The Federal Communications Commission (FCC) should take steps to ensure that the sale of a slice of wireless spectrum does not interfere with water vapor measurements, AMWA told members of a Senate committee this month ahead of an FCC oversight hearing where the topic was addressed.
AMWA’s June 11 letter, which was joined by the Water Environment Federation and the Water Utility Climate Alliance, was spurred by reports that the U.S. Navy and other stakeholders have raised concern about an FCC auction of wireless spectrum in the 24 GHz band, which will be sold to support 5G services. This band is adjacent to the 23.6-24 GHz band that is used by the National Oceanic and Atmospheric Administration (NOAA) to collect atmospheric water vapor measurements that inform local weather forecasts. According to a U.S. Navy memo written earlier this year, 5G use in the 24 GHz band could cause interference that “will result in partial-to-complete loss of remotely sensed water-vapor measurements,” with impacts expected to be “concentrated in urban areas of the United States first.”
AMWA’s letter to the Senate Commerce, Science, and Transportation Committee explained that water systems monitor and interpret weather forecasts that are informed in part by NOAA’s water vapor measurements and use this information to “make critical water supply planning and storm preparedness decisions that ensure water service will continue uninterrupted, no matter the weather.” Should the quality of this data be compromised, AMWA said it would “jeopardize the quality and reliability of municipal water service that Americans have come to expect.”
Commerce, Science, and Transportation Committee Ranking Member Maria Cantwell (D-Wash.) has highlighted this issue on Capitol Hill in recent months and raised it again during the committee’s oversight hearing. Sen. Cantwell said that by moving forward with the auction the FCC ignored concerns about the impact of the spectrum auction on forecasting capabilities and promised that “we are not going to allow this vital information to be jeopardized in the future.”
But the five FCC commissioners who testified at the hearing pushed back against claims that water vapor sensing abilities will be compromised. In response to a question from another senator, FCC Chairman Ajit Pai said that studies presented to the commission suggesting a risk to NOAA’s spectrum have been “fundamentally flawed,” and said the FCC has yet to receive a validated, peer-reviewed study showing evidence of a problem. “We can have the best of both worlds” with 5G service and consistent weather forecasting, Pai said.
In response to a later question all five commissioners indicated their support for the 24 GHz auction, with one calling the dispute “embarrassing” and an example of “one part of the [Trump] administration not talking to the others.” Pai later answered, “No, absolutely not,” when asked if he believes there is any legitimacy to concerns about 5G’s impact on adjacent bands of spectrum.
FCC’s auction of 24 GHz spectrum closed on May 28, and the commission announced that 29 bidders claimed a total of 2,904 licenses. Despite the concerns raised by Sen. Cantwell, there do not appear to be any plans on Capitol Hill for legislative action on the issue.