How does Wi-Fi work?

Wi-Fi is a wireless networking technology that uses radio waves to give devices internet access within a limited range, such as a home, office or café, without an ethernet cable (per Google Fiber). Your device turns data into a radio signal, a router receives and decodes it, and the router passes it on to the internet over a wired connection. The process runs in reverse for incoming data (per HowStuffWorks). [1] [2]

Traditional AM/FM radio and TV broadcasts carry information as continuous analog signals. According to an electrical engineer writing in The Conversation, Wi-Fi instead sends discrete values, the 0s and 1s of binary data. Digital data is easier to compress, to encode against errors and to encrypt. Wi-Fi radios are similar to those in walkie-talkies and cell phones, but they use higher frequencies, which lets the signal carry more data. [3] [2]

Wi-Fi bands are 2.4 GHz, 5 GHz and 6 GHz, each divided into channels (per eero). HowStuffWorks says the 2.4 GHz band carries lower speeds but travels farther, while 5 GHz is faster at close range but is more affected by walls and doors. [4] [2]

A router shares the connection from your modem with devices in your home, creating a local network. The modem translates digital data into a signal suited to telephone or cable lines. With fiber service, a device called an optical network terminal converts the signal into light instead. In the Conversation's description, a search query travels by radio to an access point, then over wired cables to your internet provider's gateway, and onward across many wired links to the destination server. The reply returns by a similar path. [4] [3]

Data travels in packets, small units that carry text, images or video and are guided by addresses and routes. An access point can extend the reach of a router's bandwidth so more devices can connect from farther away (per Cisco). [1] [5]

Devices from different companies can talk to each other because they follow the IEEE 802.11 standards. These specify how 0s and 1s are represented in radio waves and how devices identify themselves. Each standard is an amendment ratified over time, and they differ in frequency, bandwidth and number of channels. [3] [5]

The standards also include a rule called carrier-sense multiple access. Devices listen before transmitting to check that no nearby device is talking, pick random times to transmit, and transmit less often when more devices are present. This happens too quickly to notice. [3]

Radio signals weaken with distance. Thick walls, metal shelves and even an aquarium can obstruct them, and many nearby Wi-Fi networks can interfere with a link. If a router fails or too many people use high-bandwidth applications at once, connections can slow or drop. [3] [2]