Design of communication networks with survivability constraints

The rapid growth of telecommunication capacity, driven in part by the wide- ranging deployment of fiber-optic technology has led to increasing concern regarding the survivability of such networks. Ln communication networks, su rvivability is usually defined as the percentage of total traffic surviving some network failures in the worst case. Most of the survivable network de sign models proposed to date indirectly ensure network survivability by inv oking a connectivity constraint, which calls for a prespecified number of p aths between every distinct pair of nodes in the network. In this paper, we introduce a new network design model which directly addresses survivabilit y in terms of a survivability constraint which specifies the allowable leve l of lost traffic during a network failure under prescribed conditions. The new model enables a network designer to consider a richer set of alternati ve network topologies than the existing connectivity models, and encompasse s the connectivity models as special cases. The paper presents a procedure to compute link survivability, develops an integer programming formulation of the proposed survivability model, and discusses a special case of practi cal interest and its associated heuristic procedure. The proposed heuristic is tested on data from real-world problems as well as randomly generated p roblems.