Reconfigurable Fiber Wireless Fronthaul With A-RoF and D-RoF Co-Existence Through a Si3N4 ROADM for Heterogeneous Mmwave 5G C-RANs

Towards enabling bandwidth-hungry 5G applications, a Fiber-Wireless (FiWi) mobile fronthaul architecture is experimentally presented supporting the co-existence of spectrally efficient analog transport formats with Digital Radio over Fiber transport schemes, combined with millimeter wave (mmWave) high-capacity wireless channels. Flexible transport network reconfiguration is proposed by means of a low-loss 1 × 4 Si ₃ N ₄ Reconfigurable Optical Add/Drop Multiplexer (ROADM) on TriPleX platform, selectively dropping four FiWi mmWave fronthaul links to four different antenna location. Detailed investigations of the proposed system are reported, including frequency characterization, multi-stage EVM penalty study and analog/digital traffic coexistence PHY layer feasibility. Following, four 10 Gb/s multi-band 16-QAM WDM FiWi analog IFoF links are transmitted through 10km fiber and 1-m directional V-band antennas and flexibly reconfigured by a Si ₃ N ₄ ROADM, achieving a record 40 Gb/s wavelength-routed fronthaul capacity for mmWave 5G, while simultaneously meeting multiple 5G Use Cases within 3GPP requirements.