Is the 2.4 GHz Spectrum Making a Comeback?

By Kevin Blackburn, Blog Contributor
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When most people think about the 2.4 GHz spectrum, they think of older legacy devices. The reality is that there is a wide range of devices that exist solely in this 2.4 GHz band of wireless networking. From smart devices to IoT, and everything in between, many new devices that do not make use of the 5 GHz wireless band. This could start to present problems as the newer waves of Wi-Fi technology have focused on the 5 GHz spectrum — until now.

2.4 GHz is back!
Let’s be honest, 2.4 GHz never went away no matter how hard some of us tried to make it happen. I recently purchased a new wireless home security system with IP cameras from a major provider and it was only 2.4 GHz compatible. I like to think that 2.4 GHz is making a comeback because of the new work that 802.11ax is doing for wireless networking as a whole. Unlike 802.11ac, the new Wi-Fi 6 wireless technology will operate at both the 2.4 GHz and 5 GHz bands.

Now, I do want to call out that the speeds will vary depending on the band, but there are several important reasons that 802.11ax will improve the 2.4 GHz spectrum. The main thing that I want to focus on is total network capacity. That is what really excites me about the future possibilities of 802.11ax. It is meant to support and provide better connectivity to more devices than ever.

Pushing Capacity to the Max
Capacity is king when it comes to networking nowadays. With more and more devices swapped out for “smart” devices, wearable technologies and other general computing products, networks need to handle this mass influx of devices more than they ever. There are a few features of 802.11ax that will help handle this larger capacity of devices.

The first is target wake time (TWT). I mentioned that many of these 2.4 GHz devices will be IoT devices. These devices do not have to report in and use wireless all the time. By utilizing TWT, these devices can put their network adapter to sleep for a certain period of time, thus reducing the number of active devices on the already saturated 2.4 GHz band.

The other new feature that should especially help in 2.4 GHz networks is called channel coloring. Think of a standard 2.4 GHz setup that you might use. Utilizing best practices, you keep the radios on the non-overlapping channels of 1, 6 and 11. That is not a lot of channels to work with, especially in radio-dense environments. Channel coloring will allow two radios near to each other to use the same channel without causing interference. Take a look at this diagram:

Source: Aruba 802.11ax-Wait, Did We Just Build a Wireless Switch white paper 

On the left, all of the radios using channel 1 are subject to interference from each other. On the right, notice that there are multiple radios on channel 1. By using channel coloring, only the radios operating on the same “color” will interfere with each other. The idea is that the wireless radios with matching channel colors would be far enough apart not to cause interference, even in radio-dense environments.

You can see with both of these features that there is a special use case when it comes to 2.4 GHz. One allows for devices to reduce how often they are talking on the network (TWT) and the other allows for better utilization of the limited channels in the 2.4 GHz spectrum (channel coloring). With these being just a few of the features coming with 802.11ax, it is clear that the 2.4 GHz band of wireless is not dead by any means. Utilizing these features will allow for this band of wireless to be revamped and more reliable in the modern business network environment.

Go Deeper
Learn more about extending network capacity with 802.11ax in this Network World article by Peter Thornycroft, an engineer in the Aruba Office of the CTO. 

Learn why 802.11ax is ideal for IoT.