Cat6 or Cat6A? Choosing Copper Cabling for a Singapore Office

Most office cabling quotations in Singapore now offer a choice between Cat6 and Cat6A, and the price gap between them is real. The question is not which cable is better. Cat6A is better, on paper, in every way that can be measured. The question is whether the building will ever use what you are paying for, and whether the cable will physically fit where it has to go.

What is the difference between Cat6 and Cat6A?

The 100 metres is the channel: up to 90 metres of fixed cable from the patch panel to the outlet, plus patch cords at both ends. That limit is the same for both categories. What changes is the speed the channel can be certified to carry over that distance.

When is Cat6A worth the extra cost?

Cat6A earns its cost where a link is likely to need more than 1 Gb/s during the life of the cabling, which in an office is usually ten years or more.

• Wireless access points. Current access points can use more than 1 Gb/s, and many ship with multi-gigabit ports. They are also mounted in ceilings, where re-cabling later is disruptive. Cabling access point locations in 6A is the most common and most defensible use of it.
• Long horizontal runs. If outlets sit near the 90-metre limit, Cat6 has no headroom for 10 Gb/s at all.
• Power over Ethernet. Cameras, access points, door controllers and some lighting take power over the same cable. Large bundles carrying power run warm, and higher categories tolerate that better.
• Floors that will be re-let or re-planned. If the tenant or the layout is likely to change, the cabling is more valuable when it does not limit the next occupant.

For ordinary desk outlets in a modest office, Cat6 still carries everything a desktop needs, and many buildings mix the two: 6A to the ceiling for wireless and cameras, Cat6 to the desks.

What does Cat6A do to the containment?

This is the part that is missed. Cat6A cable is larger in diameter than Cat6, so the same number of cables needs more room. A tray, trunking run or conduit sized for Cat6 can be full, or over its fill limit, with the same count of 6A.

It is also stiffer, so bends at corners, risers and drops need more radius, and patch panels and cabinets need more space for cable management behind them. If you change from Cat6 to Cat6A after the containment is designed, the containment has to be checked again. The containment choices themselves are covered in cable tray, trunking or conduit.

Shielded or unshielded?

Both Cat6 and Cat6A come unshielded (U/UTP) and shielded (F/UTP and similar). Shielded cable gives more protection where cabling runs near heavy electrical equipment, but it only works if the shield is bonded and earthed correctly from end to end. A shielded system installed badly can perform worse than an unshielded one installed well. For a typical office, unshielded Cat6A is common; plant rooms, factories and sites with heavy machinery are where shielding is more often specified.

What about Cat7 and Cat8?

Cat7 is not a category in the TIA standards used for most Singapore commercial work. It sits in the ISO system, and its full performance relies on connectors other than the standard RJ45 that every device uses. Cat8 is designed for very short links inside data centres, around 30 metres, not for office floors.

For an office, the step beyond Cat6A is not a higher copper category. It is fibre: between floors, between the comms room and the riser, and anywhere a run passes 90 metres. Where that line falls is covered in where copper stops and fibre starts.

How do you know the cable you paid for performs?

Only by testing. A Cat6A cable terminated with Cat6 connectors, or bent too tightly, or untwisted too far at the termination, is not a Cat6A link, whatever is printed on the jacket. Every outlet should be tested with a cable certifier to the permanent link limits of the category specified, under ANSI/TIA-568 or ISO/IEC 11801, and the results handed over in the certifier's own output.

Put three things in the specification before award:

1. The category, per outlet type, not just "Cat6 or better"
2. The standard and test limit, so there is no argument about what a pass means
3. The handover: certifier results for every outlet, the labelling schedule and an as-built drawing

Where it fits in the fit-out

The category is one decision among several that have to be settled before the ceiling closes, set out in what to settle before the ceiling closes. It also changes the price, so it is one of the lines to compare when you compare structured cabling quotations. And if cameras and door access are part of the job, their cabling has its own requirements, covered in CCTV and door access cabling for offices.

Where Fiber Tech sits

Fiber Tech Solutions Pte Ltd designs, installs and certifies copper and fibre structured cabling across Singapore, from single office floors to a corporate office with 4,000 data points and 2,000 fibre points for a major shipyard group. Copper links are certified to Category 6 or 6A, as specified, under ANSI/TIA-568 or ISO/IEC 11801, and the containment is designed and installed as part of the same package. The company holds IMDA Wiring Contractor (Class) Licence No. IW105464 and has been a Singapore specialist contractor since 2007. To discuss an office or a move, get in touch.

— Written by the team at Fiber Tech Solutions Pte Ltd, IMDA-licensed wiring contractor and FOA-certified fibre specialists, Singapore.