Indoor Single-Mode Optical Cable Code

Indoor single-mode optical cables are typically designated as OS1 or OS2 and use a yellow outer jacket for easy identification, following TIA-598 color coding standards.

Fiber Type Designation

Indoor single-mode fibers are classified as OS1 or OS2:

• OS1: Optimized for indoor use with a maximum attenuation of 0.4 dB/km at 1310 nm, suitable for distances up to 10 km at 10 Gbps .
• OS2: Optimized for longer distances with a maximum attenuation of 0.3 dB/km at 1550 nm, capable of transmitting up to 40 km at 10 Gbps . Both types have a single-mode core of approximately 9 microns, allowing only one light mode to propagate, which reduces modal dispersion and supports long-distance communication .

Jacket Color Coding

According to the TIA-598 standard, indoor single-mode cables use a yellow outer jacket to distinguish them from multimode fibers, which typically use orange (OM1/OM2) or aqua (OM3/OM4) jackets . This color coding ensures quick visual identification and prevents accidental mixing of fiber types during installation.

Internal Fiber Strand Color Sequence

For multi-fiber indoor cables, each individual fiber is color-coded following a 12-color sequence for identification:

1. Blue
2. Orange
3. Green
4. Brown
5. Slate
6. White
7. Red
8. Black
9. Yellow
10. Violet
11. Rose
12. Aqua This sequence repeats with stripes for higher fiber counts, allowing technicians to identify up to 144 fibers in a single cable assembly .

Connector and Boot Color Codes

Connectors for single-mode fibers often follow color conventions:

• APC (Angled Physical Contact): Green boot, reduces back reflection (<–60 dB)
• UPC (Ultra Physical Contact): Blue boot, standard single-mode connections These color codes maintain consistency across the cable, connector, and boot, simplifying installation and maintenance .

Summary

• Cable Type: Indoor single-mode
• Designation: OS1 or OS2
• Outer Jacket Color: Yellow
• Internal Fiber Colors: Standard 12-color sequence
• Connector Boots: Blue (UPC) or Green (APC)
• Standard: TIA-598-D for color coding and identification Following these codes ensures proper identification, reduces installation errors, and supports efficient maintenance in indoor network environments.