May 19, 2020

Get proactive – Identify microwave link interference before it takes your network down

For more than two years now, the FCC has been evaluating the necessity and feasibility of opening up the 6 GHz band to unlicensed users of a wide variety of devices. They’ve published multiple notices of their findings, and on April 2, 2020, FCC Chairman Ajit Pai issued a draft version of the official rules, allowing unlicensed operation in the 6 GHz band—over the entire 1,200 MHz spectrum of that band. A final vote on April 23 opened the door to Wi-Fi 6e.

So why are the new rules shaping up to be a major problem for licensed stakeholders? Here are the main reasons:

• Wi-Fi 6e is now assured as a new consumer boost, providing enhanced speed and performance. Its certification process started in September 2019, so you can bet that new devices supporting it are being developed now
• Interference can directly cause outages and/or reduce the fade margin, so links are more susceptible to what would otherwise be minor issues.
• Interference is a problem in 5.8 GHz environments today. There is no reason to believe Wi-Fi 6e, with so many devices—and untested or hastily tested protections—will not follow suit. Plus, there are many more 6 GHz point-to-point (PtP) links than 5.8 GHz. And there will likely be many more Wi-Fi 6e outdoor access points, compared to 5.8 GHz environments.
• AFC protection mechanisms may not work well. The Universal Licensing System (ULS) data that operators use to file their applications (which includes maps showing the geographic area covered) can be based on inaccurate information and is often not correct.
• It’s difficult logistically and technically to regulate and control Wi-Fi 6e deployments. Also, many of the assumptions being made on the impact of interference to PtP links are aggressively optimistic.
• PtP systems were designed to assume interference does not exist. That’s especially true for Wi-Fi interference. So today’s systems lack effective controls and protections.
• The vast majority of 6 GHz links are used by utilities, public safety networks, and mobile operators. Interference monitoring is not available in those mission critical applications today.