HybridFiberCoaxArchitektur

Hybrid fiber-coaxial networks, commonly abbreviated as HFC, are broadband access networks that combine fiber optic backhaul with coaxial cable for the last mile. The central office or headend connects to a fiber distribution network that carries traffic to a street-level node. From the node, coaxial cable extends to individual premises, enabling shared bandwidth among connected homes or businesses.

Key components include the optical fiber backbone, fiber distribution nodes, coaxial distribution cables, line amplifiers, and customer premises equipment such as modems and set-top devices. The DOCSIS standard governs data transmission over coax, with DOCSIS 3.x enabling higher data rates and channel bonding to increase throughput. Operators have progressively pushed fiber deeper into the network to reduce coax length and improve overall performance.

History and evolution: HFC emerged in the 1990s as cable operators sought to upgrade data services while leveraging existing coaxial infrastructure. Advances in DOCSIS technology, notably DOCSIS 3.0 and 3.1, increased downstream and upstream speeds beyond 1 Gbps and supported richer modulation schemes and wider channel bonding. Some deployments also incorporate fiber to the node or closer to the customer, in combination with newer DOCSIS standards, to further expand capacity.

Performance and deployment considerations: HFC provides substantial bandwidth at a relatively lower cost compared with all-fiber alternatives, but it uses a shared medium, so peak speeds can vary with the number of users on a given segment. Network design, split ratios, amplifier placement, and signal conditioning influence performance. Ongoing upgrades focus on reducing coax distances, upgrading DOCSIS capabilities, and deploying deeper fiber to meet rising demand for high-speed services.