Is dynamic dedicated path protection tractable?

TL;DR

This paper demonstrates that the problem of finding two link-disjoint paths with minimal cost under certain constraints in optical networks is tractable when using a generic Dijkstra algorithm, contrary to previous beliefs of intractability.

Contribution

The paper introduces a polynomial-time solution for the previously intractable problem of dynamic dedicated path protection in optical networks using a generic Dijkstra algorithm.

Findings

The problem is solvable exactly with the proposed method.

The approach works within a polynomially-bounded search space.

It challenges the prior assumption of intractability for this problem.

Abstract

Intractable is the problem of finding two link-disjoint paths of minimal cost if the path cost is limited since it can be a special case of the partition problem. In optical networks, this limit can be introduced by the signal modulation reach. Even without this limit, the existing literature suggested the problem intractable because of the spectrum continuity and contiguity constraints, but we show that the problem can be solved exactly with the recently-proposed generic Dijkstra algorithm over a polynomially-bounded search space, thus proving the problem tractable.