Will 802.11af Wi-Fi Replace 802.11ac in the Home?

Wireless Wonk

Will 802.11af Wi-Fi Replace 802.11ac in the Home?

By Barlow Keener, Attorney  |  December 04, 2014

What do 802.22, WRAN, Wi-FAR, 802.11af, White-Fi, 802.19.1, and Super-Wi-Fi all have in common? They all are part of the newest IEEE (News - Alert) standards ecosystem supporting spectrum sharing for cloud-directed agile radios.  

TV white spaces was the first brand used for the spectrum-sharing method adopted by the FCC in 2010. Now, new spectrum-sharing terms like dynamic spectrum access and spectrum access system are being adopted. Spectrum (News - Alert) sharing is also moving out of the spectrum occupied by TV stations and into 3.5gHz, so TV and white spaces may no longer be applicable descriptors. With the new IEEE 802.xx standards being approved for the new spectrum-sharing radios, chip makers are looking at committing the multi-million dollar budget required for manufacturing a chip. After the chip makers start delivering the chips to the world, the new efficient spectrum-sharing system will be known by the industry with the IEEE designation: 802.22 for long-haul broadband or 802.11af for local area Wi-Fi broadband.

On July 1, 2011, IEEE published 802.22. Dubbed  Wireless Regional Area Networks, it is also known as W-FAR, a better descriptor. Apurva Mody led the IEEE 802.22 Working Group. He also is the chairman of the White Space Alliance. He and the other White Space Alliance members such as iConectiv have tirelessly promoted the spectrum-sharing method across the globe.  

Why is 802.22 a big deal? The industry press focuses on WRAN’s broadband reach of 20 to 60 miles. The service can deliver 22Mmbps over a 6mHz channel and can technically combine four channels to deliver up to 88mbps. The spectrum for the 802.22 standard is the unused TV channels ranging from 54mHz (VHF Channel 2) to 862mHz (TV channel 69).  The unused spectrum is called white spaces, and is located between active TV channels.

What is new and unique technically about 802.22 is that it establishes a method for more efficiently employing the empty TV channel spectrum and not interfering with active TV spectrum. The cloud database directs the spectrum agile broadband radios to use free TV channels based on information received from spectrum regulators like the FCC (News - Alert).      

802.22 provides for different power levels as authorized by the regulator. For fixed-outdoor uses, the maximum power allowed by the FCC is 4 Watts, but for personal portable agile radios it is 100mW. It is the 4-Watt power that allows 802.22 devices to deliver fixed, wireless broadband through 25 miles of trees, just like TV stations and two-way public safety radios.  

The applications are endless as the 802.22 fixed wireless broadband radios can potentially eliminate the use of towers because of the superior propagation characteristics through trees, buildings, and terrain. The radios can deliver intelligent transportation system applications through curves and trees found in thousands of miles of roads. 802.22 can deliver fixed broadband for mobile carrier backhaul in rural areas and to carrier small cells in urban areas. The TV white spaces radios can also deliver fixed wireless broadband across hundreds of miles of rural areas, through trees and terrain in Africa, Asia, and India, where there is no fiber. 

On Feb. 25, 2014, IEEE took another significant step, publishing 802.11af, also called White-Fi. 802.11af is a modified Wi-Fi standard building on the 802.11ac WiFi (News - Alert). It operates with spectrum-sharing techniques using a cloud geo-location database in the TV channel spectrum with agile radios. 802.11af allows radios to use 6, 7, and 8mHz channels bonded up to four channels delivering 24-32mHz of spectrum. 802.11af is meant for short-range broadband connections, and not for 802.22 long-haul connections. This means that 802.11af will be ideal for M2M connections, as it will use well-known 802.11ac methods but, using the TV spectrum, will penetrate walls, basements, and foliage. Wi-Fi using 2.4gHz, on the other hand, cannot reach into many home basements and is difficult to consistently connect M2M devices.

On Sept. 17, 2014, IEEE moved again and published 802.19.1. It established co-existence standards for agile radios operating together within the unlicensed spectrum directed by geo-location cloud databases. 802.19 requires a coexistence and information server, which gathers information regarding the location, antenna height, and power levels of other nearby agile radio networks operating in approved unlicensed spectrum slices. With the notification information from the coexistence servers, the agile radio networks can move to nearby lesser-used unlicensed channels.  

Edited by Maurice Nagle