Cycle-oriented distributed preconfiguration: ring-like speed with mesh-like capacity for self-planning network restoration

TLDR

Cycle‑oriented preconfiguration of spare capacity is a novel approach for mesh‑restorable networks that, unlike self‑healing rings, uses cycles to provide multiple restoration paths and cover more failure scenarios. The goal is to preserve mesh‑restorable networks’ capacity efficiency while achieving ring‑like restoration speed. An optimal design formulation and a distributed self‑organizing protocol enable networks to continuously approximate the optimal preconfiguration of spare capacity. The strategy achieves 100 % restoration using only two cross‑connections per path and requires little or no extra spare capacity compared to a conventional mesh network.

Abstract

Cycle-oriented preconfiguration of spare capacity is a new idea for the design and operation of mesh-restorable networks. It offers a sought-after goal: to retain the capacity-efficiency of a mesh-restorable network, while approaching the speed of line-switched self-healing rings. We show that through a strategy of pre-failure cross-connection between the spare links of a mesh network, it is possible to achieve 100% restoration with little, if any, additional spare capacity than in a mesh network. In addition, we find that this strategy requires the operation of only two cross-connections per restoration path. Although spares are connected into cycles, the method is different than self-healing rings because each preconfigured cycle contributes to the restoration of more failure scenarios than can a ring. Additionally, two restoration paths may be obtained from each pre-formed cycle, whereas a ring only yields one restoration path for each failure it addresses. We give an optimal design formulation and results for preconfiguration of spare capacity and describe a distributed self-organizing protocol through which a network can continually approximate the optimal preconfiguration state.