Fibre Optic Cabling

Fibre optic cabling is typically deployed where distances or bit rates greater than those provided by copper cabling are required – campus and building backbones usually include fibre. Costs for fibre optic cabling are typically not much greater than those for copper, but the cost of interfaces are still higher. Fibre optic cabling also offers the advantage of being immune from electromagnetic interference (EMI).

Cables and connectors

There is a range fibre optic media types, including plastic optical fibre (POF). The most commonly deployed types in premises cabling systems are:

• Multimode 50/125 µm OM3 – supporting 10GBASE-SR up to 300 m
• Singlemode 9/125 µm – supporting 10GBASE-LR up to 10 km

Driven predominantly by physical environment, the choice of construction will vary:

• Internal/external tight buffered – suitable for the majority of premises
• Loose tube construction – preferred for harsh physical environments
• Blown fibre – allows the contents to be added to or changed

Individual fibres are terminated using connectors (with adapters/couplers) or jacks:

• SC – typically used with keyed duplex adapters and cords
• LC – similar to SC but smaller, allowing higher densities
• MT-RJ – another small form factor design, with jack form too
• ST – a non-duplex legacy connector still in widespread use