The Federal Communications Commission proposes to approve a new 5G cellular network despite claims from the Department of Defense that it will interfere with Global Positioning System (GPS) services.

April 2020: According to news reports in Ars Technica, FCC Chairman Ajit Pai is asking  fellow commissioners to approve an “application to deploy a low-power terrestrial nationwide network in the L-Band that would primarily support 5G and Internet of Things services.” The application is from Ligado, previously the company LightSquared which has been trying to build out a wireless network using frequencies near those used for GPS for a decade.

However experts have warned this could impact GPS.

“In a November 2019 letter to Pai, US Secretary of Defense Mark Esper said: “there are too many unknowns and the risks are far too great to federal operations to allow Ligado’s proposed system to proceed. All independent and scientifically valid testing and technical data shows the potential for widespread disruption and degradation of GPS services from the proposed Ligado system. This could have a significant negative impact on military operations, both in peacetime and war.”

Read the letter to the FCC here. 

Some History

The FCC auctioned the 24 GHz spectrum band for 5G over the objections of Scientists from NOAA, NASA, the American Meteorological Society and even the Aerospace Industries Association who object to the use of higher frequencies warning that 5G interference could “set US weather forecasting back to somewhere around 1980.”

As detailed in Nature, 5G frequencies which could lead to incorrect storm prediction and less time to warn of hurricanes. The FCC Chair responded to these organizations objections as “exaggerated and unverified last-minute assertions,” US Senators then sent a letter urging the FCC to adopt an emission limit recommended by NOAA and NASA citing an internal Navy report that stated the 5G frequencies would probably degrade Naval  weather and ocean models, resulting in increased risk in Safety of Flight and Safety of Navigation, and degraded Battlespace Awareness for tactical / operational advantage.

The Ligado application would primarily support 5G and Internet of Things.

In November 2019, US Secretary of Defense Mark Esper urged the FCC to restrict the 5G spectrum citing  impacts to “national security, civil service, and the economic benefit of the nation” due to the potential for widespread disruption to GPS services. 

The FCC responded that, “Although I appreciate the concerns that have been raised by certain Executive Branch agencies, it is the Commission’s duty to make an independent determination based on sound engineering. And based on the painstaking technical analysis done by our expert staff, I am convinced that the conditions outlined in this draft order would permit Ligado to move forward without causing harmful interference. For example, the draft order would authorize downlink operations at a power level that represents a greater than 99 percent reduction from what Ligado proposed in its 2015 application.”

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US Secretary of Defense Warns the FCC that 5G Network Could Harm GPS