FTTH Custom Process for 850nm OPGW Fittings

Deploying FTTH over 850nm OPGW requires careful fibre handling, proper fitting selection, and adherence to installation standards to ensure minimal strain and optimal signal performance.

OPGW Cable and Fibre Considerations

OPGW cables combine optical fibres with metallic conductors for both communication and grounding purposes. For 850nm FTTH applications, multimode fibres are typically used, which are compatible with short-distance, high-bandwidth access networks. Prysmian's OPGW design uses loose-buffered fibres in Spiral Space® tubes, which prevent fibre strain during installation and allow high fibre counts in compact tubes . The cable may include aluminium-clad stainless steel strands for mechanical strength and corrosion resistance, which must be considered when selecting fittings .

Fittings and Accessories

Proper OPGW fittings are essential for anchoring, splicing, and branching. Fittings include:

• Galvanized steel clamps for tower attachment
• Branch joint closures with extension collars for multiple cable entries
• Splice trays for fibre ribbons and loose tubes
• Protective enclosures to prevent environmental damage and maintain fibre integrity These fittings must accommodate the mechanical properties of the OPGW cable, including sag, elongation, and lateral fibre positioning, to avoid fibre strain during aerial deployment .

Custom FTTH Integration Process

1. Planning and Design: Determine the fibre count, cable route, and tower attachment points. Ensure the 850nm fibre is compatible with the FTTH network's optical budget and distance requirements .
2. Cable Handling: Use reels and tension-controlled stringing equipment to prevent microbending or macrobending losses. Follow ITU-T L.151 guidelines for OPGW installation, including careful handling of reels and controlled tension during stringing .
3. Fitting Installation: Attach anchoring clamps and branch closures to towers or poles. Ensure the fibre tubes are not stressed and maintain the minimum bend radius specified by the manufacturer .
4. Splicing and Termination: Use fusion splicing or mechanical splicing within splice trays. For FTTH, terminate fibres at ONUs or ONTs depending on whether the deployment is FTTC, FTTB, or FTTH .
5. Testing and Verification: Perform OTDR and insertion loss tests to verify fibre integrity and signal performance. Ensure that all splices and terminations meet the required attenuation and bandwidth specifications for 850nm operation .
6. Documentation and Maintenance: Record cable routes, splice locations, and fitting types for future maintenance. Regular inspections are recommended to detect corrosion or mechanical stress on OPGW fittings .

Key Recommendations

• Maintain loose tube integrity to prevent fibre strain.
• Use fittings compatible with both aluminium and stainless steel strands.
• Ensure proper bend radius and sag management to avoid signal degradation.
• Follow ITU-T L.151 and manufacturer guidelines for installation and handling. By following these steps, FTTH deployment over 850nm OPGW can achieve high reliability, minimal signal loss, and long-term operational stability.