WASHINGTON — Commercial satellite fleet operators on March 11 said international regulators are using “flawed” documentation in calculating the future radio-spectrum requirements of terrestrial mobile broadband services.

The result, they said, is that overblown estimates of how much spectrum will be required for terrestrial wireless broadband will be distributed to governments worldwide in the run-up to a meeting in 2015 of global radio spectrum regulators.

Satellite companies are expecting a rerun of a 2007 fight with wireless terrestrial operators over a slice of the C-band spectrum heavily used by satellite services, particularly in less-developed nations.

The 2007 World Radiocommunication Conference (WRC) ended with what was portrayed as a victory for satellite operators in maintaining priority access to C-band. It turns out to have been only a partial victory, and perhaps only a temporary one.

WRC-15 is now shaping up to feature a renewed push for C-band by terrestrial wireless operators. Unlike in 2007, these companies can now point to millions of smartphones in service as Exhibit A in their argument that they need more spectrum.

It is here that the data produced by the International Telecommunications Union (ITU), the Geneva-based United Nations affiliate that regulates wireless spectrum and satellite orbital positions, may have a disastrous effect on governments now starting to develop policies for WRC-15.

“The ITU demand study for spectrum for mobile is simply flawed,” said Michel de Rosen, chief executive of Eutelsat of Paris. “We’ve looked at this quite carefully and this is a major exaggeration [of demand] by 10 or even more than 100 times.”

Satellite companies said after WRC -07 that they had learned their lesson and never again would be blindsided by threats to their spectrum. This time around, they said, they had begun organizing themselves and their constituencies so that they are prepared for WRC -15.

“We have been making good preparation this time,” said Romain Bausch, chief executive of SES of Luxembourg. He said SES has placed representatives on the regional ITU bodies that help prepare WRC-15, and that SES recently hosted an ITU delegation led by ITU Secretary-General Hamadoun Toure to assure that the satellite industry’s views are taken into account.

Bausch said among the subjects brought up with the ITU are “the difficulties we have with the [spectrum] requirements as defined by the mobile guys.”

“Let’s not be naïve,” de Rosen said, allowing as how he did not mean to question the competence of the ITU personnel, but rather that of the political delegates to WRC-15. “This is a real struggle with people who want to take our lunch.”

Intelsat Chief Executive David McGlade said it is understandable that governments would like to auction spectrum to fill empty government accounts. He said he agreed with de Rosen and Bausch that the ITU models used to calculate spectrum requirements are off-base by “an order of magnitude, and even two orders of magnitude, when estimating peak demand. It is flawed and it is a misrepresentation.”

Evan Lethan, Eutelsat’s director of in-orbit resources, said one example of the problem with the ITU spectrum-demand forecast has to do with estimates of peak mobile demand, defined as users in automobiles or trains moving at 50 kilometers per hour or more.

The ITU study, Lethan said, concluded that spectrum should be sufficient to permit 56,000 users in a single square mile, a demand peak he said would represent only the rarest of special events, and even then would be lessened by the fact that traffic would be rerouted for special events.

To give an idea of the scale of the ambition of terrestrial wireless operators, Gonzalo de Dios, associate general counsel of Intelsat, said these companies have said they want a total of 1,960 megahertz of new spectrum.

David Hartshorn, secretary-general of the Global VSAT Forum, reiterated the satellite industry’s 2007 argument that a high-powered terrestrial wireless operation using the same C-band spectrum as satellites would overwhelm the satellite receive-only antenna, making sharing unfeasible.

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Peter B. de Selding was the Paris Bureau Chief for SpaceNews.