Rosemary McGlashon of 3M puts the case for fibre, as opposed to copper infrastructure, in the mission critical data centre

Structured cabling can make all the difference to the quality of communications and in turn, inadequate cabling systems can lead to poor network performance or even loss of service, creating unnecessary disruptions to business operations. In the data centre, where connectivity is often cited as being 'mission critical', this is too important an issue to overlook.
Yet some network managers are still choosing the seemingly cheaper route of copper cabling at the risk of sacrificing a whole host of other benefits. Copper is a cost-effective choice in 'to the desk' applications, but fibre is the main contender for supporting high speed data centres.

The Power Argument
There is also a strong argument that when looking at the total lifetime cost of a structured cabling system, the difference between the two materials is rapidly diminishing, particularly with the rise in raw copper prices. Fibre also consumes less power. Estimates indicate that while fibre takes up just 1-5 watts per port, copper can be 10 -15 watts. Considering that many data centres are already stretched in terms of power, this is a serious consideration. Furthermore, when higher speeds are being used, copper requires cooling - estimates show that less than 10 per cent of power typically used in data centres are used to transmit actual data. The rest is used for air conditioning, cooling, lighting, powering the equipment, security systems, and
so on.

Reaching beyond limits
However, while short term cost is understandably high on the network manager's wish list, it is not the only consideration. The past few years have shown that data speeds within enterprises continue to escalate. While copper may still have some room for development in terms of data support, its capabilities are finite. The potential for fibre, on the other hand, is beyond our imaginations. Certainly, fibre optic cabling should be able to support the data speeds we will see for the next decade.
Take the 10 GB Ethernet standard, for example. It has pushed copper development to its limit and places considerable pressure on installers, who have to ensure far greater accuracy and more careful handling than ever before.
While fibre traditionally requires more skill and training to install, it is arguably now not much more difficult to work with than copper. In addition, the advent of new products that simplify the installation process has brought fibre within the range of many more communications engineers.
Pre-terminated products reduce room for error, while 'No Polish Connectors' remove the need to polish fibre ends on site, an area where costly mistakes can be made, as incorrect curvature of the cable end, effects the quality of the connection.

Other reasons to back fibre
There are yet more arguments in favour of fibre. Unlike copper, it is resistant to electrical magnetic interference (EMI) and extremely difficult to hack. It can also be safely used in hazardous areas where a spark could trigger an explosion. And fibre can be run for much longer distances than copper - up to 300 metres for multimode fibre for 10Gbit/s Ethernet and up to 5km for single-mode fibre - against the 100 metres maximum for copper lines.
The 'green IT' trend is another issue. Copper needs to be mined and although fibre cannot be recycled, its extremely long lifespan has to be taken into consideration. Typically, copper is also seven times heavier and needs five times more space than fibre, so it is more expensive to ship and harder to install in space-constrained environments.
Copper may still be king as far as desktop communications are concerned, but for any company serious about its data centre, then fibre optic structured cabling is the definitely the way to go. NC