The terrestrial wireless industry’s insatiable demand for radio spectrum is no longer just a challenge for satellite telecommunications companies: The heat is also on for operators of civilian radar imaging satellites, some of which operate in frequency bands coveted by Wi-Fi services that are becoming increasingly indispensable to modern-day life.

Advocates for opening up C-band frequencies currently reserved for civilian radar satellites like Canada’s Radarsat and Europe’s planned Sentinel-series craft have argued that the introduction of terrestrial wireless services would not impinge on the incumbent users. But that position, based on studies funded by the terrestrial broadband providers, assumes that the new services would be used almost exclusively indoors — which is a stretch.

Now comes far more definitive word from a European intergovernmental group that is beholden to neither side in the brewing dispute: the 48-nation Conference of Postal and Telecommunications Administrations (CEPT). It is CEPT’s job to try to forge a European consensus on spectrum issues to be decided at the World Radiocommunication Conference (WRC), the conclave of global radio frequency regulators that takes place every few years to hash out spectrum issues. 

After studying the issue, CEPT came to the conclusion that civilian radar satellites and Wi-Fi services simply cannot coexist in the same frequency bands.

“There is no possibility of sharing and no reliable data has been put on the table suggesting otherwise,” Eric Fornier, chairman of CEPT’s Electronic Communications Committee, said in a sharp rebuke of the wireless industry’s assertions.

Mr. Fornier did, however, acknowledge that European Union policy generally favors the expansion of terrestrial wireless services, which gives some idea what the radar satellite operators are up against. Equally daunting is a list of just some of the tech giants that have been pushing for access to the spectrum in question: Cisco Systems, Intel, Qualcomm and Broadcom. 

In other words, CEPT’s finding should by no means be regarded as the last word on the issue before the next WRC, tentatively scheduled to take place in November 2015 in Geneva. For Canada and Europe, billions of dollars of investment in radar satellites are at stake.

The wild card in the brewing confrontation is the United States, which is home to some of the biggest and most powerful wireless companies and which has not invested heavily in civilian radar satellites. Moreover, the U.S. government, like Europe, generally favors the expansion of terrestrial wireless services: The administration of U.S. President Barack Obama has been pushing to free up 500 megahertz of radio spectrum for wireless applications by 2020. 

As of late February, the U.S. government was still working with industry to determine whether the spectrum in question could be shared and had therefore had yet to forge a position going into the 2015 WRC. Although it is somewhat concerning that CEPT’s analysis has not swayed U.S. spectrum management authorities, these officials insist that they recognize the importance of international environmental monitoring satellites.

Obviously a key factor will be the results of the U.S. study of Wi-Fi’s impact on civilian C-band radar satellite systems. If the conclusion is the same as CEPT’s, the U.S. government will be hard pressed not to back the European and Canadian positions at the WRC, especially given its ties to those countries in space and in satellite-based Earth observation. 

A U.S. determination that Wi-Fi and radar satellites can coexist seems unlikely, but it’s plausible — unbiased radio frequency engineers have been known to disagree. Should that happen, NASA and the U.S. National Oceanic and Atmospheric Administration, which have an interest protecting the Sentinel and Radarsat systems — if for no other reason than to support their frequent international partners — should urge their colleagues on the U.S. WRC delegation to err on the side of caution and advocate for the status quo. The burden of proof in this debate should be with the newcomers, and unless they come up with compelling evidence that their services won’t interfere with the incumbent users, they should be directed to seek spectrum elsewhere.