Analysis of China Unicom Optical Cable Structure

China Unicom optical cables feature a multi-layered design with doped silica fiber, polymer coatings, PBT bushings, water-resistant pastes, and mechanical stress-resistant structures optimized for high-speed transmission and harsh environments.

Cable Composition and Structure

China Unicom's optical cables are composed of several key layers and components designed to ensure durability and high transmission performance :

• Doped silica fiber glass layer: The core optical fiber, responsible for light transmission, is made of doped silica to optimize signal quality and reduce attenuation.
• Polymer mechanical buffer coating: Surrounds the fiber to protect against mechanical stress and microbending.
• PBT (polybutylene terephthalate) bushing: Provides structural support and maintains fiber alignment.
• Water-resistant fiber and cable pastes: Prevent moisture ingress, which can degrade optical performance.
• Mechanical stress-resistant structure: Includes strength members and protective layers to withstand tension, bending, and environmental stress.

Environmental Adaptability

China Unicom has conducted extensive research on cable performance in extreme climates, particularly in cold regions like Heihe, Heilongjiang Province . The cables are tested for:

• Temperature fluctuations: Withstanding -40°C in winter and up to 21°C in summer.
• Material compatibility: Ensuring that coatings, pastes, and structural components maintain integrity under large diurnal temperature differences.
• Long-term attenuation stability: Continuous monitoring using OTDR systems to track fiber performance over time.

Advanced Fiber Types

China Unicom has deployed G.654.E (LEAF) optical fibers, which feature a large effective area and ultra-low loss characteristics . These fibers are designed for:

• High-speed, long-haul transmission: Supporting single-wave 100G and beyond.
• Harsh environmental conditions: Tested across deserts, snow mountains, and expressway pipelines.
• Global standards compliance: Contributing to ITU-T G.654.E standard development.

Field Deployment and Monitoring

Cables are often installed on overhead pole lines or in pipelines, with real-time monitoring systems to track:

• Temperature and environmental impact: Sensors record fluctuations affecting the cable.
• Optical performance: OTDR modules and optical switches measure attenuation and signal integrity.
• Maintenance and reliability: Data is transmitted to China Unicom Network Research Institute for analysis, ensuring long-term operational stability .

Summary

China Unicom optical cables combine robust material selection, multi-layered mechanical design, and advanced fiber technology to achieve high transmission performance and reliability. Their structure is optimized for both standard and extreme environments, with continuous monitoring and testing ensuring long-term stability. The integration of LEAF fibers further enhances capacity and efficiency for modern high-speed networks .