AST SpaceMobile Defends Plan Against Interference Concerns with Amateur Radio Operations
In response to over 2,500 complaints from the global amateur radio community, AST SpaceMobile has defended its plan to utilize the 430-440MHz radio bands for its satellite operations, outside of the US. The company submitted a letter to the US Federal Communications Commission (FCC) on Tuesday, asserting that their satellites are designed to minimize interference with amateur radio frequencies.
AST SpaceMobile argues that its proposed use of these bands will be limited and non-routine, confined to launch and early orbit phases for its 248 satellites, as well as emergency operations when other frequency bands are unavailable. The company also maintains the ability to shut down radio band usage if interference is detected.
An analysis from a third-party firm, RKF Engineering Solutions, was submitted by AST SpaceMobile, stating that the risk of interference to amateur radio operators is “extremely unlikely.” According to the report, even under worst-case conditions, the probability of interference with amateur satellite service is less than 0.1% per pass, and only a few events were observed in a 30-day simulation.
AST SpaceMobile aims to gain approval from the FCC for its plan to launch and operate commercial services through its constellation, which promises to deliver connectivity to everyday smartphones, competing with SpaceX’s cellular Starlink service already available through T-Mobile.
However, the amateur radio community has expressed opposition to AST’s request to use the 430-440MHz bands. The American Radio Relay League also sent a letter to the FCC, citing stiff resistance across the amateur radio community to the spectrum use. At least 17 national radio amateur societies from around the world have made their opposition known to the Commission, according to the league’s letter.
Some amateur radio groups claim to have detected interference in Europe from AST’s existing fleet of satellites, including the first five BlueBirds and the BlueWalker 3. The Bulgarian Federation of Radio Amateurs told the FCC that amateur radio is often the only communication system still operational during natural disasters and emergencies.
In its letter to the FCC, AST claimed it is not transmitting in the 430-440MHz band on the BB1s or BW3 satellites. However, one amateur radio group has detected evidence that AST shut down the radio communications from the BlueWalker-3 satellite two weeks ago.
