Abstract

Recently, to cope with the ever-growing traffic volumes and network services in the Internet, the coherent point-to-multipoint transceivers (P2MP-TRXs) enabled by digital subcarrier modulation (DSCM) technique have been developed and viewed as a promising replacement of conventional point-to-point transceivers (P2P-TRXs), especially for the metro-aggregation networks with hub-and-spoke traffic patterns. Nevertheless, the network planning of wavelength switched optical networks (WSONs) with P2MP-TRXs can be rather complex, as additional correlated constraints are introduced to model the routing and spectrum assignment (RSA), and thus the problem cannot be solved with existing algorithms in the literature. In this article, we study the network planning of WSONs with P2MP-TRXs, which not only includes the aforementioned subproblem of correlated RSA, but also the placement of P2MP-TRXs in hub-leaf-based groups and the corresponding subcarrier (SC) assignments. We first formulate an integer linear programming (ILP) model to formally describe and exactly solve the network planning problem. Then, two polynomial-time heuristics, based on layered auxiliary graph (LAG) and conflict graph (CG), respectively, are proposed to find near-optimal solutions. Finally, we perform extensive simulations to evaluate the proposed algorithms, and the simulation results confirm their performance and effectiveness.