This portion of extra content is part of the explainer post on the new Wi-Fi 7 standard.
1. The all-new 320MHz channel width
The first is the new and much wider channel width, up to 320MHz or double that of Wi-Fi 6/E.
Organically, this new channel width is only available on the 6GHz band, with up to three 320MHz channels. However, Wi-Fi 7 can combine portions of the 6GHz and 5GHz bands to create this new bandwidth — more on this in the Multi-Link Operation section below.
I talked about Wi-Fi channels in this post, but generally, the higher bandwidth means Wi-Fi 7 can double the base speed, from 1.2Gbps per stream (160MHz) to 2.4Gbps per stream (320MHz).
So, in theory, a 4×4 broadcaster 6GHz Wi-Fi 7 can have up to 9.6 Gbps of bandwidth — or 10Gbps when rounded up. In reality, depending on the actual configuration, Wi-Fi 6 routers and access points will be available in different speed grades, including those offering bandwidths higher than 10Gbps on the 6GHz band.
Wi-Fi 7 also supports double the amount of partial streams, up to 16. As a result, technically, a 16-stream (16×16) Wi-Fi 7 6GHz band can deliver up to over 40Gbps of bandwidth, especially when considering the new QAM support below.
Again, to use the new 320MHz channel width, you will need a compatible client. Existing clients will connect using 160MHz at best. And in reality, the 160MHz will likely be the realistic sweet-spot bandwidth of Wi-Fi 7, just like the 80MHz in the case of Wi-Fi 6.
2. The 4K-QAM
QAM or quadrature amplitude modulation is a way to manipulate the radio wave to pack more information in the Hertz.
Wi-Fi 6 supports 1024-QAM, which itself is already impressive. However, Wi-Fi 7 will have four times that, or 4096-QAM. Greater QAM is always better.
As a result, Wi-Fi 7 will have a much higher speed and efficiency than previous standards when working with supported clients.
|Wi-Fi 6/E||Wi-Fi 7|
(Up to 3 on the 5GHz band and 7 on the 6GHz band)
(Up to 3 channels on the 6GHz band)
|Highest Modulation Order||1024-QAM||4096-QAM|
of Spatial Streams
|Theoretical Full Band Bandwidth||9.6Gbps
3. Multi-Link Operation
Multi-Link Operation or MLO is the most exciting and promising feature of Wi-Fi 7.
In a nutshell, MLO is Wi-Fi band aggregation. Like Link Aggregation (or bonding) in wired networking, MLO allows combining two Wi-Fi bands, 5GHz and 6GHz, into a single Wi-Fi network/connection.
The bonded link is also available in two modes: load balance or failover.
The former allows for combining the bandwidth of both bands into a single link. It’s excellent for those wanting to get the fastest possible wireless speed but requires support on the client end to work.
The latter, however, only requires support from the broadcasting side and can be a game-changer in a wireless mesh setup. With failover MLO, we can potentially count on having no signal drop or brief disconnection. And it’s also when seamless handoff (or roaming) can become truly seamless.
On top of that, on each band, a connection can also intelligently pick the best channel, or channel width, in real-time. In other words, it can channel-hop, just like Bluetooth, though likely less frequently.
(Up to Wi-Fi 6E, a Wi-Fi connection between two direct devices takes place in a single band, using a fixed channel, at a time.)
This new capability will help increase the efficiency of Wi-Fi 7’s range, allowing all of its bands to deliver faster speed over longer distances than previous standards.
In more ways than one, MLO is the best alternative to the existing so-called “Smart Connect” — using the same SSID (network name) and password for all the bands of a broadcaster — which doesn’t always work as smartly as expected.
Clearly, how MLO pans out remains to be seen but there seems to be no downside to this new capability.
4. Automated Frequency Coordination
Automated Frequency Coordination (AFC) applies mostly to outdoor 6GHz Wi-Fi applications.
In an open environment, there can be existing applications that already use the spectrum. For example, fixed satellite services (FSS) or broadcast companies might have already had licenses to use certain parts of the band.
As a newcomer, Wi-Fi (6E and 7) must not impact those existing services — a concept similar to the use of DFS channels in the 5GHz band.
That’s when AFC comes into play. The idea is that all new 6GHz broadcasters check with a registered database in real-time to confirm that their operation will not negatively impact other registered members, including other Wi-Fi 6E or Wi-Fi 7 broadcasters.
The support for AFC means each Wi-Fi 7 broadcaster will have its own free airspace to operate, meaning vendors can use more power and more flexible antenna designs.
In short, AFC compliance will help a Wi-Fi broadcaster improve range and connection speeds by preemptively creating “private” airspace dependent on the current real-world situation, in which it can operate without the constraint of regulations.
The new chips Broadcom announced today collectively support all these new features of Wi-Fi 7.