, we illustrate the two-hop-segment strategy for node protection using

Figure

Two-hop-segment strategy for node protection with

An optical network is denoted by a graph

In order to deal with the scalability issues in the classical design, we develop a column-generation- (CG-) based optimization model. Only a very few number of promising

We denote the number of traffic units on link

Candidates are associated with the configuration set

Variables

The mathematical model can then be written as follows:

Constraints (

The pricing problem corresponds to the optimization problem for generation of the promising

The reduced cost can be written as follows:

Let us next define the following notations.

With these notations, the objective function of the pricing problem can then be written as follows:

Regarding constraints, there are two parts in the pricing problem. The first part defines a cycle, while the second part identifies the associated intermediate nodes of the working paths which can be protected by the current cycle.

In the following, the first part of constraints is presented:

Constraints (

The second part of the constraints is next presented as follows:

Constraints (

In this section, we evaluate the solution performances of our proposed design experimentally. Two metrics are exploited for evaluation, which include capacity redundancy (the ratio of spare capacity to working capacity [

Four test networks are presented in Table

Network instances.

Networks | Nodes |
Links |
Node |
Num. |
Working capacity |
---|---|---|---|---|---|

GERMANY [ |
17 | 26 | 3.1 | 136 | 4034 |

BELLCORE [ |
15 | 28 | 3.7 | 105 | 2610 |

NJLATA [ |
11 | 23 | 4.2 | 55 | 943 |

COST239 [ |
11 | 26 | 4.7 | 55 | 792 |

Experimental results regarding capacity redundancy and the average size of the

QoP

Figure

In this paper, we investigated the design of

Extensive experiments have been conducted. Experimental results show clearly that, with our proposed design method,