5G could ruin weather forecasts

A memo from the US Navy warns that 5G mobile networks are likely to interfere with weather satellites and Senators urge the Federal Communications Commission to avoid issuing new spectrum licenses to wireless telecom companies until the next day. changes to prevent damage to weather forecasts.

The FCC has already launched a 24 GHz spectrum auction that would be used in 5G networks. But Sens. Ron Wyden (D-Ore.) And Maria Cantwell (D-Wash.) Today wrote a letter to FCC President Ajit Pai asking him to avoid issuing licenses to successful bidders "until That the FCC approves passive protection limits the National Aeronautics and Space Administration (NASA) and the National Oceanic and Atmospheric Administration (NOAA) determine whether they are essential to protect the critical satellite measurements of atmospheric water needed to predict weather conditions. "

Wyden and Cantwell have stated that "the ongoing air-wave sale could undermine the effectiveness of US weather satellites and the predictions and forecasts used to protect security, property and national security." They blamed the FCC for launching the auction on objections from NASA, NOAA and members of the American Meteorological Society (AMS). These entities all argued that out-of-band emissions from future commercial broadband transmissions in the 24 GHz band would disrupt the ability to collect water vapor data measured in a neighboring frequency band (23.6%). at 24 GHz) on which meteorologists rely to predict the weather that it does. "

The internal memo to the Navy on the subject, written March 27 by the Superintendent of the US Navy Observatory, Marc Eckardt, was made public by Wyden and Cantwell today.

The subject of the note is "Operational Impacts of the Potential NOAA / NASA METOC Loss" [meteorology and oceanography] satellite data from the FCC spectrum auction for 5G. "The Navy memo summarizes the problem as follows:

• Remotely sensed observations (water vapor) may be degraded or lost due to increasing interference due to wider adoption of 5G; specifically, in the 24 GHz bands.
• Naval operations will continue, but with the likely degradation of weather and ocean models, which increases the risks of flight safety and navigation safety and degrades the battle space awareness for a benefit. tactical / operational.

"Partial to complete loss" measures

The Navy memo cites the NOAA and NASA studies on 24 GHz spectrum interference for mobile use adjacent to the spectrum used for meteorological operations.

"[A]Thus, it is expected that the interference will result in a partial or total loss of water vapor measurements measured by remote sensing, "says the memo of the Navy. Impacts are also expected to be concentrated in urban areas of the United States first. . "

The problem could affect Navy and Marine Corps forecasts of tropical cyclones, as well as rain, ice and snow, the memo said. The Navy memo recommends asking the FCC to "tighten the out-of-band interference by reducing the bleed limits to -57dB". The memo also states that the Navy should "work with NOAA and NASA to continually assess and quantify the actual impacts" and develop mitigation measures, including "limited use". other channels, substitution of lesser fidelity parameters and the development of new techniques and algorithms through new research and development. "

Meteorologists shared the Navy's concerns in a recent article in Nature.

As Wyden and Cantwell told Pai, "Many scientists in the United States and elsewhere, as well as several US federal agencies, have warned that allowing communications in the 24 GHz band to FCC-authorized interference levels would have an impact. important on the accuracy of critical weather forecasts for the region.Department of Defense (DOD), public security officials, commercial fishing sector, farmers and millions of Americans who depend on accurate flood forecasts, hurricanes, winter storms and tornadoes. "

Questions for Pai

Wyden and Cantwell asked Pai several questions before June 11. Senators then asked Pai to prove that broadband transmissions at 24 GHz "will have no impact on the applications of adjacent frequency bands, particularly the satellite measurements of water vapor in the 23.8 GHz band ". so important for weather forecasts. "The FCC should provide" computer models, assumptions and analyzes "that it used to make its decision, the senators wrote.

Wyden and Cantwell also asked Pai what the FCC would do if the International Telecommunication Union "refused to accept" the FCC emission limits in the 24 GHz band.

Senators also want Pai to provide a detailed explanation of the process used "to resolve the NASA / NOAA dispute with the FCC in favor of the FCC position".

The last request from senators to Pai is as follows:

Explain and provide supporting documentation for the FCC's public interest analysis, including any cost-benefit analysis, on the FCC's limit on emissions. In particular, explain how the FCC has managed the costs to taxpayers resulting from the loss of billions of dollars in investments in meteorological detection satellites, the costs for public and national security and the country's commercial activities based on these data. critical weather.

We contacted Pai's office about the Navy memo and the letter Wyden / Cantwell today, and we will update this story if we get an answer.