June 24, 2020
The latest attempt by Ligado Networks to deploy a 5G cellular data network across the U.S. continues to pose significant threats to the National Airspace System (NAS), presenters asserted in a June 23 NBAA News Hour webinar.
Earlier this year, the Federal Communications Commission (FCC) authorized Ligado – formerly known as LightSquared – to deploy a low power, land-based nationwide network within the 1500-1600 megahertz frequency band. The company asserted this modified network limited GPS signal disruptions to within a 500-foot diameter around transmission towers.
Although the FCC agreed with Ligado’s claims, many concerned parties – from not only within the aviation industry, but also agricultural, construction, automobile and maritime interests – remain unconvinced and allege Ligado’s claims were not properly validated by the FCC and the FAA in light of the potential detrimental impacts to safety.
“GPS reliability is more important than ever before as we transition to a performance-based [NAS],” noted webinar moderator Heidi Williams, NBAA director for air traffic services and infrastructure. Andrew Roy, director of engineering services for Aviation Spectrum Resources, Inc. added that, “from an aviation perspective, we’ve always assumed GPS will be there for us no matter where we are.”
While the threat of GPS interference commands the most attention, Roy noted several other aspects of operations in the NAS may also be impacted, including satellite communications and weather forecasting capabilities. He also acknowledged prior attempts by Ligado over the past 17 years to move its signals away from those bands reduced the threat, but did not eliminate it completely.
In one example, “the FAA said look, if you do this, GPS will be unavailable for aviation navigation systems below 1800 feet across the entire U.S., and that can’t work,” Roy said. “That’s where things started to stall.”
Despite these concerns, aviation stakeholders maintain their grievance lies with Ligado’s specific approach to deploying 5G and not the technology itself. “We are an industry that embraces innovation,” said NBAA Chief Operating Officer Steve Brown. “That’s certainly not anything that we want to obstruct, as long as it doesn’t have detrimental effects on the operations that we’re dependent on, and the safety levels that we need in the industry going forward.”
“I can make it abundantly clear that we fully support 5G,” added Max Fenkell, director for unmanned and emerging aviation technologies at the Aerospace Industries Association. “The aerospace and defense industry will be one of the largest, if not the largest user of 5G technology when it’s fully deployed. That said, this is not helping us win that race.”