fibercoaxial

Fibercoaxial, often written as fiber-coaxial or hybrid fiber-coaxial, refers to a network architecture that combines optical fiber for the main backbone and feeder links with coaxial copper cable for the final reach to subscribers. This approach preserves the high bandwidth capability of fiber while leveraging the extensive existing coaxial plant for the last mile.

Most deployments use fiber from the service provider’s central office or headend to street-side nodes. At each node, an optical network unit/terminal converts the optical signal to a format carried over coax to customer premises. The coax portion uses copper distribution networks, along with amplifiers, taps, and splitters, to reach multiple homes. Data transmission over coax is standardized by DOCSIS, with DOCSIS 3.0 and 3.1 enabling multi-gigabit services in modern networks. Network management often involves a cable modem termination system (CMTS) at the headend to direct traffic.

Applications include broadband Internet access, digital cable television, and voice services, typically delivered as a bundled offering. The architecture allows faster deployment and lower up-front costs than fiber-to-the-home by utilizing existing coaxial infrastructure. However, bandwidth is shared among users on a given segment, and coax reach and signal quality can become limiting factors as demand grows. Upgrades usually involve adding more fiber depth into the network or employing higher-capacity coax components and advanced modulation techniques.

Hybrid fiber-coax networks are common in legacy cable systems and remain a widespread choice for metropolitan broadband, balancing fiber’s capacity with the practicality of existing coaxial networks.