Wireless networks — Wi-Fi standards and security

Wireless networks are based on the IEEE 802.11 standard, which has been further developed many times since the late 1990s. Because letter combinations like 802.11ac are difficult to remember and compare, Wi-Fi Alliance introduced simple generation names a few years ago: Wi-Fi 4, 5, 6 and so on. As a technician you encounter both designations in practice, and it is important to be able to translate between them.

§From 802.11 to names you can remember

Each goods wagon has a maximum load and a maximum axle load, which is determined by the wagon's technical data and the infrastructure it runs on. Complying with this limit is just as important as securing the cargo itself: overloaded cargo — or cargo that is unevenly distributed so some axles are more loaded than others — can damage both the wagon itself and the track it runs on. Therefore, it is a fixed part of preparation to check that the total load stays within the wagon's permitted limits before it is finally secured for transport.

§Frequency bands and channels

2.4 GHz band reaches far and penetrates walls well, but has few non-overlapping channels and is often shared with other equipment like microwaves and Bluetooth — therefore most prone to noise. 5 GHz band has more channels and wider channel widths, but reaches shorter. 6 GHz band, which only came with Wi-Fi 6E, is the cleanest band with the most space because it's not yet filled with older equipment. Wi-Fi 7 uses up to 320 MHz wide channels in the 6 GHz band, which gives significantly higher data rates than previous generations.

§Safety: from WEP to WPA3

• 01WEP (Wired Equivalent Privacy) was the first standard and is today so weak that it should be considered unusable
• 02WPA and WPA2 solved WEP's weaknesses and have been common standard for many years
• 03WPA3 tightens encryption and login process further and makes it harder to guess a password by listening to traffic
• 04Wi-Fi Alliance has made WPA3 mandatory for all equipment certified for Wi-Fi 6E and Wi-Fi 7 — without backward compatibility to WPA2 on those bands

§Practical planning

A good wireless setup is about more than just putting a router up. Choose channels that overlap as little as possible with neighbours' networks — in the 2.4 GHz band channels 1 6 and 11 are typically the only ones that do not overlap. Separate guest networks from the internal network so a visitor cannot reach printers servers or other devices on the company network. Name access points and networks consistently so troubleshooting a house with many devices does not become guesswork.

“A wireless network is only as secure as the weakest device allowed to connect to it.”

— Rule of thumb from network operations.