Wi-Fi Tech of Yesterday
Wi-Fi has evolved significantly. If one goes back a decade, the Wi-Fi industry mostly comprised of 802.11g products, and was about to shift to 802.11n. Wi-Fi existed mostly in portable PCs, some desktop PCs, and a small number of PDAs. That was single-stream Wi-Fi in narrow bands. 802.11n brought the option of multiple data streams with MIMO and the use of beamforming to enable a more robust connection, but only to one device at a time. The value of a Wi-Fi access point would be limited to the highest common denominator. An 802.11n access point with 4X4 MIMO would only make use of 4X4 if there were 4X4 clients on that network, and there were practically none. The occasional 2X2 and 3X3 client – typically portable PCs and Chromebooks – would see a benefit of much higher data rates. 802.11n could work in either band, so the benefits would be greater if the both the access point and client were dual-band and connected over the 5 GHz band. 802.11ac Wave 1 continued that push, except the use of 5 GHz became mandatory; 802.11ac only works in the 5 GHz band. Of course, products are typically dual-band for backwards compatibility. 802.11ac also allowed wider channels to be used which enabled even higher data rates.
Wi-Fi Tech of Today
Today, Wi-Fi is shifting to 802.11ac Wave 2 with MU-MIMO and WiGig. Wi-Fi-enabled products now run the gamut from PCs, tablets, wearables, and a massive number of smartphones to TVs, STBs, smart home products, robots, and random IoT products. In the enterprise, the ability to connect anywhere from PCs, tablets, smartphones, and wearables that are densely packed in corporate environments is critical for ease of access to information. Broadband service providers wisely consider how they best support home broadband customers with consumer access points. Mobile operators are using Wi-Fi hotspots and small cells supporting link aggregation between LTE and Wi-Fi.
In a decade the Wi-Fi industry has gone from 20 and 40 MHz channels to 80 GHz channels (and even 160 GHz channels in 802.11ac Wave 2) and to about 2 GHz channels with 802.11ad. More spectrum is part of the picture, but complex antenna techniques are also critical. To ease wireless network congestion in the home, enterprise, and service provider markets, two very different approaches are being leveraged by the Wi-Fi market:
- The use of MU-MIMO (multi-user MIMO) and wider channels by 802.11ac Wave 2 in the 5 GHz band.
- The use of beamforming with antenna arrays in ultra wideband channels by 802.11ad, or WiGig, in the 60 GHz band.
5 GHz or 60 GHz? Both? Design Tradeoffs?
Boosting 5 GHz Wi-Fi with MU-MIMO and using WiGig in 60 GHz is not an either/or situation. The spectrum at 5 GHz will still in some cases get overcrowded necessitating the use of 60 GHz spectrum. Conversely, the need to connect through walls will require to continued use of 5 GHz bands, unless a space is set up with at least one WiGig access point in each room backhauled over 10 Gigabit Ethernet or 100 Gigabit Ethernet wiring. Since this would be too expensive, it is more likely the future will bring multiple WiGig access points in key rooms where video and VR are used while 5 GHz Wi-Fi will cover the rest.
On the client side, however, design tradeoffs can and will be made. They will run the gamut from single-band to dual-band and tri-band. A smart home product might only use 2.4 GHz or both 2.4 GHz and 5 GHz. A portable PC will use all three bands, for example. A monitor might only use 60 GHz to act as a monitor and docking station . . . or the monitor might be tri-band so the portable PC connects only to the monitor(s) over 60 GHz for the display(s), connections to peripherals, and connection to the network/Internet where the monitor is connected to the Internet.
Use the Latest Wi-Fi Protocols for the Best Future Compatibility
One of the most important considerations for product planning is to place 802.11ac Wave 2 and 802.11ad (WiGig) in the context of their evolution. The next two key Wi-Fi protocols are 802.11ax and 802.11ay. (See our Wi-Fi market data for forecasts by protocol by product category.) 802.11ax will evolve Wi-Fi in the 2.4 GHz and 5 GHz bands and will add uplink MU-MIMO. It will be backwards compatible with all older 2.4 GHz and 5 GHz protocols. By ensuring the use of 802.11ac Wave 2 in products today, downlink MU-MIMO will allow these products to be as efficient as possible on the downlink. Older Wi-Fi protocols will really start to slow 802.11ax down. The inclusion of 802.11ad will allow current products to be future compatible with 802.11ay which will be able to fall back to 802.11ad.
Two Free White Papers for More Information
ABI Research is still offering a free white paper on each of these here: https://www.abiresearch.com/pages/mu-mimo-and-802-11ad/. They discuss the issues and solutions by these technologies, the ecosystem support by chipset and product vendors, and show how rapidly they will grow in the Wi-Fi market in different product types.
