Automated Frequency Coordination (AFC) is a spectrum use coordination system designed specifically for 6 GHz operation
In order for unlicensed Wi-Fi 7 (or 802.11be) devices to play nice in the 6 GHz band with the licensed users already occupying that band, the Federal Communications Commission (FCC) established Automated Frequency Coordination (AFC), a spectrum use coordination system designed specifically for 6 GHz operation that resembles similar systems in place such as the one that supports CBRS wireless operation.
When the FCC opened up the 6 GHz band (5.925–7.125 GHz) for unlicensed Wi-Fi operation two years ago, the Wi-Fi world rejoiced. The ability to leverage this new, wide band for Wi-Fi use will deliver faster connectivity speeds and improved capacity when compared to both 2.4 GHz and 5 GHz Wi-Fi. While first made available for Wi-Fi 6 operation, Wi-Fi 7 will also rely heavily on the newest spectrum band.
However, because the 6 GHz band was already occupied by incumbent users, such as fixed satellite providers, the FCC imposed some pretty significant restrictions on the Wi-Fi devices looking to transmit in this band. More specifically, to avoid potential interference with existing 6 GHz incumbents, the FCC defined two types of device classifications with different transmit power rules for Wi-Fi devices operating on the band: low power access points (APs) for indoor Wi-Fi and standard power APs that can be used indoors and outdoors.
Standard power APs, particularly when used outdoors, are the most likely to interfere with existing 6 GHz users in the area, and therefore, AFC will prove most valuable in outdoor scenarios.
The Open Automated Frequency Coordination group
The Open AFC Group, operated by the Telecom Infra Project (TIP), works on software that will provide the flexibility for outdoor deployments of next-generation Wi-Fi.
In pursuit of its goal to develop an open-source reference implementation of an AFC system, the group recently partnered with the Wireless Broadband Alliance (WBA) to drive global adoption of Wi-Fi in the new 6 GHz unlicensed band because using the 6 GHz band — whether all or some of it — for unlicensed Wi-Fi is a government-by-government decision. According to WBA, more than 41 countries have designated 6 GHz for unlicensed use so far, with others working to do the same.
The pair said their partnership will help enable unlicensed devices in the 6 GHz band to operate outdoors, as well as increase their indoor range, while ensuring that existing services are protected from interference.
“Enabling the full benefits of 6 GHz Wi-Fi with an AFC system will deliver all the public Wi-Fi benefits of OpenRoaming including automatic friction free onboarding for users whilst managing privacy and security and enabling different identity options,” said the WBA.
“As we take steps towards optimizing the connectivity and economic benefits of the 6 GHz band, we also need to ensure fair and equitable use of the band,” commented Tiago Rodrigues, CEO of the Wireless Broadband Alliance. “Open AFC will benefit the whole Wi-Fi Industry, including networks that have adopted OpenRoaming. It will enhance Wi-Fi to provide a consistently great, secure broadband user experience in stadiums, homes, enterprises, schools, hospitals and more.”
AFC and Wi-Fi 7
AFC is expected to be a boon for Wi-Fi 7, bringing the flexibility and the range of Wi-Fi in the 5 GHz band, but with 6 GHz performance. When operating in this band, Wi-Fi 7 will maximize gigabit broadband investments by reliably delivering higher throughput, lower latency and better coverage. Additional direct enhancements over Wi-Fi 6 include support of 320 MHz transmissions, which is double the 160 MHz of 802.11ax, the use of higher modulation orders, optionally supporting 4096-QAM — up from 1024-QAM in 802.11ax — and the allocation of multiple resource units, such as groups of OFMDA tones.
