Fibre cables or copper cables? That is the question

This article originally appeared in the May '22 magazine issue of Electronic Specifier Design – see ES's Magazine Archives for more featured publications.

Both cable types transmit data, but in very different ways. Copper carries electrical pulses along its metal strands. Fibre optics, on the other hand, carry pulses of light along flexible glass threads. This difference often equates to fibre being the best solution for a new or upgraded network, and therefore being worth the heavier upfront investment.

Five reasons to choose fibre optic cables 

Fibre optic transmission is faster

The standard way to measure data transmission rates is via bandwidth. These days, it is measured in gigabits of data per second (Gbps), or even terabits per second (Tbps). When you are building a network that requires long distances, high speeds, and/or heavy bandwidth connections, there is no question: fibre optic cables win the day. But copper cables may still be the best option in certain situations. It’s important to understand the differences between the two, as Chris Whitehead, Business Continuity Product Manager, SolutionsPT explains. Fibre cables or copper cables? That is the question Copper-based transmissions currently max out at 40Gbps, whereas fibre optics can carry data at close to the speed of light. In fact, the bandwidth limits imposed on fibre are primarily theoretical, but have been tested to be measurable in hundreds of terabits per second.

Fibre optic transmission can cover greater distances

Both copper and fibre-based signalling suffers from attenuation, or a weakening of the waveform signal over distance. However, fibre optic cables can transmit data over much longer distances.

Fibre optic cables are impervious to electromagnetic interference (EMI)

By its very nature, the electrical signalling in a copper network connection generates a field of interference around the cables. When you have multiple cables running near one another this interference can bleed into the nearby cables, hindering the desired messaging. This is referred to as crosstalk, and can force expensive retransmission of the message, or even pose security risks. The light transmission in fibre optics does not generate any EMI, so fibre is more secure, and requires less retransmission, ultimately leading toward a stronger ROI.

Save space and enhance cable management

Fibre optic strands are extremely narrow. In fact, they’re measured in microns, or millionths of a metre. The most common fibre optic strand is the same diameter as a human hair. Yet as we’ve seen, they can transmit incredible amounts of data, at much higher speeds, over much longer distances than their less narrow copper counterpart. Fibre optic cables do require protective sheathing, which ‘fattens’ them up to at least two millimetres in width. A single standard category 6 copper cable is roughly four times that width, and carries a fraction of the data. When you use fibre, it takes up much less space and is more flexible (and therefore easier to manage).

Fibre optics are future-proof

Every year the amount of data we consume increases, as do bandwidth requirements. Investing in a modern fibre optic cabling infrastructure will allow your network to operate at future speeds without replacing the cabling. A solid multifibre backbone in a structured environment will last for years, if not decades, and likely will continue to support increasing bandwidth needs. The average lifespan of a copper category specification, on the other hand, is a little over five years. Also bear in mind that the technologies and equipment that use cabling (switches, signalling optics, servers, etc.) generally tend to decrease OPTRONICS: CABLES in cost as time goes by. It is therefore probable that higher-end connectivity will become even more affordable in the future.

Fibre cables are not a silver bullet solution. It is more expensive than copper, and so should be used in the appropriate places. It’s often best suited when interconnecting equipment, in between buildings, or other sites. Copper’s lower cost makes it better suited for smaller-need applications, like desktops and appliances. Smaller networks, wiring cabinets, and lower priority traffic all make for good copper applications. Also consider that there may be significant copper already in place for some of these instances, further reducing overall cost.

The right medium for your network really depends on needs. However, if you have significant bandwidth needs, investing in a robust, scalable infrastructure will pay for itself. Fibre optic cabling allows for greater ROI given its faster speeds, increased durability, and smaller physical footprint. Copper cables also have their specific applications, and will help reduce upfront cost. A combination approach, with an eye toward future growth will suit you well.