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Dominik

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Wi Fi 6 Explained

Like any other software standard, the IEEE 802.11ax specification, more commonly called Wi-Fi 6, is essentially just a collection of technologies. In this case, we’re mostly talking about communication protocols designed to help multiple devices communicate with one another in a secure and private fashion.

These individual pieces contained within any modern software specification may share some – or many – interfacing elements. But even if they are somewhat disjointed in terms of utility, these instruction sets are considered a standard first and foremost on the number, profile, and development output of the parties partial to the agreement. Everything else is just a nice coat of paint and some quality-of-life features.

As our main goal here is to provide the best, most full-featured overview of everything Wi-Fi 6 brings to the table, we’ll start by breaking down its key innovations which, by themselves, are already expected to evolve into seminal technologies, not to mention their potential as part of a well-oiled wireless machine.

But before we try to make sense of the technical terminology, let’s go over the very basics of why you, me, or anyone else should even care about this new Wi-Fi standard.

What does Wi-Fi 6 mean for things you care about?

In terms of commercial applications, there’s hardly a problem in a more dire need of a solution than the current state of public wireless networks across pretty much any industry. For example, maintaining a Wi-Fi connection in a 21st-century hotel lobby really shouldn’t have been as big of a technical challenge as it was until this latest generation of Wi-Fi was standardized, but here we are. Thanks to Wi-Fi 6, however, we’re at least – and at last – on the verge of a universal and permanent fix for public hotspots that fall apart whenever they’re asked to manage any number of device connections larger than the one they were maintaining just before your futile attempt at connecting to that cursed Starbucks_Free_WiFi AP.

You don’t have to be a regular witness to the sheer horror of the first-come-first-served principle applied in a modern networking environment in order to massively benefit from a transition to Wi-Fi 6 communications. Even your home network will likely enjoy massive performance gains as soon as your next router is up and running. In fact, not even devices that lack Wi-Fi 6 support will be able to completely negate the effects of thoroughly superior network management capabilities offered by such cutting-edge access points. Because back when Wi-Fi 5 was still being defined, the average home network comprised a handful of devices tops at any given moment. But all those Internet of Thingies you keep hearing about are only gaining traction nowadays, consequently more than doubling the aforementioned figure in just over half a decade.

That’s without even accounting for many other trends and circumstances giving rise to various forms of bad news for your home networking ambitions. E.g. the overall performance boost from Wi-Fi 6 could be the thing that ends up keeping your performance figures at levels you deem acceptable for VPN use, thus allowing you to avoid the Sophie’s Choice of weighing a poor online experience against one that’s inherently less secure and more threatening to any notion of privacy you may still cling to.

In no-nonsense terms: if you have more than two smartphone users in your household, chances are you’re on the receiving end of congestional WLAN bottlenecks on a weekly basis at best. Granted, it’s possible you ventured past that point before happening upon these words of wisdom and are now facing a much harsher reality; one in which you’re already halfway through the process of learning how your children failed to develop any meaningful sensibilities toward the challenging nature of working from home and just want to be left alone to their bandwidth-devouring habits instead of being lectured on how your blood, sweat, tears, and uninterrupted ability to send and receive large volumes of radio signals directly relate to their useless existences having the privilege of continuing. In such extreme-sounding-but-still-totally-plausible cases of techno-social challenges, the only thing separating your sanity from a one-way ticket to kookoo land is a timely Wi-Fi 6 investment. Yes, really, so let’s stop wasting any more time and get into the nitty-gritty of what makes this new technological standard so awesome.

Regarding gaming performance, if you’re in to competitive esports, forget about Wi-Fi 6, you should already be connected via LAN, let’s not argue about that. As for the mobile gamers out there, regardless if you’re in to smashing walls in Fortnite, digging through dirt in Minecraft or stacking cherries in different slots, Wi-Fi 6 could be something for you if your primary platform is a mobile phone or a tablet that connects to Wi-Fi.

Explaining Wi-Fi 6: the four core innovations

OFDMA – Part of the Long Term Evolution family that won out against Qualcomm, 4G OFDMA is shaping up to be the biggest individual upgrade to the WFA-maintained specification since at least 2003. It was back then that the now-discontinued Wi-Fi 3 moved from HR-DSSS to an early OFDM implementation – which exceeded expectations, as evidenced by its 17-year stint (during which it received some major upgrades, naturally).

