Traffic Grooming in IP-Over-Fiber Space Division Multiplexing (FSDM) Networks

Abstract

Space division multiplexing (SDM) and spatial super-channel (Spa SCh) technologies have emerged as scalable solutions to accommodate the rapidly growing capacity requirements of optical networks. This study investigates multi-fiber optical networks enhanced with Spa SCh technology, in which spatial super-channels are formed by jointly utilizing the same spectrum across multiple fibers—referred to as fiber-SDM (FSDM). A key advantage of FSDM is the ability to share common laser sources (LSs) and local oscillators (LOs) across signals transmitted in different fibers using the same spectrum, thereby significantly reducing capital expenditure (CAPEX). However, the coarse spatial granularity of Spa SCh inherently limits spectrum resource utilization (SRU). To address this, traffic grooming is introduced into IP-over-FSDM networks supporting single-hop (SH) and multi-hop (MH) traffic grooming schemes. To the best of our knowledge, this is the first work that integrates grooming mechanisms into FSDM networks. Accordingly, a mixed integer linear programming (MILP) model is formulated to jointly minimize spectrum consumption and transceiver usage. Furthermore, efficient MH traffic grooming-based heuristic algorithms are developed for both static and dynamic traffic scenarios. Simulation results show that the proposed heuristics achieve near-MILP performance in small-scale networks while remaining scalable and efficient in larger networks. More importantly, compared with non-grooming schemes, the proposed grooming schemes improve service acceptance capability by up to 50% and reducing transceiver usage by up to 30%, demonstrating the importance of incorporating traffic grooming into FSDM network design.