WASHINGTON — As the next World Radiocommunication Conference looms larger, satellite operators are growing concerned that they have not made sufficient defense of Ka-band frequencies coveted by 5G cellular networks.

Cellular operators and their allied national regulators are expected to make a push for the 28 gigahertz spectrum band at the WRC-19 conference this October and November in Sharm El-Sheikh, Egypt.

Speaking at the Satellite 2019 conference here, SES CEO Steve Collar described the potential loss of 28 gigahertz as the “single biggest threat” facing the satellite industry.

“The 28 gigahertz challenge will be perhaps the biggest we have, and I think we have not done a good enough job, to be honest,” he said. “I think we’ve done a strong job with C-band, and [then] we kind of sat back.”

At the last WRC conference in 2015, satellite operators rallied to defend C-band airwaves used mainly for television broadcasts (plus other communications services), and were successful in keeping the majority, save for a lower portion that had already been partly lost in 2007.

But while satellite operators have used C-band for decades, only in recent years have they invested heavily in Ka-band satellites, like SES’s O3b constellation, Inmarsat’s Global Xpress network and Hughes Jupiter-series satellites.

Collar described the challenge with 28 gigahertz as “completely different” from C-band.

“It will get solved in a completely different way, and my biggest fear for the future sustainability of our industry as it relates to providing and delivering broadband services is that,” he said.

Eutelsat CEO Rodolphe Belmer also described 28 gigahertz as a very strong concern for the satellite industry.

“We are hoping that mobile telcos realize that if they don’t let us continue to operate, for instance, in the 28 gigahertz frequency — and the C-band frequency where we need to — it will become a problem, not only for them but for all people,” he said. “There will be no bridging the digital divide if there is no frequency for satellite operators.”

Eutelsat has a 75 gigabit-per-second Ka-band satellite from Thales Alenia Space called Konnect that is slated to launch on an Ariane 5 rocket at the end of the year. The Paris-based operator has another satellite, Konnect VHTS, slated to launch in 2021 with a half a terabit of Ka-band capacity.

Mark Dankberg, CEO of Viasat, said he agreed with Belmer on the importance of Ka-band. Viasat’s three satellites — Wildblue, ViaSat-1 and ViaSat-2 all use Ka-band. The company has three next-generation “ViaSat-3” Ka-band satellites under construction with Boeing designed to offer at least a terabit of capacity each. In a February filing with the U.S. Securities and Exchange Commission, Viasat estimated it would spend $1.2 to $1.4 billion on deploying the first two ViaSat-3 satellites alone.