Fiber optic cables in FTTH networks are mainly classified into three categories based on their deployment location and function:
Feeder Cables: Connecting the operator's central office (OLT) to the optical distribution point (such as an optical distribution box) in the community or street, undertaking backbone transmission tasks. They typically use high-core-count, high-tensile-strength outdoor optical cables to ensure long-distance, high-reliability signal transmission.
Distribution Cables: Extending from the optical distribution point to the fiber optic distribution box (such as a fiber distribution box) in the building or unit, responsible for distributing the optical fibers from the backbone cable to multiple users. This type of cable needs to support frequent branching and splicing, and often uses skeletonized ribbon fiber optic cables or loose-tube cables to improve construction efficiency and space utilization.
Drop Cables: Laid directly from the distribution box to the user's home, connecting the optical network terminal (ONT, commonly known as a "optical modem"). This is the "last mile" of FTTH, typically using butterfly drop cables or indoor flexible optical cables. These cables are flexible, bendable, tensile-resistant, and flame-retardant, facilitating flexible cabling in confined spaces such as corners, conduits, and cable trays. They also often utilize bend-insensitive G.657 fiber, ensuring low loss even with small-radius bends (e.g., ≤15mm).