PARIS — The United States and Germany, backed by several large commercial satellite fleet operators, are fighting an uphill battle to persuade global governments to allocate Ku- or Ka-band satellite spectrum for the command and control of unmanned aerial vehicles on transoceanic or trans-continental routes.

Midway through the quadrennial World Radiocommunication Conference (WRC), meeting Nov. 2-27 in Geneva, the U.S. delegation had rallied no more than 50 governments to what has emerged as one of the U.S.’s top WRC priorities.

Government and industry officials said that opposing the pro-UAV position is an assortment of Asian, Middle Eastern, South American and European governments whose reasons appear to differ as widely as the state of their national aerospace industries.

“Some governments fear that approving this would basically mean giving military UAVs an easier access to civil airspace,” said an official from one European government supporting the measure. “Others say they are worried about safety, and still others have difficulty allocating fixed satellite service spectrum to UAVs – which are obviously mobile platforms.”

What is clear is that the U.S. delegation has made the issue a litmus test for whether the International Telecommunication Union (ITU), a United Nations body that organizes the WRC conferences, can retain its legitimacy in a world where technology is outrunning bureaucracy.

“It would be extraordinary if the conference did not act on something that really is the next wave of aviation across the globe,” said Decker Anstrom, head of the 170-member U.S. delegation to WRC.

It likely would take years before unmanned vehicles are allowed to traverse oceans and continents in civilian airspace even if the WRC approved an allocation of satellite spectrum for it. National and international aviation regulators would need to set technical standards for UAV communications links, with national regulators then harmonizing their own airspace regulations.

“It’s going to be a fairly lengthy process, but without the ITU work here, you cannot even start that process,” said Michael Biggs, a senior spectrum engineer at the U.S. Federal Aviation Administration who is on the U.S. WRC delegation.

“The difficulty we have is we don’t see any other system [aside from fixed satellite services] that could meet the requirements,” Biggs said Nov. 12 during a press briefing. “The numbers coming out talk about a data-rate requirement of 50 kilobits per second from the ground to the air, and 300 kilobits per second air-to-ground. If you look at the satellite systems out there, you are going to be hard-pressed to find a system that can support that kind of data throughput on a large scale” except for the fixed satellite services now in geostationary orbit and operated by several dozen commercial companies.

“One of the questions we have been asking these other countries is: What are you going to use instead?” Biggs said. “So far I have not gotten an answer to that.”

In a Nov. 12 briefing, Anstrom said three of ITU’s regions — the Americas, Europe and the African Telecommunications Union — on Nov. 11 agreed to combine their UAV spectrum-allocation proposals into a single document that had the support of 50 nations and the International Civil Aviation Organization.

Armed with a common position and ICAO endorsement, he said, the pro-UAV governments are more likely to persuade undecided nations – 163 nations are attending WRC – to grant the spectrum. Only a handful of nations are actively against the proposal, Anstrom said.

Anstrom said the total spectrum needed is 160 megahertz, but that a wider chunk of spectrum will be needed to allow for the differences among regions in how they use the spectrum.

Julie Zoller, the U.S. State Department’s senior deputy coordinator for Communications and Information Policy and deputy head of the U.S. WRC delegation, said just about any piece of the existing Ku- and Ka-band spectrum now in use for satellite services — with the exception of frequencies specifically reserved for national Ku-band broadcast services — could be used for UAV command and control.

Peter B. de Selding was the Paris bureau chief for SpaceNews.