The Optical Fiber and mmWave Wireless Convergence for 5G Fronthaul Networks

The most radical evolution in recent mobile communication technology is imminent in the coming years. The fronthaul network architecture is part of this evolution and is expected to support dense deployment of infrastructure to provide increased bandwidth and ultra-low latency for 5th generation (5G) networks in a cost-effective manner. The new fronthaul architecture called cloud radio access network (C-RAN) has been introduced over the last years to increase scalability, manageability, and flexibility of mobile systems. In this context, this paper addresses the principal technology enablers of the C-RAN 5G fronthaul architecture, namely radio-over-fiber, ribbon optical fibers, wavelength-division multiplexing, and millimeter wave (mmWave) frequencies. The convergence of optical fiber networks and mmWave radio pave the way towards a truly efficient fronthaul infrastructure for 5G mobile communications with seamless connectivity for millions of devices and quality-of-service guarantees in terms of latency for the first time ever. We perceive a network scenario with seamless starting and ending interfaces by exploiting space diversity in both radio frequency and optical domains with efficient integrated photonics technology. Furthermore, we introduce the ongoing developments of the Eindhoven-based 5G Brainport testbed towards an open environment for validation and test of end-to-end emerging applications benefitting from the 5G key-performance indicators.