SoftBank Trial Enables Spectrum Sharing Between HAPS and Terrestrial Networks

Key Takeaways

• SoftBank tested dynamic null‑forming for HAPS‑terrestrial coexistence.
• Technology steers nulls to suppress interference directionally.
• Enables shared spectrum for 5G and future 6G networks.
• Supports airborne base stations without harming ground network performance.
• Demonstrates real‑time adaptation to HAPS movement and orientation.

Pulse Analysis

High‑altitude platform stations (HAPS) have emerged as a promising layer for extending mobile coverage, especially in underserved or disaster‑prone regions. However, the limited radio spectrum has long constrained their integration with existing terrestrial networks. SoftBank’s recent field trial demonstrates that dynamic null‑forming can reconcile this tension by actively shaping antenna patterns to create interference‑free zones, enabling HAPS to operate on the same bands as ground‑based 5G cells without degrading service quality.

The core of the technology lies in real‑time beamforming algorithms that detect the orientation and trajectory of airborne base stations and generate precise nulls toward vulnerable terrestrial receivers. Unlike static filters, this adaptive approach continuously recalibrates as the platform drifts, maintaining optimal coexistence even in dense urban environments. By suppressing emissions only where needed, the system preserves overall network capacity and reduces the need for costly spectrum refarming, a critical advantage as operators prepare for the bandwidth‑intensive demands of 6G.

Industry analysts view SoftBank’s success as a catalyst for broader adoption of aerial‑ground spectrum sharing. Regulators may soon consider flexible licensing frameworks that recognize dynamic interference mitigation, while telecom operators can explore new revenue streams by leasing HAPS capacity for events, rural broadband, or emergency response. As the race toward ubiquitous 5G and the next‑generation 6G ecosystem intensifies, solutions that maximize existing spectrum will be essential, positioning SoftBank at the forefront of next‑level connectivity innovation.