After about five years in the making, Ligado Networks executives say they believe federal decision-makers have the last piece of information they need to approve its plan to operate a terrestrial LTE network alongside GPS devices.
That’s because, according to Ligado, a 428-page National Advanced Spectrum and Communications Test Network (NASCTN) report released last week supports the conclusions independently reached by five major GPS manufacturers that Ligado’s proposed network can operate without harming the performance of GPS devices.
“Ligado is planning to deploy an advanced satellite and ground-based network that will offer unprecedented performance for the emerging 5G and industrial IoT markets,” said Doug Smith, Ligado Networks’ president and CEO, in a prepared statement. “This report completes the technical evaluation of how Ligado proposes to use its spectrum for ground-based services, and is the last in a long line of testing by multiple stakeholders. The regulatory decision-makers now have the information they need to make this 35 MHz of vital mid-band spectrum available to serve critical American infrastructure needs and deliver substantial economic benefits to our nation.”
Ligado was known as LightSquared until the company rebranded last year after emerging from bankruptcy and settling interference disputes with the GPS vendors. The company has access to a nationwide block of 1525-1559 MHz spectrum in the L-Band; its current operations are satellite-based, and it believes that combing that with a terrestrial network would be a great asset for supporting 5G and the Internet of Things (IoT).
According to the NASCTN report (PDF), its work included 1,476 hours of testing over a three-month period that resulted in the generation of more than 19,000 parsed data files. NASCTN coordinated and performed the radiated measurements associated with the project at two facilities—a semi-anechoic chamber at National Technical Systems (NTS) in Longmont, Colorado, and at a fully-anechoic chamber at the NIST Broadband Interoperability Testbed (NBIT) facility in Boulder, Colorado.
NASCTN said it relied on technical staff from NIST and the U.S. Army’s Electronic Proving Grounds to perform and validate the measurements and collect the data. The team was multi-disciplinary, including experts in GPS devices and simulation, radiated radio-frequency measurements, timing measurements, microwave metrology, statistical analysis and data processing.
Based on its initial review, Ligado was pleased with the conclusions in the report about the compatibility of GPS devices with LTE deployed in adjacent bands. The report represents the last piece of information that regulatory decision-makers like the FCC need to move forward with Ligado’s pending application, Valerie Green, EVP and chief legal officer at Ligado, said during a conference call last week.
The report was released five years and two days to the day that the NTIA sent a letter to the FCC basically giving Ligado a to-do list to resolve the concerns about interference with GPS devices and since then, the company used that letter as a road map, “making sure that we check every box along the way,” Green said. The road they set out on about five years ago ended in Boulder with the NASCTN report, she said.
Along the way, Ligado managed to get the GPS manufacturers to come around after a bitter battle, but it still doesn’t appear to be clear sailing. Meteorologists and hydrologists who rely on real-time information transmitted through 1675-1680 MHz from NOAA’s geostationary environmental satellites have registered their concerns with the FCC, saying they use the data to produce forecasts that protect life and property.
However, the company told BuzzFeed that instead of interfering with the delivery of weather information, it will actually help get that data to thousands of other scientists who currently don’t have access to it.
Last year, Ligado welcomed former Sprint Next executive chairman Tim Donahue to its board, which also includes former Verizon Communications executive Ivan Seidenberg and former FCC Chairman Reed Hundt.