Right now, the expectations seem to be even higher, but from another perspective, every single major networking performance improvement that Wi-Fi 6 enables can be traced back directly to OFDMA – bar one. But for now, the best way to acquaint yourself with such a new and highly prospective technology platform is to start from its biggest strengths, then try to figure out how it all fits together.

Therefore, let’s first explain how OFDMA makes Wi-Fi 6 such an exciting technology to adopt, that is – what it even is.

Which actually starts with frequency division multiplexing (FDM). Its key behavior is that it splits a single wideband frequency into longer sets of narrowband subcarriers. It does so as a redundancy – sacrificing signal speed for strength – which, in theory, makes data transmissions more reliable since the single biggest cause of network performance issues in the Wi-Fi 5 era was – congestion. Paving the way for idling devices, delayed packages, and consistently dropping performances.

The last standard simply wasn’t designed with numerous simultaneous connections in mind. As for the IEEE 802.11ax, this one does its best to be a lot wiser in how it anticipates the future – not just the future of IoT and the like, but literally predicting nearby client behavior in cas

That “O” in OFDM stands for “orthogonal”, a reference to the position in which the resulting subcarriers are left relative to one another after the split. That focus on relative perpendicularity is the only way OFDM can consistently split bands while avoiding interference between the resulting subcarriers – which can manifest as a distortion of various degrees.

They’re also evenly spaced during the process, which – like the OFDM graph illustrates – means an interruption that’s long enough will still decimate the signal. Still, the solution performed decently enough on congested networks.

Finally, cue OFDMA, whose final two letters stand for “multiple access”, referencing its widened capabilities. The subcarriers created through this iterative technique are stored in two-dimensional partitions called Resource Units (RUs). As illustrated below, this makes OFDMA not just more effective, but even more efficient at splitting any potentially problematic frequencies.

The result is an RF transmitter that has a higher rate of success by being smarter about how it repackages the signal it’s transmitting. Or, from another perspective: its clients are using less bandwidth and energy while experiencing lower latencies. With the new standard’s improved ability to manage signals, the very essence of wireless communications, OFDMA alone already delivers on much of the promise of next-generation Wi-Fi given by the 802.11ax specification.

MU-MIMO – Complementing OFDMA is MU-MIMO, the other half of the most impactful technological advancements under the Wi-Fi 6 label. Note the “most impactful” distinction because MU-MIMO was officially available since Wi-Fi 5 but never made much of a difference and wasn’t expected to.

Whereas OFDMA is focused on bettering frequency space partitioning by subdividing channels, MU-MIMO is all about using different spatial streams altogether, which allows for leveraging the actual radio hardware in a much more efficient manner. This means capitalizing on the fact that contemporary devices are already equipped with multiple radios and antennas and is especially useful for high-bandwidth applications dealing with large packets. The result is significantly increased throughput, i.e. faster data transfer rates.

The key difference between Wi-Fi 5 and Wi-Fi 6 is that the former’s MU-MIMO support was limited to a four-client downlink-only group, whereas the new technology supports eight clients in both uplink and downlink mode simultaneously.

Both MU-MIMO and OFDMA hence improve multi-user access to wireless networks in the most intelligent way science managed to come up with to date: maximizing both high-end and low-end clients and doing a better job at keeping them separated so that they don’t get in one another’s way.

A common analogy used for explaining the importance of widened network capacity and RF improvements relative to a single-minded focus on raw data rates is a sports car capable of going 300mph that’s stuck in a downtown traffic jam. While OFDMA reduces the chances of that traffic jam from happening through superior signal management and additional lanes, MU-MIMO builds out numerous highways that allow those faster vehicles to completely circumvent the possibility of getting stuck downtown since they weren’t even heading for any location in the city in the first place.

The analogy applies even beyond that as the coolest thing about Wi-Fi 6 is that OFDMA and MU-MIMO can be used on a case-by-case basis. The 802.11ax specification even offers truly simultaneous use, but that’s not a particularly consequential feature given how unlikely it is to be widely adopted. After all, the scenarios in which MU-MIMO shines (low-density, many access points) tend to be the opposite of those ideal for OFDMA (high-density, few access points).

Every other component of Wi-Fi 6 lends itself to the mechanics described above, whether by supplementing them for greater versatility, or by enhancing their effects. With that said, a couple of them do so better than most.

