Flat shape of optical cable

Flat structure optical cables are fiber optic drop cables with a flat profile, reinforced for tensile and compression resistance, optimized for FTTH and last-mile deployments.

Overview

Flat structure optical cables, often used in Fiber to the Home (FTTH) networks, feature a flat, compact design that allows easy routing in ducts, conduits, or direct burial installations. The optical fibers are typically placed in the center of the cable, flanked by two parallel strength members made of FRP (Fiber Reinforced Plastic) or steel, providing tensile strength and compression resistance. The outer jacket is usually LSZH (Low Smoke Zero Halogen) or PE, ensuring fire safety and environmental protection for indoor and outdoor use ( ).

Construction

Key components of a flat optical cable include: Optical Fibers: 1–12 single-mode fibers (G. 652. D or G.

657. A1/A2) for high-speed data transmission and bend-insensitive performance ( ). Strength Members: FRP rods or steel wires symmetrically placed to support tensile loads and prevent fiber damage during installation ( ).

Tone Wire (Optional): Copper or copper-clad steel wire embedded for traceability in underground installations ( ). Outer Jacket: UV-resistant, flame-retardant LSZH or PE for durability and environmental protection ( ). Water Blocking: Optional gel or dry water-blocking yarns to prevent moisture ingress in outdoor deployments ( ).

Advantages

Compact and Flexible: Flat profile allows easy routing in tight spaces and conduits ( ). High Fiber Protection: Reinforcements prevent crushing and tensile damage ( ).

Bend-

Insensitive: Supports tight indoor bends without signal loss, especially with G. 657 fibers ( ). Traceable: Toneable variants simplify locating and maintenance in buried installations ( ).

Cost-

Efficient: Reduces installation labor and material costs compared to round or loose-tube cables ( ). ApplicationsFTTH Deployments: Connecting optical distribution points to subscriber premises ( ).

Indoor/

Outdoor Transitions: Suitable for multi-dwelling units (MDUs), office buildings, and residential areas ( ). Aerial or Buried Installations: Self-supporting or direct burial options available ( ). Rural Broadband Projects: Reliable for long-span aerial drops and underground networks ( ).

Installation Considerations

Bend Radius: Maintain minimum bend radius to prevent signal loss, especially for G. 657 fibers ( ). Splicing vs.

Connectorization: Fusion splicing offers low loss and permanent connections, while pre-terminated connectors provide flexibility for testing and reconfiguration ( ). Environmental Protection: Use conduit or wall sleeves for building entry points and ensure proper sealing for outdoor deployments ( ).

Summary

Flat structure optical cables are a robust, flexible, and cost-effective solution for last-mile fiber deployments. Their flat design, reinforced strength members, and optional tone wire make them ideal for FTTH, indoor/outdoor transitions, and traceable underground installations, ensuring high performance, durability, and ease of maintenance ( ).