Fiber to The Antenna FTTA

Dec 2, 2024

Fiber-to-the-antenna (FTTA) is a wireless site architecture where optical fiber is run all the way up the tower to replace much of what was traditionally completed with heavier coax cabling. Important components such as remote radio units (RRUs) are also positioned at the top of the tower instead of at the base location.

In a FTTA configuration case, a baseband unit (BBU) situated near the bottom of the tower is connected via a fiber optic antenna and runs to a remote radio head (RRH) positioned near the antennas at the top of the tower. The RRH converts the digital signals to analog, and the short span between RRH and antenna is still completed using traditional coax cabling.

FTTA: The Good and the Bad
The shift to FTTA obviously brings numerous benefits to consumers, operators, and technicians alike. However, as with most advancements in technology, there are some complications and challenges to work out.

Fiber-to-the-Antenna (FTTA) Advantages
Perhaps the most obvious advantage of fiber-to-the-antenna stems from the physical content of the cable itself. The smaller diameter and lighter weight allow many fiber optic cables to occupy the same amount of space as a single coax cable. Because cellular towers are naturally subject to the elements, the physical size and properties of optical cabling are much less susceptible to damage from gusts of wind.

Other advantages of fiber-to-the-antenna technology relate to the shift from analog to digital. Due to signal losses, coax cable limited the distance between the antenna and base station to as low as around 100 meters. Optical cabling can span up to 20 kilometers with minimal losses. This allows for central housing of base stations and other similar efficiencies in architecture.