Introducing Full Duplex in Hybrid Fiber Coaxial Networks

Upstream data rate constraints have long been the Achilles' heel of hybrid fiber-coaxial networks. Increasingly, cable operators face the challenge of growing demand for cloud services, symmetric services for small and medium enterprises, high definition video uploads, real-time gaming, live streaming video, and virtual or augmented reality. In this article, we discuss future HFC network architectures and system concepts that remove the restrictions on asymmetry ratio, preparing HFC networks for the anticipated growth in demand for symmetric services. The concepts detailed in this article allow multiple system operators to offer fiber-like symmetric services without the need to install fiber all the way to the home. We demonstrate that 10 Gb/s symmetric data rates are feasible with a proof-of-concept prototype system. It is achieved by enabling full duplex transmission through extremely wideband echo cancellation and effectively eliminates the extra interference that full duplex operation introduces in the shared network. This technology can be made compatible with legacy DOCSIS networks and validates Cable- Labs' Full Duplex DOCSIS 3.1 proposal.