How to Explore the Hidden World of Radio Waves All Around You

One day this fall, in an old factory in Brooklyn’s Bushwick neighborhood, a series of telephone pagers from the 1990s were chirping and buzzing. Along with their dimly lit displays sat a receipt printer — like the one you might find at the cash register — spewing long spools of paper. As my eyes scanned the printouts, I couldn’t believe what I was seeing: These were pager messages from dozens of doctors and hospital staff, full of a lot of personal information about patients.

Holypager art project. Image: Brannon Dorsey

The installation of this year’s Radical networks the conference was part of a work of art called Holypager by Brannon Dorsey, who uses a programmable radio to listen to pager traffic. While you may think that this will take away the skills and resources of a spy agency, it is actually quite easy even for modest technical knowledge.

When telephone pagers became popular in the 1990s, very few people understood how they worked and the technology they depended on was extremely expensive. In this way, the designers of the pager network got away with sending each message unencrypted, relying on the pagers themselves to show only the messages addressed to them. Today, however, it follows easily accessible instructions and using a cheap USB radio, almost anyone can build a pager that receives every message broadcast in their area, not just the ones addressed to them.

Dorsey’s project is part of a broader movement in which artists and journalists use new radio technologies to explore the policies and implications of how hidden infrastructures are designed and used.

While radio may seem like an outdated technology, it is actually a ubiquitous part of modern life. Radio signals from Wi-Fi routers, GPS satellites, Roku remotes, wireless water meters, Bluetooth keyboards, weather stations and even echo of the big bang they all saturate the air around us.

Until recently, it was relatively difficult to explore this vast and invisible world. AM / FM radios are cheap and easily accessible after the popularization of the transistor in the 1960s, but devices that allow you to tune outside frequencies such as the 88 MHz-108 MHz frequency of the FM radio were difficult to access and usually cost thousands of dollars.

All that changed in the early 2010s. Group of hackers have been found that the chips that powered were very cheap USB tuners for digital TV can be tuned to tune in an impressively wide frequency range, from 24 MHz to over 1000 MHz. Today, these software-defined radio stations (SDRs) can be taken about $ 20 on Amazon and are supported by active open source community.

The opportunities that this new technology provides to investigative journalists and socially engaged engineers have proved enormous. For example, Buzzfeed News publishes a main story in August, this revealed the extent to which law enforcement used Stingrays (devices that pretend to be cell phone towers and are used to secretly track people) by analyzing data from radio signals that planes use to report their location.

Artist Surya Mattu also uses software-defined radio stations in a recent work showed up at the Whitney Museum of American Art in New York, which revealed the names of all the Wi-Fi networks our phones have ever connected to. While the engineers who designed Wi-Fi thought it would be useful for our phones to try to connect to a network automatically, they inadvertently built a system that dropped intimate things into the air for us, like the name of a hotel. recently visited travel or network in the apartment of the former.

Adjustment in yourself

It has never been easier for anyone to study the radio spectrum. All you need to get started is $ 20 software defined radio– Essentially a USB stick that has an antenna and allows the computer to tune in to the radio waves around it.

Once you have a physical radio, you will need to use various software programs to make sense of the signals you are receiving. The easiest to work with are audio broadcasts.

Image: Screenshot / Mark DaCosta

GQRX is a popular open source radio that runs on Mac, Windows and Linux. Open it and enter 91.1 MHz and if you’re in the New York area, you’ll be pampered with some eclectic tunes from the alternative radio WFMU. However, if you enter 476.68750 MHz, you can listen to radio traffic in the 94th NYPD area, which serves the Williamsburg and Greenpoint neighborhoods of Brooklyn.

Knowing what radio frequency to tune in to can be just as challenging as knowing which URL to enter in your browser, but there are many resources that can help you.

Communities of police scanner enthusiasts have posted frequency lists you can tune in for years, but the real gold mine of information (at least in the US) is maintained by the Federal Communications Commission (FCC).

While today the FCC is best known for removing net neutrality, was originally created to regulate radio transmitters partially in response until the sinking of the Titanic in 1912. The ship’s distress signals were muffled by shore intervention, which contributed to its death.

This broad mandate gives the FCC some control over everything from microwave ovens to uplink satellite transmitters. An advantage of this regulation for amateurs is that anyone who wants to use a radio that broadcasts above a certain signal strength must obtain a license and all these licenses are public data.

This image shows how all parts of the spectrum are allocated by the FCC. Image: US Department of Commerce

Different parts of the radio spectrum are reserved for different applications such as FM radio, aeronautical navigation and satellite broadcasts. Image: US Department of Commerce / annotations added by the author

FCC License View database is a rich resource for finding out who is probably using the radio waves in your neighborhood. Taxi dispatchers, UPS sorting devices, McDonald’s walkways, radios for maintenance in office buildings – even wireless microphones like the one that Donald Trump scandalously forgot he was involved– All are reflected in the FCC data.

Enigma Public offers a more user-friendly experience when searching for FCC licenses. Image: Screenshot / Enigma

The FCC website will allow you start searches between licenses, but the interface is limited. Enigma Public– a platform for searching and discovering public data, which I helped launch – also archives FCC data and allows a richer in features and user-friendly experience. For the more adventurous, you can download the entire database with nearly 20 million licenses to work with directly (if you have experience with the database, I also did library which facilitates geographical searches).

Touch the data

Apart from just listening to voice chatter, there is a lot of interpretable data that also flows on the air. A robust open source community has made specific software pieces that allow you to convert broadcast signals at certain frequencies into readable data.

Here is just a selection of the types of things you can do:

As a child, I remember being completely amazed to learn that the visible light we can see is the same thing — the same electromagnetic radiation — as the radio waves or X-rays we can’t. What kind of eyes would it take to see these other things, I wondered.

Last year, China completed the construction of the largest radio telescope on the planetwhich makes it a world leader in the search for aliens. As the Earth rotates through space, the telescope’s antenna is aimed into the depths of the universe, hoping to hear some conversation from a distant world. While a radio plugged into the side of a laptop may be more limited in scope, it promises to open up new realities for exploration.