How Does WiFi Work?
Welcome to DevOdyssey Home Networking.
Today’s episode, we’re answering the question, What is Wifi.
Wifi is a technology we use everyday to easily connect our devices to the internet, anywhere we get a signal.
Refer bellow for the video summary.
WiFi - the radio waves that connects your devices to your router and thereby the internet.
WiFi is a play on the word, High Fidelity (HiFi), where WiFi means Wireless Fidelity, though this moniker is not official.
Wireless Router - uses Wifi to broadcast your local area network (LAN) or home network, wirelessly within your home. These radio waves are used to transmit data, in binary format, from your devices to the router.
Wifi is defined by IEEE (Institute of Electrical and Electronics Engineers) under the versioning of 802.11 family. Wifi development overseen by a group called the WiFi Alliance.
Most popular version for WiFi is WiFi 5 (802.11ac) but recently WiFi 6 (802.11ax) was released as of February 2019.
WiFi is broadcasted in 2.4 Ghz and 5 GHz bands.
Hertz is a unit of measure for a cycle, one radio wave per second
Hertz describes the size and speed of radio waves
2.4 GHz - longer and slower waves - farther reaching WiFi network, but slower internet speeds
5 GHz - smaller and faster waves - shorter reaching WiFi network, but faster internet speeds
2.4 GHz waves have more interference with devices in your home (microwave, other electronics), resulting in dropped connections, and unreliable internet speeds
Each WiFi band has channels
2.4 GHz has 11 channels
5 GHz has 23 channels
Channels help increase reliability of your connection, using different channels that other devices are not on increases your reliability
Walls, doors, and other objects in your house create “dead spots” in your home, where you can’t get internet access. This also is why the farther you’re from your router, the harder it is to get a good connection
Mesh WiFi resolves dead spots in your home, and increases the coverage of your WiFi Network
This is done by adding addition “nodes” that connect to the main node
Each node emits more WiFi radio waves, resulting in increased coverage
WiFi 5 is most most commonly secured by WiFi Protected Access 2 or WPA2 security protocol
WPA2 works by using the WiFi password also called the PreShared Key (PSK) to encrypt your Wifi Network
This process creates a 4 way handshake between device and router
First a Pairwise Master Key (PMK) is created from the PSK and WiFi name SSID (or Set Service ID)
Then a Pairwise Transient Key (PTK) or session key is created.
This is then used to encrypt the connection between device and router.
This ensures each device has its own unique encrypted connection, that other devices on the network can’t read
Wifi 6 (802.11ax) is the new improved version from Wifi 5
WiFi 6 max speeds are 9.6 Gb/s, up from 3.5 Gb/s in Wifi 5
This enables faster speeds for all devices on the network, not just a single device
Multi User Multiple Input Multiple Output (MU-MIMO) supports up to 8 devices, an increase of 4
This lets the router talk to 8 devices at once, instead of one by one, and therefore more consistent fast speeds for all devices
Compared to having more waiters at a restaurant
Orthogonal Frequency Division Multiple Access (OFDMA) means one signal transmission from the router delivers data to multiple devices
Compared to having waiters clean more tables before returning to the kitchen
Target Wait Time schedules device check ins with the router
This improves battery for Internet of Things (IoT) devices, like smart smoke detectors.
Easy Connect QR
Easily connect IoT devices to the network by scanning a QR code via an accompanied mobile app
To use these features in full, your devices and router both need to support Wifi 6
Wifi 6 uses an update to WPA2, called WPA3
WPA3 protects you from offline password attacks, where someone can steal wifi data, and try to guess the password against that encrypted data
WPA3 uses forward secrecy
WiFi data is re-encrypted every few minutes using a new encryption key. This means if an encryption key was compromised or stolen, the only data that can be decrypted is a few minutes worth, as opposed to all the data over the WiFi network