AST SpaceMobile's 800 MHz Trial Wraps Up — But the 70cm Interference Story Isn't Going Away
/Direct-to-device satellite service is one of the fastest-moving stories in the industry right now, and it keeps brushing up against amateur radio spectrum along the way.
The FCC has given Texas-based AST SpaceMobile until 12th September to complete its trial of direct-to-device cellular broadband service over the 800 MHz band. The company has been operating under a 30-day permit, testing delivery to everyday consumer mobile phones in Lanham, Maryland, and near its own headquarters in Midland, Texas.
Back in April, the regulator approved AST's use of 817–824 MHz for uplink and 862–869 MHz for downlink. AST has strategic partnerships with Verizon and AT&T, and is positioning itself as a rival to SpaceX's Starlink, which is also active in the direct-to-device space.
The 70cm Band Controversy
AST SpaceMobile drew significant pushback from the amateur radio community earlier this year after the FCC granted it limited use of part of the secondary amateur allocation between 430 and 440 MHz, for emergency telemetry and tracking/control of its satellites. At the time, the FCC characterised interference with amateur radio as "unlikely."
That authorisation was specifically for emergency and launch telemetry within the 70cm band — a narrow, defined use case. However, monitoring data from the SATNOGS network has reportedly shown AST operating outside those terms of use, with interference to the 70cm amateur allocation being reported across both North America and Europe. There are currently three AST satellites in operation, with considerably more scheduled for launch — a point that's raising concern among amateurs about how this issue scales as the constellation grows.
If you want to see the raw monitoring data for yourself, the SATNOGS observation pages are below:
