The API/A Surge: Why Manual Interference Checks No Longer Scale

A decade ago, keeping an eye on new ITU filings that might overlap your frequency plan was a manageable weekly habit. Today, the sheer volume of new satellite network filings has made that same habit close to impossible to sustain by hand — and the numbers explain why.

The scale of the shift

The growth isn't anecdotal. The ITU's own Radiocommunication Bureau has pointed out that the number of satellite filing requests it processes has grown roughly 5.5 times over the past decade — a figure the Bureau itself attributes directly to the expansion of the space economy. Separately, a 2023 study published in Science found that current ITU filings collectively represent plans for close to a million satellites across roughly 300 proposed mega-constellations, well over double the low-orbit satellite population that existed at the time. As of mid-2025, more than 11,700 satellites were already active in orbit, with LEO communication constellations driving most of that growth.

None of these filings skip the front door. Every one of them enters the public record the same way older, smaller networks always did: through a BR IFIC publication, most commonly as an early-stage API/A notice.

Why API/A specifically is where this shows up first

As covered in our notification types reference, API/A is the earliest stage at which a new network becomes visible — well before formal coordination begins. That makes it the leading indicator of frequency-band congestion: by the time a filing reaches CR/C, both sides usually already know a coordination conversation is coming. The API/A stage is where new potential interferers first appear on the radar, and it's precisely this stage that's seen the steepest growth in volume.

What this means in practice for a working spectrum engineer

A frequency plan that was clean against last month's BR IFIC isn't guaranteed to still be clean today. In a filing environment growing at this rate, "screen once before submission" quietly turns into "screen once and hope," because the population of networks you're checking against keeps expanding every single week. A network with no known overlaps in January can have three new ones by March — and none of that shows up unless someone goes back and re-runs the check.

Doing that re-check manually, for every satellite you care about, every time a new circular drops, is exactly the kind of task that scales badly with filing volume and well with automation. It's tedious in a way that makes it easy to postpone — right up until a coordination request arrives for a network nobody on the team had actually looked at.

The shift from periodic to continuous screening

The practical response to rising filing volume isn't to check more often by hand — it's to stop treating interference screening as a discrete task at all, and instead treat it as a standing watch: define the satellite and frequency range you care about once, and get notified automatically the moment a new publication introduces a genuine overlap. That turns a task that scales linearly with filing volume (and therefore gets worse every year) into one that costs nothing extra as volume grows, because the checking itself is automated.

Sources

• Mario Maniewicz, Director, ITU Radiocommunication Bureau — cited in "Fueling Connectivity from Space: Spectrum Sharing and Coexistence," New America
• "Study shows need for ITU to tighten regulations for low orbit satellites as filing numbers grow," Phys.org, reporting on a University of British Columbia study published in Science (2023)