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Wi-Fi 6E brings Wi-Fi into 6GHz Spectrum

By Sumanth posted 10 days ago

  

[Recap]

It’s now been about 2 years since Wi-Fi 6 Access Points first showed up on the market, and about one year since we first looked at Wi-Fi 6 last year on our FortiCast podcast (link) where we talked about some of the technological aspects of the standard.  The transition is now in full swing we see most customers now evaluating Wi-Fi 6 for their needs before looking at older technologies.

In many ways, Wi-Fi 6 has been one of the most successful standards as client devices have been available much quicker this time around than in previous technology shifts.

Yet even though Wi-Fi 6 isn’t yet old news, there’s a new topic on the horizon being talked about, Wi-Fi 6e.

 

[General overview]

Wi-Fi 6E is the industry name for users to identify Wi-Fi devices that will operate in 6 GHz. Wi-Fi is getting faster and faster. Faster internet is in constant demand, especially as we consume more bandwidth-demanding apps, games, and videos with our laptops, hand held devices and phones. Wi-Fi 6 and previous generations of Wi-Fi use the 2.4Ghz and 5 Ghz bands. When it comes to “Wi-Fi 6E” device, it’s the one that is capable of operating on the 6 GHz band, too.



Wi-Fi6 is not just a simple speed boost, we will have more and more benefits overtime as its designed for future-facing upgrades As shown in Figure 1, new unlicensed frequency band availability is a boom to have more contiguous wider channels with less interference. Also, Wi-Fi 6E offers the features and capabilities of Wi-Fi6—including higher performance, lower latency, and faster data rates—extended into the 6 GHz band which extrapolates the benefits of having gigabit speeds at extremely low latency and high capacity. Some of the key capabilities supported in Wi-Fi6 and being delivered by Wi-Fi6E devices are

  • Multi-user multiple input multiple output (MU-MIMO): allows more downlink data to be transferred at once and enables an access point to transmit data to a larger number of devices concurrently
  • 160 MHz channels: increases bandwidth to deliver greater performance with low latency
  • Target wake time (TWT): significantly improves battery life in Wi-Fi devices, such as Internet of Things (IoT) devices
  • 1024 quadrature amplitude modulation mode (1024-QAM): increases throughput in Wi-Fi devices by encoding more data in the same amount of spectrum
  • Transmit beamforming: enables higher data rates at a given range resulting in greater network capacity
  • Orthogonal frequency division multiple access (OFDMA): effectively shares channels to increase network efficiency and lower latency for both uplink and downlink traffic in high demand environments

 

 

The basic idea behind Wi-Fi 6e is straightforward, it’s the same Wi-Fi 6 technology, extended to the 6GHz frequency band where traditionally Wi-Fi technology has not had regulatory clearance to operate.  Of course, when you dig in a bit, there’s a bit more to it than that.

 

The 6 GHz spectrum will work similarly to Wi-Fi 6 over 5 GHz but offers additional non-overlapping channels and contiguous spectrum for. As per WFA, Wi-Fi 6E allows “14 additional 80 MHz channels and 7 additional 160 MHz channels.” These channels wouldn’t overlap with each other, which will help reduce congestion, particularly in much crowded and densely populated enterprise wireless deployments. This increase in spectrum bandwidth empowers the newest generation of Wi-Fi 6E devices to achieve faster speed, lower latency and higher capacity.



Figure 2: Channel availability and Comparison between 2.4, 5.0, 6 GHz bands
* Pic source Broadcom https://jp.broadcom.com/info/wifi6e 

From the Figure 2 above, you will notice Wi-Fi 6E has 1200 MHz of spectrum from 5.925 to 7.125 GHz for Wi-Fi applications and the its quite evident that all the devices communicating on the 6 GHz spectrum would also be Wi-Fi 6 devices. There wouldn’t be any older devices using standards like Wi-Fi 5 (802.11ac). All devices on the 6 GHz channels will be speaking the same language and can use Wi-Fi 6’s new congestion-busting features.

In other words, Wi-Fi 6E is Wi-Fi 6 (also known as 802.11ax) over 6 GHz.

 

 

How much bandwidth is available?

6 GHz addresses Wi-Fi Spectrum shortages by providing contiguous spectrum blocks to accommodate additional channels which are needed for high-bandwidth applications that require faster data throughput such as high-definition video streaming and virtual reality. Wi-Fi 6E devices will leverage wider channels and additional capacity to deliver greater network performance and support more Wi-Fi users at once, even in very dense and congested environments.

Regulations are still in flux, and of course they vary country to country, but as of this writing here’s how the new spectrum block is shaking out:

  • Most locations in Europe will receive about 500MHz of additional channel space in the 6GHz band.
  • The United States will receive roughly 1.2GHz of additional spectrum.

Now of course this bandwidth didn’t exactly appear out of thin air, this space has been used in the past, and there are incumbent technologies already using the band, which brings up the regulations for sharing this space.

 

Now, spectrum sharing isn’t anything new for Wi-Fi, it has always operated in unlicensed bands in which other technologies could potentially operate.  You may have heard that this will require Wi-Fi 6e equipment to operate at “low power” to protect the fixed microwave links, satellite services, and television/broadcast services that already operate within this band, but what’s important to remember is that this ‘low power’ in the context of large-scale RF equipment.  The power maximums being considered by bodies such as the FCC are still well within the standard operating range of existing Wi-Fi equipment, meaning that coverage areas and AP counts shouldn’t be terribly different.  [Keep in mind, many of these items are still in flux and could change.]  More limiting is that this operation requires integral (non-removable) antennas and is for indoor use only.

To be allowed to operate outdoors, at higher power, and allow for choice in antenna, there are additional requirements the FCC is looking to place on the AP.  Most notably the device must register its location with an online service that will consider any incumbent systems in the area and report back which frequency ranges and power outputs are acceptable to use.  This is a very new methodology for Wi-Fi, but has been used in other technologies for a while.

 

[Why the excitement]

 

So, with these limitations and the potential lag for clients that support Wi-Fi 6e, why is there so much excitement?  The time answer is that it’s new and there are no devices.  Wi-Fi’s success and its Achilles heel are backwards compatibility with all the previous generations of devices that people carry around.  Every older device in the system that can’t take advantage of the new technology benefits drags the entire BSS’s performance down. Since there are a ton of existing older Wi-Fi clients that only use 40 MHz, or 20 MHz channels, all networks have to struggle between compatibility and performance. But with Wi-Fi 6e being new spectrum, there will be no older slower devices in the network.  Wi-Fi technology hasn’t had this chance for ‘clean uncluttered’ operation since 802.11a first opened the 5GHz band!

 

[Wrap up]

 

So, what does all this mean for you?   Should people wait to purchase Wi-Fi 6e equipment?  Is Wi-Fi 6 already passé?  Not at all.  For many deployments Wi-Fi 6 is great technology that will serve them well for many years.  Wi-Fi 6e is an opportunity (when it arrives) to add more flexibility and capability. To use the new 6 GHz band, you’ll need a new broadcaster (a router) and clients (phones, laptops, etc.) that support it. Virtually every installation needs to service their current client set, so operation on 5GHz and 2.4GHz isn’t going away, and Wi-Fi 6 does this optimally.  However, as Wi-Fi 6e equipment rolls out in 2021, it’s worth considering what your client makeup is, whether you are likely to see Wi-Fi 6e devices start to enter your network, and look to potentially augment an existing installation with 6GHz technology.

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