How Does Wi-Fi Work?

Wi-Fi has become such a standard part of everyday life that most people accept its presence without thinking about it. We use our wireless smartphones, laptops, video game systems, even printers and other peripherals without understanding how the magic beams are zipping around the room from device to device. Ever wondered how Wi-Fi works?

What is “Wi-Fi”?

Wi-Fi is a trademark of something called the Wi-Fi Alliance, a group that (you guessed it) came up with the technology and controls the standards of Wi-Fi worldwide. Don’t give yourself a headache trying to figure out what “Wi-Fi” stands for — many people think it stands for Wireless Fidelity, much like Hi-Fi stands for High Fidelity, but that’s not true. The company made the name up on the spot. They needed something catchier than the technical name, which is “‘IEEE 802.11b Direct Sequence”. I think you’ll agree that “Wi-Fi” caught on quite nicely. Other names considered by the company — Skybridge, Torchlight, and Flyover.

Enough with the name stuff, how does Wi-Fi work? Without going into too much technical detail, Wi-Fi uses radio waves just like your cellphone, your television, or your car’s radio.

First, a wireless adapter device (like the kind found in PCs and smartphones) translates data into a radio signal and broadcasts that signal using some kind of antenna. After the message is broadcast, a wireless router device receives the message, decodes the waves back into data, and sends the information to the Internet using an Ethernet connection.

Wi-Fi also receives information. To do this, the whole process runs backwards. A router receives data from the Ethernet connection, translates it into radio waves, then broadcasts it to the wireless adapter device.

Wi-Fi “Radios”

The basic process that Wi-Fi operates on is pretty simple. The walkie-talkies you may have used as a kid to play army are similar to the Wi-Fi devices you use now to check your email.

The “radios” on Wi-Fi devices have the ability to translate 1s and 0s (the basic building blocks of computer speak) into radio waves and also to receive radio waves and translate them into 1s and 0s.  Wi-Fi radios operate at super high frequencies, well above those used by telephones and other devices, which gives them more “room” to transmit large amounts of data.

Limitation of Wi-Fi

Because of the nature of the technology, Wi-Fi networks have a limited range.

Most wireless routers using either 802.11b or 802.11g with a standard antenna can be expected to have a range of about 120 feet indoors or 300 feet outside. A new version of Wi-Fi has been developed that is purported to double that range. The limitation on the range of Wi-Fi has been the main complaint about the technology since its inception.

Wi-Fi technology seems complicated. Wi-Fi is simply a system of radios that can communicate with the Internet through a wired Ethernet connection. Think of Wi-Fi as the cellphone of the Internet, allowing people to communicate electronically without using a mile-long extension cord.

The next time you use your Blackberry device to get directions to a restaurant or send a document to your office printer without being attached to it by USB, remember that Wi-Fi technology is responsible.

This is part of a series of blog posts we’re publishing about How Stuff Works. The other posts in this series include: