Analysis of Fiber Optics
Fiber Optic Technology
In a world where people can search something up in Google (no matter if it’s a single word, phrase, or an entire sentence), once they press the “Enter” button, people can get their results back within seconds, in some cases even milliseconds. How is that possible? How is it possible for people to gain access to the web within seconds where web servers host the content of their website in California, and it doesn’t matter if the user is in New Jersey? To understand the process of requesting and accessing data from across the world, we must understand how fiber optic cabling works.
Fiber optic cables are made up of glass or plastic fibers and on top of the fibers is a glass layer called “cladding”, then on top of that layer is the jacket, which is made up of tough “Kevlar strength members.” This is done over copper cabling, which is a beneficial material since it is known to have a wide bandwidth(which bandwidth is responsible for how much data can transmit at one time), fast transmitting speed, and is one of the most abundant materials on Earth.
Fiber optics is a type of technology that can transmit data using light, in this particular case, pulsing light. Now the pulsating lights within these cables are used to transmit data representing one or zero. One being light on(or evaluating something to be true), and zero where there’s an absence of light(or evaluating something to be false). However, this is done at an intense speed where if we were to cut a cable up and transmit data through that cable, the observer will think the cable’s light is just staying on.
Another advantage that fiber optic cables have is traveling long distances. The distance can range from 2–100km. The way that light travels within these cables are reflected off the walls within the fibers. Since fiber optics are using light as a source for transmitting data, the light will eventually get weaker due to the distance it has traveled. However, there are carefully placed amplifiers in certain parts of the cables that will increase the light’s power to help it reach its destination. Below is how light travels within a cable. The image below that showcase different types of cables used and the max distance it can travel until it needs an amplifier.
This piece of technology is fascinating in the sense that this is entirely unseen (given the ubicomp nature part of it) because most of the fiber optic cables are underground. There are a few exceptions some are on telephone poles, but most of them are underground. Some of them are underwater as well. It is beneficial for scientists to use fiber optic cables to be submerged because they act as earthquake sensors. There are people whose sole job is to fix/monitor broken fiber optic cables underwater. Usually, damage to underwater cables is done by anchors, commercial fishing equipment, earthquakes, and hurricanes. The picture below showcases all existing cables in purple and all planned cables in blue.
Now, with this in mind, giving the amount of information on how fiber optic cabling works, this is why fiber optics are so common and so widely used. It is simply because of distance and speed. The only downside of using fiber optic cables is that they are pretty expensive. Even if they are expensive, they are very much reliable and effective in forming the internet that we know today. With those two advantages, it’s possible for every user within the network to quickly look up any sort of information, big or small, on the internet within a blink of an eye due to the fact we take advantage of using light energy as data to get to one place to another in the speed of light.
There is a niffy video on YouTube where an engineer explains how fiber optic technology works in general. The engineer goes into depth about how fiber optic works and what the cables are made of, he also goes into depth on how underwater fiber optic cables are made and the longest underwater cable goes from New Jersey to Europe. But the part of the video I want to emphasize is how fiber optic delivers the pre-arranged signal to be sent out to a destination, and this could be done through pulse code modulation.
How pulse modulation works is that fiber optic technology converts an analog signal into a digital signal by using discrete calculation. To make this discrete calculation, the signal needs to be represented in a wave of some sort. The image below showcases what pulse code modulation would look like. The lines that are lined up vertically are different sizes of “loudness.” These loudness come in 16 different sizes, each loudness will eventually form what look like a wave, down below is an example of a sine wave. Now each loudness is encoded using 4 bits. Meaning each loudness is represented by a variation of four digits being either a one or a zero. Now, remember that a one means that the light is on and zero means that the light is off. Well, the image right below the sine wave represents a cable sending out a sine wave-like signal in a form of light on and off, or in this case ones and zeros.
Video: https://www.youtube.com/watch?v=0MwMkBET_5I
Getting back to the story of where the user uses google to search up the phrase and gets millions of results back within seconds. Let’s imagine that a user wants to get search results for “cute cat videos.” The user will type out that particular phrase on the front end and then the search query data will be sent in radio waves from the user’s laptop to the wireless access point within the building or to their modem if they are in the comfort of their own home. Then the access point is connected to a wired network, those wires are most likely fiber optic, or they will eventually be transmitted via fiber optic. So the search query will then be sent via wires to the private network’s internet service provider, and then the service provider will then route the traffic to the correct web server location. A good portion of Google’s web servers are in California, so let’s say the search query will need to reach California, the search query then reach the web servers then the web servers will provide the given result from Google’s database that involves cat videos. The result from the database will then route all the way back to the user who made the search query by going through wires to the internet service provider and then back to the user with cute cat videos. Going back and forth all takes one second because fiber optic cables are traveling at the speed of light, the fastest known speed known to mankind.
Fiber optic cables have the ability to transfer data fast and over long distances, this is great in terms of convenience especially since everybody is on the internet nowadays. Fiber optics have a wide bandwidth that could take in around 40,000 calls at one time. All of this is happening right under our feet where users do not have to think or wonder where it is coming from because it is that effective and nobody notices fiber optic cables taking in thousands of data per second. This powerful yet somewhat simple technology makes it possible for people to create this useful and complicated network known as the internet.
