Various lightpath protection schemes for a survivable WDM grooming network with dynamic traffic were investigated in Chapter 12. The nodes in the WDM grooming network are assumed to include ADM (add–drop multiplexer)-constrained grooming nodes. This chapter deals with the static survivable WDM grooming network design with wavelength continuity constrained grooming nodes. For static traffic the problem of grooming subwavelength level requests in mesh-restorable WDM networks, the corresponding path selection and wavelength assignment problems are formulated as ILP optimization problems.

Design problem

To address the survivable grooming network design problem, a network with W wavelengths per fiber and K disjoint alternate paths for each s-d pair can be viewed as W × K networks, with each of them representing a single wavelength network. For K = 2, the first W networks contain the first alternate path for each s-d pair on each wavelength. We number the networks from 1 to W, according to the wavelengths associated with them. The second set of W networks contain the second alternate path for each s-d pair on each wavelength. These networks are numbered from W + 1 to 2W, where the (W + i)th network represents the same wavelength as the ith network, i = 1, 2, …,W. Figure 13.1 illustrates this layered model for a six-node network with three wavelengths and two link-disjoint alternate paths. For each node-pair, it also depicts routing of two alternate paths for two connections in the network.