Fibre vs. Copper

First of all, it is necessary to point out that optical fibre and copper are difficult to compare, as each one has its advantages and disadvantages. But if we had to highlight a difference on cost level, we find that the copper links and connections are much more economical than the optical fibre ones. However, if we consider yield, fibre is much more profitable than copper.

In addition, the growing demand for bandwidth in the utilities that we currently need, gives a clear advantage to optical fibre over copper cabling, also considering the long-term proposal which favours optical fibre as the best option for the future of telecommunications over short and long distances.

Below we provide 5 reasons for determining why optical fibre cabling is a better choice than copper cabling. These are as follows: bandwidth, distance and transmission speed, reliability, security and, of course, the cost.

BANDWIDTH

Although copper is perfectly suitable for a voice signal, it has a very limited bandwidth. On the other hand, fibre can provide a standardised performance of more than 10 Gbps. This means that the fibre links provide a bandwidth that is 1000 times greater than copper and over distances 100 times longer.

For example, a standard application of bandwidth distance for multi-mode fibre is 500 MHz/km, and so a 500 m cable can transmit 1 GHz. On the other hand, a copper braid optimised for high data speeds (Cat 6) can transmit 500 MHz in just 100 m. Also, it has greater signal losses (attenuation) in high frequencies, something which is insignificant over 500 m of fibre.

DISTANCE AND SPEED

Optical fibre transmits light, copper electrical current. There is no comparison between the speed of photons as opposed to the speed of electrons. The electrons used in copper travel at less than 1% of the speed of light and, although the optical fibre cables do not reach the speed of light (due to the refraction index of the medium), they are only 30% slower. This shows that there is a huge inherent speed difference between fibre and copper.

Also, while there is a distance limit of 100 m with copper braiding, there is no such limitation with fibre. Therefore, the distance may vary from 550 m for 10 Gbps multi-mode, to 40 km in a single mode fibre cable.

RELIABILITY

The optical fibre cable is much less susceptible to environmental influences than the copper cable. For example, copper degrades its transmission quality over a 2 km section while, over the same distance, an optical fibre cable maintains highly reliable transmission.  Moreover, fibre is also less sensitive to environmental factors such as temperature and electromagnetic inference, and this means fibre cabling can be laid in industrial environments where there is a high generation of electrical noise, without any problem. Sometimes, optical fibres are installed in the construction of average and high voltage conductors on overhead lines or on intercontinental underwater cables.

SECURITY

Optical fibre is totally dielectric, and so does not transmit electricity or cause radiation which can damage people or equipment. However, copper can be susceptible to being tapped, which can make the whole system fail. A broken optical fibre can be detected very quickly using the equipment needed to detect it; including certifying the transmission status at all times. For its part, the copper cable that carries a current can be cut completely or even cause a fire if it is deteriorated, old or used without applying efficient testing techniques.

COST

Although it is true that the price of the optical fibre cable was almost double the cost of the copper cable, now the difference is considerably lower, and the fibre components and everything related to handling and installing them have reduced over time.

Generally, the transmission of electrical energy over copper is more economical that the transmission of laser energy using fibre. However, this is changing thanks to the high bandwidth demand for current applications. Most users ignore the cost of all the elements needed for correctly laying copper cabling, yet this must not be overlooked. We must remember that a standard cabling cabinet includes the costs of UPS energy (Uninterrupted Power Supply), data floor, HAVC (Hybrid Automatic Voltage Control) and space occupation of the large amount of cabling needed in floors and false ceilings.

These comprehensive costs are generally more than the additional cost of the fibre equipment in a centralised fibre architecture, in the same way that they occupy considerably more working space than fibre. Therefore, a fibre LAN (Local Access Network) is really more economical and efficient in this space than a network environment based on copper for new constructions and significant renovations.

CONCLUSIONS

The arrival of the optical cable means we can transport greater bandwidth at high speed, over a longer transmission distance, with excellent reliability, great security and at an increasingly reduced cost. It has satisfactorily managed to replace the copper cabling in telecommunication and data transmission environments in any kind of network. The popularity of optical fibre has been increasing recently because of the mobility restrictions caused by COVID-19, both on a local and worldwide level, as it has facilitated online working, videoconferences, virtual communication and has provided new forms of management, entertainment and leisure; both in a professional and home environment. 

The laying down of FTTx networks has allowed users a great bandwidth service in any device both on a private and collective level and, also, at very competitive prices.

The reduction in costs, both in laying down techniques and in working this type of networks, makes optical fibre the transmission medium for the present and future of telecommunications in the short, medium and long term.