BSS Color – Also known as BSS coloring: a technique that lets APs differentiate between transmissions in their own network to neighboring activity. Failure to do so results in the infamous interference that’s been plaguing RF modulation since we found out radio frequencies are a thing that’s everywhere and doesn’t belong to anyone (which is why that second part wasn’t true for very long).

BSS is short for “basic service set”, or area of a given AP’s operation. When things get too hectic due to outside signals, you get overlapping – OBSS. OBSS interference is a pain to handle because it isn’t static and changes with client devices moving. But it can’t just be ignored because nothing would get done. Cie BSS coloring, a way for APs improve their accuracy of measuring OBSSs, which mathematically improves their ability to reuse channels by a factor of eight.

SRO – BSS coloring data is the basis for how Wi-Fi 6 approaches spatial frequency reuse; when it all comes together, it decides to push through interference with a spatial reuse operation, or SRO. The new specification also supports dynamic sensitivity and power thresholds to account for the equally dynamic nature of whatever interference data it has on hand, no matter how accurate its readings are (and BSS coloring makes them pretty accurate).

Wi Fi 6 Explained 2

Smaller Wi-Fi 6 innovations worth mentioning

160 MHz channel support – Having more channels is great for network capacity but doesn’t guarantee flashier speeds if MU-MIMO isn’t out in full force. That’s why Wi-Fi 6 widens its channel support by up to 160MHz, paving the way for even greater low-latency bandwidth gains. This support is conditioned on never being asked to become anything but, which is why it’s the MU-MIMO of this Wi-Fi generation, so to speak; its speed-boosting potential is amazing, but its lack of viability as a primary carrier delegated it to a supporting role, so its implementations will be limited to luxury electronics like high-end laptops for a good long while now.

Trigger-based Random Access – We’ve already established that OFDMA is great, but its effectiveness hinges on the volume of traffic it’s trying to direct. That is, it would, if not for trigger-based random access, a technique allowing it to mobilize nearby stations that aren’t already participating in a given exchange and are unlikely to be doing anything better with their time.

TWT- Establishing an individual target wake time for every device on the network means lowering the volume of pointless traffic. That’s another way for Wi-Fi 6 to improve transmission performance in highly contested scenarios while simultaneously reducing the network’s energy requirements. If you notice your smartphone using less battery while connected to your shiny new Wi-Fi 6 router, you have TWT to partially thank for that.

What does Wi-Fi 6 improve on existing tech

1024-QAM – Capacity, efficiency, channel breadth, interference – all of those things are important factors to consider when pushing the boundaries of wireless communications and were at least partially neglected relative to the industry’s focus on speeds. Which isn’t to say more speed is a bad thing, especially when the other pieces have fallen into place.

That’s where 1024 quadrature amplitude modulation mode comes into play by being a cutting-edge data encoding solution making spectrum do more. Compared to Wi-Fi 5 and its 256-QAM solution that modulates 8 bits per symbol, 1024-QAM does 10, or 25% more. Paired with new modulation coding schemes described above, Wi-Fi 6 can hit some pretty crazy peaks, going up to 9.6 Gbps. Compared to the last generation’s 3.5 Gbps ceiling, the new tech should also be closer to its theoretical limit when it comes to real-world scenarios, and 1024-QAM will be a large part of the reason why that’s possible.

With that said, as with any other method that brings us closer to the limits of physics, the point of diminishing returns isn’t that far away. In this instance, 10 bits of data per symbol means a signal-to-noise ratio threshold of about 35 decibels as far as Wi-Fi 6 radios are concerned, meaning 1024-QAM isn’t something that will play a large role in most Wi-Fi 6 experiences.

Extended symbol and guard interval duration – Lower effects of signal delay and all-around improved efficiency accounting for increased networking capabilities is what extending symbol interval durations and durations of guard intervals in Wi-Fi 6 are all about. These changes are equal parts improvements and something that simply had to be done given what the new tech grings to the table.

Fragmentation – Dynamic packet size has always been the goal in wireless communications but it wasn’t until now that the protocols got smart enough to be trusted with the autonomy to adjust the data as they see fit.

NAV – Introduced with Wi-Fi 5, the network allocation vector is a cool way for APs to gauge interference levels and other factors affecting how they approach the air interface without constantly pinging everything in their vicinity. NAVs proved to be so useful that the Wi-Fi 6 specification now insists on two of them, whereas the last one had but a single such abstraction unit. Further increases will depend on how far away from the point of diminishing returns we currently are.

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