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Wi-Fi Gets Multi-Gigabit, Multi-User Boost With Upgrades To 802.11ac (arstechnica.com)
The Wi-Fi Alliance has announced its certification program for IEEE 802.11ac Wave 2, a technology that has been around on the market for more than a year. Wave 2 can deliver up to 6.8Gbps and lets an access point interact with more than one device at a time. Wave 2 features MIMO (or MU-MIMO) which improves the MIMO technology that lets Wi-FI transmit over more than one stream through the air. Wave 2 standard utilizes channels up to 160MHz wide (up from 80MHz channels available with Wave 1). It also creates more spatial streams and uses spectrum more efficiently, the industry group said on Wednesday. Ars Technica adds:On top of MU-MIMO, wider channels, and more streams, the Wi-Fi Alliance says Wave 2 features now being certified bring "support for a greater number of available channels in 5GHz," a change that "makes more efficient use of available spectrum and reduces interference and congestion by minimizing the number of networks operating on overlapping channels." You may have already noticed routers supporting some of these features, since the specification details have been available for a few years. In fact, routers with MU-MIMO started appearing in July 2014, and you can find routers that use 160MHz channels. The certification program takes a while to catch up with real-world implementations, but it ensures compatibility between devices and may spur faster adoption by vendors. End-user devices such as phones, tablets, and laptops must also be updated to take advantage of new features such as MU-MIMO.
True, but keep in mind that what matters is not just bandwidth, but bandwidth*time. If you have 100Mhz of spectrum to use, and user A and user B each get 50Mhz, let's say this gives them each 50mb/s of bandwidth. But if we let them both use all 100Mhz, then they each get 100mb/s peak bandwidth, while still having ~50mb/s each if it's congested. So if each of them has a fixed amount of data that they want to transfer, they use the same bandwidth*time as before. It only becomes a problem if you have a bandwidth hog who will use any available bandwidth you give them.