China Unicom primarily uses passive optical splitters, including both Fused Biconical Taper (FBT) and Planar Lightwave Circuit (PLC) types, depending on network scale and application.

Types of Splitters

1. Fused Biconical Taper (FBT) Splitters FBT splitters are widely used in smaller-scale deployments, such as 1×2 or 1×4 configurations. They are made by fusing and tapering two or more fibers together, allowing control over the splitting ratio. FBT splitters are cost-effective and adjustable but are sensitive to wavelength and temperature variations, making them suitable for short-distance or low-port-count applications . 2. Planar Lightwave Circuit (PLC) Splitters PLC splitters are preferred for larger-scale networks, such as 1×16, 1×32, or 1×64 splits, commonly used in FTTH (Fiber-to-the-Home) and GPON deployments. They are fabricated using photolithography on silica substrates, providing uniform splitting ratios, low insertion loss, and high spectral uniformity. PLC splitters are compact, reliable, and less sensitive to environmental changes, making them ideal for carrier-grade networks like China Unicom's .

Deployment Considerations

• Split Ratios: China Unicom uses splitters with ratios ranging from 1:2 up to 1:64, depending on the number of subscribers served by a single fiber line .
• Interfaces: Splitters typically support SC, LC, FC connectors with UPC or APC polish types. APC connectors are preferred for long-distance transmission due to lower reflectance .
• Passive Operation: These splitters are passive devices, requiring no power, which enhances reliability and reduces maintenance costs .
• Durability: Carrier-grade splitters used by China Unicom are designed for high stability, low insertion loss, and resistance to environmental stress, ensuring consistent performance in residential and commercial deployments .

Summary

China Unicom's fiber optic network relies on both FBT and PLC splitters, with FBT used for smaller, simpler configurations and PLC for large-scale, high-port-count deployments. These splitters are passive, durable, and compatible with standard telecom interfaces, supporting efficient FTTH and GPON services across China .