In RAPID, we propose to use a centralized radio access (C-RAN) architecture to support high-capacity heterogeneous (3g, 4G and 60 GHz) radio access technologies through low-cost, but ultra-high-bandwidth photonic techniques for the fibre distribution. To meet the requirement to transport the high-frequency (and wide-bandwidth) wireless signals at low-cost, a novel coherent radio-over-fiber (CRoF) ...