The internet is the backbone of the modern world and rides on a variety of transmission media. These transmission media actually have some very key differences and capabilities, however. If you’ve been curious about the nature of how an internet signal is sent to and from your home, then you’re in luck.
Transmission media comes in four major varieties, at least in common use. Four are most common for typical usage for receiving external signals. The third is more commonly seen in internal wiring. Each of these transmission media has its own specifications and standards behind them, as well.
So, let’s take a closer look at what actually drives the internet. Without these transmission media, you wouldn’t be able to read this guide. This is more of a broad overview of transmission media, but there will be greater detail where needed.
Transmission Media Overview
Transmission media refers to the means by which an analog or digital signal is sent to a destination. It is the way the internet works, which has a whole other set of technical nomenclature. That isn’t super important, however, but rather a look at how transmission itself works.
By and large, residential internet usage will rely on physical cabling to receive a transmission. The actual differences between the cabling can be quite substantial. There is a rare instance of transmission media being wireless, which will also be discussed.
What is important to understand is transmission media is a two-way system. Think of it as a street, with cars passing to and from a destination and you aren’t far off the mark. This is a gross oversimplification of how network transmissions work, but this isn’t a high-level textbook.
What Is it Used For?
Transmission media is used for network communications. Without an actual viable means of carrying a signal, devices cannot communicate between endpoints. As such, there have been specifications and standards developed for these media types.
Typically, you’ll find cabling in most urban areas. Wireless means are typically used for things like satellite internet or 4G and 5G communications. There is also cabling available that is strictly meant for usage inside of a business campus or other indoor usage.
What Is the Most Common Type?
Coaxial cabling, twisted pair cabling, and space media are the most common types of transmission media you’ll see in regular usage. Fiber optic cabling is catching up but is ultimately very costly to develop the infrastructure to accommodate it.
In all honesty, you’ll see all of these types of media in regular usage. They’re all fairly common because standards have been developed around them. That said, there are some key differences between them.
Coaxial cable is perhaps the most antiquated transmission media. It uses analog signals which are later converted to digital for interpretation by computers. It has been in service for decades at this point and serves as the backbone of internet usage across the continental United States.
If you’ve done any sort of IT classes or networking classes, you’re familiar with coaxial cabling. It still sees wide use all across the world. Part of this is down to how cost-effective it is, being much cheaper than fiber optic cabling.
Coaxial cabling also benefits from being a widely understood standard. As such, you’ll see it as a more common occurrence in internet infrastructure.
Example of Usage
Coaxial cabling serves as the transmission media for broadband internet access. If you’ve got cable internet, it will use coaxial cabling. Typically the cabling will run from the power lines to your residence. From there the cable is routed to a modem.
The modem then converts the signal received from the coaxial line to a digital signal a computer can more easily interpret. This actually combines another form of transmission media, twisted pair cabling, to send the output to your computer or router.
Fiber Optic Cable
Fiber optic cabling utilizes hundreds to thousands of glass or plastic strands to transmit light from the sender to the receiver. As light travels faster than the audio-based signal of coaxial cable, this makes speeds massively faster. Fiber optic cabling gives a uniform and symmetrical upload and download rates.
The signal from a fiber optic cable is fully digital, so the modem doesn’t need to convert it to be usable for a computer. This effectively means the signal can be faster due to not having to convert transmissions on the fly.
Example of Usage
Fiber optic cabling is typically used for exterior internet connections to wide-area networks. Numerous internet service providers have begun limited rollouts of fiber optic cabling to urban areas. The cost of the cabling makes it somewhat prohibitive for wider deployments.
As time marches on, however, fiber optic internet access is likely to be more widespread. One current vendor doing wider deployments is AT&T which provides affordable fiber access for affordable rates when compared to offerings from Spectrum and Comcast.
Twisted Pair Cabling
Twisted pair cabling is the use of two or more copper strands of wire to create a transmission media. It has found a use in computer networking for a number of years and serves as the backbone for most network standards.
You likely are interacting with twisted pair cabling without even realizing it on a daily basis. If you’ve heard anyone refer to something like a CAT5e or CAT6 cable, it is a twisted pair cable.
Twisted pair cabling comes in two major variants, shielded and unshielded. Shielded twisted pair cables incorporate an inert non-conductive plastic sheath around the wiring to prevent electromagnetic interference from degrading the signal. Unshielded is the more common of the two, and is just the unshielded wires in a protective nylon or rubber cover.
Example of Usage
Twisted pair cabling is the transmission media of choice for internal network purposes. If you’ve set up a router at home, it is likely using twisted pair cabling to connect your modem to your router. It sees widespread usage in enterprise environments as well.
The CAT standard is a well-understood and developed specification and allows for fiber-equivalent speeds for local devices.
Space is perhaps the most nebulous, pardon the pun, transmission media available. Rather than using hard cabling to deliver a signal it might use radio waves, microwave frequencies, or some other unseen method of transmission to deliver a signal.
Space refers to multiple different methods of delivering a signal, but all have the common trait of being wireless by nature. As such, it is not as reliable or stable as traditional hardwired cabling infrastructure. It does have the benefit of being viable in areas where cabling might not be readily available.
Example of Usage
Space is used as a means of delivering wireless signals for cellular and satellite-based internet. These typically have less-than-ideal speeds when compared to hardwired infrastructure. It does have the added benefit of working in more remote locations, at least for satellite-based internet.
Wi-Fi also operates on a similar principle, functioning as the wireless equivalent of twisted pair cabling. As it stands, space is an extremely common transmission medium.
Transmission media is a hugely important aspect of modern living. Without it, networks simply don’t exist. Hopefully, this guide has provided some insight into the different types of media and how they apply to infrastructure around the world.
This guide will likely be relevant for a while to come since cabling infrastructure and transmission media don’t evolve at quite the same rate as the rest of the computing world. If you’re interested, check around your house and see how many examples of each are present.
The image featured at the top of this post is ©Proxima Studio/Shutterstock.com.