microducts

Microducts are small-diameter protective conduits used to route fiber optic cables in telecommunications networks. They are a key component of microduct systems, which enable modular, scalable deployment of fiber, particularly for fiber-to-the-home (FTTH) and related architectures. A microduct network often consists of many individual microducts laid in parallel or bundled inside a larger duct.

Construction and materials

Microducts are typically made from durable polymers such as HDPE or PVC. They have a smooth inner bore to reduce friction and facilitate fiber blowing or pulling, and may include lubricious or low-friction inner coatings. The outer jacket protects against environmental factors and mechanical damage. Diameters are small, usually on the order of a few millimeters for a single microduct, with bundles or sub-ducts installed inside conventional conduits or trenches. Some designs incorporate color coding, flame retardants, or UV resistance for outdoor use.

Installation and operation

Microducts are installed in trenches, duct banks, building cavities, or along existing infrastructure. They are commonly installed using blowing techniques, where compressed air pushes fiber through the duct, enabling rapid installation with minimal friction. End fittings and connectors join microducts to form continuous pathways, while access points allow future fiber addition. The network is typically designed to accommodate staged fiber installation and upgrades without repeated excavation.

Applications and advantages

Microducts support FTTH deployments, urban and rural fiber access, and campus or building networks. They enable faster deployment, reduced disruption, and easier capacity upgrades by adding fibers later. By housing fibers in multiple individual conduits within a single route, microduct systems offer flexibility and scalability for evolving telecom networks.

Limitations and considerations

System performance depends on duct cleanliness, proper lubrication, and adherence to bending radii and installation tolerances. Blowing equipment and skilled installers are often required, and occasional maintenance is needed to prevent blockages and moisture ingress.