Wi-Fi Standards Explained for the CompTIA A+ Certification Exam

By Microsoft MVP and MCT · Pluralsight Author

Published July 16, 2024 · Updated January 15, 2026 · Learning & Credentials

Studying for the CompTIA A+ 220-1101 exam? Have the Wi-Fi standards explained – including everything you need to understand for the exam – in this clip from my IT Professional Fundamentals: Networking course on Pluralsight!

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Video Summary

Here are the key points from the video:

  • Wi-Fi 5 (802.11ac): Introduced in January 2014, operates exclusively in the 5 GHz band, and can theoretically reach speeds of up to 7 Gbps by bonding multiple channels together.
  • Wi-Fi 6 (802.11ax): Launched in August 2019, works on both 2.4 GHz and 5 GHz frequencies, with a maximum theoretical speed of 14 Gbps.
  • Wi-Fi 6E (802.11ax-2021): Certified in January 2021, operates in the new 6 GHz band, offering improved efficiency by supporting only 802.11ax devices on this frequency.
  • Backward Compatibility: Previous Wi-Fi standards supported legacy devices, which sometimes limited performance. Wi-Fi 6E breaks this trend by focusing solely on newer devices for better efficiency.
  • Availability: Wi-Fi 6E is still rolling out globally and may not be available in all countries due to regulatory differences regarding the 6 GHz band.

For more information, read the transcript blog below, or watch the video above!

Video Transcript

Let’s start by talking about probably the most popular one out there, which is Wi-Fi. You have probably seen the logo on the right before, which is the Wi-Fi trademark. It means that the specific device with the logo on it uses a standard of communication approved by the IEEE, which is the Institute of Electrical and Electronics Engineers. There are quite a few of those standards that came out in the past 20-plus years, the first one being 802.11a, which came out in 1999, so really quite a while ago. 802.11a used the 5 GHz range and could reach a theoretical maximum speed of 54 megabits per second. However, it had a very low range and was easily blocked by having too many objects in the room. While you might still see the standard listed, especially for backward compatibility in modern-day devices, it’s not used anymore as multiple better Wi-Fi standards have come out since.

Our next Wi-Fi standard that we’re going to talk about is Wi-Fi 802.11b, which came out at the same time as 802.11a. The huge difference was that it used a different frequency to communicate; it used the 2.4 GHz frequency. It was much slower than 802.11a, as the theoretical maximum speed it could achieve was only 11 megabits per second. However, the advantage was that it provided a much better range. Another downside of 802.11b, or most protocols in the 2.4 GHz frequency, is that you can have interference from other household devices that operate on the same frequency, such as microwave ovens, baby monitors, cordless phones, and more. Imagine your internet being slower because somebody’s heating up something in the microwave. While it might seem a bit of a joke, that’s something that could actually happen on the 2.4 GHz frequency because that’s what microwave ovens actually use.

Now let’s fast forward a few years to 2003, when we had a new standard called 802.11g. This standard was an upgrade to 802.11b. It still worked on that 2.4 GHz range for devices, but it gave us a lot more speed. With 802.11g, we were able to go up to 54 megabits per second, so it’s about the same as 802.11a in terms of speed. However, it gave us that extra range that we can get under the 2.4 GHz frequency. The hardware used for 802.11g was fully backwards compatible with the 802.11b hardware. Again, because it used the same frequency, the 2.4 GHz frequency, the 802.11g devices could also suffer interference from other products operating in the 2.4 GHz band.

Now we will fast forward again to October of 2009 when we got 802.11n. 802.11n innovated by giving us two different types of frequencies at the same time, as you could have 802.11n in both 5 GHz and 2.4 GHz frequencies. Another big innovation was the speed achievable, as the maximum theoretical speed was 600 megabits per second, which was a huge improvement over previous standards. Before we move forward, I just wanted to stress that in the slides I’m sharing the theoretical speed for this Wi-Fi standard, but in reality, the speed that you will get is often much slower. You might see different numbers for each standard, either the theoretical speed for the standard, which is kind of, well, a standard, and this is what I’m sharing in the slides, or the other numbers that you might see is what most hardware vendors put as the maximum, which again, even the hardware vendors often have their marketed speeds lower than the maximum theoretical speed. So I just wanted to point that out in case you see conflicting numbers as you do your own research as well.

The 802.11n standard also introduced an innovation or feature called multiple input multiple output antennas, or MIMO for short. This allowed you to have multiple antennas in your access points all working at the same time, and this is really what allowed this huge increase in speed. Now, as a bit of an off-topic conversation, this is why a lot of gaming routers that you see today almost look like spiders because they have six to eight antennas on the side. This started when this MIMO feature was introduced because it allowed you to have those multiple access points all working at the same time.

Now getting closer to the present date, in January 2014, we had a new standard, 802.11ac. This also goes by the name of Wi-Fi 5. Technically, all the previous standards of Wi-Fi we talked about have a name as well. However, starting with 802.11ac, a lot of marketing material was simply using Wi-Fi 5 for the 802.11ac standard, and that’s why I put that in the slides here, both the real standard for us more geeky technical people as well as the marketing name that you might see on devices or have people ask you about. 802.11ac operates exclusively in the 5 GHz band and has increased the number of channels that can be bonded together, therefore increasing the amount of theoretical speed that we can achieve. If you combine all of the MIMO streams, the theoretical speed for Wi-Fi 802.11ac could reach 7 gigabits per second. Again, this is theoretical for all the possible MIMO streams combined, but real-world hardware was often way less.

Now let’s get closer to today. In August 2019, a new standard was introduced called Wi-Fi 802.11ax, or again from a marketing perspective, you will see this called Wi-Fi 6. Wi-Fi 6 works on both 2.4 GHz and 5 GHz frequencies and can achieve a maximum theoretical speed of 14 gigabits per second. Now let’s talk about the latest and greatest available at the time of recording this course. In September 2021, the technical name of this one is 802.11ax-2021, and the marketing name is Wi-Fi 6E. It was certified by the Wi-Fi Alliance in January 2021 and was approved by the IEEE as a standard in February 2021, so it’s recent. This is again very new. In fact, at the time of recording this course, Wi-Fi 6E was not yet available in all countries, and it was not even available to me in Canada. The reason for that is that it uses a new frequency in the 6 GHz band, so the regulations for it will depend on the country, but we’ll talk more about that in just a second. Another game changer is that the previous standards up to 802.11ax always supported all of the legacy standards, which held it back a little bit because of all the backward compatibility needed on the same frequencies. With Wi-Fi 6E, only 802.11ax devices will be supported on the 6 GHz frequency, which should make it more efficient, and many people are saying this is the biggest evolution of Wi-Fi in the last 20 years.