# How Wi-Fi Works and the Race to 5G

“Your internet connection is unstable”: this phrase has become all too familiar in these past several months due to Zoom’s incessant haranguing. Those piercing words glare back at you as you watch the stagnant screens and hear elongated fragments of speaking. You know that getting kicked off of the Zoom call lies only seconds away. The culprit of the crime— Wi-Fi.

With many of our activities having transitioned to a virtual landscape in the works of the pandemic, the once invisible force of Wi-Fi is now the only force that ties many of us together. With our increased reliance on Wi-Fi in recent times, understanding how Wi-Fi effortlessly serves us all may provide us with some insights into how Wi-Fi’s destiny will improve in the future.

The origins of Wi-Fi arose from an unsuccessful attempt to study the explosion of black holes. The story begins with Steven Hawking, who, in 1974, proposed that if one were to observe tentative subatomic black holes, black holes smaller than an atom that possibly exists, they would produce radio waves as they exploded (3).

Several years later, John O’Sullivan and his team at the Commonwealth Scientific and Industrial Research Organization (CSIRO), the national science agency of Australia, set out to find and observe these radio waves, but the daunting task came with a formidable problem. Radio waves can be easily altered, making the collection of these radio wave signals a difficult mission (3).

With the Fast Fourier Transform (FFT), this challenge became quickly surmountable (5). The FFT takes in the frequency of waves and can separate the waves into distinct segments. This separation makes it a simple feat to filter out any unwanted waves (6). Take a note on a piano. Sound travels in waves, and when two notes are played together, they make a single wave. Let’s say we want to remove one of those notes. By using the FFT, we can separate the notes into distinct waves and remove the unwanted note, leaving us with the desired note.

O’Sullivan and his team attempted to use the FFT equations to solve the problem of additional waves but were unsuccessful because no black holes were detected. These seemingly useless discoveries would later yield way to the invention of Wi-Fi (5).

In subsequent years, many scientists attempted to discover a way for devices to receive data from the internet via radio signals as opposed to the current system where devices had to be connected with wires. However, these scientists failed to do so given a flaw in the easily changeable radio waves. That’s when O’Sullivan entered the scene again. Those mathematical equations that O’Sullivan and his team had devised to detect subatomic black holes could be used to develop what we now know as Wi-Fi, as these equations could filter out the unwanted waves that came from our environment (3).

While this is the current status of Wi-Fi’s development, the next steps are happening right in front of us with the world’s race to 5G. The development of Wi-Fi is made in generations, and 5G is the next generation that will offer us faster Wi-Fi speeds and increased bandwidth, meaning more people can be connected to the Wi-Fi without sacrificing the quality of Wi-Fi service, and the time needed for communication between devices is reduced (1).

5G works based on changing the frequency of the Wi-Fi signal, but to understand how the next generation frequencies will change, we have to understand the basis for our current Wi-Fi frequencies, which relies on the measurement unit of hertz.

To understand the measurement of hertz, think of the waves crashing on the shore every second. Those waves crashing at the shore represent a frequency of 1 hertz per cycle. Wi-Fi falls into the frequency range of 2.4-5 gigahertz, meaning about crashing waves, billions of waves would be crashing at the shore per second. Wi-Fi operates at the same frequency as a microwave, which is why heating food in old microwaves can cause faulty Wi-Fi (2).

Reaching the 5G realm requires us to expand the frequency range we currently have through various means: low band network, high band network, and medium band network. The low band network offers a larger coverage area but only increases the Wi-Fi speed from the current Wi-Fi status by 20%. On the other hand, the high band network can increase the Wi-Fi speed substantially at the expense of less reach. The medium band network is a balance between the two (4).

However, such a utopia naturally has its worrying disadvantages. With most of the world relying on Wi-Fi, the 5G network brings up many security concerns, particularly concerning healthcare and newer technology. Before 5G is in full use, these security concerns must be put to rest (4).

Wi-Fi is something most people struggle to understand, but a better comprehension of what we rely on in our daily lives will allow us to progress to Wi-Fi of better capacities without falling into the trap of the many risks that the future of Wi-Fi may carry.

– Anjali Reddy

References

1. Duffy, C. (2020, March 6). 5G explained: What it is, who has 5G, and how much faster is it really? Retrieved September 29, 2020, from https://www.cnn.com/interactive/2020/03/business/what-is-5g/index.html
2. Escobar, T. T. (2015, July 15). How Does Wi-Fi Work? Retrieved September 29, 2020, from https://www.scientificamerican.com/article/how-does-wi-fi-work/
3. Kruszelnicki, K., Dr. (2018, September 02). Australian breakthroughs: The invention of wi-fi. Retrieved September 29, 2020, from https://www.australiangeographic.com.au/blogs/dr-karl-need-to-know/2016/06/australian-breakthroughs-the-invention-of-wi-fi/
4. Mims, C. (2019, June 29). The Downside of 5G: Overwhelmed Cities, Torn-Up Streets, a Decade Until Completion. Retrieved September 29, 2020, from https://www.wsj.com/articles/the-downside-of-5g-overwhelmed-cities-torn-up-streets-a-decade-until-completion-11561780801
5. Scheme=AGLSTERMS.AglsAgent; corporateName=CSIRO Australia Telescope National Facility; address=PO Box 76 Epping NSW 1710 Australia; contact= 61 2 9372 4100 (phone), 61 2 9372 4310 (fax); jurisdiction=Commonwealth. (2020, September 16). WLAN background. Retrieved September 29, 2020, from https://www.atnf.csiro.au/news/press/wlan_background.html
6. Semmlow, J. (2012). Fourier Transform. Retrieved September 29, 2020, from https://www.sciencedirect.com/topics/engineering/fourier-transform