Wireless Standards

What this chapter covers

This chapter explains the technology behind Wi-Fi speed and behaviour.

It starts with the 802.11 standards and what each one added. It then looks at how the radio turns the signal quality into a data rate, how several antennas multiply that rate, and how devices share the air. It finishes with 802.11ax, the standard that focuses on busy networks.

Each page also shows the RouterOS setting that matches the idea, so the theory links to what you configure.

How the topics fit together

The pages go from the list of standards down to the methods that make them work.

The standards page gives the names and the bands. Modulation and data rates explain why the same standard gives different speeds at different distances.

MIMO and chains show how antennas multiply the rate. Medium access and QoS explain how all the clients share the channel. The last page covers 802.11ax, which changes the way the channel is shared.

• 802.11 standards and features compares a, b, g, n, ac and ax.
• Modulation and data rates explains modulation, coding rate, MCS and rate settings.
• MIMO and chains explains chains, spatial streams and MU-MIMO.
• Wireless medium access and QoS explains CSMA/CA, RTS/CTS and WMM.
• Future standards and 802.11ax explains OFDMA, BSS colouring and the ax band names.

How to use these pages

Each topic page has the same shape, so you can skim for what you need.

• What it is: the idea in plain words.
• How it works: the mechanism, with diagrams and example commands.
• What to remember for the exam: the facts to memorise.
• Common mistakes: the classic traps.
• Check yourself: three questions to test your understanding.

Read the pages in order. Make your own one page table of the standards, with the band, the top rate and the main feature of each, and fill it in from memory before you check it.

Use the registration table on a real device to see the rate and the signal of each client. Matching those numbers to the ideas on the pages makes them easier to remember.