OTN IN THE 5G ERA: TRANSPORTING MASSIVE IP-BASED MOBILE TRAFFIC

Fifth-generation (5G) mobile networks impose unprecedented transport demands—high bandwidth, deterministic latency, and precise synchronization—driven by disaggregated RAN architectures (C-RAN/vRAN) and diverse service classes (eMBB, URLLC, mMTC) (Larsen et al., 2019; Zhang et al., 2020; Nakamura et al., 2018; Wijethilaka & Liyanage, 2021). This paper evaluates Optical Transport Network (OTN) as a foundation for 5G fronthaul and backhaul, focusing on protocol transparency, hierarchical grooming, latency determinism, operations/maintenance tooling, and carrier-grade protection (ITU-T, 2016; Cvijetic et al., 2017; Li et al., 2021). Using a synthesis of standards, deployments, and modeling, we show that OTN efficiently maps heterogeneous 5G traffic (e.g., CPRI/eCPRI, Ethernet), sustains microsecond-level latency and low jitter under load, and scales via ODUflex-based bandwidth granularity while meeting synchronization targets required by TDD and CoMP (Pizzinat et al., 2015; Velasco et al., 2014; ITU-T, 2020). Economic assessment indicates competitive lifecycle cost for high-capacity routes despite higher initial capex, especially where grooming efficiency and operational simplicity offset packet-only alternatives (Chen et al., 2019). We also discuss hybrid architectures pairing OTN with packet transport and SDN control to accelerate service provisioning and enable slice-aware automation (Raza et al., 2017; Taleb et al., 2017). The results provide an integrated framework and practical guidance for operators planning 5G transport, confirming OTN’s suitability for metro-scale fronthaul and aggregation backhaul today and its relevance as requirements evolve toward 6G (Zhang et al., 2020).