Optical Transmission in Data Communication (Part 2/2)
One major issue with copper wires is that any signals sent through them can be subjected to electromagnetic interference (EMI) or signal noise as it is called. The interference is because of a number of reasons. It could be because of the electrical motors or the power lines. It could also be due to interference from the adjacent electrical signal cables.
This is especially true for coaxial, twisted cable. Any noise, regardless of the source, degrades the signal in the electrical cable so much that the signal-to-noise-ratio (SNR) lowers the transmission range and could lead to spurious interference. This in turn results in a major increase in the number of errors in the data that is received.
Fiber optic cables are relatively immune to most sources of electromagnetic interference. They are not even affected by major electrical disruptions such as nuclear electromagnetic pulses (NMP) or lightning strikes. These cables are installed in systems that are surrounded by sources of high EMI, like around power lines or railway lines. That’s why fiber optical cables are used alongside the power distribution networks managed by utility companies.
Fiber optic cables are more secure and are not subject to interference from electromagnetic signal as they do not emit any electromagnetic energy. The light within fiber optic cables is very much controlled and the signals cannot be hacked. If there is any interference with the signals, it is quickly detected. This makes fiber optic cables perfect for transmission of ultra-sensitive data when security is a major concern.
Since fiber optic cables do not conduct electricity, they are much safer. They are immune to electromagnetic interference and are not affected by ground loops. Ground loops refer to the phenomenon wherein the ground potential differs to a certain extent between different buildings as well as between different parts of a building to an extent of a few volts. This is common with copper wires.
Ground loops can lead to an increase in stray currents and could lead to more electrical noise. When the currents are too high, this could cause a lot of damage to the electronic equipment leading to large scale failure and even the outbreak of fire. Fiber cables are not affected by electrical surges from power lines, which often happens when there is lightning. That is why these cables are much safer for use around high voltage equipments.
Moreover, you don’t have to worry about hazards such as sparking with fiber optic cables. Even low voltages could lead to small sparks in copper wires. Generally this should not be hazardous, but there are certain environments, such as in a petrochemical facility, where this can be dangerous, and could even result in explosions.
The best way to install cables for data communication is to run them through ventilation ducts. The installation of cables has to be in accordance with the strict fire codes and building regulations. They have to meet the strict fire safety standards. This is much easier to manage with fiber optic cables, which are of a much smaller size than with copper wires. Fiber optic cables don’t require as much fire-retardant material to be superimposed on them as with copper wires.
We have talked about the need to use fiber optic cables for data transmission, and more specifically, with regards to the advantages of the same in comparison with copper wires. Where you choose to utilise fiber optics or not depends on your system requirements. What this means is that if the data rate or range needed is much higher than what is possible with copper wires or electrical cables, then you will have little choice but to go with fiber optic cables.
Even if this is not the case, a number of other factors come into play, such as the cost-effectiveness and high performance delivered by fiber optics. This makes optical signaling as made possible by fiber optic fibers the best possible solution for most applications.