Disruption-Free Expansion of Protected Optical Path Networks that Utilize Subsystem Modular OXC Nodes

Abstract

We present the effectiveness of a reliable optical path network architecture that introduces scalable photonic nodes and dedicated path protection. The assumed photonic nodes consist of sparsely interconnected small-scale optical cross connect (OXC) subsystems and can substantially reduce the necessary hardware scale while improving the transmission characteristics. The node offers a graceful modular growth capability to cope with continuous traffic growth without any service disruption. The main design object is to minimize the performance gap against conventional OXC nodes, which is achieved by wisely utilizing the routing characteristic of the OXC subsystem, where the routing restriction is independent of the working and backup paths. Considering the degree of computational complexity in optical network design, which is worsened by the protection requirement, we develop a multi-stage design algorithm that finds sequentially suboptimal solutions at each stage for given sets of path setup requests. Numerical experiments verify that the proposed networks can achieve almost the same routing performance as conventional networks while substantially reducing the total hardware scale and transmission impairment, which holds true for both static and incremental design scenarios.