Virtual Optical Network Embedding (VONE) Over Elastic Optical Networks

TLDR

Optical network virtualization enables sharing of physical infrastructure among users and applications, building on the infrastructure‑as‑a‑service model. The study designs algorithms for transparent and opaque virtual optical network embedding over flexible‑grid elastic optical networks. The authors formulate ILP models and introduce a layered‑auxiliary‑graph (LAG) technique to decompose the substrate into bandwidth‑layered graphs, enabling heuristic routing and spectrum assignment algorithms (LRC‑LaSP, LaLRC‑LaSP) for transparent VONE and a consecutiveness‑aware LRC‑KSP‑FF heuristic for opaque VONE. Simulations show that LaLRC‑LaSP outperforms LRC‑LaSP and a benchmark in blocking, while CaLRC‑KSP‑FF significantly lowers request blocking probability compared to existing algorithms.

Abstract

Based on the concept of infrastructure as a service, optical network virtualization can facilitate the sharing of physical infrastructure among different users and applications. In this paper, we design algorithms for both transparent and opaque virtual optical network embedding (VONE) over flexible-grid elastic optical networks. For transparent VONE, we first formulate an integer linear programming (ILP) model that leverages the all-or-nothing multi-commodity flow in graphs. Then, to consider the continuity and consecutiveness of substrate fiber links' (SFLs') optical spectra, we propose a layered-auxiliary-graph (LAG) approach that decomposes the physical infrastructure into several layered graphs according to the bandwidth requirement of a virtual optical network request. With LAG, we design two heuristic algorithms: one applies LAG to achieve integrated routing and spectrum assignment in link mapping (i.e., local resource capacity (LRC)-layered shortest-path routing LaSP), while the other realizes coordinated node and link mapping using LAG (i.e., layered local resource capacity(LaLRC)-LaSP). The simulation results from three different substrate topologies demonstrate that LaLRC-LaSP achieves better blocking performance than LRC-LaSP and an existing benchmark algorithm. For the opaque VONE, an ILP model is also formulated. We then design a LRC metric that considers the spectrum consecutiveness of SFLs. With this metric, a novel heuristic for opaque VONE, consecutiveness-aware LRC-K shortest-path-first fit (CaLRC-KSP-FF), is proposed. Simulation results show that compared with the existing algorithms, CaLRC-KSP-FF can reduce the request blocking probability significantly.