What different levels of Internal Fibre Cables can be installed?
Internal fibre optic cables come in various types and performance levels depending on the installation environment, required bandwidth, and durability needs. Here are the main levels or categories of internal fibre optic cables commonly installed in buildings or campus networks:
Use: Ideal for indoor applications like risers, horizontal cabling, and patch cords.
Features: Each fibre is individually buffered with a 900μm coating, offering durability and easy termination.
Variants:
Simplex/Duplex: One or two fibres, used for patch cords.
Distribution Cable: Multiple tight-buffered fibres under one jacket.
Riser-rated (OFNR) and Plenum-rated (OFNP) options for fire code compliance.
Use: More common in outdoor or mixed-use (indoor/outdoor) environments but can be used indoors with proper fire rating.
Features: Fibres are in a gel-filled or dry water-blocked tube; better for harsh environments.
Indoor-Outdoor Variant: With fire-resistant jackets for transitioning from outside to inside.
Use: Suitable for environments where cables need to be broken out directly to equipment.
Features: Each fibre has its own jacket and strength member—essentially multiple simplex cables bundled together.
Advantage: Easy to fan out and terminate, strong and rugged.
Use: Areas where physical protection is important, like data centers or industrial settings.
Features: Extra steel or aluminum armor between the cable jacket and the fibre.
Benefit: Protects against rodent damage and crushing.
Use: Required by building codes in risers, plenums, and fire escape routes.
Types:
OFNR (Optical Fibre Nonconductive Riser): Vertical shafts.
OFNP (Optical Fibre Nonconductive Plenum): Air handling spaces.
LSZH (Low Smoke Zero Halogen): Emits less toxic gas in a fire.
Use: Modern buildings with space constraints.
Features: Very small diameter, high fibre count (e.g., 144 or 288 fibres).
Installed in: Conduits or ducts, often blown in using air pressure.
Use: Plug-and-play applications where time and termination skill are limited.
Features: Factory-terminated and tested cables.
Applications: Data centers, modular office builds.
Here’s a comparison chart of the main internal fibre optic cable types, showing their typical applications, strengths, and limitations:
| Type | Structure | Use Case | Strengths | Limitations | Fire Rating Options |
|---|---|---|---|---|---|
| Tight Buffered | 900μm buffer | Horizontal/riser cabling, patch cords | Easy termination, good for indoor use | Not suitable for outdoor environments | OFNR, OFNP, LSZH |
| Loose Tube | Gel/dry-filled tubes | Indoor/outdoor transitions | Moisture protection, supports high fibre counts | Harder to terminate, not ideal for indoor-only use | Indoor/Outdoor jacket (OFNR/OFNP available) |
| Breakout | Multiple simplex units | Direct equipment connections | Rugged, easy to fan out and terminate individually | Larger and more expensive than distribution cable | OFNR, OFNP |
| Armoured | Steel/aluminum layer | Industrial or high-risk areas | Crush and rodent resistant | Stiffer, heavier, harder to handle in tight spaces | OFNR, OFNP, LSZH |
| Fire-Rated (OFNR/OFNP) | Jacket rating | Vertical shafts, plenums | Code-compliant, fire safe | Must select proper rating for building codes | OFNR (Riser), OFNP (Plenum) |
| LSZH | Low smoke jacket | Safety-critical buildings | Low smoke/toxicity in fire, good for public areas | Can be less flexible or durable in some versions | LSZH |
| High-Density/Microduct | Small form factor | Conduit-based installs | Very space-efficient, supports high fibre count | Needs special installation (e.g., air-blown) | LSZH, OFNR |
| Pre-Terminated | Factory-fitted connectors | Plug-and-play, fast deployment | Saves time, no termination skills needed | Costlier upfront, fixed lengths can reduce flexibility | Varies by jacket |