Global 5G Wireless Deal Threatens Weather/Climate Forecasts

Companies are beginning to roll out their 5G networks around the globe, this new agreement is meant to designate the radio frequencies over which the equipment can transmit. The problem is that some of those are close to those used by satellites to gather weather and climate data; to keep the signals from interfering with each other researchers proposed turning down the amount of noise allowed to leak from the 5G transmissions. 

Negotiators in a meeting of the International Telecommunication Union in Egypt agreed to introduce 2 stages of protection for frequencies near the 24 gigahertz range which is close to weather satellites. However, companies will have a loose standard from now until 2027, after which time the regulations will become stricter; the plan is to let 5G companies begin building the networks now and add more protection for Earth observations as 5G transmission get stronger. 

Having 8 years worth of lax regulation is still “of grave concern” to Earth observations from space, according to Eric Allaix, a meteorologist at Météo-France in Toulouse who heads a World Meteorological Organization (WMO) group on radio-frequency coordination.

“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.

5G transmission are going to involve many frequencies, but the key one under concern here is the 23.8 gigahertz frequency; water vapour in the atmosphere naturally produces a weak signal here that satellites use to measure humidity, the data is fed to weather forecasts. Any 5G station transmitting near this frequency would be picked up by a weather satellite and be interpreted as water vapor, this bad data will corrupt weather/climate forecasts. This problem is suggested to be manageable if there is enough of a noise buffer between this frequency and 5G transmissions, akin to turning down the volume on your stereo as to not bother the neighbours. 

Meteorologists, the wireless industry, and government regulators are arguing over how to define an appropriate level of interference. The latest standard is set at -33 decibel watts until 09/01/2027 when it increases to -39 decibel watts; WMO is pushing for a buffer of -55 decibel watts, while the European regulators have settled for a less stringent recommendation of -42 decibel watts for 5G base stations. In America there is an even looser restriction of only -20 decibel watts recommended by the Federal Communications Commission which will allow more than 150 times more noise than the European proposal. 

“These two values were set by long negotiations between the member states,” said David Botha, a counsellor with the International Telecommunication Union, at a 22 November media briefing. “These values were considered to be adequate, in the sense that they would provide protection to the weather satellite systems, to Earth-exploration satellite systems. We have nevertheless noted that there were concerns that were issued.”

Even the stricter level may not be enough to avoid interference with weather observations of Earth from space, as Leduc explains, “Thirty-nine is still not where we need to be,” as NASA and the US National Oceanic and Atmospheric Administration has conducted a study which has found that 5G base stations need to transmit with a noise buffer of -52.4 decible watts in order to protect the crucial Earth observations. A report from the National Academies of Sciences, Engineering and Medicine concluded that losing scientific access to the 23.8 gigahertz signal would eliminate 30% of all useful data which contributes significantly to global forecasts. 

Meteorologists will need to figure out how to mitigate the impact of 5G on satellite observations, perhaps they may have to work with the wireless industry to research ways to shut down or redirect 5G transmissions when an Earth observation satellite is required to be accessed to acquire its measurements. 

According to Botha this new agreement requires a “continued monitoring” of how 5G networks will affect Earth observations, but no details have been provided on what this monitoring will involve or what the consequences will be when the observation data becomes degraded. 

Other agreements reached in the meeting included how quickly big fleets of satellites must launch to avoid hogging the radio frequency spectrum and on what frequencies “pseudo satellites” such as high altitude dirigibles and drones can transmit.