The advent of beyond 5G and 6G technologies will necessitate the flow of massive volumes of information (10s or even 100s Gbps) through fixed and wireless broadband networks between billions of devices and mobile users. Leveraging existing and future optical access network deployments to radio cell sites in a spectrally efficient, cost-effective and sustainable manner is critical. With the recent standardization of the mmWave 5G New Radio (NR) Frequency Range 2 (FR2) band between 24-71 GHz for high throughput applications, the impact on radio access networks (RANs) is the densification of cell sites and deployed radio units (RUs). To this end, a centralized/cloud radio access network (C-RAN) approach is considered an indispensable solution enabling this densification of cell sites [2]. Moreover, its amalgamation with analog radio-over-fiber (ARoF) technology can immensely reduce the complexity of the RUs, making the cell sites more economical and thereby facilitating wide deployment. 

Considering the enormous volume of traffic and vast array of services expected from optical links between RUs and central office (CO), the advances in flexible optical networking technologies must be leveraged in C-RANs to provide a high-speed, sustainable and multi-vendor networking platform in support of current and emerging wireless technologies/ connectivity.

A highly flexible wavelength and space switched analog radio-over-fiber (ARoF) fronthaul transmission of a millimeter-wave (mmWave) emerging 6G waveform over a centralized/cloud radio access network (C-RAN) is experimentally demonstrated in this DCU research collaboration. A signal constituting Wi-Fi and 5G NR standard compatible 64-QAM orthogonal frequency division multiplexing (OFDM) bands, at 10 GHz and 24 GHz respectively, are also transmitted and evaluated in the proposed system with EVM performances below 64-QAM EVM limit (8%) achieved, thus demonstrating the system’s potential in a future converged multi-service environment.