Survivable Wavelength-Division-Multiplexed Passive Optical Network for Fronthaul in 5G and Beyond

Nowadays, fronthaul network plays an increasingly important role in the fifth generation (5G) and beyond cellular networks because of higher Quality of Service (QoS) requirements of subscribers. Wavelength-division-multiplexed passive optical network (WDM-PON), which copes with the requirements of low latency and large capacity, is a good option for fronthaul in 5G and beyond. To serve subscribers without interruption, improvement of survivability which should address both fiber cuts and link congestion is a challenging problem. Because of the high cost of fiber and small-cells in fronthaul for 5G and beyond, a cost-efficient solution to survivability improvement of WDM-PON is critical. Towards this challenge, this paper proposes a Cost-Efficient Multi-hop Survivability (CEMS) scheme which can provide multi-hop backup paths for each optical network unit (ONU). In order to execute CEMS scheme in WDM-PON, we propose a modified ONU architecture. To determine the positions of backup fibers and backup paths of each ONU, Greedy Cost-Efficiency (GCE) algorithm is proposed. Simulation results based on practical parameters of WDM-PONs for fronthaul in 5G show the advantages of CEMS scheme.