As the hybrid fiber-coax, or HFC, networks evolve toward remote PHY architectures, fiber is being deployed deeper in the network. 10G optical interfaces are pushed closer to the end users resulting in aggregation points in the network where 10-20 remote PHY devices come together.
Coherent can be an effective way to transport these aggregated signals back to the hub. In some cases, it may only be necessary to transport a single coherent wavelength back to the hub, but since coherent is inherently a DWDM technology, this approach provides the capability to expand capacity by up to two orders of magnitude in the future.
CableLabs is the standards organization of the cable industry and has recognized the need for this solution in the market. In 2017, they kicked off a project to define coherent standards for cable access aggregation applications. This project includes participation of many leading optical networking vendors, as well as several large MSOs.