While 802.11ac Wave 2 may be getting all the headlines, there is another 802.11 standard -- 802.11ad -- that should...
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be attracting your attention.
Make no mistake: Wave 2 will become the mainstream wireless LAN technology that will carry the industry for the rest of the decade and maybe longer. The benefits here are both clear and enormous, particularly with respect to beamforming, which improves rate-versus-range performance; multiuser MIMO, which improves capacity; and beefed-up throughput -- exceeding 1.7 Gbps, at least according to the specs.
But 802.11ad is worth noting. Known as the other gigabit WLAN specification, the 802.11ad standard can offer peak throughput of more than 6.75 Gbps on each of the four channels defined in the spec. But that comes with a couple of catches.
Wider channels support higher throughput
First, let's explain the reason for that throughput. The 802.11ad channels are 2.16 GHz wide -- compare that with the 80 MHz channels common in Wave 2. More spectrum means more bits over the air per unit of time. But that spectrum is located around 60 GHz, as opposed to the 5 GHz of 802.11ac. And 60 GHz signals don't propagate very far through the air -- the oxygen in the atmosphere actually absorbs radio energy at those frequencies -- and these signals do not pass through walls very well, either. Bottom line: Lots of spectrum, but this spectrum isn't as robust as that at 5 GHz.
Or, is it? Back in the days of 802.11g, another virtually identical standard, 802.11a, was specified using only the 5 GHz bands -- like 802.11ac, oddly enough. The .11a was essentially ignored, based on numerous reports that it simply could not match the range of 802.11g. But what the analysts missed was at any range over which .11a worked, it universally delivered better throughput than .11g. The reason for this was a lack of interference at 5 GHz, plus some clever radio technology compensating for the nature of RF propagation at 5 GHz. And similar misconceptions now accompany these early days of 80211.ad, as its capabilities become more recognized.
Capacity the key to 802.11ad standard
The key issue today, after all, isn't range; everyone knows -- or should know -- that less range means higher throughput, along with the ability to reuse channels over shorter distances. The net-net here is capacity is now the key objective -- and that's why the 802.11ad standard will see major applications in the coming years. Many applications, such as virtual docking stations, HDMI cable replacement, virtual reality headsets and other bandwidth hogs, will find a perfect home with 802.11.ad. Range issues simply won't be on the table, and performance within open-office environments, and, interestingly, within closed rooms, should be nothing short of amazing.
What are we waiting for with this newest entrant? Products. The Wi-Fi Alliance is still developing its specification for .11ad -- you will hear the term WiGig used here. This should be issued shortly, along with triple-band clients, infrastructure chipsets and the specialized antennas required -- don't worry, they're tiny. Our early experiments with 60 GHz have been really encouraging -- you won't find higher throughput, or, again, more capacity -- with any other Wi-Fi technology. And even as the 802.11ad standard rolls out, an even higher-speed spec -- 802.11ay, with a throughput of 20 Gbps -- is under development.
As wireless progresses from the primary or default access for clients to the only access required or even available, 60 GHz options will play an increasing role in meeting end-user demand. To that end, the 802.11ad standard belongs on your research list for this year. It's not an alternative to 802.11ac yet, but for many emerging applications, it just may well be.
Understanding gigabit WLAN standards
First 802.11ad products ship for wireless offices
Debating the throughput of 802.11ad