Weather forecasters pushing for strict limits on 5G rapidly growing footprint were dealt a blow today by the World Radiocommunication Conference in Egypt. Delegates there voted to create a new international standard that places much looser limits on interference from 5G operating in a specific radio frequency that’s crucial to accurate weather forecasting.
Wireless companies are beginning to roll out their next-generation networks, known as 5G, around the world. The new agreement is meant to designate the radio frequencies over which 5G equipment can transmit. But some of the frequencies come perilously close to those used by satellites to gather crucial weather and climate data. To keep the signals from interfering with one another, researchers have proposed turning down the amount of noise allowed to leak from 5G transmissions.
Specifically, these highly technical analyses concluded that if deployed widely and without adequate constraints, telecommunications equipment operating in the 24 GHz frequency band would bleed into the frequencies that NOAA and NASA satellite sensors also use to sense the presence and properties of water vapor in the atmosphere, significantly interfering with the collection and transmission of critical weather data.
Report from NOAA
The NOAA report, for example, warned of a potential loss of 77.4 percent of data coming from microwave sounders mounted on the agency’s polar-orbiting satellites.
The United Nations International Telecommunication Union convenes the World Radiocommunication Conference once every three or four years to hash out new radio regulations on contested frequencies like 24GHz. Their job is particularly tricky because radio frequencies are messy, with lots of different technologies and natural phenomena operating in a highly crowded space on the spectrum. To keep order, the conference tries to establish buffers between groups that use similar frequencies to avoid conflict. These buffers are called out-of-band emissions limits. They are measured in units called decibel watts (dBW), which tell people the strength of a signal that’s strayed out of its boundaries. A strict interference limit leaves a larger gap between frequencies, preventing stronger signals from spilling over into signals that have been deemed particularly important or protected by world governments and industry.
“The race for 5G is going to go fast,” says Renée Leduc, a consultant with Narayan Strategy in Washington DC who works on spectrum-sharing issues. “In the early-to-mid-2020s we’re going to see a very quick uptick.” Although more protections for Earth observations will take effect in 2027, “I’m still really concerned about the time period between now and then”, she says.
“We need our weather models to be improving, not getting worse, and that’s something that President Trump has said himself,” she said.
Even the stricter level is not enough to avoid interfering with water-vapor measurements, says Leduc. however, on the other hand “Therefore Thirty-nine is still not where we need to be,” she says. A study conducted by NASA and the US National Oceanic and Atmospheric Administration found that 5G base stations needed to transmit with a noise buffer of –52.4 decibel watts to protect the water-vapor observations.
In case forecasts are degraded because of 5G interference, NOAA is considering plans to avoid worst-case scenarios. For example, it could use water-vapor-sensing channels only over oceans and exclude land, which would be the likely source of interference
“We will not be able at that time to make the distinction between the observation of the earth and atmospheric radiation, and the interference coming from 5G.”