The Federal Communication Commission recently issued a Notice of Apparent Liability finding that Towerstream Corporation repeatedly interfered with the Federal Aviation Administration’s Terminal Doppler Weather Radar systems through operations of its Unlicensed National Information Infrastructure transmissions systems. TDWR systems are used near airports to monitor weather conditions that could pose risks to aircraft. The FCC noted, any “interference [with TDWR systems] poses a clear hazard to air traffic safety and requires aggressive enforcement, proposing a penalty of $202,000.
Towerstream provides “advanced, high-speed Internet access to businesses in 12 markets” and “owns, operates, and leases Wi-Fi and Small Cell rooftop tower locations to cellular phone operators, tower, Internet and cable companies and hosts a variety of customers on its network” using U-NII spectrum.
In 2003, the FCC allocated additional spectrum for unlicensed use in the 5 GHz band and established the U-NII service to encourage and facilitate the deployment of short-range, high-speed wireless networking communication. The FCC’s rules allow for certain devices that use low-level radiofrequency signals to operate without individual licenses in the 5 GHz band, as long as such operations does not cause harmful interference to licensed services and the devices do not generate emissions above a certain level.
In Towerstream’s case, the FCC had been investigating various complaints since 2009 stemming from alleged TDWR interference at major international airports in New York, Chicago, Miami, and Fort Lauderdale. In 2010, the FCC also released a memorandum, describing steps that U-NII operators could take to eliminate TDWR interference. The NAL alleges that despite repeated warnings, FCC guidance, and a meeting with FCC staff in 2011 to discuss corrective measures, Towerstream’s activities still resulted in TDWR interference.
While the FCC has taken steps to allocate spectrum for unlicensed use and encouraged the development of unlicensed devices, it has recently dealt with a number of situations where U-NII devices have caused TDWR interference. While fines in similar enforcement actions have typically been $25,000, this case shows the potential risk that operators face if their unlicensed devices cause harmful interference to licensed operations.