Satellites, HAPS Pose Lots of Spectrum Challenges, Top FCC Engineer Says

Finding spectrum will increasingly become a challenge as space and airborne wireless becomes a bigger part of communications, said Julius Knapp, chief of the FCC Office of Engineering and Technology, at a Silicon Flatirons conference Wednesday, streamed from Boulder, Colorado. The session was on 3D wireless, from satellites to high-altitude platform stations (HAPS) to drones. “It’s getting more complicated,” he said. “There’s a lot more things going up in the sky” and the FCC doesn’t have the luxury of giving all the users their own bands, he said. Like in chess, “2D is challenging, 3D, mind-boggling.” Knapp said 3D wireless is “at the intersection of policy, engineering, economics, and the services that they provide.” Geostationary orbit satellites, roughly 22,000 miles in space, have major latency issues, “not necessarily a complete" impediment, he said. Non-geostationary satellites offer worldwide coverage and are comparable to inverted cellular systems, he said. “Instead of having all of the base stations on the ground, now the base stations are in the air and the handoff is happening between satellites.” HAPS, at close to 60,000 feet high, have a role, he said. They are “low to the Earth, so they don’t have the latency issue,” Knapp said. “The power levels are higher so I can get penetration on the ground. I can use them to fill in areas.” There’s only one global allocation for HAPS now, he said. The "good news” is ITU is looking at more spectrum for HAPS as an agenda item at the 2019 World Radiocommunication Conference, he said. “Because the technology has advanced, and the need to provide service to fill in” at various locations bigger, “it’s all being studied,” he said. Unmanned aerial vehicles, much lower than HAPS, are seeing work at NASA and the FAA and within industry, Knapp said. UAVs now mostly use unlicensed spectrum, “which always makes me a little bit nervous because there’s no interference protections,” Knapp said. UAVs need spectrum for command and control, but also for their payload, he said. People want HD video from the UAV and that takes a lot more bandwidth than the operations themselves, he said. “Where is that going to come from?" he said. "There has been much more focus on the control.” The big challenge for all the systems is spectrum, agreed Bobby Braun, dean of the College of Engineering and Applied Science at the University of Colorado Boulder. “If you think of where we’re headed … I actually don’t think that there’s going to be enough spectrum,” he said. “I imagine there will some kind of allocation, sharing scheme in time.”