A Silicon Photonic Switching Platform for Flexible Converged Centralized-Radio Access Networking

Unprecedented levels of device connectivity and the emergence of futuristic digital services are driving fundamental changes to underlying fixed and wireless data transport networks. Projected bandwidth requirements, coupled with increased network centralization and virtualization, will lead to the convergence of data-center, fixed and wireless systems, and a greater onus being placed on the optical routing/transport portion of these networks. Such converged networks will require the development of optical technologies capable of servicing a multitude of network user types. In this work, we propose the use of a Silicon Photonic (SiP) space-and-wavelength selective switch fabric as a flexible wavelength provisioning platform for converged optical networks. The envisaged converged network is presented and an experimental test-bed which demonstrates flexible Cloud Radio Access Networking (C-RAN), using a 4 × 4 micro-ring resonator based switch, is described. Successful provisioning and transmission of Wavelength Division Multiplexed (WDM) based analog Radio-over-Fiber (RoF) services, over 10 km of fiber, in the converged test-bed is demonstrated and evaluated in terms of the received Bit Error Rate (BER) and Error Vector Magnitude (EVM). Furthermore, the wavelength multi-casting capabilities of the SiP switch is shown to enable dynamic resource allocation in the optical domain, and this is highlighted through the experimental implementation and evaluation of two C-RAN use cases - representing high and low mobile traffic demand scenarios.