Wi-Fi has an additional 6 GHz band for what?

The 6 GHz band on Wi-Fi 6E, Wi-Fi 7 and Wi-Fi 8 not only increases speeds, but also expands the number of channels, reduces contention and improves the ability to serve multiple devices. When it comes to Wi-Fi 6E or Wi-Fi 7, there's one change that's easy to overlook: Wi-Fi adds the 6 GHz band. It sounds simple, like "one more band will make Wi-Fi faster". But in fact, the biggest benefit of 6 GHz isn't just about increasing speed. It's like an already crowded road being opened up to a new, wider route with fewer cars. And this is why 6 GHz is remarkable.

2.4 GHz and 5 GHz are starting to get tight

Before Wi-Fi 6E, Wi-Fi mainly operated on two bands, 2.4 GHz and 5 GHz. The problem is that these two bands are already used for many different devices. Especially at 2.4 GHz, Bluetooth and many other wireless devices also operate here, making the wave environment increasingly crowded.

But the bigger problem lies in the number of channels. At 2.4 GHz, if you use a 20 MHz channel width and want to limit overlap, in reality only about 3 channels can be used effectively.

This especially becomes a problem in environments with multiple Access Points. Imagine an event with over 1,000 attendees but only about 35 Access Points. If you want to design high-density Wi-Fi, it is ideal to limit the use of multiple channels by Access Points. But when the number of channels is insufficient, channel reuse is almost inevitable. And when multiple Access Points use the same channel, they must share radio space with each other.

6 GHz is like opening a new route

This is the valuable point of 6 GHz. The 6 GHz band has up to 59 20 MHz channels, significantly more than 5 GHz.

Simply put, instead of all the devices having to squeeze onto the old roads, Wi-Fi has a new spectrum area to allocate devices. With 59 20 MHz channels, a system with 35 Access Points will have more room to arrange channels without having to reuse too much. This is the first and very important benefit of 6 GHz: it makes Wi-Fi less crowded. And when Wi-Fi is less crowded, real-world performance can be more stable, especially in high-density locations.

But 6 GHz has another benefit: it makes it easier to use wider channels

Fast Wi-Fi requires more than just a good signal. It also needs a wide enough channel width. You can think of 20 MHz as one lane, 40 MHz as two lanes, 80 MHz as four lanes, and 160 MHz as eight lanes. The wider the channel, the more data it can theoretically transmit in the same amount of time. But the wider the road, the more spectrum is needed. That's why 160 MHz over 5 GHz isn't always easy to deploy in crowded environments. There are few channel widths to choose from, so using a large channel width can increase the possibility of conflicts and interference between Access Points.

So does Wi-Fi become twice as fast at 6 GHz?

Not necessarily. This is where it is easy to misunderstand. A device connecting at 6 GHz is not automatically faster than a device connecting at 5 GHz just because the number 6 is larger. Actual speed depends on many factors: which Wi-Fi standard the device supports, number of spatial streams, channel width, signal conditions, capabilities of the Access Point and terminal... 6 GHz creates more spectrum resources so Wi-Fi can operate more efficiently.

If a device supports 160 MHz, for example, having more 160 MHz channels will make deployment easier in multi-device environments. In other words, the benefit of 6 GHz is not just peak speed, but also capacity. These are two quite different concepts. Peak speed is the maximum speed a device can achieve. Capacity can be simply understood as the ability to serve many devices at the same time while the network still maintains good performance. And with modern Wi-Fi, capacity is increasingly important.

6 GHz also has the advantage of being a relatively new "land".

Another problem with 2.4 GHz and 5 GHz is that they have been in use for a long time. Not only Wi-Fi, many other types of wireless devices also operate on these spectrum areas. When multiple sources appear at the same time, the risk of interference increases. 6 GHz is different. This is a new spectrum band put into use by Wi-Fi 6E, then continued to be exploited by Wi-Fi 7. So, in properly licensed environments, it creates a new and less “legacy” radio space than 2.4 GHz and 5 GHz.

Of course, it should not be understood as “6 GHz is completely free of interference”. It is still radio waves and can still be affected by the environment and other systems depending on each country's regulations. But in terms of Wi-Fi design, having a new spectrum band with more channels is clearly a big advantage.

So what does 6 GHz ultimately bring?

If I had to shorten it into one sentence, I would say this: 6 GHz does not simply make Wi-Fi faster, but it gives Wi-Fi more space to operate. More space means more channels. Having more channels means less need to share and reuse channels. Having more channels makes it easier to deploy wide channel widths such as 80 MHz, 160 MHz or 320 MHz. And when there are many devices accessing the network, especially in offices, hotels, conferences, stadiums or crowded places, this benefit can be even more important than a very large maximum speed number on the product box. That's also the reason why if we look at Wi-Fi 7 only through the number 46 Gbps, we will miss a quite important part of the story. Next-generation Wi-Fi isn't just trying to make a device faster. It's also trying to make the entire Wi-Fi network serve more devices, have less resource contention, and maintain more stable performance. And that is one of the most significant reasons for us to care about the 6 GHz band. In Vietnam, although devices supporting the 6 GHz band have been officially allowed to be imported, in order for this feature to be provided to users, the device still needs to meet compliance requirements according to domestic regulations.

The problem lies in each specific product. Just because a smartphone or laptop has Wi-Fi hardware that supports 6 GHz does not mean that users in Vietnam will be able to use this band. The manufacturer must also put the device through the necessary testing and certification/conformity processes for the Vietnamese market. Therefore, it may happen that the same model supports Wi-Fi 6E or Wi-Fi 7 in hardware and can use 6 GHz in another market, but when officially sold in Vietnam, this band has not yet been activated. At that time, the story no longer lies in the capabilities of the Wi-Fi chip, but in whether the manufacturer has completed the necessary procedures to bring the 6 GHz feature to the version for the Vietnamese market or not. You just wait for the devices to gradually appear and the "networkers" in the community will assist in providing this information.