Long-distance communication has come a long way since the rotary dialer and the manual switchboard. Even the days of flip phones, detachable cameras, and polyphonic tones feel like ancient history. Today, it is about updates, Zoom meetings, Snapchat, Facetime, and social media – and we treat these privileges as if they have been around forever.
Have you ever wondered, though, what the invisible ingredient was and still is that permitted us to discard that twirly rubberized wire that anchored us to the phone booth?
The answer is radio waves. The same magic that gives TV its pictures and radio its music. The only difference is we call it “signal” or “connectivity” – which brings us to the question: What are radio waves?
The Radio Waves
Radio waves are electromagnetic pulses that can travel further than infrared light, and penetrate solid materials like brick walls – which is why we can make calls from inside buildings, per Northwestern University, Fermi National Accelerator Laboratory.
Radio waves can vibrate at different speeds creating various frequencies. According to NASA, they are “generated by a transmitter and then detected by a receiver.” It is on this basic principle we are able to facetime and voice call uncle Johnny who now lives in Germany.
But it is not that simple: The radio waves cellphones work on, range between 40 and 935 Megahertz (the unit of measurement for 1,000,000 waves passing a specific point in a second), says Vedantu. Crazy, huh? But what about the transmitters and receivers?
Cell Towers
Your cellphone, tablet, and phablet are the transmitters. When you use them, they send an electromagnetic pulse to the nearest cellphone tower. This tower – which is not always a tower but can also be an antenna on any elevated structure – receives said pulse (per Connecticut’s Department of Public Health). It then relays these signals, using a switching station, per Millman Land.
A switching station, according to the Collins Online Dictionary, “is the equipment used to tie together two or more electric circuits through switches.” In terms of cellphone connectivity, this is a contemporary and autonomous version of the old telephone exchange.
Once the switching station determines where uncle John is, it finds the antenna closest to him and sends his device the radio wave.
“How does the network know where uncle John is? For all we know, he could be “working” in Amsterdam as he usually likes to do every other weekend.” Well, as long as uncle John’s device is on, the network can locate him through an automatic process called “pinging”.
A ping transmits a small amount of information to a cellphone tower. This helps the network/s locate a user’s device. According to TechWithTech, it happens when you change locations, activate airplane mode, deactivate it, turn your cellphone off, and then again when you turn it on.
The Cellphone Network
You must have heard about 5G by now and seen the 4G and 3G icons on your phone. And you may realize that as the number goes up, so does everyone’s expectations of the network’s performance. But what do these symbols actually mean?
Respectively, 2G, 3G, 4G, and 5G are the second, third, fourth, and fifth generations of digital cellphone connectivity, the advents of which – also respectively – were in 1991, 2001, 2009, and 2019. Each generation of network technology came with a new set of standards and radio technology.
- First Generation (1G)
First-generation cellular networks were analog and humanity’s original cellphone network. As you can imagine, it was pathetic compared to what we have today. The fastest it could transfer information was at a measly 2.4 Kbps.
This was the in thing in the 70s and 80s, and dropped calls were the order of the day, per Net-informations.
- Second Generation (2G)
Second-generation networks were digital, and for the first time, cellphone networks were able to run more than one user on a single channel. This new capability allowed speeds of up to 64 Kbps and frequencies of 1.8 Gigahertz (1800 Megahertz).
- Third Generation (3G)
Third-generation connectivity was a drastic upgrade on 2G. It allowed for faster internet browsing and boasted download speeds of up to 43 MBps It was here that we got a taste of high-speed downloads and video streaming.
- Fourth Generation (4G)
With the advent of 4G, things got wild: The technology changed and allowed for multiple inputs and multiple outputs (MIMO). Simply put, this merant no more buffering, 100MBps data transfer capabilities when traveling by car, and 1GBps when walking or standing still, per Net Informations.
- Fifth Generation (5G)
5G is associated with the New Radio(NR) standard, per Comms Brief. It is the Avant Garde and not limited to cellphones. We are talking about the fastest data transfers known to man, the internet of things becoming a reality, unlimited network space, and an eventuality, “iRobot” like automations (possibly).
How do Networks Operate?
Networks operate in coverage swathes or “cells” that cover square or hexagonal-shaped areas. According to Tutorials Point, each cell is defined by a base station(cellphone tower) that receives and transmits signals. Cell coverage overlaps neighboring cells, and individual cells have unique frequency spans within the 40 to 935 Megahertz range.
This brings us to the point of different network providers: Each network provider is responsible for maintaining their infrastructure (hardware and software). Since network providers can not have cells everywhere, they allow competitor’s customers to “roam” off their cells. The latter is particularly helpful in instances when a required provider does not have a cell or tower in range, per the Cellular Telecommunications Industry Association(CTIA).
Data Transmission
Now that we know electromagnetic radio waves carry our phone and video calls to towers or base stations, one has to wonder: How do these signals do it?
Each cellphone has a unique frequency – and this is how base stations identify where the data originates, and it’s destination.
The complexities of audio, visual, and combinations of the two, are broken up into ones and zeros, per the Public Broadcasting Service. They are beamed at towers in this simple form, then relayed to and digested by devices on the receiving end using Packet Switching.
Unlike its predecessor, Circuit Switching, Packet Switching breaks up the information into small units of data called packets, sends them across multiple networks via multiple routes, and the recieving device reassembles them at their destination, per Avine Networks. The latter prevents resources from being wasted and allows for the fast and efficient exchange of information.
In a Nutshell
A cellphone or any device connected to a cellular network uses radio waves. If you have not caught on by now, these electromagnetic waves – often referred to as signals – do it at the speed of light – and this is why we can have conversations and video calls with uncle John at a questionable Amsterdam bar in real time.
The embedded technologies are always improving, and as Verizon explains – with the advent of the latest communication network technology – 5G – the possibilities are colossal.