Fiberradio

Fiberradio is a telecommunications concept describing the use of optical fiber networks to transport radio-frequency signals and related control data to wireless infrastructure. By carrying both voice and data traffic and radio signals over a shared fiber medium, fiberradio supports centralized processing and extended reach between core networks and remote radio units, often within a cloud or software-defined radio framework.

Two main approaches are used: analog radio over fiber (RoF), where RF signals are modulated onto an optical carrier near the transmitter and converted back to RF at the receiver, and digital fronthaul, where digitized baseband samples are transmitted over fiber to centralized processing units. Digital fronthaul commonly employs CPRI or eCPRI protocols and may use wavelength-division multiplexing to carry multiple channels.

Fiberradio can increase spectral efficiency by centralizing processing, reduce RF equipment at remote sites, and enable higher bandwidth and longer reach for urban and rural deployments. It introduces challenges, including higher capital costs, RF impairments over long fiber links, dispersion and latency budgets, synchronization requirements, and the complexity of managing fiber fault domains.

Applications include 4G and 5G mobile networks, large venues, campus networks, and broadcast deployments where fiber backhaul is available. Standards and industry activity involve ITU-T recommendations for RoF and fronthaul, IEEE work on Ethernet-based fronthaul, and 3GPP specifications for CPRI/eCPRI interfaces.

See also: fronthaul, C-RAN, Radio over Fiber, fiber to the antenna.