Carrier-grade KPI closure for HAPS communications

Determine whether any flown HAPS communications system can measure and close the carrier-grade KPI four-tuple required for operator deployment, including Block Error Rate under load and mobility, mean time between platform losses with the necessary fleet multiplier, and meter-class station-keeping precision for repeat-pass interferometry.

Background

The authors define carrier-grade HAPS service through four empirical measures: Block Error Rate under full traffic-channel load, mobility-related re-establishment and throughput continuity, mean time between platform losses and the fleet size needed for continuous regional coverage, and station-keeping precision. The AALTO, PHASA-35, and Sunglider demonstrations each measured only a subset of these requirements.

The unresolved issue is whether these demonstrations can be extended into sustained, multi-user, fleet-level service with quantified reliability and availability. The paper identifies this as the main empirical barrier to commercial HAPS communications.

References

Closing the carrier-grade gap is the single largest empirical question for HAPS comms over the next three years.

— HAPS through the Lens of Satellites and UAVs: A Function-Level Perspective on the Emerging High Altitude Economy  (2608.16828 - Ahmad et al., 17 Aug 2026) in Section 5.8, “Carrier-Grade KPIs beyond the Flight Demonstrations”