When it comes to network communication cables, fiber optic and copper cables are pretty much the only options. Today we focus on how they differ. Let's start with the main features of old reliable copper telephone lines - the same basic infrastructure we've been using since the early 1900s.

copper cable

Copper is highly conductive. That's why it's perfect for bringing power home. Copper wire uses the movement of electrons to transmit signals by modulating the waveform at one end and then demodulating it at the other. And converts the patterns in the waveform into an analog or digital signal.

Devices that are modulated and demodulated are called modems. The problem with copper cables is that even higher bandwidth coaxial cables can only transmit a small number of waveforms. This limits their maximum data capacity. In addition, these waveforms degrade quickly as the distance between devices increases.

In fact, copper has only two main advantages. One is that copper cable is much cheaper per unit distance than fiber optics. Second, copper cable infrastructure has been widely deployed due to the advent of telephones and television.

optical fiber

Corning's invention of fiber-optic cables in the 1970s revolutionized the game, allowing the use of pulses of light to transmit signals instead of waves traveling through metal. Today, cables are made of highly transparent flexible glass cores wrapped in multiple layers.

These layers protect the integrity of the signal as well as the structure of the glass. Since this is light passing through an almost transparent medium, it moves at a speed of about 200,000 km/s. It is actually no different from an electrical signal transmitted through copper.

The advantages of optical fiber

Easy to interpret the "light on and light off" signal at either end, maintaining signal integrity; although the switching speed is higher and the distance is longer. We are talking thousands of kilometers, like crossing the ocean. This gives fiber optic cables a huge advantage in speed and distance.

Optical signals are protected from electromagnetic interference. Therefore, single fibers can be bundled together during installation.

Upon request, optical fibers can be used with LEDs or lasers.

A single fiber can simultaneously transmit multiple wavelengths or colors of light. Then separate them at the other end to further increase capacity.

Is there no downside to fiber optic cables?

Everything sounds perfect, right? Why not just use fiber optic cables for everything? Well, life is rarely that simple. And we're moving in that direction. But right now, fiber optics are much more expensive per unit length than copper. The good news is that copper comes with some additional hidden costs, which further increases the appeal of fiber optics.

Additionally, copper cables are thicker and heavier. As a result, they are more difficult to install and may require larger clearances than existing underground conduits. When multiple connections can leverage a single backbone network, the cost per unit of capacity comes into play.

Even if two fibres cost a thousand times as much as copper, carrying more than a thousand times the amount of data, the cost per customer will be lower. Reduced costs for internet service providers (ISPs). Distance comes into play again, too. ISPs can save on repeaters needed to maintain signal integrity on copper wires.

Hybrid deployments using both fiber and copper cables are very common. This works in conjunction with fiber backbones serving many customers and copper cables for the last-mile runs to individuals. They offer stable speeds and reliability while saving significant costs for ISPs managing the infrastructure. No matter how long it takes, the inevitable outcome seems to be that fiber cables will replace copper cables—don't you think?