This content is part of the Essential Guide: An 802.11ax survival guide: Expectations for the Wi-Fi standard
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Wireless capacity more important than fast Wi-Fi 6 speed

Wi-Fi 6 speed may be getting all the attention, but the most compelling advantages of the new standard are techniques engineered to increase wireless capacity.

Every new generation of Wi-Fi -- and just about every new Wi-Fi product -- usually leads with one key marketing message: more speed. But speed is more accurately defined as enhanced throughput.

Consider this Wi-Fi 6 speed marketing message: A recent advertisement for a Wi-Fi 6 home router touted the device as having "up to 10.8 Gbps combined wireless speed." That's impressive. And, believe it or not, the claim is legitimate. But let's explore further and see how numbers like these are derived, and why such claims are misleading or entirely irrelevant.

In this specific case, the router has three radios that can operate simultaneously, spec'ed as 1.2 Gbps for one and 4.8 Gbps for the other two. Now, keep in mind that these are the theoretical peak numbers possible. It's the speed that the vendor's marketing team guarantees the product will never exceed.

In this example, that 4.8 Gbps number assumes a 4x4 multiple input, multiple output (MIMO) connection, representing the unlikely configuration of four stream-capable devices on both ends and a 160 MHz radio channel representing physical throughput at Layer 1, not application performance at Layer 7. This means the Wi-Fi 6 speed numbers quoted are, respectively, peak, theoretical, ideal and real. Yet, they are essentially unachievable values that simply do not reflect what end users can realistically expect.

Other factors limit Wi-Fi 6 speed

Even if Layer 7 throughput on that order could be realized, the fastest Ethernet port provisioned for this particular product is 2.5 Gbps, with other ports limited to 1 Gbps each. Also, few or maybe no home users will have internet service provider (ISP) routers with 2.5 Gbps ports, never mind ISP speeds above 1 Gbps.

These peak numbers may mesmerize the less-educated, easily impressed buyer, but the ROI from these otherwise impressive specs simply won't and can't be realized.

Organizational deployments using channels larger than 80 MHz are generally discouraged -- with 40 MHz still very common -- because having more channels is a better option in high-demand environments. Keep in mind that Wi-Fi 6's throughput in a 40 MHz channel can reach 287 Mbps per MIMO stream -- in other words, plenty for typical users.

These peak numbers may mesmerize the less-educated, easily impressed buyer, but the ROI from these otherwise impressive specs simply won't and can't be realized. What, then, can you expect?

A general rule is to design systems with the assumption that they will operate successfully even if they only generate one-third to one-half of their full peak-rated throughput. Setting expectations properly is the best way to assure a satisfied customer.

The real benefit of Wi-Fi 6 is expanding capacity

Now let's really put the nail in the coffin of Wi-Fi 6 speed as a meaningful metric. In most Wi-Fi installations today -- and especially those in organizational settings -- the real issue isn't throughput. Rather, it's capacity.

Throughput can be easily provisioned for any application by using smaller channels, smaller cells, and vendor-provided radio resource management and analytics capabilities.

Capacity is the ability to meet the performance requirements of a large, growing and demanding user base. In a BYOD environment, users today routinely operate multiple devices simultaneously, all with multiple applications, including voice and video.

Sprinkle in additional performance requirements -- such as security, reliability, coverage and management -- and it becomes clear that peak throughput shouldn't be in the top 10 list of considerations when mulling your next installation or upgrade.

Wi-Fi 6 will support more throughput than any individual user might need. The standard's real advantages hinge on its technological capabilities, which optimize overall system capacity. Thanks to techniques such as orthogonal frequency-division multiple access, 1024 quadrature amplitude modulation, bidirectional MIMO and basic service set coloring, more users can get more done -- and all at the same time.

My advice: Ignore the throughput claims and instead rely on the advanced technologies of Wi-Fi 6. Those, along with advances in analytics and management, will make your users more productive at work and more satisfied when they leave the office for the day.

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