Alexandre Vallet, head of space services department, International Telecommunication Union (ITU). Credit: ITU

PARIS — The use of Ka-band broadband satellites to deliver internet is substantially less affected by rain-fade than previous modeling suggested, removing an issue that has long been used to question the move from C- and Ku-band to higher frequencies, an International Telecommunication Union (ITU) official said.

Alexandre Vallet, head of the ITU’s space services department, said that in addition to Ka-band’s better-than-predicted resistance to rain, future 5G wireless deployment in Europe and elsewhere will use three groups of spectrum, not just Ka-band.

“5G will be distributed among three groups of frequency: 700 MHz, which is best for coverage and has no rain issues: the lower C-band, around 3.4 GHz, which offers a good compromise between coverage and capacity, here too without rain problems; and, for very high throughput, the Ka-band,” Vallet said here Oct. 16 during a conference organized by France’s frequency regulator, ANFR.

“This model is going to exist in other regions of the world as well, so rain is not the principal problem,” he said.

As DirecTV in the United States has been saying for several years since it moved much of its direct-to-home television satellite broadcasting to Ka-band, the rain fade issues are manageable without compromising service quality, Vallet said.

“The service-availability data on Ka-band, even in tropical regions, shows better performance than was forecast by the models,” Vallet said. “This is an important point. And it will surely improve with deployment of satellite sites.”

Vallet said that even in cases of particularly heavy rains, Ka-band satellite operators are now able to adapt the service so that users continue to receive a signal, but at a lower bandwidth. “The connection is maintained,” he said.

Satellite operators currently battling — and in the United States, negotiating — with terrestrial 5G operators for access to C-band satellite-dedicated spectrum are preparing a similar confrontation over Ka-band, specifically the 28-GHz spectrum that is the focus of investment in very-high-throughput satellites.

Gilles Bregant, head of the ANFR, issued a muted statement during the conference saying that in the sunup to the 2019 ITU World Radiocommunications Conference (WRC), governments needed to give clear indications of what the rules of the game will be for 28 GHz before too much investment is made.

He offered no opinion on whether France and Europe would defend 28 GHz for the satellite sector.

Rodolphe Belmer, chief executive of satellite fleet operator Eutelsat, which is headquartered here, said industry and governments needed to be vigilant in protecting 28 GHz as satellite spectrum.

Eutelsat Chief Executive Rodolphe Belmer. Credit: ANFR/Station F video

Eutelsat’s VHTS satellite, scheduled for launch in 2021, uses 28 GHz.

Eutelsat has operated its Ka-Sat broadband satellite over Europe since 2011 and now has about 200,00 subscribers. It is this business that was the subject of a Eutelsat-Viasat Inc. joint venture whose development was stopped in its tracks when the two companies decided not to join forces on a higher-power Viasat 3 satellite over Europe, the Middle East and Africa.

Eutelsat opted for a satellite to be built by Thales Alenia Space of France and Italy when French mobile network operator Orange and Thales Group both agreed to commit to purchasing a large piece of the satellite’s capacity.

Belmer echoed Vallet’s statements, saying Ka-Sat, even during periods of heavy rain, is just as resistant as Ku-band and superior to terrestrial internet service when measured by overall service reliability.

In other geographic regions, the difference in availability between Ka- and Ku-band — particularly in equatorial zones — is negligible,” Belmer said. “When it rains very heavily, everything is cut off. So the difference is not material.”

The 28-GHz threat at the ITU’s WRC-19 conference

On 28 GHz, Belmer said:

“The 28-GHz band used by satellite operators will permit the deployment of 4G, and tomorrow, 5G, ion zones where terrestrial networks will not be deployed.

“Certain nations are under pressure from terrestrial operators that want to use this resource. But there will be no 4G or 5G that is widely deployed without satellites.

“In these conditions, the 28-GHz spectrum needs to be protected in order to protect the colossal investment that satellite operators have committed to build satellites that operate in this band. We call on nations to remain in a high state of vigilance with respect to WRC-19.”

Eutelsat is investing in both narrowband and broadband applications. In narrowband, it has joined with Internet of Things provider SigFox to build a demonstrator satellite, called ELO, to operate in very low Earth orbit to set direct sensor-to-satellite links.

“We think there are lots of applications for which satellites are necessary to complement” terrestrial applications, he said.

Eutelsat is one of the top four fixed-satellite-services operators. Unlike Intelsat, SES and Telesat, it has made no move to invest in a non-geostationary-orbit system.

Belmer said Eutelsat is sticking with geostationary orbit because GEO satellites can deliver a large amount of data to a particular region at a cost that is similar to terrestrial means.

“The mass-market demand for internet today and even more so in the future is insensitive to latency,” Belmer said, defending GEO against non-GEO solutions. “80% of internet use today is video streaming. Our big market is internet for the wider public in planes, low-population-density zones from geostationary orbit, which offer us the possibility of providing the service at an affordable price.”