Dynamic Provisioning and Stability of p-Cycles in WDM Networks

p-Cycles correspond to an efficient pre-configured and pre-cross-connected Please check `pre-cross connected´ throughout. Should this be `pre-cross-connected´? protection scheme which can achieve ring-like recovery speed while retaining the capacity efficiency of mesh-based schemes. While most studies have focused on static traffic, we study here the stability and efficient reconfiguration of p-cycles in the context of dynamic traffic. We design two new highly scalable mathematical models and algorithms for dynamic p-cycles. We consider two objectives, the classical one with the minimization of the spare bandwidth requirements and the objective of minimizing the number of optical bypasses to be newly established or reset while reusing as much as possible the previously established optical bypasses. We use integer linear programming formulations relying on decomposition techniques. The results confirm that not only are the proposed models and algorithms highly scalable but, in addition, they show that p-cycles are highly stable protection schemes.