Demystifying the Concept that 2.4GHz is Slower than 5GHz

Wi-Fi WiMax
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We’re tired of hearing that Wi-Fi operating at 5.0GHz is faster than 2.4GHz, aren’t we?

We’ve heard it so often that most people accept it as truth, often dismissing the use of 2.4GHz or thinking the connection is “bad” if it operates on that frequency.

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But let’s look at the facts:

When using a 20 MHz channel width, both 2.4 GHz and 5 GHz bands can achieve the SAME maximum data rates for a given Modulation and Coding Scheme (MCS) index under ideal conditions (i.e., no interference and optimal signal quality).

The MCS index table defines data rates based on various factors such as the type of modulation (e.g., QPSK, 16-QAM, 64-QAM), coding rate, and the number of spatial streams. These factors are the same regardless of whether you’re operating in the 2.4 GHz or 5 GHz band.

The maximum data rate is lower with a 20 MHz channel compared to wider aggregated channels (40 MHz, 80 MHz, etc.), but the achievable rates are the same for both 2.4 GHz and 5 GHz for the same MCS index.

In reality, the main limitation of the 2.4 GHz band is the reduced number of available channels. Practically, it’s only possible to operate with a 20 MHz width on 3 non-overlapping channels, which prevents channel aggregation. In contrast, the 5 GHz band, due to the greater number of available channels, allows the combination of multiple 20 MHz channels to increase bandwidth.

Examples of Data Rates:

  • If we are using a single spatial stream (1x1 MIMO) with MCS index 7, we get 64-QAM modulation with 5/6 coding, which can achieve a theoretical maximum rate of 72.2 Mbps for a 20 MHz channel —> on both 2.4 GHz and 5 GHz.

The 2.4GHz band is not “bad” or “obsolete” at all, as it remains strong in Wi-Fi 7!

What factors should we consider then?

  • Although the theoretical rates are the same, the 2.4 GHz band is more susceptible to interference due to the larger number of devices operating on that band (e.g., Bluetooth, microwaves, etc.). In some real-world scenarios, this could result in lower effective data rates on 2.4 GHz compared to 5 GHz.
  • Range and Penetration: The 2.4 GHz band generally offers better range and penetration through walls, while the 5 GHz band provides better performance at shorter distances with less interference. This means that in some environments, the 2.4 GHz band may perform better due to better signal strength despite potentially higher interference. Practical examples include industrial areas or warehouses, where coverage is prioritized.

So, before dismissing 2.4GHz from your Wi-Fi project, understand that there are indeed applications and advantages to using it. It’s all about knowing where and how, and even combining both bands to get the most out of your investment!

Source (in Portuguese): :point_down:

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What about outdoor Long Range WiFi devices where the devices are lesser and interference from other devices

Ubiquiti airMAX NanoStation AC NS-5AC

(Ubiquiti airMAX NanoStation AC NS-5AC)

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2.4 GHz vs. 5 GHz vs. 6 GHz WiFi - What’s the Difference?

In this video, it is explained the difference between 2.4 GHz, 5 GHz, and 6 GHz WiFi networks, with details when to use each one.

0:00 Introduction
0:24 Why I created this video
1:33 What 2.4 GHz, 5 GHz, and 6 GHz networks are
2:20 Why you might not have a 6 GHz WiFi network
4:05 The drawbacks of higher frequency networks
5:02 When to use 2.4 GHz, 5 GHz, and 6 GHz networks
7:10 Explaining the Smart Connect feature that some routers have
8:31 Summary and conclusion

What are the different frequencies of wireless networks?

I’m sure you’ve seen “2G”, “5G”, and maybe even “6G” after wireless network names when you connect to them.

These additions to the network name are to identify the frequency of the wireless network.

Higher frequency wireless networks provide faster speeds than 2.4 GHz networks, but their wireless signals do not travel as far from the router.

In other words, you need to be physically closer to the router if you want to use the higher frequency networks without any problems.

This makes higher frequency wireless networks ideal for bandwidth-intensive activities like streaming, video conferencing, and online gaming.

Any internet activities that don’t require extensive bandwidth are best suited for a 2.4 GHz wireless network.

The 2.4 GHz wireless network is also a good option when you need to access the internet and you are far away from your router and out of range of the higher frequency networks.

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