- A panel of policy experts thinks existing satellite power rules are outdated
- EPFD limits were originally established decades ago to mitigate interference between LEO and GEO satellites
- But now there are obviously a lot more LEO satellites in orbit
NEW AMERICA LEO SATELLITE POLICY SYMPOSIUM, WASHINGTON DC - Power limits – not just lack of spectrum – are a key bottleneck for low earth orbit (LEO) satellite deployment, panelists argued at a New America policy event.
As the Federal Communications Commission (FCC) considers how to update its satellite spectrum sharing rules, it’s also thinking about revamping its Equivalent Power Flux Density (EPFD) limits so that LEO providers can boost their satellite power levels – and in turn up their capacity.
Joe Kane, director of broadband and spectrum policy at ITIF, said revising the existing rules makes sense because they “don’t really envision a world in which we have [thousands of schedules] in multiple different constellations going around the earth all the time.”
The FCC’s EPFD limits are based on standards established by the International Telecommunication Union (ITU) in the 1990s. The idea was to prevent interference between geostationary (GEO) and non-geostationary satellites.
Obviously, there are a lot more LEO satellites now than there were thirty years ago.
Not only are there thousands of satellites currently in orbit, but the ITU counts more than 1.7 million registered non-geostationary satellites in its filings, Patricia Cooper, president and founder at Constellation Advisory, LLC, noted in a separate keynote.
The question isn’t about comparing LEO to GEO, said Jeff Carlisle, managing member of Lerman Senter PLLC. It’s whether “the current regime [makes sense] anymore.” He noted the GEO satellites that are operating now are based on “engineering assumptions” from the 60s and 70s.
“The reason those have persisted for so long is that there hasn’t really been a reason to change them, because the environment didn’t demand it,” Carlisle explained.
“Now we have technology and constellations that promise significant additional service and functionality…and they’re bumping up against what increasingly look like arbitrary kind of power limits,” he said, but added GEO satellites are still important for emergency support and similar services.
Conversely, upping EPFD limits could potentially hinder further LEO deployment, according to Armand Musey, president and founder of Summit Ridge Group LLC.
He noted while LEO power levels “can probably be increased safely,” and give providers more capacity from their existing satellites, that could make it harder for providers to add more constellations.
Where to find more spectrum for satellite gateways
Panelists also discussed the need for more spectrum to support satellite gateways, which are the ground stations that transmit data to and from the satellite to the local area network.
These gateways are usually restricted to remote areas and sharing spectrum requires the approval of mobile carriers in those areas, said Michael Calabrese, director of the Wireless Future Project at New America’s Open Technology Institute.
In Carlisle’s opinion, a simple solution could just be database coordination of spectrum (such as dynamic spectrum sharing), which has helped fixed wireless access (FWA) providers offer service in the Citizen Broadband Radio Service (CBRS) band.
“Has it been a totally obstacle free implementation? No, but the concept does work,” he said. “I think we’ve now seen what not to do in terms of implementing these systems.”
Museey thinks spectrum coordination between FWA and fixed satellite service – particularly millimeter wave (mmWave) spectrum – should in theory be “really simple sharing.”
In his view, sharing that spectrum with satellite providers is beneficial because mobile operators “kind of jumped the gun” and purchased mmWave licenses when they are “not able to use it well.” Verizon, however, is one operator that’s notably stepping up its mmWave rollouts for FWA in multi-dwelling units.
Kane agreed there should be more ways to “enhance the productivity of the spectrum” that also maintain some kind of priority for carriers that initially purchased licenses.
“I just sort of worry about the FCC pulling the rug out from people who have paid for the spectrum,” he said.