Requirements for the Use of Butterfly-shaped Optical Cable Equipment

Butterfly-shaped optical cables are designed with a flat, compact profile, bend-resistant fibers, and reinforced strength members to meet FTTH and FTTB deployment requirements.Structural DesignButterfly-shaped optical cables feature a flat, butterfly-like profile with optical fibers centrally positioned and flanked by parallel strength members on both sides, typically made of FRP (Fiber Reinforced Plastic) or steel wire for tensile strength and compression resistance . This design reduces bending stress, prevents rolling or twisting during installation, and simplifies routing along walls, corners, and conduits . The flat geometry is particularly suitable for indoor, aerial, and last-mile network installations.Optical FiberThese cables generally use single-mode fibers, such as ITU-T G.657A1 or G.657A2, which are optimized for tight bend resistance and minimal signal loss in compact indoor environments . The fibers are engineered to maintain high bandwidth and low attenuation, ensuring reliable high-speed broadband performance.Jacket and Sheath MaterialsThe outer sheath is typically LSZH (Low Smoke Zero Halogen) for indoor safety, reducing toxic emissions in case of fire, or UV-resistant PE for outdoor and wall-mounted applications . These materials provide mechanical protection, fire safety, and environmental durability.Mechanical and Environmental PropertiesButterfly cables are designed to withstand tensile stress, compression, and environmental exposure. The combination of FRP and steel wire strength members ensures high tensile performance for self-supporting aerial installations and indoor pulling . The cables are also resistant to bending, crushing, and temperature variations, meeting the requirements of IEC 60794-1-1:2023 for optical fiber cables .Installation AdvantagesThe flat, lightweight, and compact design allows for easy stripping, splicing, and routing, reducing installation time and labor costs . They are suitable for duct, riser, direct surface, and short aerial spans, making them versatile for both FTTH and FTTB networks.Compliance and StandardsButterfly-shaped optical cables should comply with IEC 60794 series for mechanical and environmental performance, and ITU-T G.657 for bend-insensitive single-mode fibers . These standards ensure signal integrity, durability, and interoperability across different network deployments.Summary of Key RequirementsFiber Type: Single-mode, bend-insensitive (G.657A1/A2)Strength Members: FRP and/or steel wire for tensile and compression resistanceOuter Sheath: LSZH for indoor, UV-resistant PE for outdoorMechanical Properties: High tensile strength, bend resistance, crush resistanceEnvironmental Resistance: Temperature, UV, and fire safety complianceStandards Compliance: IEC 60794-1-1:2023, ITU-T G.657Installation: Flat profile for easy routing, splicing, and reduced labor These specifications ensure that butterfly-shaped optical cables provide durable, safe, and high-performance solutions for modern fiber access networks.