Remote PHY (RPHY) deployment started in 2017 in some MSO networks. RPHY works well in deep fiber architecture; it puts RF modulation devices deep in the field, attached to the N+0 coax outside plant, while keeping MAC and higher layer devices in the center of the network,e.g., in the Headend or data center. One of the main advantages of RPHY architecture is the efficiency. By moving RF modulators closer to the customers, higher order modulations such as2K and 4K QAM can be used, therefore increasing the network efficiency. However, there are challenges for RPHY architecture. Besides the technical challenge of synchronizing RPHY and MAC, it also poses challenges on the backhaul network for RPHY. The communication protocol between RPHY and MAC is Ethernet at a rate of multiple Gigabit/s. To backhaul large amounts of high-speed Ethernet traffic in MSO’s access networks is a challenge.
Another deployment in the communication industry is coming 5G wireless network services.
Although most of the MSOs do not directly provide wireless services (not including Wi-Fi) to the end-customers today, many of them are contracted by wireless carriers to provide wireless backhaul and/or front haul services in their networks. The amount of data to backhaul 5G wireless is expected to increase greatly and pose a challenge to MSO’s metro and access networks.
RPHY and 5G backhauls are new to MSO; it poses big challenges to MSO’s access network.
To design a unified and converged access network to backhaul RPHY and 5G traffic and at the same time align with the MSO long term migration direction to passive all fiber access networks is an even bigger challenge.
In this paper, we first analyze MSO’s current access network architectures for DOCSIS andPON services, then discuss the options for RPHY and 5G wireless backhauls. We then propose two unified fiber access network architectures. One is based on DWDM and the other is based on PON, to backhaul RHPY and 5G wireless traffic.