How does WiFi work?
For something that most of us use everyday, not many people understand how WiFi actually works. Without getting into too much of the nitty gritty, here’s an overview. Say you’re sending an email. Your computer encodes the email into a digital signal. It then uses its WiFi radio to send the message across the room to your router using radio frequency technology. Your router then sends the encoded email along to your modem. Your modem receives the digital data from your router and translates it into an electrical signal for transmission to the Internet. This signal travels out of your house through your phone or cable line using an Internet Service Provider like Comcast Xfinity. As your data travels across the Internet, it encounters a series of checkpoints, including other routers and servers (the machines that store the information you're attempting to access on the Internet). Each time you receive information, the process works in reverse, with the router receiving information from the Internet, translating it to a radio signal, and sending it to your device’s wireless adapter.
Instead of sending packets of data through cables and wires, WiFi uses radio frequencies to send signals between devices. The frequencies for WiFi are 2.4 Gigahertz (GHz) and 5 GHz. This puts WiFi frequencies in a much higher range than cell phone and television frequencies, meaning their signal can carry more data. A governing body called the IEEE sets the standards for networking transmission methods. In their most recent protocol releases, throughput has increased over time, greatly improving data transmission rates. This is in large part due to the fact that modern WiFi devices can utilize both 2.4 and 5 GHz frequencies.
What's a router?
Your router is a small box that enables connected devices to access your Internet network. The router receives a digital signal from your modem and shares it with the wireless devices in your house, creating a Local-Area Network (LAN).
To connect devices on the network to the Internet, routers must be connected to a modem. When your modem gets information from the Internet, your router distributes that information to your devices. The same process works in reverse when you’re sending information out to the Internet.
More from the eero blog: What is a router?
What's a modem?
A modem is a device that helps you to connect to the Internet by translating the digital data of your computer into an analog signal that can be transmitted over telephone or cable lines.
There are two types of modems: cable modems and DSL modems. Cable modems have a coaxial (or "coax") connection, which connects to a cable port on the wall. DSL modems have a telephone connector, which connects to a telephone socket on the wall. In a typical setup, data will travel from your computer to a router, through a modem, and out to the Internet over a phone or cable line.
What's an ISP?
An Internet Service Provider (ISP) is a company that charges a fee to provide you with Internet access. Customers usually connect to an ISP using a phone line (dial-up) or broadband (cable or DSL) connection. ISPs generally offer multiple options for connecting to the Internet. These options are characterized by different speeds and prices. Large ISPs in the US include Comcast Xfinity, AT&T, and Time Warner Cable.
From the blog: What is an IP address?