A few weeks ago marked a pivotal moment in the realm of wireless technology as the Wi-Fi 7 standard was officially ratified. With this milestone, new standards promising increased throughput and reliability are poised to reshape the RF landscape. In my latest blog titled ‘To 802.11be or not to 802.11be,’ I delve into the implications of this development. Yet, the rapid pace of technological evolution leaves no room for rest, as the IEEE has already set its sights on the next horizon. Since its establishment in July 2022, the study group for Wi-Fi 8 (802.11bn) has been diligently crafting the blueprint for the future of wireless connectivity.  Here’s a sneak peak into what we might expect:

The 802.11bn standard will also have the designation “UHR” or “Ultra High Reliability”.  The release of Wi-Fi 7 introduced the idea of Multi-Link Operation (MLO), which leverages different bands (typically the 5 GHz and 6 GHz) as a sort of port channel to provide both an increase in potential bandwidth as well as redundancy.  But this technology may be more beneficial to increase reliability by choosing a link based on signal quality or duplicating packets on both links with the assumption that at least one of the packets will arrive at the receiver.  This is likely where Wi-Fi 8 will continue to make improvements to MLO.

Wi-Fi 8 will take MLO to the next level by implementing it in a distributed architecture (i.e. stations connected to two APs simultaneously).  One of the goals of this new MLO operation is for improved roaming capabilities.  Essentially, one radio will perform fast roaming to the next AP, while the other remains fully associated with the current one.  This allows the client to perform the authentication/reassociation/EAPOL exchange on one link, while the other continues to send and receive traffic without interruption until the new PTK is generated.  This will reduce the amount of time a client spends not transmitting or receiving data traffic while it transitions.  Increased reliability while roaming, would be a welcomed change, at least until we need to collect on more channels during over-the-air packet capture, but I digress.

All this comes with the caveat that devices that leverage multiple radios will undoubtedly have greater power consumption.  As of now, I have yet to see anything to suggest that 802.11bn will make changes to client-side power utilization beyond the WMM Power Save standard. Wi-Fi 8, however, is expected to address and reduce AP power consumption.

Another possibility for Wi-Fi 8 is the use of mmWave spectrum.  A lot of people in the industry have wanted to see WLANs expand into the 60 GHz frequency spectrum to be able to better support high bandwidth/low latency applications, such as augmented reality.  The last thing I heard, is that 802.11bn will focus on the sub 7 GHz spectrum, and support for mmWave will be addressed by a different group.  This, however, may change.

One thing that is certain about the new soon to be standard, is there will be a heavy focus on multi-AP coordination.  In the past, APs have relied on CSMA/CA (collision avoidance) with carrier sense to avoid stepping over each other.  Some improvements, such as auto tuning radios to select channels and transmit power have helped keep APs from stepping on each other’s toes, but Wi-Fi 8 will take AP coordination to a new level.  In fact, new frame types will likely need to be created to facilitate this level of synchronization.  Some of these proposed improvements include the following:

• Shared Spectrum: Through C-TDMA (contention time-division multiple access) WLANs will be able to divide the TXOP (transmit opportunity) into slots allocated to different APs. Another possibility is the use of C-OFDMA (coordinated Orthogonal Frequency Division Multiple Access) to share frequency resource units between neighboring APs, so long as the entire channel is not required.  This will allow APs to send at the same time contention free.
• Coordinated Spatial Reuse (C-SR): This focuses more on the transmit power of the APs, but not to be confused with RRM or AirMatch. By measuring RSSI information of potential interferers in an OBSS (overlapping BSS), C-SR will manage the tx power to allow APs to send at the same time while maintaining adequate SINR at the receiver.  Access Points will not need to win contention as often and will increase through-put for all devices.
• Distributed MIMO: Multiple APs will be able send data jointly to a MLD, as opposed to just one AP sending multiple streams. The Access Points would need to be able to first share the data to be sent and then coordinate that transmission.  A rather ambition proposition IMO.
• Coordinate Beamforming: Access Point have been able to use spatial multiplexing to allow multiple signal streams to arrive at a receiving station in phase, thus increasing the SNR and allowing greater data rates. Coordinated beamforming (CBF) will allow an AP to send null streams to stations in an OBSS.  These streams will cancel each other out, thus reducing interference.

As demonstrated, Wi-Fi 8 promises significant advancements in network reliability and performance, presenting an exciting frontier for businesses. While some proposed features may undergo refinement or modification before the standard’s release in 2028, the ongoing innovation in wireless technology underscores a promising future for our industry. With greater reliability taking center stage, businesses can anticipate enhanced connectivity solutions that empower productivity and drive success in an increasingly wireless world.