Wi-Fi 6E and Automated Frequency Coordination (AFC): What You Need to Know


Wi-Fi 6E, we have all heard the hyperbole surrounding it - the Wi-Fi superhighway, huge bandwidth, greater performance, elimination of slower technology devices, more secure, enhanced user experiences, and on and on. It’s just perfect, right? In reality, all of this is pretty much true, however, there are always caveats to be considered with any new technology.

Open Field

The Dream


The Reality

One of these is that although the 6 GHz band is new to Wi-Fi, it’s not the wide-open frontier waiting to be populated everyone talks about. There are plenty of early settlers (carriers and such) who have already staked out some property and aren’t too happy about all the new wireless homesteaders showing up. As a result, some additional rules are required to make sure all stayed peaceful on the prairie. While the FCC opened up the 6 GHz band for unlicensed operation for Wi-Fi, they also included some significant restrictions. To begin with, the FCC defines two types of device classifications with very different transmit power rules. Once again, the goal is to avoid potential interference with existing 6 GHz incumbents. The choices now are low power APs for indoor Wi-Fi and standard power APs for outdoor Wi-Fi. The low power APs, as the name implies, have reduced power levels since they are only used indoors. Any building walls will further attenuate the signals, making any potential interference with existing 6 GHz users very unlikely.

Now the outdoor, or standard power APs, are a different story as these have a serious potential of interfering with existing 6 GHz users in the area. Fixed satellite services (FSS) used in the broadcast and cable industries might already have a license for the channels in use. Therefore, any new unlicensed users (Wi-Fi) must ensure they do not impact the current services. As identified by the FCC, the answer to this is to create a way to coordinate the spectrum use to avoid interference issues. A spectrum use coordination system is not new – similar systems exist to support white space (White-Fi) and CBRS wireless operation. The basic concept in all these wireless technologies is that a new wireless device (access point) will consult a registered database to confirm its operation will not impact a registered user. For 6 GHz operation, this is called an Automated Frequency Coordination (AFC) provider.

Standard power APs must use an AFC service to protect incumbent 6 GHz operations from RF interference. Using the above graphic, we can see the process required for an AP to operate in the 6 GHz band:

An AFC provider will have been defined and approved (as of this writing, this is still 6-12 months away)

The AFC provider will contain a database of existing 6 GHz operators, including geolocation, frequencies, power levels, antenna coverage, etc.

  • The AFC database is built from the existing FCC database in which incumbent users are required to register their transmitters.

Once this system is in place, outdoor/standard power 6 GHz Wi-Fi may be deployed.

Before transmitting, a standard power AP must consult a local AFC system to validate frequency operation

  • Communication can be directly from AP to AFC or more likely via a proxy, such as a network management system
  • Just like the incumbent 6 GHz transmitter, the AP must provide all information about its location, coverage, and planned frequencies/power to be used
  • The AFC will either approve the usage request or provide alternatives, available channels, etc.
  • Only then can the 6 GHz access point start operation
  • Be aware this process is still in development, so the actual approval and specific rules are yet to be determined

In my opinion, I would not expect to see AFC systems operational until 2022.

Hopefully, this information is useful, and if it piqued your interest, please check out my Wi-Fi 6E session, which I delivered for a deeper dive: Wi-Fi NOW Virtual Wi-Fi World Congress

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About the Author
David Coleman
Director, Wireless Networking at the Office of the CTO

David D. Coleman is the Director of Wireless Networking at the Office of the CTO for Extreme Networks. David is a technology evangelist, public speaker and proficient author.

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